Merge branch 'dializer' into 'master'

Various typespec and compilation improvements

See merge request framasoft/mobilizon!1062

.doctor.exs

@@ -0,0 +1,15 @@
+%Doctor.Config{
+  exception_moduledoc_required: true,
+  failed: false,
+  ignore_modules: [Mobilizon.Web, Mobilizon.GraphQL.Schema, Mobilizon.Service.Activity.Renderer, Mobilizon.Service.Workers.Helper],
+  ignore_paths: [],
+  min_module_doc_coverage: 100,
+  min_module_spec_coverage: 50,
+  min_overall_doc_coverage: 100,
+  min_overall_spec_coverage: 90,
+  moduledoc_required: true,
+  raise: false,
+  reporter: Doctor.Reporters.Full,
+  struct_type_spec_required: true,
+  umbrella: false
+}

config/config.exs

@@ -179,6 +179,8 @@ config :phoenix, :filter_parameters, ["password", "token"]
 config :absinthe, schema: Mobilizon.GraphQL.Schema
 config :absinthe, Absinthe.Logger, filter_variables: ["token", "password", "secret"]
 
+config :mobilizon, Mobilizon.Web.Gettext, one_module_per_locale: true
+
 config :ex_cldr,
   default_locale: "en",
   default_backend: Mobilizon.Cldr
@@ -189,7 +191,8 @@ config :http_signatures,
 config :mobilizon, :cldr,
   locales: [
     "fr",
-    "en"
+    "en",
+    "ru"
   ]
 
 config :mobilizon, :activitypub,

config/dev.exs

@@ -58,6 +58,8 @@ config :logger, :console, format: "[$level] $message\n", level: :debug
 
 config :mobilizon, Mobilizon.Service.Geospatial, service: Mobilizon.Service.Geospatial.Nominatim
 
+config :mobilizon, Mobilizon.Web.Gettext, allowed_locales: ["fr", "en"]
+
 # Set a higher stacktrace during development. Avoid configuring such
 # in production as building large stacktraces may be expensive.
 config :phoenix, :stacktrace_depth, 20

config/test.exs

@@ -77,6 +77,8 @@ config :mobilizon, Mobilizon.Web.Auth.Guardian, secret_key: "some secret"
 
 config :mobilizon, :activitypub, sign_object_fetches: false
 
+config :mobilizon, Mobilizon.Web.Gettext, allowed_locales: ["fr", "en", "es", "ru"]
+
 config :junit_formatter, report_dir: "."
 
 if System.get_env("DOCKER", "false") == "false" && File.exists?("./config/test.secret.exs") do

js/src/components/Event/TagInput.vue

@@ -29,19 +29,28 @@
 </template>
 <script lang="ts">
 import { Component, Prop, Vue } from "vue-property-decorator";
-import get from "lodash/get";
 import differenceBy from "lodash/differenceBy";
 import { ITag } from "../../types/tag.model";
+import { FILTER_TAGS } from "@/graphql/tags";
 
-@Component
+@Component({
+  apollo: {
+    tags: {
+      query: FILTER_TAGS,
+      variables() {
+        return {
+          filter: this.text,
+        };
+      },
+    },
+  },
+})
 export default class TagInput extends Vue {
-  @Prop({ required: false, default: () => [] }) data!: ITag[];
-
-  @Prop({ required: true, default: "value" }) path!: string;
-
   @Prop({ required: true }) value!: ITag[];
 
-  filteredTags: ITag[] = [];
+  tags!: ITag[];
+
+  text = "";
 
   private static componentId = 0;
 
@@ -53,13 +62,20 @@ export default class TagInput extends Vue {
     return `tag-input-${TagInput.componentId}`;
   }
 
-  getFilteredTags(text: string): void {
+  async getFilteredTags(text: string): Promise<void> {
-    this.filteredTags = differenceBy(this.data, this.value, "id").filter(
+    this.text = text;
+    await this.$apollo.queries.tags.refetch();
+  }
+
+  get filteredTags(): ITag[] {
+    return differenceBy(this.tags, this.value, "id").filter(
       (option) =>
-        get(option, this.path)
+        option.title
           .toString()
           .toLowerCase()
-          .indexOf(text.toLowerCase()) >= 0
+          .indexOf(this.text.toLowerCase()) >= 0 ||
+        option.slug.toString().toLowerCase().indexOf(this.text.toLowerCase()) >=
+          0
     );
   }
 

js/src/graphql/tags.ts

@@ -9,16 +9,22 @@ export const TAG_FRAGMENT = gql`
 `;
 
 export const TAGS = gql`
-  query {
+  query Tags {
     tags {
-      id
       related {
-        id
+        ...TagFragment
-        slug
-        title
       }
-      slug
+      ...TagFragment
-      title
     }
   }
+  ${TAG_FRAGMENT}
+`;
+
+export const FILTER_TAGS = gql`
+  query FilterTags($filter: String) {
+    tags(filter: $filter) {
+      ...TagFragment
+    }
+  }
+  ${TAG_FRAGMENT}
 `;

js/src/i18n/es.json

@@ -21,7 +21,6 @@
   "A discussion has been created or updated": "Se ha creado o actualizado una discusión",
   "A federated software": "Un software federado",
   "A fediverse account URL to follow for event updates": "Una URL de cuenta de fediverse a seguir para actualizaciones de eventos",
-  "A group with this name already exists": "Ya existe un grupo con este nombre",
   "A link to a page presenting the event schedule": "Un enlace a una página que presenta el calendario del evento",
   "A link to a page presenting the price options": "Un enlace a una página que presenta las opciones de precio",
   "A member has been updated": "Un miembro ha sido actualizado",

js/src/i18n/fr_FR.json

@@ -19,7 +19,6 @@
   "A discussion has been created or updated": "Une discussion a été créée ou mise à jour",
   "A federated software": "Un logiciel fédéré",
   "A fediverse account URL to follow for event updates": "Un compte sur le fediverse à suivre pour les mises à jour de l'événement",
-  "A group with this name already exists": "Un groupe avec ce nom existe déjà",
   "A link to a page presenting the event schedule": "Un lien vers une page présentant le programme de l'événement",
   "A link to a page presenting the price options": "Un lien vers une page présentant la tarification",
   "A member has been updated": "Un membre a été mis à jour",

js/src/views/Event/Edit.vue

@@ -31,7 +31,7 @@
           />
         </b-field>
 
-        <tag-input v-model="event.tags" :data="tags" path="title" />
+        <tag-input v-model="event.tags" />
 
         <b-field
           horizontal
@@ -556,8 +556,6 @@ import {
   IPerson,
   usernameWithDomain,
 } from "../../types/actor";
-import { TAGS } from "../../graphql/tags";
-import { ITag } from "../../types/tag.model";
 import {
   buildFileFromIMedia,
   buildFileVariable,
@@ -590,7 +588,6 @@ const DEFAULT_LIMIT_NUMBER_OF_PLACES = 10;
   },
   apollo: {
     currentActor: CURRENT_ACTOR_CLIENT,
-    tags: TAGS,
     config: CONFIG,
     identities: IDENTITIES,
     event: {
@@ -643,8 +640,6 @@ export default class EditEvent extends Vue {
 
   currentActor!: IActor;
 
-  tags: ITag[] = [];
-
   event: IEvent = new EventModel();
 
   unmodifiedEvent: IEvent = new EventModel();

js/src/views/Posts/Edit.vue

@@ -67,7 +67,7 @@
           />
         </b-field>
 
-        <tag-input v-model="editablePost.tags" :data="tags" path="title" />
+        <tag-input v-model="editablePost.tags" />
 
         <div class="field">
           <label class="label">{{ $t("Post") }}</label>
@@ -166,7 +166,6 @@ import {
 } from "@/utils/image";
 import GroupMixin from "@/mixins/group";
 import { PostVisibility } from "@/types/enums";
-import { TAGS } from "../../graphql/tags";
 import { CONFIG } from "../../graphql/config";
 import {
   FETCH_POST,
@@ -187,7 +186,6 @@ import { FETCH_GROUP } from "@/graphql/group";
 
 @Component({
   apollo: {
-    tags: TAGS,
     config: CONFIG,
     group: {
       query: FETCH_GROUP,

js/src/views/Settings/AccountSettings.vue

@@ -320,6 +320,8 @@ export default class AccountSettings extends Vue {
         },
       });
 
+      this.oldPassword = "";
+      this.newPassword = "";
       this.$notifier.success(
         this.$t("The password was successfully changed") as string
       );

lib/config_provider.ex

@@ -4,8 +4,10 @@ defmodule Mobilizon.ConfigProvider do
   """
   @behaviour Config.Provider
 
+  @spec init(String.t()) :: String.t()
   def init(path) when is_binary(path), do: path
 
+  @spec load(Keyword.t(), String.t()) :: Keyword.t()
   def load(config, path) do
     config_path = System.get_env("MOBILIZON_CONFIG_PATH") || path
 

lib/federation/activity_pub/actions/accept.ex

@@ -0,0 +1,169 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Accept do
+  @moduledoc """
+  Accept things
+  """
+
+  alias Mobilizon.{Actors, Events}
+  alias Mobilizon.Actors.{Actor, Follower, Member}
+  alias Mobilizon.Events.Participant
+  alias Mobilizon.Federation.ActivityPub.{Audience, Refresher}
+  alias Mobilizon.Federation.ActivityStream
+  alias Mobilizon.Federation.ActivityStream.Convertible
+  alias Mobilizon.Service.Notifications.Scheduler
+  alias Mobilizon.Web.Endpoint
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      make_accept_join_data: 2,
+      create_activity: 2,
+      maybe_federate: 1,
+      maybe_relay_if_group_activity: 1
+    ]
+
+  @type acceptable_types :: :join | :follow | :invite
+  @type acceptable_entities ::
+          accept_join_entities | accept_follow_entities | accept_invite_entities
+
+  @spec accept(acceptable_types, acceptable_entities, boolean, map) ::
+          {:ok, ActivityStream.t(), acceptable_entities}
+  def accept(type, entity, local \\ true, additional \\ %{}) do
+    Logger.debug("We're accepting something")
+
+    accept_res =
+      case type do
+        :join -> accept_join(entity, additional)
+        :follow -> accept_follow(entity, additional)
+        :invite -> accept_invite(entity, additional)
+      end
+
+    with {:ok, entity, update_data} <- accept_res do
+      {:ok, activity} = create_activity(update_data, local)
+      maybe_federate(activity)
+      maybe_relay_if_group_activity(activity)
+      {:ok, activity, entity}
+    end
+  end
+
+  @type accept_follow_entities :: Follower.t()
+
+  @spec accept_follow(Follower.t(), map) ::
+          {:ok, Follower.t(), Activity.t()} | {:error, Ecto.Changeset.t()}
+  defp accept_follow(%Follower{} = follower, additional) do
+    with {:ok, %Follower{} = follower} <- Actors.update_follower(follower, %{approved: true}) do
+      follower_as_data = Convertible.model_to_as(follower)
+
+      update_data =
+        make_accept_join_data(
+          follower_as_data,
+          Map.merge(additional, %{
+            "id" => "#{Endpoint.url()}/accept/follow/#{follower.id}",
+            "to" => [follower.actor.url],
+            "cc" => [],
+            "actor" => follower.target_actor.url
+          })
+        )
+
+      {:ok, follower, update_data}
+    end
+  end
+
+  @type accept_join_entities :: Participant.t() | Member.t()
+
+  @spec accept_join(Participant.t() | Member.t(), map) ::
+          {:ok, Participant.t() | Member.t(), Activity.t()} | {:error, Ecto.Changeset.t()}
+  defp accept_join(%Participant{} = participant, additional) do
+    with {:ok, %Participant{} = participant} <-
+           Events.update_participant(participant, %{role: :participant}) do
+      Absinthe.Subscription.publish(Endpoint, participant.actor,
+        event_person_participation_changed: participant.actor.id
+      )
+
+      Scheduler.trigger_notifications_for_participant(participant)
+      participant_as_data = Convertible.model_to_as(participant)
+      audience = Audience.get_audience(participant)
+
+      accept_join_data =
+        make_accept_join_data(
+          participant_as_data,
+          Map.merge(Map.merge(audience, additional), %{
+            "id" => "#{Endpoint.url()}/accept/join/#{participant.id}"
+          })
+        )
+
+      {:ok, participant, accept_join_data}
+    end
+  end
+
+  defp accept_join(%Member{} = member, additional) do
+    with {:ok, %Member{} = member} <-
+           Actors.update_member(member, %{role: :member}) do
+      Mobilizon.Service.Activity.Member.insert_activity(member,
+        subject: "member_approved"
+      )
+
+      maybe_refresh_group(member)
+
+      Absinthe.Subscription.publish(Endpoint, member.actor,
+        group_membership_changed: [
+          Actor.preferred_username_and_domain(member.parent),
+          member.actor.id
+        ]
+      )
+
+      member_as_data = Convertible.model_to_as(member)
+      audience = Audience.get_audience(member)
+
+      accept_join_data =
+        make_accept_join_data(
+          member_as_data,
+          Map.merge(Map.merge(audience, additional), %{
+            "id" => "#{Endpoint.url()}/accept/join/#{member.id}"
+          })
+        )
+
+      {:ok, member, accept_join_data}
+    end
+  end
+
+  @type accept_invite_entities :: Member.t()
+
+  @spec accept_invite(Member.t(), map()) ::
+          {:ok, Member.t(), Activity.t()} | {:error, Ecto.Changeset.t()}
+  defp accept_invite(
+         %Member{invited_by_id: invited_by_id, actor_id: actor_id} = member,
+         _additional
+       ) do
+    with %Actor{} = inviter <- Actors.get_actor!(invited_by_id),
+         %Actor{url: actor_url} <- Actors.get_actor!(actor_id),
+         {:ok, %Member{id: member_id} = member} <-
+           Actors.update_member(member, %{role: :member}) do
+      Mobilizon.Service.Activity.Member.insert_activity(member,
+        subject: "member_accepted_invitation"
+      )
+
+      maybe_refresh_group(member)
+
+      accept_data = %{
+        "type" => "Accept",
+        "attributedTo" => member.parent.url,
+        "to" => [inviter.url, member.parent.members_url],
+        "cc" => [member.parent.url],
+        "actor" => actor_url,
+        "object" => Convertible.model_to_as(member),
+        "id" => "#{Endpoint.url()}/accept/invite/member/#{member_id}"
+      }
+
+      {:ok, member, accept_data}
+    end
+  end
+
+  @spec maybe_refresh_group(Member.t()) :: :ok | nil
+  defp maybe_refresh_group(%Member{
+         parent: %Actor{domain: parent_domain, url: parent_url},
+         actor: %Actor{} = actor
+       }) do
+    unless is_nil(parent_domain),
+      do: Refresher.fetch_group(parent_url, actor)
+  end
+end

lib/federation/activity_pub/actions/announce.ex

@@ -0,0 +1,60 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Announce do
+  @moduledoc """
+  Announce things
+  """
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Federation.ActivityPub.Activity
+  alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
+  alias Mobilizon.Federation.ActivityStream
+  alias Mobilizon.Share
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      make_announce_data: 3,
+      make_announce_data: 4,
+      make_unannounce_data: 3
+    ]
+
+  @doc """
+  Announce (reshare) an activity to the world, using an activity of type `Announce`.
+  """
+  @spec announce(Actor.t(), ActivityStream.t(), String.t() | nil, boolean, boolean) ::
+          {:ok, Activity.t(), ActivityStream.t()} | {:error, any()}
+  def announce(
+        %Actor{} = actor,
+        object,
+        activity_id \\ nil,
+        local \\ true,
+        public \\ true
+      ) do
+    with {:ok, %Actor{id: object_owner_actor_id}} <-
+           ActivityPubActor.get_or_fetch_actor_by_url(object["actor"]),
+         {:ok, %Share{} = _share} <- Share.create(object["id"], actor.id, object_owner_actor_id) do
+      announce_data = make_announce_data(actor, object, activity_id, public)
+      {:ok, activity} = create_activity(announce_data, local)
+      :ok = maybe_federate(activity)
+      {:ok, activity, object}
+    end
+  end
+
+  @doc """
+  Cancel the announcement of an activity to the world, using an activity of type `Undo` an `Announce`.
+  """
+  @spec unannounce(Actor.t(), ActivityStream.t(), String.t() | nil, String.t() | nil, boolean) ::
+          {:ok, Activity.t(), ActivityStream.t()}
+  def unannounce(
+        %Actor{} = actor,
+        object,
+        activity_id \\ nil,
+        cancelled_activity_id \\ nil,
+        local \\ true
+      ) do
+    announce_activity = make_announce_data(actor, object, cancelled_activity_id)
+    unannounce_data = make_unannounce_data(actor, announce_activity, activity_id)
+    {:ok, unannounce_activity} = create_activity(unannounce_data, local)
+    maybe_federate(unannounce_activity)
+    {:ok, unannounce_activity, object}
+  end
+end

lib/federation/activity_pub/actions/create.ex

@@ -0,0 +1,71 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Create do
+  @moduledoc """
+  Create things
+  """
+  alias Mobilizon.Tombstone
+  alias Mobilizon.Federation.ActivityPub.{Activity, Types}
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      maybe_relay_if_group_activity: 1
+    ]
+
+  @type create_entities ::
+          :event | :comment | :discussion | :actor | :todo_list | :todo | :resource | :post
+
+  @doc """
+  Create an activity of type `Create`
+
+    * Creates the object, which returns AS data
+    * Wraps ActivityStreams data into a `Create` activity
+    * Creates an `Mobilizon.Federation.ActivityPub.Activity` from this
+    * Federates (asynchronously) the activity
+    * Returns the activity
+  """
+  @spec create(create_entities(), map(), boolean, map()) ::
+          {:ok, Activity.t(), Entity.t()}
+          | {:error, :entity_tombstoned | atom() | Ecto.Changeset.t()}
+  def create(type, args, local \\ false, additional \\ %{}) do
+    Logger.debug("creating an activity")
+    Logger.debug(inspect(args))
+
+    case check_for_tombstones(args) do
+      nil ->
+        case do_create(type, args, additional) do
+          {:ok, entity, create_data} ->
+            {:ok, activity} = create_activity(create_data, local)
+            maybe_federate(activity)
+            maybe_relay_if_group_activity(activity)
+            {:ok, activity, entity}
+
+          {:error, err} ->
+            {:error, err}
+        end
+
+      %Tombstone{} ->
+        {:error, :entity_tombstoned}
+    end
+  end
+
+  @spec do_create(create_entities(), map(), map()) ::
+          {:ok, Entity.t(), Activity.t()} | {:error, Ecto.Changeset.t() | atom()}
+  defp do_create(type, args, additional) do
+    case type do
+      :event -> Types.Events.create(args, additional)
+      :comment -> Types.Comments.create(args, additional)
+      :discussion -> Types.Discussions.create(args, additional)
+      :actor -> Types.Actors.create(args, additional)
+      :todo_list -> Types.TodoLists.create(args, additional)
+      :todo -> Types.Todos.create(args, additional)
+      :resource -> Types.Resources.create(args, additional)
+      :post -> Types.Posts.create(args, additional)
+    end
+  end
+
+  @spec check_for_tombstones(map()) :: Tombstone.t() | nil
+  defp check_for_tombstones(%{url: url}), do: Tombstone.find_tombstone(url)
+  defp check_for_tombstones(_), do: nil
+end

lib/federation/activity_pub/actions/delete.ex

@@ -0,0 +1,33 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Delete do
+  @moduledoc """
+  Delete things
+  """
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Federation.ActivityPub.Activity
+  alias Mobilizon.Federation.ActivityPub.Types.{Entity, Managable, Ownable}
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      maybe_relay_if_group_activity: 2,
+      check_for_actor_key_rotation: 1
+    ]
+
+  @doc """
+  Delete an entity, using an activity of type `Delete`
+  """
+  @spec delete(Entity.t(), Actor.t(), boolean, map) :: {:ok, Activity.t(), Entity.t()}
+  def delete(object, actor, local \\ true, additional \\ %{}) do
+    with {:ok, activity_data, actor, object} <-
+           Managable.delete(object, actor, local, additional),
+         group <- Ownable.group_actor(object),
+         :ok <- check_for_actor_key_rotation(actor),
+         {:ok, activity} <- create_activity(activity_data, local),
+         :ok <- maybe_federate(activity),
+         :ok <- maybe_relay_if_group_activity(activity, group) do
+      {:ok, activity, object}
+    end
+  end
+end

lib/federation/activity_pub/actions/flag.ex

@@ -0,0 +1,31 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Flag do
+  @moduledoc """
+  Delete things
+  """
+  alias Mobilizon.Users
+  alias Mobilizon.Federation.ActivityPub.{Activity, Types}
+  alias Mobilizon.Web.Email.{Admin, Mailer}
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1
+    ]
+
+  @spec flag(map, boolean, map) :: {:ok, Activity.t(), Report.t()} | {:error, Ecto.Changeset.t()}
+  def flag(args, local \\ false, additional \\ %{}) do
+    with {:ok, report, report_as_data} <- Types.Reports.flag(args, local, additional) do
+      {:ok, activity} = create_activity(report_as_data, local)
+      maybe_federate(activity)
+
+      Enum.each(Users.list_moderators(), fn moderator ->
+        moderator
+        |> Admin.report(report)
+        |> Mailer.send_email_later()
+      end)
+
+      {:ok, activity, report}
+    end
+  end
+end

lib/federation/activity_pub/actions/follow.ex

@@ -0,0 +1,74 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Follow do
+  @moduledoc """
+  Follow people
+  """
+
+  alias Mobilizon.Actors
+  alias Mobilizon.Actors.{Actor, Follower}
+  alias Mobilizon.Federation.ActivityPub.Types
+  alias Mobilizon.Federation.ActivityStream.Convertible
+  alias Mobilizon.Web.Endpoint
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      make_unfollow_data: 4
+    ]
+
+  @doc """
+  Make an actor follow another, using an activity of type `Follow`
+  """
+  @spec follow(Actor.t(), Actor.t(), String.t() | nil, boolean, map) ::
+          {:ok, Activity.t(), Follower.t()} | {:error, atom | Ecto.Changeset.t() | String.t()}
+  def follow(
+        %Actor{} = follower,
+        %Actor{} = followed,
+        activity_id \\ nil,
+        local \\ true,
+        additional \\ %{}
+      ) do
+    if followed.id != follower.id do
+      case Types.Actors.follow(
+             follower,
+             followed,
+             local,
+             Map.merge(additional, %{"activity_id" => activity_id})
+           ) do
+        {:ok, activity_data, %Follower{} = follower} ->
+          {:ok, activity} = create_activity(activity_data, local)
+          maybe_federate(activity)
+          {:ok, activity, follower}
+
+        {:error, err} ->
+          {:error, err}
+      end
+    else
+      {:error, "Can't follow yourself"}
+    end
+  end
+
+  @doc """
+  Make an actor unfollow another, using an activity of type `Undo` a `Follow`.
+  """
+  @spec unfollow(Actor.t(), Actor.t(), String.t() | nil, boolean()) ::
+          {:ok, Activity.t(), Follower.t()} | {:error, String.t()}
+  def unfollow(%Actor{} = follower, %Actor{} = followed, activity_id \\ nil, local \\ true) do
+    with {:ok, %Follower{id: follow_id} = follow} <- Actors.unfollow(followed, follower) do
+      # We recreate the follow activity
+      follow_as_data =
+        Convertible.model_to_as(%{follow | actor: follower, target_actor: followed})
+
+      {:ok, follow_activity} = create_activity(follow_as_data, local)
+      activity_unfollow_id = activity_id || "#{Endpoint.url()}/unfollow/#{follow_id}/activity"
+
+      unfollow_data =
+        make_unfollow_data(follower, followed, follow_activity, activity_unfollow_id)
+
+      {:ok, activity} = create_activity(unfollow_data, local)
+      maybe_federate(activity)
+      {:ok, activity, follow}
+    end
+  end
+end

lib/federation/activity_pub/actions/invite.ex

@@ -0,0 +1,86 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Invite do
+  @moduledoc """
+  Invite people to things
+  """
+  alias Mobilizon.Actors
+  alias Mobilizon.Actors.{Actor, Member}
+  alias Mobilizon.Web.Email.Group
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      maybe_relay_if_group_activity: 1
+    ]
+
+  @spec invite(Actor.t(), Actor.t(), Actor.t(), boolean, map()) ::
+          {:ok, map(), Member.t()} | {:error, :not_able_to_invite | Ecto.Changeset.t()}
+  def invite(
+        %Actor{url: group_url, id: group_id, members_url: members_url} = group,
+        %Actor{url: actor_url, id: actor_id} = actor,
+        %Actor{url: target_actor_url, id: target_actor_id} = _target_actor,
+        local \\ true,
+        additional \\ %{}
+      ) do
+    Logger.debug("Handling #{actor_url} invite to #{group_url} sent to #{target_actor_url}")
+
+    if is_able_to_invite?(actor, group) do
+      with {:ok, %Member{url: member_url} = member} <-
+             Actors.create_member(%{
+               parent_id: group_id,
+               actor_id: target_actor_id,
+               role: :invited,
+               invited_by_id: actor_id,
+               url: Map.get(additional, :url)
+             }) do
+        Mobilizon.Service.Activity.Member.insert_activity(member,
+          moderator: actor,
+          subject: "member_invited"
+        )
+
+        {:ok, activity} =
+          create_activity(
+            %{
+              "type" => "Invite",
+              "attributedTo" => group_url,
+              "actor" => actor_url,
+              "object" => group_url,
+              "target" => target_actor_url,
+              "id" => member_url
+            }
+            |> Map.merge(%{"to" => [target_actor_url, members_url], "cc" => [group_url]})
+            |> Map.merge(additional),
+            local
+          )
+
+        maybe_federate(activity)
+        maybe_relay_if_group_activity(activity)
+        Group.send_invite_to_user(member)
+        {:ok, activity, member}
+      end
+    else
+      {:error, :not_able_to_invite}
+    end
+  end
+
+  @spec is_able_to_invite?(Actor.t(), Actor.t()) :: boolean
+  defp is_able_to_invite?(%Actor{domain: actor_domain, id: actor_id}, %Actor{
+         domain: group_domain,
+         id: group_id
+       }) do
+    # If the actor comes from the same domain we trust it
+    if actor_domain == group_domain do
+      true
+    else
+      # If local group, we'll send the invite
+      case Actors.get_member(actor_id, group_id) do
+        {:ok, %Member{} = admin_member} ->
+          Member.is_administrator(admin_member)
+
+        _ ->
+          false
+      end
+    end
+  end
+end

lib/federation/activity_pub/actions/join.ex

@@ -0,0 +1,51 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Join do
+  @moduledoc """
+  Join things
+  """
+
+  alias Mobilizon.Actors.{Actor, Member}
+  alias Mobilizon.Events.{Event, Participant}
+  alias Mobilizon.Federation.ActivityPub.Types
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1
+    ]
+
+  @doc """
+  Join an entity (an event or a group), using an activity of type `Join`
+  """
+  @spec join(Event.t(), Actor.t(), boolean, map) ::
+          {:ok, Activity.t(), Participant.t()} | {:error, :maximum_attendee_capacity}
+  @spec join(Actor.t(), Actor.t(), boolean, map) :: {:ok, Activity.t(), Member.t()}
+  def join(entity_to_join, actor_joining, local \\ true, additional \\ %{})
+
+  def join(%Event{} = event, %Actor{} = actor, local, additional) do
+    case Types.Events.join(event, actor, local, additional) do
+      {:ok, activity_data, participant} ->
+        {:ok, activity} = create_activity(activity_data, local)
+        maybe_federate(activity)
+        {:ok, activity, participant}
+
+      {:error, :maximum_attendee_capacity_reached} ->
+        {:error, :maximum_attendee_capacity_reached}
+
+      {:accept, accept} ->
+        accept
+    end
+  end
+
+  def join(%Actor{type: :Group} = group, %Actor{} = actor, local, additional) do
+    with {:ok, activity_data, %Member{} = member} <-
+           Types.Actors.join(group, actor, local, additional),
+         {:ok, activity} <- create_activity(activity_data, local),
+         :ok <- maybe_federate(activity) do
+      {:ok, activity, member}
+    else
+      {:accept, accept} ->
+        accept
+    end
+  end
+end

lib/federation/activity_pub/actions/leave.ex

@@ -0,0 +1,104 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Leave do
+  @moduledoc """
+  Leave things
+  """
+
+  alias Mobilizon.{Actors, Events}
+  alias Mobilizon.Actors.{Actor, Member}
+  alias Mobilizon.Events.{Event, Participant}
+  alias Mobilizon.Federation.ActivityPub.Audience
+  alias Mobilizon.Web.Endpoint
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      maybe_relay_if_group_activity: 1
+    ]
+
+  @spec leave(Event.t(), Actor.t(), boolean, map) ::
+          {:ok, Activity.t(), Participant.t()}
+          | {:error, :is_only_organizer | :participant_not_found | Ecto.Changeset.t()}
+  @spec leave(Actor.t(), Actor.t(), boolean, map) ::
+          {:ok, Activity.t(), Member.t()} | {:error, atom() | Ecto.Changeset.t()}
+  def leave(object, actor, local \\ true, additional \\ %{})
+
+  @doc """
+  Leave an event or a group
+  """
+  def leave(
+        %Event{id: event_id, url: event_url} = _event,
+        %Actor{id: actor_id, url: actor_url} = _actor,
+        local,
+        additional
+      ) do
+    if Participant.is_not_only_organizer(event_id, actor_id) do
+      {:error, :is_only_organizer}
+    else
+      case Mobilizon.Events.get_participant(
+             event_id,
+             actor_id,
+             Map.get(additional, :metadata, %{})
+           ) do
+        {:ok, %Participant{} = participant} ->
+          case Events.delete_participant(participant) do
+            {:ok, %{participant: %Participant{} = participant}} ->
+              leave_data = %{
+                "type" => "Leave",
+                # If it's an exclusion it should be something else
+                "actor" => actor_url,
+                "object" => event_url,
+                "id" => "#{Endpoint.url()}/leave/event/#{participant.id}"
+              }
+
+              audience = Audience.get_audience(participant)
+              {:ok, activity} = create_activity(Map.merge(leave_data, audience), local)
+              maybe_federate(activity)
+              {:ok, activity, participant}
+
+            {:error, _type, %Ecto.Changeset{} = err, _} ->
+              {:error, err}
+          end
+
+        {:error, :participant_not_found} ->
+          {:error, :participant_not_found}
+      end
+    end
+  end
+
+  def leave(
+        %Actor{type: :Group, id: group_id, url: group_url, members_url: group_members_url},
+        %Actor{id: actor_id, url: actor_url},
+        local,
+        additional
+      ) do
+    with {:member, {:ok, %Member{id: member_id} = member}} <-
+           {:member, Actors.get_member(actor_id, group_id)},
+         {:is_not_only_admin, true} <-
+           {:is_not_only_admin,
+            Map.get(additional, :force_member_removal, false) ||
+              !Actors.is_only_administrator?(member_id, group_id)},
+         {:delete, {:ok, %Member{} = member}} <- {:delete, Actors.delete_member(member)} do
+      Mobilizon.Service.Activity.Member.insert_activity(member, subject: "member_quit")
+
+      leave_data = %{
+        "to" => [group_members_url],
+        "cc" => [group_url],
+        "attributedTo" => group_url,
+        "type" => "Leave",
+        "actor" => actor_url,
+        "object" => group_url
+      }
+
+      {:ok, activity} = create_activity(leave_data, local)
+      maybe_federate(activity)
+      maybe_relay_if_group_activity(activity)
+      {:ok, activity, member}
+    else
+      {:member, nil} -> {:error, :member_not_found}
+      {:is_not_only_admin, false} -> {:error, :is_not_only_admin}
+      {:error, %Ecto.Changeset{} = err} -> {:error, err}
+    end
+  end
+end

lib/federation/activity_pub/actions/move.ex

@@ -0,0 +1,30 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Move do
+  @moduledoc """
+  Move things
+  """
+  alias Mobilizon.Resources.Resource
+  alias Mobilizon.Federation.ActivityPub.{Activity, Types}
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1
+    ]
+
+  @spec move(:resource, Resource.t(), map, boolean, map) ::
+          {:ok, Activity.t(), Resource.t()} | {:error, Ecto.Changeset.t() | atom()}
+  def move(type, old_entity, args, local \\ false, additional \\ %{}) do
+    Logger.debug("We're moving something")
+    Logger.debug(inspect(args))
+
+    with {:ok, entity, update_data} <-
+           (case type do
+              :resource -> Types.Resources.move(old_entity, args, additional)
+            end) do
+      {:ok, activity} = create_activity(update_data, local)
+      maybe_federate(activity)
+      {:ok, activity, entity}
+    end
+  end
+end

lib/federation/activity_pub/actions/reject.ex

@@ -0,0 +1,127 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Reject do
+  @moduledoc """
+  Reject things
+  """
+
+  alias Mobilizon.{Actors, Events}
+  alias Mobilizon.Actors.{Actor, Follower, Member}
+  alias Mobilizon.Events.Participant
+  alias Mobilizon.Federation.ActivityPub.Actions.Accept
+  alias Mobilizon.Federation.ActivityPub.Audience
+  alias Mobilizon.Federation.ActivityStream
+  alias Mobilizon.Federation.ActivityStream.Convertible
+  alias Mobilizon.Web.Endpoint
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      maybe_relay_if_group_activity: 1
+    ]
+
+  @spec reject(Accept.acceptable_types(), Accept.acceptable_entities(), boolean, map) ::
+          {:ok, ActivityStream.t(), Accept.acceptable_entities()}
+  def reject(type, entity, local \\ true, additional \\ %{}) do
+    {:ok, entity, update_data} =
+      case type do
+        :join -> reject_join(entity, additional)
+        :follow -> reject_follow(entity, additional)
+        :invite -> reject_invite(entity, additional)
+      end
+
+    with {:ok, activity} <- create_activity(update_data, local),
+         :ok <- maybe_federate(activity),
+         :ok <- maybe_relay_if_group_activity(activity) do
+      {:ok, activity, entity}
+    else
+      err ->
+        Logger.error("Something went wrong while creating an activity")
+        Logger.debug(inspect(err))
+        err
+    end
+  end
+
+  @spec reject_join(Participant.t(), map()) :: {:ok, Participant.t(), Activity.t()} | any()
+  defp reject_join(%Participant{} = participant, additional) do
+    with {:ok, %Participant{} = participant} <-
+           Events.update_participant(participant, %{role: :rejected}),
+         Absinthe.Subscription.publish(Endpoint, participant.actor,
+           event_person_participation_changed: participant.actor.id
+         ),
+         participant_as_data <- Convertible.model_to_as(participant),
+         audience <-
+           participant
+           |> Audience.get_audience()
+           |> Map.merge(additional),
+         reject_data <- %{
+           "type" => "Reject",
+           "object" => participant_as_data
+         },
+         update_data <-
+           reject_data
+           |> Map.merge(audience)
+           |> Map.merge(%{
+             "id" => "#{Endpoint.url()}/reject/join/#{participant.id}"
+           }) do
+      {:ok, participant, update_data}
+    else
+      err ->
+        Logger.error("Something went wrong while creating an update activity")
+        Logger.debug(inspect(err))
+        err
+    end
+  end
+
+  @spec reject_follow(Follower.t(), map()) :: {:ok, Follower.t(), Activity.t()} | any()
+  defp reject_follow(%Follower{} = follower, additional) do
+    with {:ok, %Follower{} = follower} <- Actors.delete_follower(follower),
+         follower_as_data <- Convertible.model_to_as(follower),
+         audience <-
+           follower.actor |> Audience.get_audience() |> Map.merge(additional),
+         reject_data <- %{
+           "to" => [follower.actor.url],
+           "type" => "Reject",
+           "actor" => follower.target_actor.url,
+           "object" => follower_as_data
+         },
+         update_data <-
+           audience
+           |> Map.merge(reject_data)
+           |> Map.merge(%{
+             "id" => "#{Endpoint.url()}/reject/follow/#{follower.id}"
+           }) do
+      {:ok, follower, update_data}
+    else
+      err ->
+        Logger.error("Something went wrong while creating an update activity")
+        Logger.debug(inspect(err))
+        err
+    end
+  end
+
+  @spec reject_invite(Member.t(), map()) :: {:ok, Member.t(), Activity.t()} | any
+  defp reject_invite(
+         %Member{invited_by_id: invited_by_id, actor_id: actor_id} = member,
+         _additional
+       ) do
+    with %Actor{} = inviter <- Actors.get_actor(invited_by_id),
+         %Actor{url: actor_url} <- Actors.get_actor(actor_id),
+         {:ok, %Member{url: member_url, id: member_id} = member} <-
+           Actors.delete_member(member),
+         Mobilizon.Service.Activity.Member.insert_activity(member,
+           subject: "member_rejected_invitation"
+         ),
+         accept_data <- %{
+           "type" => "Reject",
+           "actor" => actor_url,
+           "attributedTo" => member.parent.url,
+           "to" => [inviter.url, member.parent.members_url],
+           "cc" => [member.parent.url],
+           "object" => member_url,
+           "id" => "#{Endpoint.url()}/reject/invite/member/#{member_id}"
+         } do
+      {:ok, member, accept_data}
+    end
+  end
+end

lib/federation/activity_pub/actions/remove.ex

@@ -0,0 +1,56 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Remove do
+  @moduledoc """
+  Remove things
+  """
+  alias Mobilizon.Actors
+  alias Mobilizon.Actors.{Actor, Member}
+  alias Mobilizon.Federation.ActivityPub.Activity
+  alias Mobilizon.Web.Email.Group
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      maybe_relay_if_group_activity: 1
+    ]
+
+  @doc """
+  Remove an activity, using an activity of type `Remove`
+  """
+  @spec remove(Member.t(), Actor.t(), Actor.t(), boolean, map) ::
+          {:ok, Activity.t(), Member.t()} | {:error, :member_not_found | Ecto.Changeset.t()}
+  def remove(
+        %Member{} = member,
+        %Actor{type: :Group, url: group_url, members_url: group_members_url},
+        %Actor{url: moderator_url} = moderator,
+        local,
+        _additional \\ %{}
+      ) do
+    with {:ok, %Member{id: member_id}} <- Actors.update_member(member, %{role: :rejected}),
+         %Member{} = member <- Actors.get_member(member_id) do
+      Mobilizon.Service.Activity.Member.insert_activity(member,
+        moderator: moderator,
+        subject: "member_removed"
+      )
+
+      Group.send_notification_to_removed_member(member)
+
+      remove_data = %{
+        "to" => [group_members_url],
+        "type" => "Remove",
+        "actor" => moderator_url,
+        "object" => member.url,
+        "origin" => group_url
+      }
+
+      {:ok, activity} = create_activity(remove_data, local)
+      maybe_federate(activity)
+      maybe_relay_if_group_activity(activity)
+      {:ok, activity, member}
+    else
+      nil -> {:error, :member_not_found}
+      {:error, %Ecto.Changeset{} = err} -> {:error, err}
+    end
+  end
+end

lib/federation/activity_pub/actions/update.ex

@@ -0,0 +1,44 @@
+defmodule Mobilizon.Federation.ActivityPub.Actions.Update do
+  @moduledoc """
+  Update things
+  """
+  alias Mobilizon.Federation.ActivityPub.Activity
+  alias Mobilizon.Federation.ActivityPub.Types.Managable
+  require Logger
+
+  import Mobilizon.Federation.ActivityPub.Utils,
+    only: [
+      create_activity: 2,
+      maybe_federate: 1,
+      maybe_relay_if_group_activity: 1
+    ]
+
+  @doc """
+  Create an activity of type `Update`
+
+    * Updates the object, which returns AS data
+    * Wraps ActivityStreams data into a `Update` activity
+    * Creates an `Mobilizon.Federation.ActivityPub.Activity` from this
+    * Federates (asynchronously) the activity
+    * Returns the activity
+  """
+  @spec update(Entity.t(), map(), boolean, map()) ::
+          {:ok, Activity.t(), Entity.t()} | {:error, atom() | Ecto.Changeset.t()}
+  def update(old_entity, args, local \\ false, additional \\ %{}) do
+    Logger.debug("updating an activity")
+    Logger.debug(inspect(args))
+
+    case Managable.update(old_entity, args, additional) do
+      {:ok, entity, update_data} ->
+        {:ok, activity} = create_activity(update_data, local)
+        maybe_federate(activity)
+        maybe_relay_if_group_activity(activity)
+        {:ok, activity, entity}
+
+      {:error, err} ->
+        Logger.error("Something went wrong while creating an activity")
+        Logger.debug(inspect(err))
+        {:error, err}
+    end
+  end
+end

lib/federation/activity_pub/activity.ex

@@ -4,7 +4,7 @@ defmodule Mobilizon.Federation.ActivityPub.Activity do
   """
 
   @type t :: %__MODULE__{
-          data: String.t(),
+          data: map(),
           local: boolean,
           actor: Actor.t(),
           recipients: [String.t()]

lib/federation/activity_pub/activity_pub.ex

@@ -12,77 +12,45 @@ defmodule Mobilizon.Federation.ActivityPub do
 
   alias Mobilizon.{
     Actors,
-    Config,
     Discussions,
     Events,
     Posts,
-    Resources,
+    Resources
-    Share,
-    Users
   }
 
-  alias Mobilizon.Actors.{Actor, Follower, Member}
+  alias Mobilizon.Actors.Actor
   alias Mobilizon.Discussions.Comment
-  alias Mobilizon.Events.{Event, Participant}
+  alias Mobilizon.Events.Event
   alias Mobilizon.Tombstone
 
   alias Mobilizon.Federation.ActivityPub.{
     Activity,
-    Audience,
-    Federator,
     Fetcher,
     Preloader,
-    Refresher,
+    Relay
-    Relay,
-    Transmogrifier,
-    Types,
-    Visibility
   }
 
-  alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
-
-  alias Mobilizon.Federation.ActivityPub.Types.{Managable, Ownable}
-
   alias Mobilizon.Federation.ActivityStream.Convertible
-  alias Mobilizon.Federation.HTTPSignatures.Signature
 
-  alias Mobilizon.Service.Notifications.Scheduler
   alias Mobilizon.Storage.Page
 
   alias Mobilizon.Web.Endpoint
-  alias Mobilizon.Web.Email.{Admin, Group, Mailer}
 
   require Logger
 
   @public_ap_adress "https://www.w3.org/ns/activitystreams#Public"
 
-  @doc """
-  Wraps an object into an activity
-  """
-  @spec create_activity(map(), boolean()) :: {:ok, Activity.t()}
-  def create_activity(map, local \\ true) when is_map(map) do
-    with map <- lazy_put_activity_defaults(map) do
-      {:ok,
-       %Activity{
-         data: map,
-         local: local,
-         actor: map["actor"],
-         recipients: get_recipients(map)
-       }}
-    end
-  end
-
   @doc """
   Fetch an object from an URL, from our local database of events and comments, then eventually remote
   """
   # TODO: Make database calls parallel
   @spec fetch_object_from_url(String.t(), Keyword.t()) ::
-          {:ok, struct()} | {:error, any()}
+          {:ok, struct()} | {:ok, atom(), struct()} | {:error, any()}
   def fetch_object_from_url(url, options \\ []) do
     Logger.info("Fetching object from url #{url}")
 
-    with {:not_http, true} <- {:not_http, String.starts_with?(url, "http")},
+    if String.starts_with?(url, "http") do
-         {:existing, nil} <-
+      with {:existing, nil} <-
              {:existing, Tombstone.find_tombstone(url)},
            {:existing, nil} <- {:existing, Events.get_event_by_url(url)},
            {:existing, nil} <-
@@ -104,16 +72,15 @@ defmodule Mobilizon.Federation.ActivityPub do
         {:error, e} ->
           Logger.warn("Something failed while fetching url #{url} #{inspect(e)}")
           {:error, e}
-
+      end
-      e ->
+    else
-        Logger.warn("Something failed while fetching url #{url} #{inspect(e)}")
+      {:error, :url_not_http}
-        {:error, e}
     end
   end
 
   @spec handle_existing_entity(String.t(), struct(), Keyword.t()) ::
           {:ok, struct()}
-          | {:ok, struct()}
+          | {:ok, atom(), struct()}
           | {:error, String.t(), struct()}
           | {:error, String.t()}
   defp handle_existing_entity(url, entity, options) do
@@ -128,13 +95,13 @@ defmodule Mobilizon.Federation.ActivityPub do
         {:ok, entity} = Preloader.maybe_preload(entity)
         {:error, status, entity}
 
-      err ->
+      {:error, err} ->
-        err
+        {:error, err}
     end
   end
 
   @spec refresh_entity(String.t(), struct(), Keyword.t()) ::
-          {:ok, struct()} | {:error, String.t(), struct()} | {:error, String.t()}
+          {:ok, struct()} | {:error, atom(), struct()} | {:error, atom()}
   defp refresh_entity(url, entity, options) do
     force_fetch = Keyword.get(options, :force, false)
 
@@ -145,573 +112,24 @@ defmodule Mobilizon.Federation.ActivityPub do
         {:ok, _activity, entity} ->
           {:ok, entity}
 
-        {:error, "Gone"} ->
+        {:error, :http_gone} ->
-          {:error, "Gone", entity}
+          {:error, :http_gone, entity}
 
-        {:error, "Not found"} ->
+        {:error, :http_not_found} ->
-          {:error, "Not found", entity}
+          {:error, :http_not_found, entity}
 
-        {:error, "Object origin check failed"} ->
+        {:error, err} ->
-          {:error, "Object origin check failed"}
+          {:error, err}
       end
     else
       {:ok, entity}
     end
   end
 
-  @doc """
-  Create an activity of type `Create`
-
-    * Creates the object, which returns AS data
-    * Wraps ActivityStreams data into a `Create` activity
-    * Creates an `Mobilizon.Federation.ActivityPub.Activity` from this
-    * Federates (asynchronously) the activity
-    * Returns the activity
-  """
-  @spec create(atom(), map(), boolean, map()) :: {:ok, Activity.t(), struct()} | any()
-  def create(type, args, local \\ false, additional \\ %{}) do
-    Logger.debug("creating an activity")
-    Logger.debug(inspect(args))
-
-    with {:tombstone, nil} <- {:tombstone, check_for_tombstones(args)},
-         {:ok, entity, create_data} <-
-           (case type do
-              :event -> Types.Events.create(args, additional)
-              :comment -> Types.Comments.create(args, additional)
-              :discussion -> Types.Discussions.create(args, additional)
-              :actor -> Types.Actors.create(args, additional)
-              :todo_list -> Types.TodoLists.create(args, additional)
-              :todo -> Types.Todos.create(args, additional)
-              :resource -> Types.Resources.create(args, additional)
-              :post -> Types.Posts.create(args, additional)
-            end),
-         {:ok, activity} <- create_activity(create_data, local),
-         :ok <- maybe_federate(activity),
-         :ok <- maybe_relay_if_group_activity(activity) do
-      {:ok, activity, entity}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  @doc """
-  Create an activity of type `Update`
-
-    * Updates the object, which returns AS data
-    * Wraps ActivityStreams data into a `Update` activity
-    * Creates an `Mobilizon.Federation.ActivityPub.Activity` from this
-    * Federates (asynchronously) the activity
-    * Returns the activity
-  """
-  @spec update(struct(), map(), boolean, map()) :: {:ok, Activity.t(), struct()} | any()
-  def update(old_entity, args, local \\ false, additional \\ %{}) do
-    Logger.debug("updating an activity")
-    Logger.debug(inspect(args))
-
-    with {:ok, entity, update_data} <- Managable.update(old_entity, args, additional),
-         {:ok, activity} <- create_activity(update_data, local),
-         :ok <- maybe_federate(activity),
-         :ok <- maybe_relay_if_group_activity(activity) do
-      {:ok, activity, entity}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  def accept(type, entity, local \\ true, additional \\ %{}) do
-    Logger.debug("We're accepting something")
-
-    {:ok, entity, update_data} =
-      case type do
-        :join -> accept_join(entity, additional)
-        :follow -> accept_follow(entity, additional)
-        :invite -> accept_invite(entity, additional)
-      end
-
-    with {:ok, activity} <- create_activity(update_data, local),
-         :ok <- maybe_federate(activity),
-         :ok <- maybe_relay_if_group_activity(activity) do
-      {:ok, activity, entity}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  def reject(type, entity, local \\ true, additional \\ %{}) do
-    {:ok, entity, update_data} =
-      case type do
-        :join -> reject_join(entity, additional)
-        :follow -> reject_follow(entity, additional)
-        :invite -> reject_invite(entity, additional)
-      end
-
-    with {:ok, activity} <- create_activity(update_data, local),
-         :ok <- maybe_federate(activity),
-         :ok <- maybe_relay_if_group_activity(activity) do
-      {:ok, activity, entity}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  def announce(
-        %Actor{} = actor,
-        object,
-        activity_id \\ nil,
-        local \\ true,
-        public \\ true
-      ) do
-    with {:ok, %Actor{id: object_owner_actor_id}} <-
-           ActivityPubActor.get_or_fetch_actor_by_url(object["actor"]),
-         {:ok, %Share{} = _share} <- Share.create(object["id"], actor.id, object_owner_actor_id),
-         announce_data <- make_announce_data(actor, object, activity_id, public),
-         {:ok, activity} <- create_activity(announce_data, local),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity, object}
-    else
-      error ->
-        {:error, error}
-    end
-  end
-
-  def unannounce(
-        %Actor{} = actor,
-        object,
-        activity_id \\ nil,
-        cancelled_activity_id \\ nil,
-        local \\ true
-      ) do
-    with announce_activity <- make_announce_data(actor, object, cancelled_activity_id),
-         unannounce_data <- make_unannounce_data(actor, announce_activity, activity_id),
-         {:ok, unannounce_activity} <- create_activity(unannounce_data, local),
-         :ok <- maybe_federate(unannounce_activity) do
-      {:ok, unannounce_activity, object}
-    else
-      _e -> {:ok, object}
-    end
-  end
-
-  @doc """
-  Make an actor follow another
-  """
-  def follow(
-        %Actor{} = follower,
-        %Actor{} = followed,
-        activity_id \\ nil,
-        local \\ true,
-        additional \\ %{}
-      ) do
-    with {:different_actors, true} <- {:different_actors, followed.id != follower.id},
-         {:ok, activity_data, %Follower{} = follower} <-
-           Types.Actors.follow(
-             follower,
-             followed,
-             local,
-             Map.merge(additional, %{"activity_id" => activity_id})
-           ),
-         {:ok, activity} <- create_activity(activity_data, local),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity, follower}
-    else
-      {:error, err, msg} when err in [:already_following, :suspended, :no_person] ->
-        {:error, msg}
-
-      {:different_actors, _} ->
-        {:error, "Can't follow yourself"}
-    end
-  end
-
-  @doc """
-  Make an actor unfollow another
-  """
-  @spec unfollow(Actor.t(), Actor.t(), String.t(), boolean()) :: {:ok, map()} | any()
-  def unfollow(%Actor{} = follower, %Actor{} = followed, activity_id \\ nil, local \\ true) do
-    with {:ok, %Follower{id: follow_id} = follow} <- Actors.unfollow(followed, follower),
-         # We recreate the follow activity
-         follow_as_data <-
-           Convertible.model_to_as(%{follow | actor: follower, target_actor: followed}),
-         {:ok, follow_activity} <- create_activity(follow_as_data, local),
-         activity_unfollow_id <-
-           activity_id || "#{Endpoint.url()}/unfollow/#{follow_id}/activity",
-         unfollow_data <-
-           make_unfollow_data(follower, followed, follow_activity, activity_unfollow_id),
-         {:ok, activity} <- create_activity(unfollow_data, local),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity, follow}
-    else
-      err ->
-        Logger.debug("Error while unfollowing an actor #{inspect(err)}")
-        err
-    end
-  end
-
-  def delete(object, actor, local \\ true, additional \\ %{}) do
-    with {:ok, activity_data, actor, object} <-
-           Managable.delete(object, actor, local, additional),
-         group <- Ownable.group_actor(object),
-         :ok <- check_for_actor_key_rotation(actor),
-         {:ok, activity} <- create_activity(activity_data, local),
-         :ok <- maybe_federate(activity),
-         :ok <- maybe_relay_if_group_activity(activity, group) do
-      {:ok, activity, object}
-    end
-  end
-
-  def join(entity_to_join, actor_joining, local \\ true, additional \\ %{})
-
-  def join(%Event{} = event, %Actor{} = actor, local, additional) do
-    with {:ok, activity_data, participant} <- Types.Events.join(event, actor, local, additional),
-         {:ok, activity} <- create_activity(activity_data, local),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity, participant}
-    else
-      {:maximum_attendee_capacity, err} ->
-        {:maximum_attendee_capacity, err}
-
-      {:accept, accept} ->
-        accept
-    end
-  end
-
-  def join(%Actor{type: :Group} = group, %Actor{} = actor, local, additional) do
-    with {:ok, activity_data, %Member{} = member} <-
-           Types.Actors.join(group, actor, local, additional),
-         {:ok, activity} <- create_activity(activity_data, local),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity, member}
-    else
-      {:accept, accept} ->
-        accept
-    end
-  end
-
-  def leave(object, actor, local \\ true, additional \\ %{})
-
-  @doc """
-  Leave an event or a group
-  """
-  def leave(
-        %Event{id: event_id, url: event_url} = _event,
-        %Actor{id: actor_id, url: actor_url} = _actor,
-        local,
-        additional
-      ) do
-    with {:only_organizer, false} <-
-           {:only_organizer, Participant.is_not_only_organizer(event_id, actor_id)},
-         {:ok, %Participant{} = participant} <-
-           Mobilizon.Events.get_participant(
-             event_id,
-             actor_id,
-             Map.get(additional, :metadata, %{})
-           ),
-         {:ok, %Participant{} = participant} <-
-           Events.delete_participant(participant),
-         leave_data <- %{
-           "type" => "Leave",
-           # If it's an exclusion it should be something else
-           "actor" => actor_url,
-           "object" => event_url,
-           "id" => "#{Endpoint.url()}/leave/event/#{participant.id}"
-         },
-         audience <-
-           Audience.get_audience(participant),
-         {:ok, activity} <- create_activity(Map.merge(leave_data, audience), local),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity, participant}
-    end
-  end
-
-  def leave(
-        %Actor{type: :Group, id: group_id, url: group_url, members_url: group_members_url},
-        %Actor{id: actor_id, url: actor_url},
-        local,
-        additional
-      ) do
-    with {:member, {:ok, %Member{id: member_id} = member}} <-
-           {:member, Actors.get_member(actor_id, group_id)},
-         {:is_not_only_admin, true} <-
-           {:is_not_only_admin,
-            Map.get(additional, :force_member_removal, false) ||
-              !Actors.is_only_administrator?(member_id, group_id)},
-         {:delete, {:ok, %Member{} = member}} <- {:delete, Actors.delete_member(member)},
-         Mobilizon.Service.Activity.Member.insert_activity(member, subject: "member_quit"),
-         leave_data <- %{
-           "to" => [group_members_url],
-           "cc" => [group_url],
-           "attributedTo" => group_url,
-           "type" => "Leave",
-           "actor" => actor_url,
-           "object" => group_url
-         },
-         {:ok, activity} <- create_activity(leave_data, local),
-         :ok <- maybe_federate(activity),
-         :ok <- maybe_relay_if_group_activity(activity) do
-      {:ok, activity, member}
-    end
-  end
-
-  def remove(
-        %Member{} = member,
-        %Actor{type: :Group, url: group_url, members_url: group_members_url},
-        %Actor{url: moderator_url} = moderator,
-        local,
-        _additional \\ %{}
-      ) do
-    with {:ok, %Member{id: member_id}} <- Actors.update_member(member, %{role: :rejected}),
-         %Member{} = member <- Actors.get_member(member_id),
-         {:ok, _} <-
-           Mobilizon.Service.Activity.Member.insert_activity(member,
-             moderator: moderator,
-             subject: "member_removed"
-           ),
-         :ok <- Group.send_notification_to_removed_member(member),
-         remove_data <- %{
-           "to" => [group_members_url],
-           "type" => "Remove",
-           "actor" => moderator_url,
-           "object" => member.url,
-           "origin" => group_url
-         },
-         {:ok, activity} <- create_activity(remove_data, local),
-         :ok <- maybe_federate(activity),
-         :ok <- maybe_relay_if_group_activity(activity) do
-      {:ok, activity, member}
-    end
-  end
-
-  @spec invite(Actor.t(), Actor.t(), Actor.t(), boolean, map()) ::
-          {:ok, map(), Member.t()} | {:error, :member_not_found}
-  def invite(
-        %Actor{url: group_url, id: group_id, members_url: members_url} = group,
-        %Actor{url: actor_url, id: actor_id} = actor,
-        %Actor{url: target_actor_url, id: target_actor_id} = _target_actor,
-        local \\ true,
-        additional \\ %{}
-      ) do
-    Logger.debug("Handling #{actor_url} invite to #{group_url} sent to #{target_actor_url}")
-
-    with {:is_able_to_invite, true} <- {:is_able_to_invite, is_able_to_invite(actor, group)},
-         {:ok, %Member{url: member_url} = member} <-
-           Actors.create_member(%{
-             parent_id: group_id,
-             actor_id: target_actor_id,
-             role: :invited,
-             invited_by_id: actor_id,
-             url: Map.get(additional, :url)
-           }),
-         {:ok, _} <-
-           Mobilizon.Service.Activity.Member.insert_activity(member,
-             moderator: actor,
-             subject: "member_invited"
-           ),
-         invite_data <- %{
-           "type" => "Invite",
-           "attributedTo" => group_url,
-           "actor" => actor_url,
-           "object" => group_url,
-           "target" => target_actor_url,
-           "id" => member_url
-         },
-         {:ok, activity} <-
-           create_activity(
-             invite_data
-             |> Map.merge(%{"to" => [target_actor_url, members_url], "cc" => [group_url]})
-             |> Map.merge(additional),
-             local
-           ),
-         :ok <- maybe_federate(activity),
-         :ok <- maybe_relay_if_group_activity(activity),
-         :ok <- Group.send_invite_to_user(member) do
-      {:ok, activity, member}
-    end
-  end
-
-  defp is_able_to_invite(%Actor{domain: actor_domain, id: actor_id}, %Actor{
-         domain: group_domain,
-         id: group_id
-       }) do
-    # If the actor comes from the same domain we trust it
-    if actor_domain == group_domain do
-      true
-    else
-      # If local group, we'll send the invite
-      with {:ok, %Member{} = admin_member} <- Actors.get_member(actor_id, group_id) do
-        Member.is_administrator(admin_member)
-      end
-    end
-  end
-
-  def move(type, old_entity, args, local \\ false, additional \\ %{}) do
-    Logger.debug("We're moving something")
-    Logger.debug(inspect(args))
-
-    with {:ok, entity, update_data} <-
-           (case type do
-              :resource -> Types.Resources.move(old_entity, args, additional)
-            end),
-         {:ok, activity} <- create_activity(update_data, local),
-         :ok <- maybe_federate(activity) do
-      {:ok, activity, entity}
-    else
-      err ->
-        Logger.error("Something went wrong while creating a Move activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  def flag(args, local \\ false, additional \\ %{}) do
-    with {report, report_as_data} <- Types.Reports.flag(args, local, additional),
-         {:ok, activity} <- create_activity(report_as_data, local),
-         :ok <- maybe_federate(activity) do
-      Enum.each(Users.list_moderators(), fn moderator ->
-        moderator
-        |> Admin.report(report)
-        |> Mailer.send_email_later()
-      end)
-
-      {:ok, activity, report}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  @spec is_create_activity?(Activity.t()) :: boolean
-  defp is_create_activity?(%Activity{data: %{"type" => "Create"}}), do: true
-  defp is_create_activity?(_), do: false
-
-  @spec convert_members_in_recipients(list(String.t())) :: {list(String.t()), list(Actor.t())}
-  defp convert_members_in_recipients(recipients) do
-    Enum.reduce(recipients, {recipients, []}, fn recipient, {recipients, member_actors} = acc ->
-      case Actors.get_group_by_members_url(recipient) do
-        # If the group is local just add external members
-        %Actor{domain: domain} = group when is_nil(domain) ->
-          {Enum.filter(recipients, fn recipient -> recipient != group.members_url end),
-           member_actors ++ Actors.list_external_actors_members_for_group(group)}
-
-        # If it's remote add the remote group actor as well
-        %Actor{} = group ->
-          {Enum.filter(recipients, fn recipient -> recipient != group.members_url end),
-           member_actors ++ Actors.list_external_actors_members_for_group(group) ++ [group]}
-
-        _ ->
-          acc
-      end
-    end)
-  end
-
-  defp convert_followers_in_recipients(recipients) do
-    Enum.reduce(recipients, {recipients, []}, fn recipient, {recipients, follower_actors} = acc ->
-      case Actors.get_actor_by_followers_url(recipient) do
-        %Actor{} = group ->
-          {Enum.filter(recipients, fn recipient -> recipient != group.followers_url end),
-           follower_actors ++ Actors.list_external_followers_for_actor(group)}
-
-        _ ->
-          acc
-      end
-    end)
-  end
-
-  # @spec is_announce_activity?(Activity.t()) :: boolean
-  # defp is_announce_activity?(%Activity{data: %{"type" => "Announce"}}), do: true
-  # defp is_announce_activity?(_), do: false
-
-  @doc """
-  Publish an activity to all appropriated audiences inboxes
-  """
-  # credo:disable-for-lines:47
-  @spec publish(Actor.t(), Activity.t()) :: :ok
-  def publish(actor, %Activity{recipients: recipients} = activity) do
-    Logger.debug("Publishing an activity")
-    Logger.debug(inspect(activity, pretty: true))
-
-    public = Visibility.is_public?(activity)
-    Logger.debug("is public ? #{public}")
-
-    if public && is_create_activity?(activity) && Config.get([:instance, :allow_relay]) do
-      Logger.info(fn -> "Relaying #{activity.data["id"]} out" end)
-
-      Relay.publish(activity)
-    end
-
-    recipients = Enum.uniq(recipients)
-
-    {recipients, followers} = convert_followers_in_recipients(recipients)
-
-    {recipients, members} = convert_members_in_recipients(recipients)
-
-    remote_inboxes =
-      (remote_actors(recipients) ++ followers ++ members)
-      |> Enum.map(fn actor -> actor.shared_inbox_url || actor.inbox_url end)
-      |> Enum.uniq()
-
-    {:ok, data} = Transmogrifier.prepare_outgoing(activity.data)
-    json = Jason.encode!(data)
-    Logger.debug(fn -> "Remote inboxes are : #{inspect(remote_inboxes)}" end)
-
-    Enum.each(remote_inboxes, fn inbox ->
-      Federator.enqueue(:publish_single_ap, %{
-        inbox: inbox,
-        json: json,
-        actor: actor,
-        id: activity.data["id"]
-      })
-    end)
-  end
-
-  @doc """
-  Publish an activity to a specific inbox
-  """
-  def publish_one(%{inbox: inbox, json: json, actor: actor, id: id}) do
-    Logger.info("Federating #{id} to #{inbox}")
-    %URI{host: host, path: path} = URI.parse(inbox)
-
-    digest = Signature.build_digest(json)
-    date = Signature.generate_date_header()
-
-    # request_target = Signature.generate_request_target("POST", path)
-
-    signature =
-      Signature.sign(actor, %{
-        "(request-target)": "post #{path}",
-        host: host,
-        "content-length": byte_size(json),
-        digest: digest,
-        date: date
-      })
-
-    Tesla.post(
-      inbox,
-      json,
-      headers: [
-        {"Content-Type", "application/activity+json"},
-        {"signature", signature},
-        {"digest", digest},
-        {"date", date}
-      ]
-    )
-  end
-
   @doc """
   Return all public activities (events & comments) for an actor
   """
-  @spec fetch_public_activities_for_actor(Actor.t(), integer(), integer()) :: map()
+  @spec fetch_public_activities_for_actor(Actor.t(), pos_integer(), pos_integer()) :: map()
   def fetch_public_activities_for_actor(%Actor{id: actor_id} = actor, page \\ 1, limit \\ 10) do
     %Actor{id: relay_actor_id} = Relay.get_actor()
 
@@ -758,217 +176,4 @@ defmodule Mobilizon.Federation.ActivityPub do
       local: local
     }
   end
-
-  # Get recipients for an activity or object
-  @spec get_recipients(map()) :: list()
-  defp get_recipients(data) do
-    Map.get(data, "to", []) ++ Map.get(data, "cc", [])
-  end
-
-  @spec check_for_tombstones(map()) :: Tombstone.t() | nil
-  defp check_for_tombstones(%{url: url}), do: Tombstone.find_tombstone(url)
-  defp check_for_tombstones(_), do: nil
-
-  @spec accept_follow(Follower.t(), map) :: {:ok, Follower.t(), Activity.t()} | any
-  defp accept_follow(%Follower{} = follower, additional) do
-    with {:ok, %Follower{} = follower} <- Actors.update_follower(follower, %{approved: true}),
-         follower_as_data <- Convertible.model_to_as(follower),
-         update_data <-
-           make_accept_join_data(
-             follower_as_data,
-             Map.merge(additional, %{
-               "id" => "#{Endpoint.url()}/accept/follow/#{follower.id}",
-               "to" => [follower.actor.url],
-               "cc" => [],
-               "actor" => follower.target_actor.url
-             })
-           ) do
-      {:ok, follower, update_data}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an update activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  @spec accept_join(Participant.t(), map) :: {:ok, Participant.t(), Activity.t()} | any
-  defp accept_join(%Participant{} = participant, additional) do
-    with {:ok, %Participant{} = participant} <-
-           Events.update_participant(participant, %{role: :participant}),
-         Absinthe.Subscription.publish(Endpoint, participant.actor,
-           event_person_participation_changed: participant.actor.id
-         ),
-         {:ok, _} <-
-           Scheduler.trigger_notifications_for_participant(participant),
-         participant_as_data <- Convertible.model_to_as(participant),
-         audience <-
-           Audience.get_audience(participant),
-         accept_join_data <-
-           make_accept_join_data(
-             participant_as_data,
-             Map.merge(Map.merge(audience, additional), %{
-               "id" => "#{Endpoint.url()}/accept/join/#{participant.id}"
-             })
-           ) do
-      {:ok, participant, accept_join_data}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an update activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  @spec accept_join(Member.t(), map) :: {:ok, Member.t(), Activity.t()} | any
-  defp accept_join(%Member{} = member, additional) do
-    with {:ok, %Member{} = member} <-
-           Actors.update_member(member, %{role: :member}),
-         {:ok, _} <-
-           Mobilizon.Service.Activity.Member.insert_activity(member,
-             subject: "member_approved"
-           ),
-         _ <- maybe_refresh_group(member),
-         Absinthe.Subscription.publish(Endpoint, member.actor,
-           group_membership_changed: [
-             Actor.preferred_username_and_domain(member.parent),
-             member.actor.id
-           ]
-         ),
-         member_as_data <- Convertible.model_to_as(member),
-         audience <-
-           Audience.get_audience(member),
-         accept_join_data <-
-           make_accept_join_data(
-             member_as_data,
-             Map.merge(Map.merge(audience, additional), %{
-               "id" => "#{Endpoint.url()}/accept/join/#{member.id}"
-             })
-           ) do
-      {:ok, member, accept_join_data}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an update activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  @spec accept_invite(Member.t(), map()) :: {:ok, Member.t(), Activity.t()} | any
-  defp accept_invite(
-         %Member{invited_by_id: invited_by_id, actor_id: actor_id} = member,
-         _additional
-       ) do
-    with %Actor{} = inviter <- Actors.get_actor(invited_by_id),
-         %Actor{url: actor_url} <- Actors.get_actor(actor_id),
-         {:ok, %Member{id: member_id} = member} <-
-           Actors.update_member(member, %{role: :member}),
-         {:ok, _} <-
-           Mobilizon.Service.Activity.Member.insert_activity(member,
-             subject: "member_accepted_invitation"
-           ),
-         _ <- maybe_refresh_group(member),
-         accept_data <- %{
-           "type" => "Accept",
-           "attributedTo" => member.parent.url,
-           "to" => [inviter.url, member.parent.members_url],
-           "cc" => [member.parent.url],
-           "actor" => actor_url,
-           "object" => Convertible.model_to_as(member),
-           "id" => "#{Endpoint.url()}/accept/invite/member/#{member_id}"
-         } do
-      {:ok, member, accept_data}
-    end
-  end
-
-  defp maybe_refresh_group(%Member{
-         parent: %Actor{domain: parent_domain, url: parent_url},
-         actor: %Actor{} = actor
-       }) do
-    unless is_nil(parent_domain),
-      do: Refresher.fetch_group(parent_url, actor)
-  end
-
-  @spec reject_join(Participant.t(), map()) :: {:ok, Participant.t(), Activity.t()} | any()
-  defp reject_join(%Participant{} = participant, additional) do
-    with {:ok, %Participant{} = participant} <-
-           Events.update_participant(participant, %{role: :rejected}),
-         Absinthe.Subscription.publish(Endpoint, participant.actor,
-           event_person_participation_changed: participant.actor.id
-         ),
-         participant_as_data <- Convertible.model_to_as(participant),
-         audience <-
-           participant
-           |> Audience.get_audience()
-           |> Map.merge(additional),
-         reject_data <- %{
-           "type" => "Reject",
-           "object" => participant_as_data
-         },
-         update_data <-
-           reject_data
-           |> Map.merge(audience)
-           |> Map.merge(%{
-             "id" => "#{Endpoint.url()}/reject/join/#{participant.id}"
-           }) do
-      {:ok, participant, update_data}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an update activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  @spec reject_follow(Follower.t(), map()) :: {:ok, Follower.t(), Activity.t()} | any()
-  defp reject_follow(%Follower{} = follower, additional) do
-    with {:ok, %Follower{} = follower} <- Actors.delete_follower(follower),
-         follower_as_data <- Convertible.model_to_as(follower),
-         audience <-
-           follower.actor |> Audience.get_audience() |> Map.merge(additional),
-         reject_data <- %{
-           "to" => [follower.actor.url],
-           "type" => "Reject",
-           "actor" => follower.target_actor.url,
-           "object" => follower_as_data
-         },
-         update_data <-
-           audience
-           |> Map.merge(reject_data)
-           |> Map.merge(%{
-             "id" => "#{Endpoint.url()}/reject/follow/#{follower.id}"
-           }) do
-      {:ok, follower, update_data}
-    else
-      err ->
-        Logger.error("Something went wrong while creating an update activity")
-        Logger.debug(inspect(err))
-        err
-    end
-  end
-
-  @spec reject_invite(Member.t(), map()) :: {:ok, Member.t(), Activity.t()} | any
-  defp reject_invite(
-         %Member{invited_by_id: invited_by_id, actor_id: actor_id} = member,
-         _additional
-       ) do
-    with %Actor{} = inviter <- Actors.get_actor(invited_by_id),
-         %Actor{url: actor_url} <- Actors.get_actor(actor_id),
-         {:ok, %Member{url: member_url, id: member_id} = member} <-
-           Actors.delete_member(member),
-         Mobilizon.Service.Activity.Member.insert_activity(member,
-           subject: "member_rejected_invitation"
-         ),
-         accept_data <- %{
-           "type" => "Reject",
-           "actor" => actor_url,
-           "attributedTo" => member.parent.url,
-           "to" => [inviter.url, member.parent.members_url],
-           "cc" => [member.parent.url],
-           "object" => member_url,
-           "id" => "#{Endpoint.url()}/reject/invite/member/#{member_id}"
-         } do
-      {:ok, member, accept_data}
-    end
-  end
 end

lib/federation/activity_pub/actor.ex

@@ -14,65 +14,57 @@ defmodule Mobilizon.Federation.ActivityPub.Actor do
   @doc """
   Getting an actor from url, eventually creating it if we don't have it locally or if it needs an update
   """
-  @spec get_or_fetch_actor_by_url(String.t(), boolean) :: {:ok, Actor.t()} | {:error, String.t()}
+  @spec get_or_fetch_actor_by_url(url :: String.t(), preload :: boolean()) ::
+          {:ok, Actor.t()}
+          | {:error, make_actor_errors}
+          | {:error, :no_internal_relay_actor}
+          | {:error, :url_nil}
   def get_or_fetch_actor_by_url(url, preload \\ false)
 
-  def get_or_fetch_actor_by_url(nil, _preload), do: {:error, "Can't fetch a nil url"}
+  def get_or_fetch_actor_by_url(nil, _preload), do: {:error, :url_nil}
 
   def get_or_fetch_actor_by_url("https://www.w3.org/ns/activitystreams#Public", _preload) do
-    with %Actor{url: url} <- Relay.get_actor() do
+    %Actor{url: url} = Relay.get_actor()
     get_or_fetch_actor_by_url(url)
   end
-  end
 
-  @spec get_or_fetch_actor_by_url(String.t(), boolean()) :: {:ok, Actor.t()} | {:error, any()}
   def get_or_fetch_actor_by_url(url, preload) do
-    with {:ok, %Actor{} = cached_actor} <- Actors.get_actor_by_url(url, preload),
+    case Actors.get_actor_by_url(url, preload) do
-         false <- Actors.needs_update?(cached_actor) do
+      {:ok, %Actor{} = cached_actor} ->
-      {:ok, cached_actor}
+        if Actors.needs_update?(cached_actor) do
+          __MODULE__.make_actor_from_url(url, preload)
         else
-      _ ->
+          {:ok, cached_actor}
-        # For tests, see https://github.com/jjh42/mock#not-supported---mocking-internal-function-calls and Mobilizon.Federation.ActivityPubTest
+        end
-        case __MODULE__.make_actor_from_url(url, preload) do
-          {:ok, %Actor{} = actor} ->
-            {:ok, actor}
 
-          {:error, err} ->
+      {:error, :actor_not_found} ->
-            Logger.debug("Could not fetch by AP id")
+        # For tests, see https://github.com/jjh42/mock#not-supported---mocking-internal-function-calls and Mobilizon.Federation.ActivityPubTest
-            Logger.debug(inspect(err))
+        __MODULE__.make_actor_from_url(url, preload)
-            {:error, "Could not fetch by AP id"}
-        end
     end
   end
 
+  @type make_actor_errors :: Fetcher.fetch_actor_errors() | :actor_is_local
+
   @doc """
   Create an actor locally by its URL (AP ID)
   """
-  @spec make_actor_from_url(String.t(), boolean()) ::
+  @spec make_actor_from_url(url :: String.t(), preload :: boolean()) ::
-          {:ok, %Actor{}} | {:error, :actor_deleted} | {:error, :http_error} | {:error, any()}
+          {:ok, Actor.t()} | {:error, make_actor_errors}
   def make_actor_from_url(url, preload \\ false) do
     if are_same_origin?(url, Endpoint.url()) do
-      {:error, "Can't make a local actor from URL"}
+      {:error, :actor_is_local}
     else
       case Fetcher.fetch_and_prepare_actor_from_url(url) do
-        # Just in case
+        {:ok, data} when is_map(data) ->
-        {:ok, {:error, _e}} ->
-          raise ArgumentError, message: "Failed to make actor from url #{url}"
-
-        {:ok, data} ->
           Actors.upsert_actor(data, preload)
 
         # Request returned 410
         {:error, :actor_deleted} ->
-          Logger.info("Actor was deleted")
+          Logger.info("Actor #{url} was deleted")
           {:error, :actor_deleted}
 
-        {:error, :http_error} ->
+        {:error, err} when err in [:http_error, :json_decode_error] ->
-          {:error, :http_error}
+          {:error, err}
-
-        {:error, e} ->
-          Logger.warn("Failed to make actor from url #{url}")
-          {:error, e}
       end
     end
   end
@@ -80,8 +72,8 @@ defmodule Mobilizon.Federation.ActivityPub.Actor do
   @doc """
   Find an actor in our local database or call WebFinger to find what's its AP ID is and then fetch it
   """
-  @spec find_or_make_actor_from_nickname(String.t(), atom() | nil) ::
+  @spec find_or_make_actor_from_nickname(nickname :: String.t(), type :: atom() | nil) ::
-          {:ok, Actor.t()} | {:error, any()}
+          {:ok, Actor.t()} | {:error, make_actor_errors | WebFinger.finger_errors()}
   def find_or_make_actor_from_nickname(nickname, type \\ nil) do
     case Actors.get_actor_by_name_with_preload(nickname, type) do
       %Actor{url: actor_url} = actor ->
@@ -96,20 +88,22 @@ defmodule Mobilizon.Federation.ActivityPub.Actor do
     end
   end
 
-  @spec find_or_make_group_from_nickname(String.t()) :: tuple()
+  @spec find_or_make_group_from_nickname(nick :: String.t()) ::
+          {:error, make_actor_errors | WebFinger.finger_errors()}
   def find_or_make_group_from_nickname(nick), do: find_or_make_actor_from_nickname(nick, :Group)
 
   @doc """
   Create an actor inside our database from username, using WebFinger to find out its AP ID and then fetch it
   """
-  @spec make_actor_from_nickname(String.t()) :: {:ok, %Actor{}} | {:error, any()}
+  @spec make_actor_from_nickname(nickname :: String.t(), preload :: boolean) ::
+          {:ok, Actor.t()} | {:error, make_actor_errors | WebFinger.finger_errors()}
   def make_actor_from_nickname(nickname, preload \\ false) do
     case WebFinger.finger(nickname) do
       {:ok, url} when is_binary(url) ->
         make_actor_from_url(url, preload)
 
-      _e ->
+      {:error, e} ->
-        {:error, "No ActivityPub URL found in WebFinger"}
+        {:error, e}
     end
   end
 end

lib/federation/activity_pub/audience.ex

@@ -7,6 +7,7 @@ defmodule Mobilizon.Federation.ActivityPub.Audience do
   alias Mobilizon.Actors.{Actor, Member}
   alias Mobilizon.Discussions.{Comment, Discussion}
   alias Mobilizon.Events.{Event, Participant}
+  alias Mobilizon.Federation.ActivityPub.Types.Entity
   alias Mobilizon.Posts.Post
   alias Mobilizon.Storage.Repo
 
@@ -99,6 +100,8 @@ defmodule Mobilizon.Federation.ActivityPub.Audience do
     }
   end
 
+  @spec get_to_and_cc(Actor.t(), list(), :direct | :private | :public | :unlisted | {:list, any}) ::
+          {list(), list()}
   @doc """
   Determines the full audience based on mentions for an audience
 
@@ -118,7 +121,6 @@ defmodule Mobilizon.Federation.ActivityPub.Audience do
     * `to` : the mentioned actors and the eventual actor we're replying to
     * `cc` : none
   """
-  @spec get_to_and_cc(Actor.t(), list(), String.t()) :: {list(), list()}
   def get_to_and_cc(%Actor{} = actor, mentions, :public) do
     to = [@ap_public | mentions]
     cc = [actor.followers_url]
@@ -128,7 +130,6 @@ defmodule Mobilizon.Federation.ActivityPub.Audience do
     {to, cc}
   end
 
-  @spec get_to_and_cc(Actor.t(), list(), String.t()) :: {list(), list()}
   def get_to_and_cc(%Actor{} = actor, mentions, :unlisted) do
     to = [actor.followers_url | mentions]
     cc = [@ap_public]
@@ -138,7 +139,6 @@ defmodule Mobilizon.Federation.ActivityPub.Audience do
     {to, cc}
   end
 
-  @spec get_to_and_cc(Actor.t(), list(), String.t()) :: {list(), list()}
   def get_to_and_cc(%Actor{} = actor, mentions, :private) do
     {to, cc} = get_to_and_cc(actor, mentions, :direct)
 
@@ -147,7 +147,6 @@ defmodule Mobilizon.Federation.ActivityPub.Audience do
     {to, cc}
   end
 
-  @spec get_to_and_cc(Actor.t(), list(), String.t()) :: {list(), list()}
   def get_to_and_cc(_actor, mentions, :direct) do
     {mentions, []}
   end
@@ -156,22 +155,20 @@ defmodule Mobilizon.Federation.ActivityPub.Audience do
     {mentions, []}
   end
 
-  @spec maybe_add_group_members(List.t(), Actor.t()) :: List.t()
+  @spec maybe_add_group_members(list(String.t()), Actor.t()) :: list(String.t())
   defp maybe_add_group_members(collection, %Actor{type: :Group, members_url: members_url}) do
     [members_url | collection]
   end
 
   defp maybe_add_group_members(collection, %Actor{type: _}), do: collection
 
-  @spec maybe_add_followers(List.t(), Actor.t()) :: List.t()
+  @spec maybe_add_followers(list(String.t()), Actor.t()) :: list(String.t())
   defp maybe_add_followers(collection, %Actor{type: :Group, followers_url: followers_url}) do
     [followers_url | collection]
   end
 
   defp maybe_add_followers(collection, %Actor{type: _}), do: collection
 
-  def get_addressed_actors(mentioned_users, _), do: mentioned_users
-
   defp add_in_reply_to(%Comment{actor: %Actor{url: url}} = _comment), do: [url]
   defp add_in_reply_to(%Event{organizer_actor: %Actor{url: url}} = _event), do: [url]
   defp add_in_reply_to(_), do: []
@@ -239,29 +236,27 @@ defmodule Mobilizon.Federation.ActivityPub.Audience do
 
   @spec extract_actors_from_mentions(list(), Actor.t(), atom()) :: {list(), list()}
   defp extract_actors_from_mentions(mentions, actor, visibility) do
-    with mentioned_actors <- Enum.map(mentions, &process_mention/1),
+    get_to_and_cc(actor, Enum.map(mentions, &process_mention/1), visibility)
-         addressed_actors <- get_addressed_actors(mentioned_actors, nil) do
-      get_to_and_cc(actor, addressed_actors, visibility)
-    end
   end
 
+  @spec extract_actors_from_event(Event.t()) :: %{
+          String.t() => list(String.t())
+        }
   defp extract_actors_from_event(%Event{} = event) do
-    with {to, cc} <-
+    {to, cc} =
       extract_actors_from_mentions(
         event.mentions,
         group_or_organizer_event(event),
         event.visibility
-           ),
+      )
-         {to, cc} <-
+
+    {to, cc} =
       {to,
        Enum.uniq(
          cc ++ add_comments_authors(event.comments) ++ add_shares_actors_followers(event.url)
-            )} do
+       )}
+
     %{"to" => to, "cc" => cc}
-    else
-      _ ->
-        %{"to" => [], "cc" => []}
-    end
   end
 
   @spec group_or_organizer_event(Event.t()) :: Actor.t()

lib/federation/activity_pub/federator.ex

@@ -12,17 +12,19 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
 
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Federation.ActivityPub
-  alias Mobilizon.Federation.ActivityPub.{Activity, Transmogrifier}
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
+  alias Mobilizon.Federation.ActivityPub.Transmogrifier
 
   require Logger
 
   @max_jobs 20
 
+  @spec init(any()) :: {:ok, any()}
   def init(args) do
     {:ok, args}
   end
 
+  @spec start_link(any) :: GenServer.on_start()
   def start_link(_) do
     spawn(fn ->
       # 1 minute
@@ -39,6 +41,8 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
     )
   end
 
+  @spec handle(:publish | :publish_single_ap | atom(), Activity.t() | map()) ::
+          :ok | {:ok, Activity.t()} | Tesla.Env.result() | {:error, String.t()}
   def handle(:publish, activity) do
     Logger.debug(inspect(activity))
     Logger.debug(fn -> "Running publish for #{activity.data["id"]}" end)
@@ -46,7 +50,7 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
     with {:ok, %Actor{} = actor} <-
            ActivityPubActor.get_or_fetch_actor_by_url(activity.data["actor"]) do
       Logger.info(fn -> "Sending #{activity.data["id"]} out via AP" end)
-      ActivityPub.publish(actor, activity)
+      ActivityPub.Publisher.publish(actor, activity)
     end
   end
 
@@ -58,9 +62,6 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
       {:ok, activity, _data} ->
         {:ok, activity}
 
-      %Activity{} ->
-        Logger.info("Already had #{params["id"]}")
-
       e ->
         # Just drop those for now
         Logger.debug("Unhandled activity")
@@ -70,7 +71,7 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
   end
 
   def handle(:publish_single_ap, params) do
-    ActivityPub.publish_one(params)
+    ActivityPub.Publisher.publish_one(params)
   end
 
   def handle(type, _) do
@@ -78,6 +79,7 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
     {:error, "Don't know what to do with this"}
   end
 
+  @spec enqueue(atom(), map(), pos_integer()) :: :ok | {:ok, any()} | {:error, any()}
   def enqueue(type, payload, priority \\ 1) do
     Logger.debug("enqueue something with type #{inspect(type)}")
 
@@ -88,6 +90,7 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
     end
   end
 
+  @spec maybe_start_job(any(), any()) :: {any(), any()}
   def maybe_start_job(running_jobs, queue) do
     if :sets.size(running_jobs) < @max_jobs && queue != [] do
       {{type, payload}, queue} = queue_pop(queue)
@@ -99,6 +102,7 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
     end
   end
 
+  @spec handle_cast(any(), any()) :: {:noreply, any()}
   def handle_cast({:enqueue, type, payload, _priority}, state)
       when type in [:incoming_doc, :incoming_ap_doc] do
     %{in: {i_running_jobs, i_queue}, out: {o_running_jobs, o_queue}} = state
@@ -122,6 +126,7 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
     {:noreply, state}
   end
 
+  @spec handle_info({:DOWN, any(), :process, any, any()}, any) :: {:noreply, map()}
   def handle_info({:DOWN, ref, :process, _pid, _reason}, state) do
     %{in: {i_running_jobs, i_queue}, out: {o_running_jobs, o_queue}} = state
     i_running_jobs = :sets.del_element(ref, i_running_jobs)
@@ -132,11 +137,13 @@ defmodule Mobilizon.Federation.ActivityPub.Federator do
     {:noreply, %{in: {i_running_jobs, i_queue}, out: {o_running_jobs, o_queue}}}
   end
 
+  @spec enqueue_sorted(any(), any(), pos_integer()) :: any()
   def enqueue_sorted(queue, element, priority) do
     [%{item: element, priority: priority} | queue]
     |> Enum.sort_by(fn %{priority: priority} -> priority end)
   end
 
+  @spec queue_pop(list(any())) :: {any(), list(any())}
   def queue_pop([%{item: element} | queue]) do
     {element, queue}
   end

lib/federation/activity_pub/fetcher.ex

@@ -15,107 +15,141 @@ defmodule Mobilizon.Federation.ActivityPub.Fetcher do
   import Mobilizon.Federation.ActivityPub.Utils,
     only: [maybe_date_fetch: 2, sign_fetch: 4, origin_check?: 2]
 
-  @spec fetch(String.t(), Keyword.t()) :: {:ok, map()}
+  import Mobilizon.Service.Guards, only: [is_valid_string: 1]
+
+  @spec fetch(String.t(), Keyword.t()) ::
+          {:ok, map()}
+          | {:error,
+             :invalid_url | :http_gone | :http_error | :http_not_found | :content_not_json}
   def fetch(url, options \\ []) do
     on_behalf_of = Keyword.get(options, :on_behalf_of, Relay.get_actor())
+    date = Signature.generate_date_header()
 
-    with false <- address_invalid(url),
+    headers =
-         date <- Signature.generate_date_header(),
-         headers <-
       [{:Accept, "application/activity+json"}]
       |> maybe_date_fetch(date)
-           |> sign_fetch(on_behalf_of, url, date),
+      |> sign_fetch(on_behalf_of, url, date)
-         client <-
+
-           ActivityPubClient.client(headers: headers),
+    client = ActivityPubClient.client(headers: headers)
-         {:ok, %Tesla.Env{body: data, status: code}} when code in 200..299 <-
+
-           ActivityPubClient.get(client, url) do
+    if address_valid?(url) do
+      case ActivityPubClient.get(client, url) do
+        {:ok, %Tesla.Env{body: data, status: code}} when code in 200..299 and is_map(data) ->
           {:ok, data}
-    else
+
         {:ok, %Tesla.Env{status: 410}} ->
           Logger.debug("Resource at #{url} is 410 Gone")
-        {:error, "Gone"}
+          {:error, :http_gone}
 
         {:ok, %Tesla.Env{status: 404}} ->
           Logger.debug("Resource at #{url} is 404 Gone")
-        {:error, "Not found"}
+          {:error, :http_not_found}
+
+        {:ok, %Tesla.Env{body: data}} when is_binary(data) ->
+          {:error, :content_not_json}
 
         {:ok, %Tesla.Env{} = res} ->
-        {:error, res}
+          Logger.debug("Resource returned bad HTTP code inspect #{res}")
-
+          {:error, :http_error}
-      {:error, err} ->
+      end
-        {:error, err}
+    else
+      {:error, :invalid_url}
     end
   end
 
-  @spec fetch_and_create(String.t(), Keyword.t()) :: {:ok, map(), struct()}
+  @spec fetch_and_create(String.t(), Keyword.t()) ::
+          {:ok, map(), struct()} | {:error, atom()} | :error
   def fetch_and_create(url, options \\ []) do
-    with {:ok, data} when is_map(data) <- fetch(url, options),
+    case fetch(url, options) do
-         {:origin_check, true} <- {:origin_check, origin_check?(url, data)},
+      {:ok, data} when is_map(data) ->
-         params <- %{
+        if origin_check?(url, data) do
+          case Transmogrifier.handle_incoming(%{
                  "type" => "Create",
                  "to" => data["to"],
                  "cc" => data["cc"],
                  "actor" => data["actor"] || data["attributedTo"],
                  "attributedTo" => data["attributedTo"] || data["actor"],
                  "object" => data
-         } do
+               }) do
-      Transmogrifier.handle_incoming(params)
+            {:ok, entity, structure} ->
-    else
+              {:ok, entity, structure}
-      {:origin_check, false} ->
-        Logger.warn("Object origin check failed")
-        {:error, "Object origin check failed"}
 
-      # Returned content is not JSON
+            {:error, error} when is_atom(error) ->
-      {:ok, data} when is_binary(data) ->
+              {:error, error}
-        {:error, "Failed to parse content as JSON"}
+
+            :error ->
+              {:error, :transmogrifier_error}
+          end
+        else
+          Logger.warn("Object origin check failed")
+          {:error, :object_origin_check_failed}
+        end
 
       {:error, err} ->
         {:error, err}
     end
   end
 
-  @spec fetch_and_update(String.t(), Keyword.t()) :: {:ok, map(), struct()}
+  @spec fetch_and_update(String.t(), Keyword.t()) ::
+          {:ok, map(), struct()} | {:error, atom()}
   def fetch_and_update(url, options \\ []) do
-    with {:ok, data} when is_map(data) <- fetch(url, options),
+    case fetch(url, options) do
-         {:origin_check, true} <- {:origin_check, origin_check(url, data)},
+      {:ok, data} when is_map(data) ->
-         params <- %{
+        if origin_check(url, data) do
+          Transmogrifier.handle_incoming(%{
             "type" => "Update",
             "to" => data["to"],
             "cc" => data["cc"],
             "actor" => data["actor"] || data["attributedTo"],
             "attributedTo" => data["attributedTo"] || data["actor"],
             "object" => data
-         } do
+          })
-      Transmogrifier.handle_incoming(params)
         else
-      {:origin_check, false} ->
+          Logger.warn("Object origin check failed")
-        {:error, "Object origin check failed"}
+          {:error, :object_origin_check_failed}
+        end
 
       {:error, err} ->
         {:error, err}
     end
   end
 
+  @type fetch_actor_errors ::
+          :json_decode_error | :actor_deleted | :http_error | :actor_not_allowed_type
+
   @doc """
   Fetching a remote actor's information through its AP ID
   """
-  @spec fetch_and_prepare_actor_from_url(String.t()) :: {:ok, map()} | {:error, atom()} | any()
+  @spec fetch_and_prepare_actor_from_url(String.t()) ::
+          {:ok, map()} | {:error, fetch_actor_errors}
   def fetch_and_prepare_actor_from_url(url) do
     Logger.debug("Fetching and preparing actor from url")
     Logger.debug(inspect(url))
 
-    res =
+    case Tesla.get(url,
-      with {:ok, %{status: 200, body: body}} <-
-             Tesla.get(url,
            headers: [{"Accept", "application/activity+json"}],
            follow_redirect: true
-             ),
+         ) do
-           :ok <- Logger.debug("response okay, now decoding json"),
+      {:ok, %{status: 200, body: body}} ->
-           {:ok, data} <- Jason.decode(body) do
+        Logger.debug("response okay, now decoding json")
+
+        case Jason.decode(body) do
+          {:ok, data} when is_map(data) ->
             Logger.debug("Got activity+json response at actor's endpoint, now converting data")
-        {:ok, ActorConverter.as_to_model_data(data)}
+
-      else
+            case ActorConverter.as_to_model_data(data) do
-        # Actor is gone, probably deleted
+              {:error, :actor_not_allowed_type} ->
+                {:error, :actor_not_allowed_type}
+
+              map when is_map(map) ->
+                {:ok, map}
+            end
+
+          {:error, %Jason.DecodeError{} = e} ->
+            Logger.warn("Could not decode actor at fetch #{url}, #{inspect(e)}")
+            {:error, :json_decode_error}
+        end
+
       {:ok, %{status: 410}} ->
         Logger.info("Response HTTP 410")
         {:error, :actor_deleted}
@@ -124,16 +158,10 @@ defmodule Mobilizon.Federation.ActivityPub.Fetcher do
         Logger.info("Non 200 HTTP Code")
         {:error, :http_error}
 
-        {:error, e} ->
+      {:error, error} ->
-          Logger.warn("Could not decode actor at fetch #{url}, #{inspect(e)}")
+        Logger.warn("Could not fetch actor at fetch #{url}, #{inspect(error)}")
-          {:error, e}
+        {:error, :http_error}
-
-        e ->
-          Logger.warn("Could not decode actor at fetch #{url}, #{inspect(e)}")
-          {:error, e}
     end
-
-    res
   end
 
   @spec origin_check(String.t(), map()) :: boolean()
@@ -147,11 +175,9 @@ defmodule Mobilizon.Federation.ActivityPub.Fetcher do
     end
   end
 
-  @spec address_invalid(String.t()) :: false | {:error, :invalid_url}
+  @spec address_valid?(String.t()) :: boolean
-  defp address_invalid(address) do
+  defp address_valid?(address) do
-    with %URI{host: host, scheme: scheme} <- URI.parse(address),
+    %URI{host: host, scheme: scheme} = URI.parse(address)
-         true <- is_nil(host) or is_nil(scheme) do
+    is_valid_string(host) and is_valid_string(scheme)
-      {:error, :invalid_url}
-    end
   end
 end

lib/federation/activity_pub/permission.ex

@@ -13,6 +13,17 @@ defmodule Mobilizon.Federation.ActivityPub.Permission do
 
   @member_roles [:member, :moderator, :administrator]
 
+  @type object :: %{id: String.t(), url: String.t()}
+
+  @type permissions_member_role :: nil | :member | :moderator | :administrator
+
+  @type t :: %__MODULE__{
+          access: permissions_member_role,
+          create: permissions_member_role,
+          update: permissions_member_role,
+          delete: permissions_member_role
+        }
+
   @doc """
   Check that actor can access the object
   """
@@ -66,8 +77,8 @@ defmodule Mobilizon.Federation.ActivityPub.Permission do
 
   @spec can_manage_group_object?(
           existing_object_permissions(),
-          Actor.t(),
+          %Actor{url: String.t()},
-          any()
+          object()
         ) :: boolean()
   defp can_manage_group_object?(permission, %Actor{url: actor_url} = actor, object) do
     if Ownable.group_actor(object) != nil do
@@ -94,7 +105,7 @@ defmodule Mobilizon.Federation.ActivityPub.Permission do
     end
   end
 
-  @spec activity_actor_is_group_member?(Actor.t(), Entity.t(), atom()) :: boolean()
+  @spec activity_actor_is_group_member?(Actor.t(), object(), atom()) :: boolean()
   defp activity_actor_is_group_member?(
          %Actor{id: actor_id, url: actor_url},
          object,

lib/federation/activity_pub/publisher.ex

@@ -0,0 +1,128 @@
+defmodule Mobilizon.Federation.ActivityPub.Publisher do
+  @moduledoc """
+  Handle publishing activities
+  """
+  alias Mobilizon.Actors
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Config
+  alias Mobilizon.Federation.ActivityPub.{Activity, Federator, Relay, Transmogrifier, Visibility}
+  alias Mobilizon.Federation.HTTPSignatures.Signature
+  require Logger
+  import Mobilizon.Federation.ActivityPub.Utils, only: [remote_actors: 1]
+
+  @doc """
+  Publish an activity to all appropriated audiences inboxes
+  """
+  # credo:disable-for-lines:47
+  @spec publish(Actor.t(), Activity.t()) :: :ok
+  def publish(actor, %Activity{recipients: recipients} = activity) do
+    Logger.debug("Publishing an activity")
+    Logger.debug(inspect(activity, pretty: true))
+
+    public = Visibility.is_public?(activity)
+    Logger.debug("is public ? #{public}")
+
+    if public && is_create_activity?(activity) && Config.get([:instance, :allow_relay]) do
+      Logger.info(fn -> "Relaying #{activity.data["id"]} out" end)
+
+      Relay.publish(activity)
+    end
+
+    recipients = Enum.uniq(recipients)
+
+    {recipients, followers} = convert_followers_in_recipients(recipients)
+
+    {recipients, members} = convert_members_in_recipients(recipients)
+
+    remote_inboxes =
+      (remote_actors(recipients) ++ followers ++ members)
+      |> Enum.map(fn actor -> actor.shared_inbox_url || actor.inbox_url end)
+      |> Enum.uniq()
+
+    {:ok, data} = Transmogrifier.prepare_outgoing(activity.data)
+    json = Jason.encode!(data)
+    Logger.debug(fn -> "Remote inboxes are : #{inspect(remote_inboxes)}" end)
+
+    Enum.each(remote_inboxes, fn inbox ->
+      Federator.enqueue(:publish_single_ap, %{
+        inbox: inbox,
+        json: json,
+        actor: actor,
+        id: activity.data["id"]
+      })
+    end)
+  end
+
+  @doc """
+  Publish an activity to a specific inbox
+  """
+  @spec publish_one(%{inbox: String.t(), json: String.t(), actor: Actor.t(), id: String.t()}) ::
+          Tesla.Env.result()
+  def publish_one(%{inbox: inbox, json: json, actor: actor, id: id}) do
+    Logger.info("Federating #{id} to #{inbox}")
+    %URI{host: host, path: path} = URI.parse(inbox)
+
+    digest = Signature.build_digest(json)
+    date = Signature.generate_date_header()
+
+    # request_target = Signature.generate_request_target("POST", path)
+
+    signature =
+      Signature.sign(actor, %{
+        "(request-target)": "post #{path}",
+        host: host,
+        "content-length": byte_size(json),
+        digest: digest,
+        date: date
+      })
+
+    Tesla.post(
+      inbox,
+      json,
+      headers: [
+        {"Content-Type", "application/activity+json"},
+        {"signature", signature},
+        {"digest", digest},
+        {"date", date}
+      ]
+    )
+  end
+
+  @spec convert_followers_in_recipients(list(String.t())) :: {list(String.t()), list(String.t())}
+  defp convert_followers_in_recipients(recipients) do
+    Enum.reduce(recipients, {recipients, []}, fn recipient, {recipients, follower_actors} = acc ->
+      case Actors.get_actor_by_followers_url(recipient) do
+        %Actor{} = group ->
+          {Enum.filter(recipients, fn recipient -> recipient != group.followers_url end),
+           follower_actors ++ Actors.list_external_followers_for_actor(group)}
+
+        nil ->
+          acc
+      end
+    end)
+  end
+
+  @spec is_create_activity?(Activity.t()) :: boolean
+  defp is_create_activity?(%Activity{data: %{"type" => "Create"}}), do: true
+  defp is_create_activity?(_), do: false
+
+  @spec convert_members_in_recipients(list(String.t())) :: {list(String.t()), list(Actor.t())}
+  defp convert_members_in_recipients(recipients) do
+    Enum.reduce(recipients, {recipients, []}, fn recipient, {recipients, member_actors} = acc ->
+      case Actors.get_group_by_members_url(recipient) do
+        # If the group is local just add external members
+        %Actor{domain: domain} = group when is_nil(domain) ->
+          {Enum.filter(recipients, fn recipient -> recipient != group.members_url end),
+           member_actors ++ Actors.list_external_actors_members_for_group(group)}
+
+        # If it's remote add the remote group actor as well
+        %Actor{} = group ->
+          {Enum.filter(recipients, fn recipient -> recipient != group.members_url end),
+           member_actors ++ Actors.list_external_actors_members_for_group(group) ++ [group]}
+
+        _ ->
+          acc
+      end
+    end)
+  end
+end

lib/federation/activity_pub/refresher.ex

@@ -8,13 +8,12 @@ defmodule Mobilizon.Federation.ActivityPub.Refresher do
   alias Mobilizon.Federation.ActivityPub
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
   alias Mobilizon.Federation.ActivityPub.{Fetcher, Relay, Transmogrifier, Utils}
-  alias Mobilizon.Service.ErrorReporting.Sentry
   require Logger
 
   @doc """
   Refresh a remote profile
   """
-  @spec refresh_profile(Actor.t()) :: {:ok, Actor.t()}
+  @spec refresh_profile(Actor.t()) :: {:ok, Actor.t()} | {:error, fetch_actor_errors()} | {:error}
   def refresh_profile(%Actor{domain: nil}), do: {:error, "Can only refresh remote actors"}
 
   def refresh_profile(%Actor{type: :Group, url: url, id: group_id} = group) do
@@ -27,22 +26,39 @@ defmodule Mobilizon.Federation.ActivityPub.Refresher do
           Relay.get_actor()
       end
 
-    with :ok <- fetch_group(url, on_behalf_of) do
+    case fetch_group(url, on_behalf_of) do
+      {:error, error} ->
+        {:error, error}
+
+      :ok ->
         {:ok, group}
     end
   end
 
   def refresh_profile(%Actor{type: type, url: url}) when type in [:Person, :Application] do
-    with {:ok, %Actor{outbox_url: outbox_url} = actor} <-
+    case ActivityPubActor.make_actor_from_url(url) do
-           ActivityPubActor.make_actor_from_url(url),
+      {:error, error} ->
-         :ok <- fetch_collection(outbox_url, Relay.get_actor()) do
+        {:error, error}
-      {:ok, actor}
+
+      {:ok, %Actor{outbox_url: outbox_url} = actor} ->
+        case fetch_collection(outbox_url, Relay.get_actor()) do
+          :ok -> {:ok, actor}
+          {:error, error} -> {:error, error}
+        end
     end
   end
 
-  @spec fetch_group(String.t(), Actor.t()) :: :ok
+  @type fetch_actor_errors :: ActivityPubActor.make_actor_errors() | fetch_collection_errors()
+
+  @spec fetch_group(String.t(), Actor.t()) :: :ok | {:error, fetch_actor_errors}
   def fetch_group(group_url, %Actor{} = on_behalf_of) do
-    with {:ok,
+    case ActivityPubActor.make_actor_from_url(group_url) do
+      {:error, err}
+      when err in [:actor_deleted, :http_error, :json_decode_error, :actor_is_local] ->
+        Logger.debug("Error while making actor")
+        {:error, err}
+
+      {:ok,
        %Actor{
          outbox_url: outbox_url,
          resources_url: resources_url,
@@ -51,9 +67,10 @@ defmodule Mobilizon.Federation.ActivityPub.Refresher do
          todos_url: todos_url,
          discussions_url: discussions_url,
          events_url: events_url
-          }} <-
+       }} ->
-           ActivityPubActor.make_actor_from_url(group_url),
+        Logger.debug("Fetched group OK, now doing collections")
-         :ok <- fetch_collection(outbox_url, on_behalf_of),
+
+        with :ok <- fetch_collection(outbox_url, on_behalf_of),
              :ok <- fetch_collection(members_url, on_behalf_of),
              :ok <- fetch_collection(resources_url, on_behalf_of),
              :ok <- fetch_collection(posts_url, on_behalf_of),
@@ -62,49 +79,45 @@ defmodule Mobilizon.Federation.ActivityPub.Refresher do
              :ok <- fetch_collection(events_url, on_behalf_of) do
           :ok
         else
-      {:error, :actor_deleted} ->
-        {:error, :actor_deleted}
-
-      {:error, :http_error} ->
-        {:error, :http_error}
-
-      {:error, err} ->
-        Logger.error("Error while refreshing a group")
-
-        Sentry.capture_message("Error while refreshing a group",
-          extra: %{group_url: group_url}
-        )
-
-        Logger.debug(inspect(err))
           {:error, err}
-
+          when err in [:error, :process_error, :fetch_error, :collection_url_nil] ->
-      err ->
+            Logger.debug("Error while fetching actor collection")
-        Logger.error("Error while refreshing a group")
+            {:error, err}
-
+        end
-        Sentry.capture_message("Error while refreshing a group",
-          extra: %{group_url: group_url}
-        )
-
-        Logger.debug(inspect(err))
-        err
     end
   end
 
-  def fetch_collection(nil, _on_behalf_of), do: :error
+  @typep fetch_collection_errors :: :process_error | :fetch_error | :collection_url_nil
+
+  @spec fetch_collection(String.t() | nil, any) ::
+          :ok | {:error, fetch_collection_errors}
+  def fetch_collection(nil, _on_behalf_of), do: {:error, :collection_url_nil}
 
   def fetch_collection(collection_url, on_behalf_of) do
     Logger.debug("Fetching and preparing collection from url")
     Logger.debug(inspect(collection_url))
 
-    with {:ok, data} <- Fetcher.fetch(collection_url, on_behalf_of: on_behalf_of),
+    case Fetcher.fetch(collection_url, on_behalf_of: on_behalf_of) do
-         :ok <- Logger.debug("Fetch ok, passing to process_collection"),
+      {:ok, data} when is_map(data) ->
-         :ok <- process_collection(data, on_behalf_of) do
+        Logger.debug("Fetch ok, passing to process_collection")
+
+        case process_collection(data, on_behalf_of) do
+          :ok ->
             Logger.debug("Finished processing a collection")
             :ok
+
+          :error ->
+            Logger.debug("Failed to process collection #{collection_url}")
+            {:error, :process_error}
+        end
+
+      {:error, _err} ->
+        Logger.debug("Failed to fetch collection #{collection_url}")
+        {:error, :fetch_error}
     end
   end
 
-  @spec fetch_element(String.t(), Actor.t()) :: any()
+  @spec fetch_element(String.t(), Actor.t()) :: {:ok, struct()} | {:error, any()}
   def fetch_element(url, %Actor{} = on_behalf_of) do
     with {:ok, data} <- Fetcher.fetch(url, on_behalf_of: on_behalf_of) do
       case handling_element(data) do
@@ -114,6 +127,9 @@ defmodule Mobilizon.Federation.ActivityPub.Refresher do
         {:ok, entity} ->
           {:ok, entity}
 
+        :error ->
+          {:error, :err_fetching_element}
+
         err ->
           {:error, err}
       end
@@ -127,6 +143,7 @@ defmodule Mobilizon.Federation.ActivityPub.Refresher do
     |> Enum.each(&refresh_profile/1)
   end
 
+  @spec process_collection(map(), any()) :: :ok | :error
   defp process_collection(%{"type" => type, "orderedItems" => items}, _on_behalf_of)
        when type in ["OrderedCollection", "OrderedCollectionPage"] do
     Logger.debug(
@@ -168,6 +185,8 @@ defmodule Mobilizon.Federation.ActivityPub.Refresher do
   defp process_collection(_, _), do: :error
 
   # If we're handling an activity
+  @spec handling_element(map()) :: {:ok, any, struct} | :error
+  @spec handling_element(String.t()) :: {:ok, struct} | {:error, any()}
   defp handling_element(%{"type" => activity_type} = data)
        when activity_type in ["Create", "Update", "Delete"] do
     object = get_in(data, ["object"])

lib/federation/activity_pub/relay.ex

@@ -11,8 +11,7 @@ defmodule Mobilizon.Federation.ActivityPub.Relay do
   alias Mobilizon.Actors
   alias Mobilizon.Actors.{Actor, Follower}
 
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity, Transmogrifier}
-  alias Mobilizon.Federation.ActivityPub.{Activity, Transmogrifier}
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
   alias Mobilizon.Federation.WebFinger
   alias Mobilizon.Service.Workers.Background
@@ -27,76 +26,100 @@ defmodule Mobilizon.Federation.ActivityPub.Relay do
     get_actor()
   end
 
-  @spec get_actor() :: Actor.t() | {:error, Ecto.Changeset.t()}
+  @spec get_actor() :: Actor.t() | no_return
   def get_actor do
-    with {:ok, %Actor{} = actor} <-
+    case Actors.get_or_create_internal_actor("relay") do
-           Actors.get_or_create_internal_actor("relay") do
+      {:ok, %Actor{} = actor} ->
         actor
+
+      {:error, %Ecto.Changeset{} = _err} ->
+        raise("Relay actor not found")
     end
   end
 
-  @spec follow(String.t()) :: {:ok, Activity.t(), Follower.t()}
+  @spec follow(String.t()) ::
+          {:ok, Activity.t(), Follower.t()} | {:error, atom()} | {:error, String.t()}
   def follow(address) do
+    %Actor{} = local_actor = get_actor()
+
     with {:ok, target_instance} <- fetch_actor(address),
-         %Actor{} = local_actor <- get_actor(),
          {:ok, %Actor{} = target_actor} <-
            ActivityPubActor.get_or_fetch_actor_by_url(target_instance),
          {:ok, activity, follow} <- Follows.follow(local_actor, target_actor) do
       Logger.info("Relay: followed instance #{target_instance}; id=#{activity.data["id"]}")
       {:ok, activity, follow}
     else
+      {:error, :person_no_follow} ->
+        Logger.warn("Only group and instances can be followed")
+        {:error, :person_no_follow}
+
       {:error, e} ->
         Logger.warn("Error while following remote instance: #{inspect(e)}")
         {:error, e}
-
-      e ->
-        Logger.warn("Error while following remote instance: #{inspect(e)}")
-        {:error, e}
     end
   end
 
-  @spec unfollow(String.t()) :: {:ok, Activity.t(), Follower.t()}
+  @spec unfollow(String.t()) ::
+          {:ok, Activity.t(), Follower.t()} | {:error, atom()} | {:error, String.t()}
   def unfollow(address) do
+    %Actor{} = local_actor = get_actor()
+
     with {:ok, target_instance} <- fetch_actor(address),
-         %Actor{} = local_actor <- get_actor(),
          {:ok, %Actor{} = target_actor} <-
            ActivityPubActor.get_or_fetch_actor_by_url(target_instance),
          {:ok, activity, follow} <- Follows.unfollow(local_actor, target_actor) do
       Logger.info("Relay: unfollowed instance #{target_instance}: id=#{activity.data["id"]}")
       {:ok, activity, follow}
     else
-      e ->
+      {:error, e} ->
         Logger.warn("Error while unfollowing remote instance: #{inspect(e)}")
         {:error, e}
     end
   end
 
-  @spec accept(String.t()) :: {:ok, Activity.t(), Follower.t()}
+  @spec accept(String.t()) ::
+          {:ok, Activity.t(), Follower.t()} | {:error, atom()} | {:error, String.t()}
   def accept(address) do
     Logger.debug("We're trying to accept a relay subscription")
+    %Actor{} = local_actor = get_actor()
 
     with {:ok, target_instance} <- fetch_actor(address),
-         %Actor{} = local_actor <- get_actor(),
          {:ok, %Actor{} = target_actor} <-
            ActivityPubActor.get_or_fetch_actor_by_url(target_instance),
          {:ok, activity, follow} <- Follows.accept(target_actor, local_actor) do
       {:ok, activity, follow}
+    else
+      {:error, e} ->
+        Logger.warn("Error while accepting remote instance follow: #{inspect(e)}")
+        {:error, e}
     end
   end
 
+  @spec reject(String.t()) ::
+          {:ok, Activity.t(), Follower.t()} | {:error, atom()} | {:error, String.t()}
   def reject(address) do
     Logger.debug("We're trying to reject a relay subscription")
+    %Actor{} = local_actor = get_actor()
 
     with {:ok, target_instance} <- fetch_actor(address),
-         %Actor{} = local_actor <- get_actor(),
          {:ok, %Actor{} = target_actor} <-
            ActivityPubActor.get_or_fetch_actor_by_url(target_instance),
          {:ok, activity, follow} <- Follows.reject(target_actor, local_actor) do
       {:ok, activity, follow}
+    else
+      {:error, e} ->
+        Logger.warn("Error while rejecting remote instance follow: #{inspect(e)}")
+        {:error, e}
     end
   end
 
-  @spec refresh(String.t()) :: {:ok, any()}
+  @spec refresh(String.t()) ::
+          {:ok, Oban.Job.t()}
+          | {:error, Ecto.Changeset.t()}
+          | {:error, :bad_url}
+          | {:error, ActivityPubActor.make_actor_errors()}
+          | {:error, :no_internal_relay_actor}
+          | {:error, :url_nil}
   def refresh(address) do
     Logger.debug("We're trying to refresh a remote instance")
 
@@ -106,6 +129,10 @@ defmodule Mobilizon.Federation.ActivityPub.Relay do
       Background.enqueue("refresh_profile", %{
         "actor_id" => target_actor_id
       })
+    else
+      {:error, e} ->
+        Logger.warn("Error while refreshing remote instance: #{inspect(e)}")
+        {:error, e}
     end
   end
 
@@ -117,7 +144,7 @@ defmodule Mobilizon.Federation.ActivityPub.Relay do
          {object, object_id} <- fetch_object(object),
          id <- "#{object_id}/announces/#{actor_id}" do
       Logger.info("Publishing activity #{id} to all relays")
-      ActivityPub.announce(actor, object, id, true, false)
+      Actions.Announce.announce(actor, object, id, true, false)
     else
       e ->
         Logger.error("Error while getting local instance actor: #{inspect(e)}")
@@ -138,7 +165,8 @@ defmodule Mobilizon.Federation.ActivityPub.Relay do
 
   defp fetch_object(object) when is_binary(object), do: {object, object}
 
-  @spec fetch_actor(String.t()) :: {:ok, String.t()} | {:error, String.t()}
+  @spec fetch_actor(String.t()) ::
+          {:ok, String.t()} | {:error, WebFinger.finger_errors() | :bad_url}
   # Dirty hack
   defp fetch_actor("https://" <> address), do: fetch_actor(address)
   defp fetch_actor("http://" <> address), do: fetch_actor(address)
@@ -154,26 +182,15 @@ defmodule Mobilizon.Federation.ActivityPub.Relay do
         check_actor("relay@#{host}")
 
       true ->
-        {:error, "Bad URL"}
+        {:error, :bad_url}
     end
   end
 
-  @spec check_actor(String.t()) :: {:ok, String.t()} | {:error, String.t()}
+  @spec check_actor(String.t()) :: {:ok, String.t()} | {:error, WebFinger.finger_errors()}
   defp check_actor(username_and_domain) do
     case Actors.get_actor_by_name(username_and_domain) do
       %Actor{url: url} -> {:ok, url}
-      nil -> finger_actor(username_and_domain)
+      nil -> WebFinger.finger(username_and_domain)
-    end
-  end
-
-  @spec finger_actor(String.t()) :: {:ok, String.t()} | {:error, String.t()}
-  defp finger_actor(nickname) do
-    case WebFinger.finger(nickname) do
-      {:ok, url} when is_binary(url) ->
-        {:ok, url}
-
-      _e ->
-        {:error, "No ActivityPub URL found in WebFinger"}
     end
   end
 end

lib/federation/activity_pub/transmogrifier.ex

@@ -17,7 +17,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   alias Mobilizon.Todos.{Todo, TodoList}
 
   alias Mobilizon.Federation.ActivityPub
-  alias Mobilizon.Federation.ActivityPub.{Activity, Permission, Relay, Utils}
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity, Permission, Relay, Utils}
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
   alias Mobilizon.Federation.ActivityPub.Types.Ownable
   alias Mobilizon.Federation.ActivityStream.{Converter, Convertible}
@@ -32,6 +32,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   @doc """
   Handle incoming activities
   """
+  @spec handle_incoming(map()) :: :error | {:ok, any(), struct()}
   def handle_incoming(%{"id" => nil}), do: :error
   def handle_incoming(%{"id" => ""}), do: :error
 
@@ -49,7 +50,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
         local: false
       }
 
-      ActivityPub.flag(params, false)
+      Actions.Flag.flag(params, false)
     end
   end
 
@@ -76,17 +77,17 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:ok, %Activity{} = activity, entity} <-
            (if is_data_for_comment_or_discussion?(object_data) do
               Logger.debug("Chosing to create a regular comment")
-              ActivityPub.create(:comment, object_data, false)
+              Actions.Create.create(:comment, object_data, false)
             else
               Logger.debug("Chosing to initialize or add a comment to a conversation")
-              ActivityPub.create(:discussion, object_data, false)
+              Actions.Create.create(:discussion, object_data, false)
             end) do
       {:ok, activity, entity}
     else
       {:existing_comment, {:ok, %Comment{} = comment}} ->
         {:ok, nil, comment}
 
-      {:error, :event_comments_are_closed} ->
+      {:error, :event_not_allow_commenting} ->
         Logger.debug("Tried to reply to an event for which comments are closed")
         :error
     end
@@ -109,7 +110,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
            object |> Converter.Event.as_to_model_data(),
          {:existing_event, nil} <- {:existing_event, Events.get_event_by_url(object_data.url)},
          {:ok, %Activity{} = activity, %Event{} = event} <-
-           ActivityPub.create(:event, object_data, false) do
+           Actions.Create.create(:event, object_data, false) do
       {:ok, activity, event}
     else
       {:existing_event, %Event{} = event} -> {:ok, nil, event}
@@ -145,7 +146,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
            %Actor{type: :Group} = group <- Actors.get_actor(object_data.parent_id),
            %Actor{} = actor <- Actors.get_actor(object_data.actor_id),
            {:ok, %Activity{} = activity, %Member{} = member} <-
-             ActivityPub.join(group, actor, false, %{
+             Actions.Join.join(group, actor, false, %{
                url: object_data.url,
                metadata: %{role: object_data.role}
              }) do
@@ -172,7 +173,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:existing_post, nil} <-
            {:existing_post, Posts.get_post_by_url(object_data.url)},
          {:ok, %Activity{} = activity, %Post{} = post} <-
-           ActivityPub.create(:post, object_data, false) do
+           Actions.Create.create(:post, object_data, false) do
       {:ok, activity, post}
     else
       {:existing_post, %Post{} = post} ->
@@ -197,7 +198,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
         {:ok, nil, comment}
 
       {:ok, entity} ->
-        ActivityPub.delete(entity, Relay.get_actor(), false)
+        Actions.Delete.delete(entity, Relay.get_actor(), false)
     end
   end
 
@@ -206,10 +207,15 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
       ) do
     with {:ok, %Actor{} = followed} <- ActivityPubActor.get_or_fetch_actor_by_url(followed, true),
          {:ok, %Actor{} = follower} <- ActivityPubActor.get_or_fetch_actor_by_url(follower),
-         {:ok, activity, object} <- ActivityPub.follow(follower, followed, id, false) do
+         {:ok, activity, object} <-
+           Actions.Follow.follow(follower, followed, id, false) do
       {:ok, activity, object}
     else
-      e ->
+      {:error, :person_no_follow} ->
+        Logger.warn("Only group and instances can be followed")
+        :error
+
+      {:error, e} ->
         Logger.warn("Unable to handle Follow activity #{inspect(e)}")
         :error
     end
@@ -228,7 +234,9 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          object_data when is_map(object_data) <-
            object |> Converter.TodoList.as_to_model_data(),
          {:ok, %Activity{} = activity, %TodoList{} = todo_list} <-
-           ActivityPub.create(:todo_list, object_data, false, %{"actor" => actor_url}) do
+           Actions.Create.create(:todo_list, object_data, false, %{
+             "actor" => actor_url
+           }) do
       {:ok, activity, todo_list}
     else
       {:error, :group_not_found} -> :error
@@ -247,7 +255,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          object_data <-
            object |> Converter.Todo.as_to_model_data(),
          {:ok, %Activity{} = activity, %Todo{} = todo} <-
-           ActivityPub.create(:todo, object_data, false) do
+           Actions.Create.create(:todo, object_data, false) do
       {:ok, activity, todo}
     else
       {:existing_todo, %Todo{} = todo} -> {:ok, nil, todo}
@@ -272,7 +280,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:member, true} <-
            {:member, Actors.is_member?(object_data.creator_id, object_data.actor_id)},
          {:ok, %Activity{} = activity, %Resource{} = resource} <-
-           ActivityPub.create(:resource, object_data, false) do
+           Actions.Create.create(:resource, object_data, false) do
       {:ok, activity, resource}
     else
       {:existing_resource, %Resource{} = resource} ->
@@ -383,7 +391,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          object_data <-
            object |> Converter.Actor.as_to_model_data(),
          {:ok, %Activity{} = activity, %Actor{} = new_actor} <-
-           ActivityPub.update(old_actor, object_data, false) do
+           Actions.Update.update(old_actor, object_data, false) do
       {:ok, activity, new_actor}
     else
       e ->
@@ -411,7 +419,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
             Utils.origin_check?(actor_url, update_data) ||
               Permission.can_update_group_object?(actor, old_event)},
          {:ok, %Activity{} = activity, %Event{} = new_event} <-
-           ActivityPub.update(old_event, object_data, false) do
+           Actions.Update.update(old_event, object_data, false) do
       {:ok, activity, new_event}
     else
       _e ->
@@ -433,7 +441,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:ok, old_entity} <- object |> Utils.get_url() |> ActivityPub.fetch_object_from_url(),
          object_data <- transform_object_data_for_discussion(object_data),
          {:ok, %Activity{} = activity, new_entity} <-
-           ActivityPub.update(old_entity, object_data, false) do
+           Actions.Update.update(old_entity, object_data, false) do
       {:ok, activity, new_entity}
     else
       _e ->
@@ -456,7 +464,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
             Utils.origin_check?(actor_url, update_data["object"]) ||
               Permission.can_update_group_object?(actor, old_post)},
          {:ok, %Activity{} = activity, %Post{} = new_post} <-
-           ActivityPub.update(old_post, object_data, false) do
+           Actions.Update.update(old_post, object_data, false) do
       {:ok, activity, new_post}
     else
       {:origin_check, _} ->
@@ -484,7 +492,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
             Utils.origin_check?(actor_url, update_data) ||
               Permission.can_update_group_object?(actor, old_resource)},
          {:ok, %Activity{} = activity, %Resource{} = new_resource} <-
-           ActivityPub.update(old_resource, object_data, false) do
+           Actions.Update.update(old_resource, object_data, false) do
       {:ok, activity, new_resource}
     else
       _e ->
@@ -505,7 +513,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          object_data <- Converter.Member.as_to_model_data(object),
          {:ok, old_entity} <- object |> Utils.get_url() |> ActivityPub.fetch_object_from_url(),
          {:ok, %Activity{} = activity, new_entity} <-
-           ActivityPub.update(old_entity, object_data, false, %{moderator: actor}) do
+           Actions.Update.update(old_entity, object_data, false, %{moderator: actor}) do
       {:ok, activity, new_entity}
     else
       _e ->
@@ -522,7 +530,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
 
     with object_url <- Utils.get_url(object),
          {:ok, entity} <- ActivityPub.fetch_object_from_url(object_url) do
-      ActivityPub.delete(entity, Relay.get_actor(), false)
+      Actions.Delete.delete(entity, Relay.get_actor(), false)
     else
       {:ok, %Tombstone{} = tombstone} ->
         {:ok, nil, tombstone}
@@ -545,7 +553,13 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:ok, %Actor{} = actor} <- ActivityPubActor.get_or_fetch_actor_by_url(actor),
          {:ok, object} <- fetch_obj_helper_as_activity_streams(object_id),
          {:ok, activity, object} <-
-           ActivityPub.unannounce(actor, object, id, cancelled_activity_id, false) do
+           Actions.Announce.unannounce(
+             actor,
+             object,
+             id,
+             cancelled_activity_id,
+             false
+           ) do
       {:ok, activity, object}
     else
       _e -> :error
@@ -563,7 +577,8 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
     with {:ok, %Actor{domain: nil} = followed} <-
            ActivityPubActor.get_or_fetch_actor_by_url(followed),
          {:ok, %Actor{} = follower} <- ActivityPubActor.get_or_fetch_actor_by_url(follower),
-         {:ok, activity, object} <- ActivityPub.unfollow(follower, followed, id, false) do
+         {:ok, activity, object} <-
+           Actions.Follow.unfollow(follower, followed, id, false) do
       {:ok, activity, object}
     else
       e ->
@@ -577,6 +592,8 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   def handle_incoming(
         %{"type" => "Delete", "object" => object, "actor" => _actor, "id" => _id} = data
       ) do
+    Logger.info("Handle incoming to delete an object")
+
     with actor_url <- Utils.get_actor(data),
          {:actor, {:ok, %Actor{} = actor}} <-
            {:actor, ActivityPubActor.get_or_fetch_actor_by_url(actor_url)},
@@ -586,14 +603,14 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
            {:origin_check,
             Utils.origin_check_from_id?(actor_url, object_id) ||
               Permission.can_delete_group_object?(actor, object)},
-         {:ok, activity, object} <- ActivityPub.delete(object, actor, false) do
+         {:ok, activity, object} <- Actions.Delete.delete(object, actor, false) do
       {:ok, activity, object}
     else
       {:origin_check, false} ->
         Logger.warn("Object origin check failed")
         :error
 
-      {:actor, {:error, "Could not fetch by AP id"}} ->
+      {:actor, {:error, _err}} ->
         {:error, :unknown_actor}
 
       {:error, e} ->
@@ -630,7 +647,8 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
            {:origin_check,
             Utils.origin_check?(actor_url, data) ||
               Permission.can_update_group_object?(actor, old_resource)},
-         {:ok, activity, new_resource} <- ActivityPub.move(:resource, old_resource, object_data) do
+         {:ok, activity, new_resource} <-
+           Actions.Move.move(:resource, old_resource, object_data) do
       {:ok, activity, new_resource}
     else
       e ->
@@ -658,7 +676,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          object <- Utils.get_url(object),
          {:ok, object} <- ActivityPub.fetch_object_from_url(object),
          {:ok, activity, object} <-
-           ActivityPub.join(object, actor, false, %{
+           Actions.Join.join(object, actor, false, %{
              url: id,
              metadata: %{message: Map.get(data, "participationMessage")}
            }) do
@@ -675,7 +693,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:ok, %Actor{} = actor} <- ActivityPubActor.get_or_fetch_actor_by_url(actor),
          object <- Utils.get_url(object),
          {:ok, object} <- ActivityPub.fetch_object_from_url(object),
-         {:ok, activity, object} <- ActivityPub.leave(object, actor, false) do
+         {:ok, activity, object} <- Actions.Leave.leave(object, actor, false) do
       {:ok, activity, object}
     else
       {:only_organizer, true} ->
@@ -707,7 +725,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:ok, %Actor{} = target} <-
            target |> Utils.get_url() |> ActivityPubActor.get_or_fetch_actor_by_url(),
          {:ok, activity, %Member{} = member} <-
-           ActivityPub.invite(object, actor, target, false, %{url: id}) do
+           Actions.Invite.invite(object, actor, target, false, %{url: id}) do
       {:ok, activity, member}
     end
   end
@@ -727,7 +745,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
            {:is_admin, Actors.get_member(moderator_id, group_id)},
          {:is_member, {:ok, %Member{role: role} = member}} when role != :rejected <-
            {:is_member, Actors.get_member(person_id, group_id)} do
-      ActivityPub.remove(member, group, moderator, false)
+      Actions.Remove.remove(member, group, moderator, false)
     else
       {:is_admin, {:ok, %Member{}}} ->
         Logger.warn(
@@ -779,7 +797,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
            {:follow, get_follow(follow_object)},
          {:same_actor, true} <- {:same_actor, actor.id == followed.id},
          {:ok, %Activity{} = activity, %Follower{approved: true} = follow} <-
-           ActivityPub.accept(
+           Actions.Accept.accept(
              :follow,
              follow,
              false
@@ -817,7 +835,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
            {:follow, get_follow(follow_object)},
          {:same_actor, true} <- {:same_actor, actor.id == followed.id},
          {:ok, activity, _} <-
-           ActivityPub.reject(:follow, follow) do
+           Actions.Reject.reject(:follow, follow) do
       {:ok, activity, follow}
     else
       {:follow, _err} ->
@@ -872,7 +890,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:can_accept_event_join, true} <-
            {:can_accept_event_join, can_manage_event?(actor_accepting, event)},
          {:ok, %Activity{} = activity, %Participant{role: :participant} = participant} <-
-           ActivityPub.accept(
+           Actions.Accept.accept(
              :join,
              participant,
              false
@@ -904,7 +922,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
        when role in [:not_approved, :rejected, :invited] and type in [:join, :invite] do
     # Or maybe for groups it's the group that sends the Accept activity
     with {:ok, %Activity{} = activity, %Member{role: :member} = member} <-
-           ActivityPub.accept(
+           Actions.Accept.accept(
              type,
              member,
              false
@@ -922,7 +940,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
          {:can_accept_event_reject, true} <-
            {:can_accept_event_reject, can_manage_event?(actor_accepting, event)},
          {:ok, activity, participant} <-
-           ActivityPub.reject(:join, participant, false),
+           Actions.Reject.reject(:join, participant, false),
          :ok <- Participation.send_emails_to_local_user(participant) do
       {:ok, activity, participant}
     else
@@ -951,9 +969,9 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   defp do_handle_incoming_reject_invite(invite_object, %Actor{} = actor_rejecting) do
     with {:invite, {:ok, %Member{role: :invited, actor_id: actor_id} = member}} <-
            {:invite, get_member(invite_object)},
-         {:same_actor, true} <- {:same_actor, actor_rejecting.id === actor_id},
+         {:same_actor, true} <- {:same_actor, actor_rejecting.id == actor_id},
          {:ok, activity, member} <-
-           ActivityPub.reject(:invite, member, false) do
+           Actions.Reject.reject(:invite, member, false) do
       {:ok, activity, member}
     end
   end
@@ -992,7 +1010,6 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   end
 
   # Comment initiates a whole discussion only if it has full title
-  @spec is_data_for_comment_or_discussion?(map()) :: boolean()
   defp is_data_a_discussion_initialization?(object_data) do
     not Map.has_key?(object_data, :title) or
       is_nil(object_data.title) or object_data.title == ""
@@ -1106,22 +1123,22 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   end
 
   defp is_group_object_gone(object_id) do
-    case ActivityPub.fetch_object_from_url(object_id, force: true) do
+    Logger.debug("is_group_object_gone #{object_id}")
-      {:error, error_message, object} when error_message in ["Gone", "Not found"] ->
-        {:ok, object}
 
+    case ActivityPub.fetch_object_from_url(object_id, force: true) do
       # comments are just emptied
       {:ok, %Comment{deleted_at: deleted_at} = object} when not is_nil(deleted_at) ->
         {:ok, object}
 
+      {:error, :http_gone, object} ->
+        Logger.debug("object is really gone")
+        {:ok, object}
+
       {:ok, %{url: url} = object} ->
         if Utils.are_same_origin?(url, Endpoint.url()),
           do: {:ok, object},
           else: {:error, "Group object URL remote"}
 
-      {:error, {:error, err}} ->
-        {:error, err}
-
       {:error, err} ->
         {:error, err}
 
@@ -1133,7 +1150,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
   # Before 1.0.4 the object of a "Remove" activity was an actor's URL
   # instead of the member's URL.
   # TODO: Remove in 1.2
-  @spec get_remove_object(map() | String.t()) :: {:ok, String.t() | integer()}
+  @spec get_remove_object(map() | String.t()) :: {:ok, integer()}
   defp get_remove_object(object) do
     case object |> Utils.get_url() |> ActivityPub.fetch_object_from_url() do
       {:ok, %Member{actor: %Actor{id: person_id}}} -> {:ok, person_id}
@@ -1156,7 +1173,7 @@ defmodule Mobilizon.Federation.ActivityPub.Transmogrifier do
     organizer_actor_id == actor_id
   end
 
-  defp can_manage_event?(_actor, _event) do
+  defp can_manage_event?(%Actor{} = _actor, %Event{} = _event) do
     false
   end
 end

lib/federation/activity_pub/types/actors.ex

@@ -1,10 +1,10 @@
 defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
   @moduledoc false
   alias Mobilizon.Actors
-  alias Mobilizon.Actors.{Actor, Follower, Member}
+  alias Mobilizon.Actors.{Actor, Follower, Member, MemberRole}
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Audience, Permission, Relay}
-  alias Mobilizon.Federation.ActivityPub.{Audience, Permission, Relay}
   alias Mobilizon.Federation.ActivityPub.Types.Entity
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.GraphQL.API.Utils, as: APIUtils
   alias Mobilizon.Service.Activity.Group, as: GroupActivity
@@ -17,46 +17,57 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
   @behaviour Entity
 
   @impl Entity
-  @spec create(map(), map()) :: {:ok, map()}
+  @spec create(map(), map()) ::
+          {:ok, Actor.t(), ActivityStream.t()} | {:error, Ecto.Changeset.t()}
   def create(args, additional) do
-    with args <- prepare_args_for_actor(args),
+    args = prepare_args_for_actor(args)
-         {:ok, %Actor{} = actor} <- Actors.create_actor(args),
+
-         {:ok, _} <-
+    case Actors.create_actor(args) do
+      {:ok, %Actor{} = actor} ->
         GroupActivity.insert_activity(actor,
           subject: "group_created",
           actor_id: args.creator_actor_id
-           ),
+        )
-         actor_as_data <- Convertible.model_to_as(actor),
+
-         audience <- %{"to" => ["https://www.w3.org/ns/activitystreams#Public"], "cc" => []},
+        actor_as_data = Convertible.model_to_as(actor)
-         create_data <-
+        audience = %{"to" => ["https://www.w3.org/ns/activitystreams#Public"], "cc" => []}
-           make_create_data(actor_as_data, Map.merge(audience, additional)) do
+        create_data = make_create_data(actor_as_data, Map.merge(audience, additional))
         {:ok, actor, create_data}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
   @impl Entity
-  @spec update(Actor.t(), map, map) :: {:ok, Actor.t(), Activity.t()} | any
+  @spec update(Actor.t(), map, map) ::
+          {:ok, Actor.t(), ActivityStream.t()} | {:error, Ecto.Changeset.t()}
   def update(%Actor{} = old_actor, args, additional) do
-    with {:ok, %Actor{} = new_actor} <- Actors.update_actor(old_actor, args),
+    case Actors.update_actor(old_actor, args) do
-         {:ok, _} <-
+      {:ok, %Actor{} = new_actor} ->
         GroupActivity.insert_activity(new_actor,
           subject: "group_updated",
           old_group: old_actor,
           updater_actor: Map.get(args, :updater_actor)
-           ),
+        )
-         actor_as_data <- Convertible.model_to_as(new_actor),
+
-         {:ok, true} <- Cachex.del(:activity_pub, "actor_#{new_actor.preferred_username}"),
+        actor_as_data = Convertible.model_to_as(new_actor)
-         audience <-
+        Cachex.del(:activity_pub, "actor_#{new_actor.preferred_username}")
-           Audience.get_audience(new_actor),
+        audience = Audience.get_audience(new_actor)
-         additional <- Map.merge(additional, %{"actor" => old_actor.url}),
+        additional = Map.merge(additional, %{"actor" => old_actor.url})
-         update_data <- make_update_data(actor_as_data, Map.merge(audience, additional)) do
+        update_data = make_update_data(actor_as_data, Map.merge(audience, additional))
         {:ok, new_actor, update_data}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
   @public_ap "https://www.w3.org/ns/activitystreams#Public"
 
   @impl Entity
+  @spec delete(Actor.t(), Actor.t(), boolean, map) ::
+          {:ok, ActivityStream.t(), Actor.t(), Actor.t()} | {:error, Ecto.Changeset.t()}
   def delete(
         %Actor{
           followers_url: followers_url,
@@ -89,21 +100,27 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
 
     suspension = Map.get(additionnal, :suspension, false)
 
-    with {:ok, %Oban.Job{}} <-
+    case Actors.delete_actor(target_actor,
-           Actors.delete_actor(target_actor,
            # We completely delete the actor if the actor is remote
            reserve_username: is_nil(domain),
            suspension: suspension,
            author_id: author_id
          ) do
+      {:ok, %Oban.Job{}} ->
         {:ok, activity_data, actor, target_actor}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
+  @spec actor(Actor.t()) :: Actor.t() | nil
   def actor(%Actor{} = actor), do: actor
 
+  @spec group_actor(Actor.t()) :: Actor.t() | nil
   def group_actor(%Actor{} = actor), do: actor
 
+  @spec permissions(Actor.t()) :: Permission.t()
   def permissions(%Actor{} = _group) do
     %Permission{
       access: :member,
@@ -113,14 +130,14 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
     }
   end
 
-  @spec join(Actor.t(), Actor.t(), boolean(), map()) :: {:ok, map(), Member.t()}
+  @spec join(Actor.t(), Actor.t(), boolean(), map()) :: {:ok, ActivityStreams.t(), Member.t()}
   def join(%Actor{type: :Group} = group, %Actor{} = actor, _local, additional) do
-    with role <-
+    role =
       additional
       |> Map.get(:metadata, %{})
-           |> Map.get(:role, Mobilizon.Actors.get_default_member_role(group)),
+      |> Map.get(:role, Mobilizon.Actors.get_default_member_role(group))
-         {:ok, %Member{} = member} <-
+
-           Mobilizon.Actors.create_member(%{
+    case Mobilizon.Actors.create_member(%{
            role: role,
            parent_id: group.id,
            actor_id: actor.id,
@@ -129,20 +146,23 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
              additional
              |> Map.get(:metadata, %{})
              |> Map.update(:message, nil, &String.trim(HTML.strip_tags(&1)))
-           }),
+         }) do
-         {:ok, _} <-
+      {:ok, %Member{} = member} ->
-           Mobilizon.Service.Activity.Member.insert_activity(member, subject: "member_joined"),
+        Mobilizon.Service.Activity.Member.insert_activity(member, subject: "member_joined")
+
         Absinthe.Subscription.publish(Endpoint, actor,
           group_membership_changed: [Actor.preferred_username_and_domain(group), actor.id]
-         ),
+        )
-         join_data <- %{
+
+        join_data = %{
           "type" => "Join",
           "id" => member.url,
           "actor" => actor.url,
           "object" => group.url
-         },
+        }
-         audience <-
+
-           Audience.get_audience(member) do
+        audience = Audience.get_audience(member)
+
         approve_if_default_role_is_member(
           group,
           actor,
@@ -150,21 +170,34 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
           member,
           role
         )
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
+  @spec follow(Actor.t(), Actor.t(), boolean, map) ::
+          {:accept, any}
+          | {:ok, ActivityStreams.t(), Follower.t()}
+          | {:error,
+             :person_no_follow | :already_following | :followed_suspended | Ecto.Changeset.t()}
   def follow(%Actor{} = follower_actor, %Actor{type: type} = followed, _local, additional)
       when type != :Person do
-    with {:ok, %Follower{} = follower} <-
+    case Mobilizon.Actors.follow(followed, follower_actor, additional["activity_id"], false) do
-           Mobilizon.Actors.follow(followed, follower_actor, additional["activity_id"], false),
+      {:ok, %Follower{} = follower} ->
-         :ok <- FollowMailer.send_notification_to_admins(follower),
+        FollowMailer.send_notification_to_admins(follower)
-         follower_as_data <- Convertible.model_to_as(follower) do
+        follower_as_data = Convertible.model_to_as(follower)
         approve_if_manually_approves_followers(follower, follower_as_data)
+
+      {:error, error} ->
+        {:error, error}
     end
   end
 
-  def follow(_, _, _, _), do: {:error, :no_person, "Only group and instances can be followed"}
+  # "Only group and instances can be followed"
+  def follow(_, _, _, _), do: {:error, :person_no_follow}
 
+  @spec prepare_args_for_actor(map) :: map
   defp prepare_args_for_actor(args) do
     args
     |> maybe_sanitize_username()
@@ -191,8 +224,14 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
   defp maybe_sanitize_summary(args), do: args
 
   # Set the participant to approved if the default role for new participants is :participant
-  @spec approve_if_default_role_is_member(Actor.t(), Actor.t(), map(), Member.t(), atom()) ::
+  @spec approve_if_default_role_is_member(
-          {:ok, map(), Member.t()}
+          Actor.t(),
+          Actor.t(),
+          ActivityStreams.t(),
+          Member.t(),
+          MemberRole.t()
+        ) ::
+          {:ok, ActivityStreams.t(), Member.t()}
   defp approve_if_default_role_is_member(
          %Actor{type: :Group} = group,
          %Actor{} = actor,
@@ -202,17 +241,17 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
        ) do
     if is_nil(group.domain) && !is_nil(actor.domain) do
       cond do
-        Mobilizon.Actors.get_default_member_role(group) === :member &&
+        Mobilizon.Actors.get_default_member_role(group) == :member &&
             role == :member ->
           {:accept,
-           ActivityPub.accept(
+           Actions.Accept.accept(
              :join,
              member,
              true,
              %{"actor" => group.url}
            )}
 
-        Mobilizon.Actors.get_default_member_role(group) === :not_approved &&
+        Mobilizon.Actors.get_default_member_role(group) == :not_approved &&
             role == :not_approved ->
           Scheduler.pending_membership_notification(group)
           {:ok, activity_data, member}
@@ -225,6 +264,11 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
     end
   end
 
+  @spec approve_if_manually_approves_followers(
+          follower :: Follower.t(),
+          follow_as_data :: ActivityStreams.t()
+        ) ::
+          {:accept, any} | {:ok, ActivityStreams.t(), Follower.t()}
   defp approve_if_manually_approves_followers(
          %Follower{} = follower,
          follow_as_data
@@ -237,7 +281,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Actors do
       Logger.debug("Target doesn't manually approves followers, we can accept right away")
 
       {:accept,
-       ActivityPub.accept(
+       Actions.Accept.accept(
          :follow,
          follower,
          true,

lib/federation/activity_pub/types/comments.ex

@@ -6,6 +6,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
   alias Mobilizon.Events.{Event, EventOptions}
   alias Mobilizon.Federation.ActivityPub.{Audience, Permission}
   alias Mobilizon.Federation.ActivityPub.Types.Entity
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Converter.Utils, as: ConverterUtils
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.GraphQL.API.Utils, as: APIUtils
@@ -20,47 +21,56 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
   @behaviour Entity
 
   @impl Entity
-  @spec create(map(), map()) :: {:ok, map()}
+  @spec create(map(), map()) ::
+          {:ok, Comment.t(), ActivityStream.t()}
+          | {:error, Ecto.Changeset.t()}
+          | {:error, :event_not_allow_commenting}
   def create(args, additional) do
-    with args <- prepare_args_for_comment(args),
+    args = prepare_args_for_comment(args)
-         :ok <- make_sure_event_allows_commenting(args),
+
-         {:ok, %Comment{discussion_id: discussion_id} = comment} <-
+    if event_allows_commenting?(args) do
-           Discussions.create_comment(args),
+      case Discussions.create_comment(args) do
-         {:ok, _} <-
+        {:ok, %Comment{discussion_id: discussion_id} = comment} ->
           CommentActivity.insert_activity(comment,
             subject: "comment_posted"
-           ),
+          )
-         :ok <- maybe_publish_graphql_subscription(discussion_id),
+
-         comment_as_data <- Convertible.model_to_as(comment),
+          maybe_publish_graphql_subscription(discussion_id)
-         audience <-
+          comment_as_data = Convertible.model_to_as(comment)
-           Audience.get_audience(comment),
+          audience = Audience.get_audience(comment)
-         create_data <-
+          create_data = make_create_data(comment_as_data, Map.merge(audience, additional))
-           make_create_data(comment_as_data, Map.merge(audience, additional)) do
           {:ok, comment, create_data}
-    end
-  end
 
-  @impl Entity
+        {:error, %Ecto.Changeset{} = err} ->
-  @spec update(Comment.t(), map(), map()) :: {:ok, Comment.t(), Activity.t()} | any()
+          {:error, err}
-  def update(%Comment{} = old_comment, args, additional) do
+      end
-    with args <- prepare_args_for_comment_update(args),
-         {:ok, %Comment{} = new_comment} <- Discussions.update_comment(old_comment, args),
-         {:ok, true} <- Cachex.del(:activity_pub, "comment_#{new_comment.uuid}"),
-         comment_as_data <- Convertible.model_to_as(new_comment),
-         audience <-
-           Audience.get_audience(new_comment),
-         update_data <- make_update_data(comment_as_data, Map.merge(audience, additional)) do
-      {:ok, new_comment, update_data}
     else
-      err ->
+      {:error, :event_not_allow_commenting}
-        Logger.error("Something went wrong while creating an update activity")
-        Logger.debug(inspect(err))
-        err
     end
   end
 
   @impl Entity
-  @spec delete(Comment.t(), Actor.t(), boolean, map()) :: {:ok, Comment.t()}
+  @spec update(Comment.t(), map(), map()) ::
+          {:ok, Comment.t(), ActivityStream.t()} | {:error, Ecto.Changeset.t()}
+  def update(%Comment{} = old_comment, args, additional) do
+    args = prepare_args_for_comment_update(args)
+
+    case Discussions.update_comment(old_comment, args) do
+      {:ok, %Comment{} = new_comment} ->
+        {:ok, true} = Cachex.del(:activity_pub, "comment_#{new_comment.uuid}")
+        comment_as_data = Convertible.model_to_as(new_comment)
+        audience = Audience.get_audience(new_comment)
+        update_data = make_update_data(comment_as_data, Map.merge(audience, additional))
+        {:ok, new_comment, update_data}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
+    end
+  end
+
+  @impl Entity
+  @spec delete(Comment.t(), Actor.t(), boolean, map()) ::
+          {:error, Ecto.Changeset.t()} | {:ok, ActivityStream.t(), Actor.t(), Comment.t()}
   def delete(
         %Comment{url: url, id: comment_id},
         %Actor{} = actor,
@@ -79,18 +89,21 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
 
     force_deletion = Map.get(options, :force, false)
 
-    with audience <-
+    audience = Audience.get_audience(comment)
-           Audience.get_audience(comment),
+
-         {:ok, %Comment{} = updated_comment} <-
+    case Discussions.delete_comment(comment, force: force_deletion) do
-           Discussions.delete_comment(comment, force: force_deletion),
+      {:ok, %Comment{} = updated_comment} ->
-         {:ok, true} <- Cachex.del(:activity_pub, "comment_#{comment.uuid}"),
+        Cachex.del(:activity_pub, "comment_#{comment.uuid}")
-         {:ok, %Tombstone{} = _tombstone} <-
+        Tombstone.create_tombstone(%{uri: comment.url, actor_id: actor.id})
-           Tombstone.create_tombstone(%{uri: comment.url, actor_id: actor.id}) do
         Share.delete_all_by_uri(comment.url)
         {:ok, Map.merge(activity_data, audience), actor, updated_comment}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
+  @spec actor(Comment.t()) :: Actor.t() | nil
   def actor(%Comment{actor: %Actor{} = actor}), do: actor
 
   def actor(%Comment{actor_id: actor_id}) when not is_nil(actor_id),
@@ -98,6 +111,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
 
   def actor(_), do: nil
 
+  @spec group_actor(Comment.t()) :: Actor.t() | nil
   def group_actor(%Comment{attributed_to: %Actor{} = group}), do: group
 
   def group_actor(%Comment{attributed_to_id: attributed_to_id}) when not is_nil(attributed_to_id),
@@ -105,6 +119,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
 
   def group_actor(_), do: nil
 
+  @spec permissions(Comment.t()) :: Permission.t()
   def permissions(%Comment{}),
     do: %Permission{
       access: :member,
@@ -114,6 +129,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
     }
 
   # Prepare and sanitize arguments for comments
+  @spec prepare_args_for_comment(map) :: map
   defp prepare_args_for_comment(args) do
     with in_reply_to_comment <-
            args |> Map.get(:in_reply_to_comment_id) |> Discussions.get_comment_with_preload(),
@@ -150,6 +166,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
     end
   end
 
+  @spec prepare_args_for_comment_update(map) :: map
   defp prepare_args_for_comment_update(args) do
     with {text, mentions, tags} <-
            APIUtils.make_content_html(
@@ -174,32 +191,39 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Comments do
 
   defp handle_event_for_comment(nil), do: nil
 
+  @spec maybe_publish_graphql_subscription(String.t() | integer() | nil) :: :ok
   defp maybe_publish_graphql_subscription(nil), do: :ok
 
   defp maybe_publish_graphql_subscription(discussion_id) do
-    with %Discussion{} = discussion <- Discussions.get_discussion(discussion_id) do
+    case Discussions.get_discussion(discussion_id) do
+      %Discussion{} = discussion ->
         Absinthe.Subscription.publish(Endpoint, discussion,
           discussion_comment_changed: discussion.slug
         )
 
         :ok
+
+      nil ->
+        :ok
     end
   end
 
-  defp make_sure_event_allows_commenting(%{
+  @spec event_allows_commenting?(%{
+          required(:actor_id) => String.t() | integer,
+          required(:event) => Event.t() | nil,
+          optional(atom) => any()
+        }) :: boolean
+  defp event_allows_commenting?(%{
          actor_id: actor_id,
          event: %Event{
            options: %EventOptions{comment_moderation: comment_moderation},
            organizer_actor_id: organizer_actor_id
          }
        }) do
-    if comment_moderation != :closed ||
+    comment_moderation != :closed ||
-         to_string(actor_id) == to_string(organizer_actor_id) do
+      to_string(actor_id) == to_string(organizer_actor_id)
-      :ok
-    else
-      {:error, :event_comments_are_closed}
-    end
   end
 
-  defp make_sure_event_allows_commenting(_), do: :ok
+  # Comments not attached to events
+  defp event_allows_commenting?(_), do: true
 end

lib/federation/activity_pub/types/discussions.ex

@@ -6,6 +6,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Discussions do
   alias Mobilizon.Discussions.{Comment, Discussion}
   alias Mobilizon.Federation.ActivityPub.{Audience, Permission}
   alias Mobilizon.Federation.ActivityPub.Types.Entity
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.GraphQL.API.Utils, as: APIUtils
   alias Mobilizon.Service.Activity.Discussion, as: DiscussionActivity
@@ -16,83 +17,100 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Discussions do
   @behaviour Entity
 
   @impl Entity
-  @spec create(map(), map()) :: {:ok, map()}
+  @spec create(map(), map()) ::
+          {:ok, Discussion.t(), ActivityStream.t()}
+          | {:error, :discussion_not_found | :last_comment_not_found | Ecto.Changeset.t()}
   def create(%{discussion_id: discussion_id} = args, additional) when not is_nil(discussion_id) do
-    with args <- prepare_args(args),
+    args = prepare_args(args)
-         %Discussion{} = discussion <- Discussions.get_discussion(discussion_id),
+
-         {:ok, %Discussion{last_comment_id: last_comment_id} = discussion} <-
+    case Discussions.get_discussion(discussion_id) do
-           Discussions.reply_to_discussion(discussion, args),
+      %Discussion{} = discussion ->
-         {:ok, _} <-
+        case Discussions.reply_to_discussion(discussion, args) do
+          {:ok, %Discussion{last_comment_id: last_comment_id} = discussion} ->
             DiscussionActivity.insert_activity(discussion,
               subject: "discussion_replied",
               actor_id: Map.get(args, :creator_id, args.actor_id)
-           ),
+            )
-         %Comment{} = last_comment <- Discussions.get_comment_with_preload(last_comment_id),
+
-         :ok <- maybe_publish_graphql_subscription(discussion),
+            case Discussions.get_comment_with_preload(last_comment_id) do
-         comment_as_data <- Convertible.model_to_as(last_comment),
+              %Comment{} = last_comment ->
-         audience <-
+                maybe_publish_graphql_subscription(discussion)
-           Audience.get_audience(discussion),
+                comment_as_data = Convertible.model_to_as(last_comment)
-         create_data <-
+                audience = Audience.get_audience(discussion)
-           make_create_data(comment_as_data, Map.merge(audience, additional)) do
+                create_data = make_create_data(comment_as_data, Map.merge(audience, additional))
                 {:ok, discussion, create_data}
+
+              nil ->
+                {:error, :last_comment_not_found}
+            end
+
+          {:error, _, %Ecto.Changeset{} = err, _} ->
+            {:error, err}
+        end
+
+      nil ->
+        {:error, :discussion_not_found}
     end
   end
 
   @impl Entity
-  @spec create(map(), map()) :: {:ok, map()}
   def create(args, additional) do
-    with args <- prepare_args(args),
+    args = prepare_args(args)
-         {:ok, %Discussion{} = discussion} <-
+
-           Discussions.create_discussion(args),
+    case Discussions.create_discussion(args) do
-         {:ok, _} <-
+      {:ok, %Discussion{} = discussion} ->
-           DiscussionActivity.insert_activity(discussion, subject: "discussion_created"),
+        DiscussionActivity.insert_activity(discussion, subject: "discussion_created")
-         discussion_as_data <- Convertible.model_to_as(discussion),
+        discussion_as_data = Convertible.model_to_as(discussion)
-         audience <-
+        audience = Audience.get_audience(discussion)
-           Audience.get_audience(discussion),
+        create_data = make_create_data(discussion_as_data, Map.merge(audience, additional))
-         create_data <-
-           make_create_data(discussion_as_data, Map.merge(audience, additional)) do
         {:ok, discussion, create_data}
+
+      {:error, _, %Ecto.Changeset{} = err, _} ->
+        {:error, err}
     end
   end
 
   @impl Entity
-  @spec update(Discussion.t(), map(), map()) :: {:ok, Discussion.t(), Activity.t()} | any()
+  @spec update(Discussion.t(), map(), map()) ::
+          {:ok, Discussion.t(), ActivityStream.t()} | {:error, Ecto.Changeset.t()}
   def update(%Discussion{} = old_discussion, args, additional) do
-    with {:ok, %Discussion{} = new_discussion} <-
+    case Discussions.update_discussion(old_discussion, args) do
-           Discussions.update_discussion(old_discussion, args),
+      {:ok, %Discussion{} = new_discussion} ->
-         {:ok, _} <-
         DiscussionActivity.insert_activity(new_discussion,
           subject: "discussion_renamed",
           old_discussion: old_discussion
-           ),
+        )
-         {:ok, true} <- Cachex.del(:activity_pub, "discussion_#{new_discussion.slug}"),
+
-         discussion_as_data <- Convertible.model_to_as(new_discussion),
+        Cachex.del(:activity_pub, "discussion_#{new_discussion.slug}")
-         audience <-
+        discussion_as_data = Convertible.model_to_as(new_discussion)
-           Audience.get_audience(new_discussion),
+        audience = Audience.get_audience(new_discussion)
-         update_data <- make_update_data(discussion_as_data, Map.merge(audience, additional)) do
+        update_data = make_update_data(discussion_as_data, Map.merge(audience, additional))
         {:ok, new_discussion, update_data}
-    else
+
-      err ->
+      {:error, %Ecto.Changeset{} = err} ->
-        Logger.error("Something went wrong while creating an update activity")
+        {:error, err}
-        Logger.debug(inspect(err))
-        err
     end
   end
 
   @impl Entity
-  @spec delete(Discussion.t(), Actor.t(), boolean, map()) :: {:ok, Discussion.t()}
+  @spec delete(Discussion.t(), Actor.t(), boolean, map()) ::
+          {:error, Ecto.Changeset.t()} | {:ok, ActivityStream.t(), Actor.t(), Discussion.t()}
   def delete(
         %Discussion{actor: group, url: url} = discussion,
         %Actor{} = actor,
         _local,
         _additionnal
       ) do
-    with {:ok, _} <- Discussions.delete_discussion(discussion),
+    case Discussions.delete_discussion(discussion) do
-         {:ok, _} <-
+      {:error, _, %Ecto.Changeset{} = err, _} ->
+        {:error, err}
+
+      {:ok, %{comments: {_, _}}} ->
         DiscussionActivity.insert_activity(discussion,
           subject: "discussion_deleted",
           moderator: actor
-           ) do
+        )
+
         # This is just fake
         activity_data = %{
           "type" => "Delete",
@@ -106,10 +124,13 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Discussions do
     end
   end
 
+  @spec actor(Discussion.t()) :: Actor.t() | nil
   def actor(%Discussion{creator_id: creator_id}), do: Actors.get_actor(creator_id)
 
+  @spec group_actor(Discussion.t()) :: Actor.t() | nil
   def group_actor(%Discussion{actor_id: actor_id}), do: Actors.get_actor(actor_id)
 
+  @spec permissions(Discussion.t()) :: Permission.t()
   def permissions(%Discussion{}) do
     %Permission{access: :member, create: :member, update: :moderator, delete: :moderator}
   end
@@ -123,6 +144,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Discussions do
     :ok
   end
 
+  @spec prepare_args(map) :: map
   defp prepare_args(args) do
     {text, _mentions, _tags} =
       APIUtils.make_content_html(

lib/federation/activity_pub/types/entity.ex

@@ -28,16 +28,16 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Entity do
   @moduledoc """
   ActivityPub entity behaviour
   """
-  @type t :: %{id: String.t()}
+  @type t :: %{required(:id) => any(), optional(:url) => String.t(), optional(atom()) => any()}
 
   @callback create(data :: any(), additionnal :: map()) ::
-              {:ok, t(), ActivityStream.t()}
+              {:ok, t(), ActivityStream.t()} | {:error, any()}
 
-  @callback update(struct :: t(), attrs :: map(), additionnal :: map()) ::
+  @callback update(structure :: t(), attrs :: map(), additionnal :: map()) ::
-              {:ok, t(), ActivityStream.t()}
+              {:ok, t(), ActivityStream.t()} | {:error, any()}
 
-  @callback delete(struct :: t(), Actor.t(), local :: boolean(), map()) ::
+  @callback delete(structure :: t(), actor :: Actor.t(), local :: boolean(), additionnal :: map()) ::
-              {:ok, ActivityStream.t(), Actor.t(), t()}
+              {:ok, ActivityStream.t(), Actor.t(), t()} | {:error, any()}
 end
 
 defprotocol Mobilizon.Federation.ActivityPub.Types.Managable do
@@ -45,46 +45,61 @@ defprotocol Mobilizon.Federation.ActivityPub.Types.Managable do
   ActivityPub entity Managable protocol.
   """
 
-  @spec update(Entity.t(), map(), map()) :: {:ok, Entity.t(), ActivityStream.t()}
   @doc """
   Updates a `Managable` entity with the appropriate attributes and returns the updated entity and an activitystream representation for it
   """
+  @spec update(Entity.t(), map(), map()) ::
+          {:ok, Entity.t(), ActivityStream.t()} | {:error, any()}
   def update(entity, attrs, additionnal)
 
-  @spec delete(Entity.t(), Actor.t(), boolean(), map()) ::
-          {:ok, ActivityStream.t(), Actor.t(), Entity.t()}
   @doc "Deletes an entity and returns the activitystream representation for it"
+  @spec delete(Entity.t(), Actor.t(), boolean(), map()) ::
+          {:ok, ActivityStream.t(), Actor.t(), Entity.t()} | {:error, any()}
   def delete(entity, actor, local, additionnal)
 end
 
 defprotocol Mobilizon.Federation.ActivityPub.Types.Ownable do
-  @type group_role :: :member | :moderator | :administrator | nil
-
-  @spec group_actor(Entity.t()) :: Actor.t() | nil
   @doc "Returns an eventual group for the entity"
+  @spec group_actor(Entity.t()) :: Actor.t() | nil
   def group_actor(entity)
 
-  @spec actor(Entity.t()) :: Actor.t() | nil
   @doc "Returns the actor for the entity"
+  @spec actor(Entity.t()) :: Actor.t() | nil
   def actor(entity)
 
+  @doc """
+  Returns the list of permissions for an entity
+  """
   @spec permissions(Entity.t()) :: Permission.t()
   def permissions(entity)
 end
 
 defimpl Managable, for: Event do
+  @spec update(Event.t(), map, map) ::
+          {:error, atom() | Ecto.Changeset.t()} | {:ok, Event.t(), ActivityStream.t()}
   defdelegate update(entity, attrs, additionnal), to: Events
+
+  @spec delete(entity :: Event.t(), actor :: Actor.t(), local :: boolean(), additionnal :: map()) ::
+          {:ok, ActivityStream.t(), Actor.t(), Event.t()} | {:error, atom() | Ecto.Changeset.t()}
   defdelegate delete(entity, actor, local, additionnal), to: Events
 end
 
 defimpl Ownable, for: Event do
+  @spec group_actor(Event.t()) :: Actor.t() | nil
   defdelegate group_actor(entity), to: Events
+  @spec actor(Event.t()) :: Actor.t() | nil
   defdelegate actor(entity), to: Events
+  @spec permissions(Event.t()) :: Permission.t()
   defdelegate permissions(entity), to: Events
 end
 
 defimpl Managable, for: Comment do
+  @spec update(Comment.t(), map, map) ::
+          {:error, Ecto.Changeset.t()} | {:ok, Comment.t(), ActivityStream.t()}
   defdelegate update(entity, attrs, additionnal), to: Comments
+
+  @spec delete(Comment.t(), Actor.t(), boolean, map) ::
+          {:error, Ecto.Changeset.t()} | {:ok, ActivityStream.t(), Actor.t(), Comment.t()}
   defdelegate delete(entity, actor, local, additionnal), to: Comments
 end
 

lib/federation/activity_pub/types/events.ex

@@ -3,10 +3,10 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
   alias Mobilizon.Actors
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Events, as: EventsManager
-  alias Mobilizon.Events.{Event, Participant}
+  alias Mobilizon.Events.{Event, Participant, ParticipantRole}
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Audience, Permission}
-  alias Mobilizon.Federation.ActivityPub.{Audience, Permission}
   alias Mobilizon.Federation.ActivityPub.Types.Entity
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Converter.Utils, as: ConverterUtils
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.GraphQL.API.Utils, as: APIUtils
@@ -22,44 +22,53 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
   @behaviour Entity
 
   @impl Entity
-  @spec create(map(), map()) :: {:ok, map()}
+  @spec create(map(), map()) ::
+          {:ok, Event.t(), ActivityStream.t()} | {:error, Ecto.Changeset.t()}
   def create(args, additional) do
-    with args <- prepare_args_for_event(args),
+    args = prepare_args_for_event(args)
-         {:ok, %Event{} = event} <- EventsManager.create_event(args),
+
-         {:ok, _} <-
+    case EventsManager.create_event(args) do
-           EventActivity.insert_activity(event, subject: "event_created"),
+      {:ok, %Event{} = event} ->
-         event_as_data <- Convertible.model_to_as(event),
+        EventActivity.insert_activity(event, subject: "event_created")
-         audience <-
+        event_as_data = Convertible.model_to_as(event)
-           Audience.get_audience(event),
+        audience = Audience.get_audience(event)
-         create_data <-
+        create_data = make_create_data(event_as_data, Map.merge(audience, additional))
-           make_create_data(event_as_data, Map.merge(audience, additional)) do
         {:ok, event, create_data}
+
+      {:error, _step, %Ecto.Changeset{} = err, _} ->
+        {:error, err}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
   @impl Entity
-  @spec update(Event.t(), map(), map()) :: {:ok, Event.t(), Activity.t()} | any()
+  @spec update(Event.t(), map(), map()) ::
+          {:ok, Event.t(), ActivityStream.t()} | {:error, Ecto.Changeset.t()}
   def update(%Event{} = old_event, args, additional) do
-    with args <- prepare_args_for_event(args),
+    args = prepare_args_for_event(args)
-         {:ok, %Event{} = new_event} <- EventsManager.update_event(old_event, args),
+
-         {:ok, _} <-
+    case EventsManager.update_event(old_event, args) do
-           EventActivity.insert_activity(new_event, subject: "event_updated"),
+      {:ok, %Event{} = new_event} ->
-         {:ok, true} <- Cachex.del(:activity_pub, "event_#{new_event.uuid}"),
+        EventActivity.insert_activity(new_event, subject: "event_updated")
-         event_as_data <- Convertible.model_to_as(new_event),
+        Cachex.del(:activity_pub, "event_#{new_event.uuid}")
-         audience <-
+        event_as_data = Convertible.model_to_as(new_event)
-           Audience.get_audience(new_event),
+        audience = Audience.get_audience(new_event)
-         update_data <- make_update_data(event_as_data, Map.merge(audience, additional)) do
+        update_data = make_update_data(event_as_data, Map.merge(audience, additional))
         {:ok, new_event, update_data}
-    else
+
-      err ->
+      {:error, _step, %Ecto.Changeset{} = err, _} ->
-        Logger.error("Something went wrong while creating an update activity")
+        {:error, err}
-        Logger.debug(inspect(err))
+
-        err
+      {:error, err} ->
+        {:error, err}
     end
   end
 
   @impl Entity
-  @spec delete(Event.t(), Actor.t(), boolean, map()) :: {:ok, Event.t()}
+  @spec delete(Event.t(), Actor.t(), boolean, map()) ::
+          {:ok, ActivityStream.t(), Actor.t(), Event.t()} | {:error, Ecto.Changeset.t()}
   def delete(%Event{url: url} = event, %Actor{} = actor, _local, _additionnal) do
     activity_data = %{
       "type" => "Delete",
@@ -69,19 +78,27 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
       "id" => url <> "/delete"
     }
 
-    with audience <-
+    audience = Audience.get_audience(event)
-           Audience.get_audience(event),
+
-         {:ok, %Event{} = event} <- EventsManager.delete_event(event),
+    case EventsManager.delete_event(event) do
-         {:ok, _} <-
+      {:ok, %Event{} = event} ->
-           EventActivity.insert_activity(event, subject: "event_deleted"),
+        case Tombstone.create_tombstone(%{uri: event.url, actor_id: actor.id}) do
-         {:ok, true} <- Cachex.del(:activity_pub, "event_#{event.uuid}"),
+          {:ok, %Tombstone{} = _tombstone} ->
-         {:ok, %Tombstone{} = _tombstone} <-
+            EventActivity.insert_activity(event, subject: "event_deleted")
-           Tombstone.create_tombstone(%{uri: event.url, actor_id: actor.id}) do
+            Cachex.del(:activity_pub, "event_#{event.uuid}")
             Share.delete_all_by_uri(event.url)
             {:ok, Map.merge(activity_data, audience), actor, event}
+
+          {:error, %Ecto.Changeset{} = err} ->
+            {:error, err}
+        end
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
+  @spec actor(Event.t()) :: Actor.t() | nil
   def actor(%Event{organizer_actor: %Actor{} = actor}), do: actor
 
   def actor(%Event{organizer_actor_id: organizer_actor_id}),
@@ -89,6 +106,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
 
   def actor(_), do: nil
 
+  @spec group_actor(Event.t()) :: Actor.t() | nil
   def group_actor(%Event{attributed_to: %Actor{} = group}), do: group
 
   def group_actor(%Event{attributed_to_id: attributed_to_id}) when not is_nil(attributed_to_id),
@@ -96,6 +114,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
 
   def group_actor(_), do: nil
 
+  @spec permissions(Event.t()) :: Permission.t()
   def permissions(%Event{draft: draft, attributed_to_id: _attributed_to_id}) do
     %Permission{
       access: if(draft, do: nil, else: :member),
@@ -105,15 +124,18 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
     }
   end
 
+  @spec join(Event.t(), Actor.t(), boolean, map) ::
+          {:ok, ActivityStreams.t(), Participant.t()}
+          | {:accept, any()}
+          | {:error, :maximum_attendee_capacity_reached}
   def join(%Event{} = event, %Actor{} = actor, _local, additional) do
-    with {:maximum_attendee_capacity, true} <-
+    if check_attendee_capacity?(event) do
-           {:maximum_attendee_capacity, check_attendee_capacity(event)},
+      role =
-         role <-
         additional
         |> Map.get(:metadata, %{})
-           |> Map.get(:role, Mobilizon.Events.get_default_participant_role(event)),
+        |> Map.get(:role, Mobilizon.Events.get_default_participant_role(event))
-         {:ok, %Participant{} = participant} <-
+
-           Mobilizon.Events.create_participant(%{
+      case Mobilizon.Events.create_participant(%{
              role: role,
              event_id: event.id,
              actor_id: actor.id,
@@ -122,31 +144,41 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
                additional
                |> Map.get(:metadata, %{})
                |> Map.update(:message, nil, &String.trim(HTML.strip_tags(&1)))
-           }),
+           }) do
-         join_data <- Convertible.model_to_as(participant),
+        {:ok, %Participant{} = participant} ->
-         audience <-
+          join_data = Convertible.model_to_as(participant)
-           Audience.get_audience(participant) do
+          audience = Audience.get_audience(participant)
+
           approve_if_default_role_is_participant(
             event,
             Map.merge(join_data, audience),
             participant,
             role
           )
+
+        {:error, %Ecto.Changeset{} = err} ->
+          {:error, err}
+      end
     else
-      {:maximum_attendee_capacity, err} ->
+      {:error, :maximum_attendee_capacity_reached}
-        {:maximum_attendee_capacity, err}
     end
   end
 
-  defp check_attendee_capacity(%Event{options: options} = event) do
+  @spec check_attendee_capacity?(Event.t()) :: boolean
-    with maximum_attendee_capacity <-
+  defp check_attendee_capacity?(%Event{options: options} = event) do
-           Map.get(options, :maximum_attendee_capacity) || 0 do
+    maximum_attendee_capacity = Map.get(options, :maximum_attendee_capacity) || 0
+
     maximum_attendee_capacity == 0 ||
       Mobilizon.Events.count_participant_participants(event.id) < maximum_attendee_capacity
   end
-  end
 
   # Set the participant to approved if the default role for new participants is :participant
+  @spec approve_if_default_role_is_participant(
+          Event.t(),
+          ActivityStreams.t(),
+          Participant.t(),
+          ParticipantRole.t()
+        ) :: {:ok, ActivityStreams.t(), Participant.t()} | {:accept, any()}
   defp approve_if_default_role_is_participant(event, activity_data, participant, role) do
     case event do
       %Event{attributed_to: %Actor{id: group_id, url: group_url}} ->
@@ -161,29 +193,31 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
             {:ok, activity_data, participant}
         end
 
-      %Event{local: true} ->
+      %Event{attributed_to: nil, local: true} ->
         do_approve(event, activity_data, participant, role, %{
           "actor" => event.organizer_actor.url
         })
 
-      _ ->
+      %Event{} ->
         {:ok, activity_data, participant}
     end
   end
 
+  @spec do_approve(Event.t(), ActivityStreams.t(), Particpant.t(), ParticipantRole.t(), map()) ::
+          {:accept, any} | {:ok, ActivityStreams.t(), Participant.t()}
   defp do_approve(event, activity_data, participant, role, additionnal) do
     cond do
-      Mobilizon.Events.get_default_participant_role(event) === :participant &&
+      Mobilizon.Events.get_default_participant_role(event) == :participant &&
           role == :participant ->
         {:accept,
-         ActivityPub.accept(
+         Actions.Accept.accept(
            :join,
            participant,
            true,
            additionnal
          )}
 
-      Mobilizon.Events.get_default_participant_role(event) === :not_approved &&
+      Mobilizon.Events.get_default_participant_role(event) == :not_approved &&
           role == :not_approved ->
         Scheduler.pending_participation_notification(event)
         {:ok, activity_data, participant}
@@ -194,6 +228,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Events do
   end
 
   # Prepare and sanitize arguments for events
+  @spec prepare_args_for_event(map) :: map
   defp prepare_args_for_event(args) do
     # If title is not set: we are not updating it
     args =

lib/federation/activity_pub/types/members.ex

@@ -1,14 +1,18 @@
 defmodule Mobilizon.Federation.ActivityPub.Types.Members do
   @moduledoc false
   alias Mobilizon.Actors
-  alias Mobilizon.Actors.{Actor, Member}
+  alias Mobilizon.Actors.{Actor, Member, MemberRole}
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.Service.Activity.Member, as: MemberActivity
   alias Mobilizon.Web.Endpoint
   require Logger
   import Mobilizon.Federation.ActivityPub.Utils, only: [make_update_data: 2]
 
+  @spec update(Member.t(), map, map) ::
+          {:ok, Member.t(), ActivityStream.t()}
+          | {:error, :member_not_found | :only_admin_left | Ecto.Changeset.t()}
   def update(
         %Member{
           parent: %Actor{id: group_id} = group,
@@ -19,43 +23,51 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Members do
         %{role: updated_role} = args,
         %{moderator: %Actor{url: moderator_url, id: moderator_id} = moderator} = additional
       ) do
-    with additional <- Map.delete(additional, :moderator),
+    additional = Map.delete(additional, :moderator)
-         {:has_rights_to_update_role, {:ok, %Member{role: moderator_role}}}
+
-         when moderator_role in [:moderator, :administrator, :creator] <-
+    case Actors.get_member(moderator_id, group_id) do
-           {:has_rights_to_update_role, Actors.get_member(moderator_id, group_id)},
+      {:error, :member_not_found} ->
-         {:is_only_admin, false} <-
+        {:error, :member_not_found}
-           {:is_only_admin, check_admins_left(member_id, group_id, current_role, updated_role)},
+
-         {:ok, %Member{} = member} <-
+      {:ok, %Member{role: moderator_role}}
-           Actors.update_member(old_member, args),
+      when moderator_role in [:moderator, :administrator, :creator] ->
-         {:ok, _} <-
+        if check_admins_left?(member_id, group_id, current_role, updated_role) do
+          {:error, :only_admin_left}
+        else
+          case Actors.update_member(old_member, args) do
+            {:error, %Ecto.Changeset{} = err} ->
+              {:error, err}
+
+            {:ok, %Member{} = member} ->
               MemberActivity.insert_activity(member,
                 old_member: old_member,
                 moderator: moderator,
                 subject: "member_updated"
-           ),
+              )
+
               Absinthe.Subscription.publish(Endpoint, actor,
                 group_membership_changed: [Actor.preferred_username_and_domain(group), actor_id]
-         ),
+              )
-         {:ok, true} <- Cachex.del(:activity_pub, "member_#{member_id}"),
+
-         member_as_data <-
+              Cachex.del(:activity_pub, "member_#{member_id}")
-           Convertible.model_to_as(member),
+              member_as_data = Convertible.model_to_as(member)
-         audience <- %{
+
+              audience = %{
                 "to" => [member.parent.members_url, member.actor.url],
                 "cc" => [member.parent.url],
                 "actor" => moderator_url,
                 "attributedTo" => [member.parent.url]
-         } do
+              }
-      update_data = make_update_data(member_as_data, Map.merge(audience, additional))
 
+              update_data = make_update_data(member_as_data, Map.merge(audience, additional))
               {:ok, member, update_data}
-    else
+          end
-      err ->
+        end
-        Logger.debug(inspect(err))
-        err
     end
   end
 
   # Used only when a group is suspended
+  @spec delete(Member.t(), Actor.t(), boolean(), map()) :: {:ok, Activity.t(), Member.t()}
   def delete(
         %Member{parent: %Actor{} = group, actor: %Actor{} = actor} = _member,
         %Actor{},
@@ -63,16 +75,24 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Members do
         _additionnal
       ) do
     Logger.debug("Deleting a member")
-    ActivityPub.leave(group, actor, local, %{force_member_removal: true})
+    Actions.Leave.leave(group, actor, local, %{force_member_removal: true})
   end
 
+  @spec actor(Member.t()) :: Actor.t() | nil
   def actor(%Member{actor_id: actor_id}),
     do: Actors.get_actor(actor_id)
 
+  @spec group_actor(Member.t()) :: Actor.t() | nil
   def group_actor(%Member{parent_id: parent_id}),
     do: Actors.get_actor(parent_id)
 
-  defp check_admins_left(member_id, group_id, current_role, updated_role) do
+  @spec check_admins_left?(
+          String.t() | integer,
+          String.t() | integer,
+          MemberRole.t(),
+          MemberRole.t()
+        ) :: boolean
+  defp check_admins_left?(member_id, group_id, current_role, updated_role) do
     Actors.is_only_administrator?(member_id, group_id) && current_role == :administrator &&
       updated_role != :administrator
   end

lib/federation/activity_pub/types/posts.ex

@@ -4,6 +4,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Federation.ActivityPub.{Audience, Permission}
   alias Mobilizon.Federation.ActivityPub.Types.Entity
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Converter.Utils, as: ConverterUtils
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.Posts.Post
@@ -17,6 +18,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
   @public_ap "https://www.w3.org/ns/activitystreams#Public"
 
   @impl Entity
+  @spec create(map(), map()) :: {:ok, Post.t(), ActivityStream.t()}
   def create(args, additional) do
     with args <- prepare_args(args),
          {:ok, %Post{attributed_to_id: group_id, author_id: creator_id} = post} <-
@@ -37,6 +39,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
   end
 
   @impl Entity
+  @spec update(Post.t(), map(), map()) :: {:ok, Post.t(), ActivityStream.t()}
   def update(%Post{} = post, args, additional) do
     with args <- prepare_args(args),
          {:ok, %Post{attributed_to_id: group_id, author_id: creator_id} = post} <-
@@ -60,6 +63,8 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
   end
 
   @impl Entity
+  @spec delete(Post.t(), Actor.t(), boolean, map) ::
+          {:ok, ActivityStream.t(), Actor.t(), Post.t()}
   def delete(
         %Post{
           url: url,
@@ -86,12 +91,15 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
     end
   end
 
+  @spec actor(Post.t()) :: Actor.t() | nil
   def actor(%Post{author_id: author_id}),
     do: Actors.get_actor(author_id)
 
+  @spec group_actor(Post.t()) :: Actor.t() | nil
   def group_actor(%Post{attributed_to_id: attributed_to_id}),
     do: Actors.get_actor(attributed_to_id)
 
+  @spec permissions(Post.t()) :: Permission.t()
   def permissions(%Post{}) do
     %Permission{
       access: :member,
@@ -101,6 +109,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Posts do
     }
   end
 
+  @spec prepare_args(map()) :: map
   defp prepare_args(args) do
     args
     |> Map.update(:tags, [], &ConverterUtils.fetch_tags/1)

lib/federation/activity_pub/types/reports.ex

@@ -1,36 +1,47 @@
 defmodule Mobilizon.Federation.ActivityPub.Types.Reports do
   @moduledoc false
-  alias Mobilizon.{Actors, Discussions, Reports}
+  alias Mobilizon.{Actors, Discussions, Events, Reports}
   alias Mobilizon.Actors.Actor
+  alias Mobilizon.Events.Event
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.Reports.Report
   alias Mobilizon.Service.Formatter.HTML
   require Logger
 
+  @spec flag(map(), boolean(), map()) ::
+          {:ok, Report.t(), ActivityStream.t()} | {:error, Ecto.Changeset.t()}
   def flag(args, local \\ false, _additional \\ %{}) do
-    with {:build_args, args} <- {:build_args, prepare_args_for_report(args)},
+    with {:ok, %Report{} = report} <- args |> prepare_args_for_report() |> Reports.create_report() do
-         {:create_report, {:ok, %Report{} = report}} <-
+      report_as_data = Convertible.model_to_as(report)
-           {:create_report, Reports.create_report(args)},
+      cc = if(local, do: [report.reported.url], else: [])
-         report_as_data <- Convertible.model_to_as(report),
+      report_as_data = Map.merge(report_as_data, %{"to" => [], "cc" => cc})
-         cc <- if(local, do: [report.reported.url], else: []),
+      {:ok, report, report_as_data}
-         report_as_data <- Map.merge(report_as_data, %{"to" => [], "cc" => cc}) do
-      {report, report_as_data}
     end
   end
 
+  @spec prepare_args_for_report(map()) :: map()
   defp prepare_args_for_report(args) do
-    with {:reporter, %Actor{} = reporter_actor} <-
+    %Actor{} = reporter_actor = Actors.get_actor!(args.reporter_id)
-           {:reporter, Actors.get_actor!(args.reporter_id)},
+    %Actor{} = reported_actor = Actors.get_actor!(args.reported_id)
-         {:reported, %Actor{} = reported_actor} <-
+    content = HTML.strip_tags(args.content)
-           {:reported, Actors.get_actor!(args.reported_id)},
+
-         content <- HTML.strip_tags(args.content),
+    event_id = Map.get(args, :event_id)
-         event <- Discussions.get_comment(Map.get(args, :event_id)),
+
-         {:get_report_comments, comments} <-
+    event =
-           {:get_report_comments,
+      if is_nil(event_id) do
+        nil
+      else
+        {:ok, %Event{} = event} = Events.get_event(event_id)
+        event
+      end
+
+    comments =
       Discussions.list_comments_by_actor_and_ids(
         reported_actor.id,
         Map.get(args, :comments_ids, [])
-            )} do
+      )
+
     Map.merge(args, %{
       reporter: reporter_actor,
       reported: reported_actor,
@@ -40,4 +51,3 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Reports do
     })
   end
 end
-end

lib/federation/activity_pub/types/resources.ex

@@ -4,6 +4,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Resources do
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Federation.ActivityPub.Permission
   alias Mobilizon.Federation.ActivityPub.Types.Entity
+  alias alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.Resources.Resource
   alias Mobilizon.Service.Activity.Resource, as: ResourceActivity
@@ -16,6 +17,9 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Resources do
   @behaviour Entity
 
   @impl Entity
+  @spec create(map(), map()) ::
+          {:ok, Resource.t(), ActivityStream.t()}
+          | {:error, Ecto.Changeset.t() | :creator_not_found | :group_not_found}
   def create(%{type: type} = args, additional) do
     args =
       case type do
@@ -35,17 +39,18 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Resources do
     with {:ok,
           %Resource{actor_id: group_id, creator_id: creator_id, parent_id: parent_id} = resource} <-
            Resources.create_resource(args),
-         {:ok, _} <- ResourceActivity.insert_activity(resource, subject: "resource_created"),
+         {:ok, %Actor{} = group, %Actor{url: creator_url} = creator} <-
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
+           group_and_creator(group_id, creator_id) do
-         %Actor{url: creator_url} = creator <- Actors.get_actor(creator_id),
+      ResourceActivity.insert_activity(resource, subject: "resource_created")
-         resource_as_data <-
+      resource_as_data = Convertible.model_to_as(%{resource | actor: group, creator: creator})
-           Convertible.model_to_as(%{resource | actor: group, creator: creator}),
+
-         audience <- %{
+      audience = %{
         "to" => [group.members_url],
         "cc" => [],
         "actor" => creator_url,
         "attributedTo" => [creator_url]
-         } do
+      }
+
       create_data =
         case parent_id do
           nil ->
@@ -58,14 +63,13 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Resources do
         end
 
       {:ok, resource, create_data}
-    else
-      err ->
-        Logger.debug(inspect(err))
-        err
     end
   end
 
   @impl Entity
+  @spec update(Resource.t(), map(), map()) ::
+          {:ok, Resource.t(), ActivityStream.t()}
+          | {:error, Ecto.Changeset.t() | :creator_not_found | :group_not_found}
   def update(
         %Resource{parent_id: old_parent_id} = old_resource,
         %{parent_id: parent_id} = args,
@@ -79,31 +83,35 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Resources do
   def update(%Resource{} = old_resource, %{title: title} = _args, additional) do
     with {:ok, %Resource{actor_id: group_id, creator_id: creator_id} = resource} <-
            Resources.update_resource(old_resource, %{title: title}),
-         {:ok, _} <-
+         {:ok, %Actor{} = group, %Actor{url: creator_url}} <-
+           group_and_creator(group_id, creator_id) do
       ResourceActivity.insert_activity(resource,
         subject: "resource_renamed",
         old_resource: old_resource
-           ),
+      )
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
+
-         %Actor{url: creator_url} <- Actors.get_actor(creator_id),
+      resource_as_data = Convertible.model_to_as(%{resource | actor: group})
-         resource_as_data <-
+
-           Convertible.model_to_as(%{resource | actor: group}),
+      audience = %{
-         audience <- %{
         "to" => [group.members_url],
         "cc" => [],
         "actor" => creator_url,
         "attributedTo" => [creator_url]
-         },
+      }
-         update_data <-
+
-           make_update_data(resource_as_data, Map.merge(audience, additional)) do
+      update_data = make_update_data(resource_as_data, Map.merge(audience, additional))
       {:ok, resource, update_data}
-    else
-      err ->
-        Logger.debug(inspect(err))
-        err
     end
   end
 
+  @spec move(Resource.t(), map(), map()) ::
+          {:ok, Resource.t(), ActivityStream.t()}
+          | {:error,
+             Ecto.Changeset.t()
+             | :creator_not_found
+             | :group_not_found
+             | :new_parent_not_found
+             | :old_parent_not_found}
   def move(
         %Resource{parent_id: old_parent_id} = old_resource,
         %{parent_id: _new_parent_id} = args,
@@ -113,35 +121,34 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Resources do
           %Resource{actor_id: group_id, creator_id: creator_id, parent_id: new_parent_id} =
             resource} <-
            Resources.update_resource(old_resource, args),
-         {:ok, _} <- ResourceActivity.insert_activity(resource, subject: "resource_moved"),
+         {:ok, old_parent, new_parent} <- parents(old_parent_id, new_parent_id),
-         old_parent <- Resources.get_resource(old_parent_id),
+         {:ok, %Actor{} = group, %Actor{url: creator_url}} <-
-         new_parent <- Resources.get_resource(new_parent_id),
+           group_and_creator(group_id, creator_id) do
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
+      ResourceActivity.insert_activity(resource, subject: "resource_moved")
-         %Actor{url: creator_url} <- Actors.get_actor(creator_id),
+      resource_as_data = Convertible.model_to_as(%{resource | actor: group})
-         resource_as_data <-
+
-           Convertible.model_to_as(%{resource | actor: group}),
+      audience = %{
-         audience <- %{
         "to" => [group.members_url],
         "cc" => [],
         "actor" => creator_url,
         "attributedTo" => [creator_url]
-         },
+      }
-         move_data <-
+
+      move_data =
         make_move_data(
           resource_as_data,
           old_parent,
           new_parent,
           Map.merge(audience, additional)
-           ) do
+        )
+
       {:ok, resource, move_data}
-    else
-      err ->
-        Logger.debug(inspect(err))
-        err
     end
   end
 
   @impl Entity
+  @spec delete(Resource.t(), Actor.t(), boolean, map()) ::
+          {:ok, ActivityStream.t(), Actor.t(), Resource.t()} | {:error, Ecto.Changeset.t()}
   def delete(
         %Resource{url: url, actor: %Actor{url: group_url, members_url: members_url}} = resource,
         %Actor{url: actor_url} = actor,
@@ -159,19 +166,50 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Resources do
       "to" => [members_url]
     }
 
-    with {:ok, _resource} <- Resources.delete_resource(resource),
+    case Resources.delete_resource(resource) do
-         {:ok, _} <- ResourceActivity.insert_activity(resource, subject: "resource_deleted"),
+      {:ok, _resource} ->
-         {:ok, true} <- Cachex.del(:activity_pub, "resource_#{resource.id}") do
+        ResourceActivity.insert_activity(resource, subject: "resource_deleted")
+        Cachex.del(:activity_pub, "resource_#{resource.id}")
         {:ok, activity_data, actor, resource}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
+  @spec actor(Todo.t()) :: Actor.t() | nil
   def actor(%Resource{creator_id: creator_id}),
     do: Actors.get_actor(creator_id)
 
+  @spec group_actor(Todo.t()) :: Actor.t() | nil
   def group_actor(%Resource{actor_id: actor_id}), do: Actors.get_actor(actor_id)
 
+  @spec permissions(TodoList.t()) :: Permission.t()
   def permissions(%Resource{}) do
     %Permission{access: :member, create: :member, update: :member, delete: :member}
   end
+
+  @spec group_and_creator(integer(), integer()) ::
+          {:ok, Actor.t(), Actor.t()} | {:error, :creator_not_found | :group_not_found}
+  defp group_and_creator(group_id, creator_id) do
+    case Actors.get_group_by_actor_id(group_id) do
+      {:ok, %Actor{} = group} ->
+        case Actors.get_actor(creator_id) do
+          %Actor{} = creator ->
+            {:ok, group, creator}
+
+          nil ->
+            {:error, :creator_not_found}
+        end
+
+      {:error, :group_not_found} ->
+        {:error, :group_not_found}
+    end
+  end
+
+  @spec parents(String.t(), String.t()) ::
+          {:ok, Resource.t(), Resource.t()}
+  defp parents(old_parent_id, new_parent_id) do
+    {:ok, Resources.get_resource(old_parent_id), Resources.get_resource(new_parent_id)}
+  end
 end

lib/federation/activity_pub/types/todo_lists.ex

@@ -13,36 +13,37 @@ defmodule Mobilizon.Federation.ActivityPub.Types.TodoLists do
   @behaviour Entity
 
   @impl Entity
-  @spec create(map(), map()) :: {:ok, map()}
+  @spec create(map(), map()) ::
+          {:ok, TodoList.t(), ActivityStream.t()}
+          | {:error, :group_not_found | Ecto.Changeset.t()}
   def create(args, additional) do
     with {:ok, %TodoList{actor_id: group_id} = todo_list} <- Todos.create_todo_list(args),
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
+         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id) do
-         todo_list_as_data <- Convertible.model_to_as(%{todo_list | actor: group}),
+      todo_list_as_data = Convertible.model_to_as(%{todo_list | actor: group})
-         audience <- %{"to" => [group.members_url], "cc" => []},
+      audience = %{"to" => [group.members_url], "cc" => []}
-         create_data <-
+      create_data = make_create_data(todo_list_as_data, Map.merge(audience, additional))
-           make_create_data(todo_list_as_data, Map.merge(audience, additional)) do
       {:ok, todo_list, create_data}
     end
   end
 
   @impl Entity
-  @spec update(TodoList.t(), map, map) :: {:ok, TodoList.t(), Activity.t()} | any
+  @spec update(TodoList.t(), map, map) ::
+          {:ok, TodoList.t(), ActivityStream.t()}
+          | {:error, Ecto.Changeset.t() | :group_not_found}
   def update(%TodoList{} = old_todo_list, args, additional) do
     with {:ok, %TodoList{actor_id: group_id} = todo_list} <-
            Todos.update_todo_list(old_todo_list, args),
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
+         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id) do
-         todo_list_as_data <-
+      todo_list_as_data = Convertible.model_to_as(%{todo_list | actor: group})
-           Convertible.model_to_as(%{todo_list | actor: group}),
+      audience = %{"to" => [group.members_url], "cc" => []}
-         audience <- %{"to" => [group.members_url], "cc" => []},
+      update_data = make_update_data(todo_list_as_data, Map.merge(audience, additional))
-         update_data <-
-           make_update_data(todo_list_as_data, Map.merge(audience, additional)) do
       {:ok, todo_list, update_data}
     end
   end
 
   @impl Entity
   @spec delete(TodoList.t(), Actor.t(), boolean(), map()) ::
-          {:ok, ActivityStream.t(), Actor.t(), TodoList.t()}
+          {:ok, ActivityStream.t(), Actor.t(), TodoList.t()} | {:error, Ecto.Changeset.t()}
   def delete(
         %TodoList{url: url, actor: %Actor{url: group_url}} = todo_list,
         %Actor{url: actor_url} = actor,
@@ -59,16 +60,23 @@ defmodule Mobilizon.Federation.ActivityPub.Types.TodoLists do
       "to" => [group_url]
     }
 
-    with {:ok, _todo_list} <- Todos.delete_todo_list(todo_list),
+    case Todos.delete_todo_list(todo_list) do
-         {:ok, true} <- Cachex.del(:activity_pub, "todo_list_#{todo_list.id}") do
+      {:ok, _todo_list} ->
+        Cachex.del(:activity_pub, "todo_list_#{todo_list.id}")
         {:ok, activity_data, actor, todo_list}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
+  @spec actor(TodoList.t()) :: nil
   def actor(%TodoList{}), do: nil
 
+  @spec group_actor(TodoList.t()) :: Actor.t() | nil
   def group_actor(%TodoList{actor_id: actor_id}), do: Actors.get_actor(actor_id)
 
+  @spec permissions(TodoList.t()) :: Permission.t()
   def permissions(%TodoList{}) do
     %Permission{access: :member, create: :member, update: :member, delete: :member}
   end

lib/federation/activity_pub/types/todos.ex

@@ -1,9 +1,12 @@
 defmodule Mobilizon.Federation.ActivityPub.Types.Todos do
-  @moduledoc false
+  @moduledoc """
+  ActivityPub type handler for Todos
+  """
   alias Mobilizon.{Actors, Todos}
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Federation.ActivityPub.Permission
   alias Mobilizon.Federation.ActivityPub.Types.Entity
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Federation.ActivityStream.Convertible
   alias Mobilizon.Todos.{Todo, TodoList}
   import Mobilizon.Federation.ActivityPub.Utils, only: [make_create_data: 2, make_update_data: 2]
@@ -12,41 +15,75 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Todos do
   @behaviour Entity
 
   @impl Entity
-  @spec create(map(), map()) :: {:ok, map()}
+  @spec create(map(), map()) ::
+          {:ok, Todo.t(), ActivityStream.t()} | {:error, Ecto.Changeset.t() | atom()}
   def create(args, additional) do
     with {:ok, %Todo{todo_list_id: todo_list_id, creator_id: creator_id} = todo} <-
            Todos.create_todo(args),
-         %TodoList{actor_id: group_id} = todo_list <- Todos.get_todo_list(todo_list_id),
+         {:ok, %Actor{} = creator, %TodoList{} = todo_list, %Actor{} = group} <-
-         %Actor{} = creator <- Actors.get_actor(creator_id),
+           creator_todo_list_and_group(creator_id, todo_list_id) do
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
+      todo = %{todo | todo_list: %{todo_list | actor: group}, creator: creator}
-         todo <- %{todo | todo_list: %{todo_list | actor: group}, creator: creator},
+      todo_as_data = Convertible.model_to_as(todo)
-         todo_as_data <-
+      audience = %{"to" => [group.members_url], "cc" => []}
-           Convertible.model_to_as(todo),
+      create_data = make_create_data(todo_as_data, Map.merge(audience, additional))
-         audience <- %{"to" => [group.members_url], "cc" => []},
-         create_data <-
-           make_create_data(todo_as_data, Map.merge(audience, additional)) do
       {:ok, todo, create_data}
     end
   end
 
   @impl Entity
-  @spec update(Todo.t(), map, map) :: {:ok, Todo.t(), Activity.t()} | any
+  @spec update(Todo.t(), map, map) ::
+          {:ok, Todo.t(), ActivityStream.t()}
+          | {:error, atom() | Ecto.Changeset.t()}
   def update(%Todo{} = old_todo, args, additional) do
     with {:ok, %Todo{todo_list_id: todo_list_id} = todo} <- Todos.update_todo(old_todo, args),
-         %TodoList{actor_id: group_id} = todo_list <- Todos.get_todo_list(todo_list_id),
+         {:ok, %TodoList{} = todo_list, %Actor{} = group} <- todo_list_and_group(todo_list_id) do
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
+      todo_as_data = Convertible.model_to_as(%{todo | todo_list: %{todo_list | actor: group}})
-         todo_as_data <-
+      audience = %{"to" => [group.members_url], "cc" => []}
-           Convertible.model_to_as(%{todo | todo_list: %{todo_list | actor: group}}),
+      update_data = make_update_data(todo_as_data, Map.merge(audience, additional))
-         audience <- %{"to" => [group.members_url], "cc" => []},
-         update_data <-
-           make_update_data(todo_as_data, Map.merge(audience, additional)) do
       {:ok, todo, update_data}
     end
   end
 
+  @spec creator_todo_list_and_group(integer(), String.t()) ::
+          {:ok, Actor.t(), TodoList.t(), Actor.t()}
+          | {:error, :creator_not_found | :group_not_found | :todo_list_not_found}
+  defp creator_todo_list_and_group(creator_id, todo_list_id) do
+    case Actors.get_actor(creator_id) do
+      %Actor{} = creator ->
+        case todo_list_and_group(todo_list_id) do
+          {:ok, %TodoList{} = todo_list, %Actor{} = group} ->
+            {:ok, creator, todo_list, group}
+
+          {:error, err} ->
+            {:error, err}
+        end
+
+      nil ->
+        {:error, :creator_not_found}
+    end
+  end
+
+  @spec todo_list_and_group(String.t()) ::
+          {:ok, TodoList.t(), Actor.t()} | {:error, :group_not_found | :todo_list_not_found}
+  defp todo_list_and_group(todo_list_id) do
+    case Todos.get_todo_list(todo_list_id) do
+      %TodoList{actor_id: group_id} = todo_list ->
+        case Actors.get_group_by_actor_id(group_id) do
+          {:ok, %Actor{} = group} ->
+            {:ok, todo_list, group}
+
+          {:error, :group_not_found} ->
+            {:error, :group_not_found}
+        end
+
+      nil ->
+        {:error, :todo_list_not_found}
+    end
+  end
+
   @impl Entity
-  @spec delete(Todo.t(), Actor.t(), boolean(), map()) ::
+  @spec delete(Todo.t(), Actor.t(), any(), any()) ::
-          {:ok, ActivityStream.t(), Actor.t(), Todo.t()}
+          {:ok, ActivityStream.t(), Actor.t(), Todo.t()} | {:error, Ecto.Changeset.t()}
   def delete(
         %Todo{url: url, creator: %Actor{url: group_url}} = todo,
         %Actor{url: actor_url} = actor,
@@ -59,18 +96,24 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Todos do
       "actor" => actor_url,
       "type" => "Delete",
       "object" => Convertible.model_to_as(url),
-      "id" => url <> "/delete",
+      "id" => "#{url}/delete",
       "to" => [group_url]
     }
 
-    with {:ok, _todo} <- Todos.delete_todo(todo),
+    case Todos.delete_todo(todo) do
-         {:ok, true} <- Cachex.del(:activity_pub, "todo_#{todo.id}") do
+      {:ok, _todo} ->
+        Cachex.del(:activity_pub, "todo_#{todo.id}")
         {:ok, activity_data, actor, todo}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        {:error, err}
     end
   end
 
+  @spec actor(Todo.t()) :: Actor.t() | nil
   def actor(%Todo{creator_id: creator_id}), do: Actors.get_actor(creator_id)
 
+  @spec group_actor(Todo.t()) :: Actor.t() | nil
   def group_actor(%Todo{todo_list_id: todo_list_id}) do
     case Todos.get_todo_list(todo_list_id) do
       %TodoList{actor_id: group_id} ->
@@ -81,6 +124,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Todos do
     end
   end
 
+  @spec permissions(Todo.t()) :: Permission.t()
   def permissions(%Todo{}) do
     %Permission{access: :member, create: :member, update: :member, delete: :member}
   end

lib/federation/activity_pub/types/tombstones.ex

@@ -4,6 +4,7 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Tombstones do
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Federation.ActivityPub.Permission
 
+  @spec actor(Tombstone.t()) :: Actor.t() | nil
   def actor(%Tombstone{actor: %Actor{id: actor_id}}), do: Actors.get_actor(actor_id)
 
   def actor(%Tombstone{actor_id: actor_id}) when not is_nil(actor_id),
@@ -11,8 +12,10 @@ defmodule Mobilizon.Federation.ActivityPub.Types.Tombstones do
 
   def actor(_), do: nil
 
+  @spec group_actor(any()) :: nil
   def group_actor(_), do: nil
 
+  @spec permissions(any()) :: Permission.t()
   def permissions(_) do
     %Permission{access: nil, create: nil, update: nil, delete: nil}
   end

lib/federation/activity_pub/utils.ex

@@ -12,8 +12,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Medias.Media
 
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity, Federator, Relay}
-  alias Mobilizon.Federation.ActivityPub.{Activity, Federator, Relay}
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
   alias Mobilizon.Federation.ActivityStream.Converter
   alias Mobilizon.Federation.HTTPSignatures
@@ -23,13 +22,35 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
 
   @actor_types ["Group", "Person", "Application"]
 
+  # Wraps an object into an activity
+  @spec create_activity(map(), boolean()) :: {:ok, Activity.t()}
+  def create_activity(map, local) when is_map(map) do
+    with map <- lazy_put_activity_defaults(map) do
+      {:ok,
+       %Activity{
+         data: map,
+         local: local,
+         actor: map["actor"],
+         recipients: get_recipients(map)
+       }}
+    end
+  end
+
+  # Get recipients for an activity or object
+  @spec get_recipients(map()) :: list()
+  defp get_recipients(data) do
+    Map.get(data, "to", []) ++ Map.get(data, "cc", [])
+  end
+
   # Some implementations send the actor URI as the actor field, others send the entire actor object,
   # so figure out what the actor's URI is based on what we have.
+  @spec get_url(map() | String.t() | list(String.t()) | any()) :: String.t() | nil
   def get_url(%{"id" => id}), do: id
   def get_url(id) when is_binary(id), do: id
   def get_url(ids) when is_list(ids), do: get_url(hd(ids))
   def get_url(_), do: nil
 
+  @spec make_json_ld_header :: map()
   def make_json_ld_header do
     %{
       "@context" => [
@@ -99,6 +120,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
     }
   end
 
+  @spec make_date :: String.t()
   def make_date do
     DateTime.utc_now() |> DateTime.truncate(:second) |> DateTime.to_iso8601()
   end
@@ -106,6 +128,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
   @doc """
   Enqueues an activity for federation if it's local
   """
+  @spec maybe_federate(activity :: Activity.t()) :: :ok
   def maybe_federate(%Activity{local: true} = activity) do
     Logger.debug("Maybe federate an activity")
 
@@ -129,6 +152,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
   Applies to activities sent by group members from outside this instance to a group of this instance,
   we then need to relay (`Announce`) the object to other members on other instances.
   """
+  @spec maybe_relay_if_group_activity(Activity.t(), Actor.t() | nil | list(Actor.t())) :: :ok
   def maybe_relay_if_group_activity(activity, attributed_to \\ nil)
 
   def maybe_relay_if_group_activity(
@@ -144,7 +168,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
         %Activity{data: %{"object" => object}},
         %Actor{url: attributed_to_url}
       )
-      when is_binary(object) do
+      when is_binary(object) and is_binary(attributed_to_url) do
     do_maybe_relay_if_group_activity(object, attributed_to_url)
   end
 
@@ -152,6 +176,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
     :ok
   end
 
+  @spec do_maybe_relay_if_group_activity(map(), list(String.t()) | String.t()) :: :ok
   defp do_maybe_relay_if_group_activity(object, attributed_to) when is_list(attributed_to),
     do: do_maybe_relay_if_group_activity(object, hd(attributed_to))
 
@@ -160,17 +185,17 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
 
     case Actors.get_local_group_by_url(attributed_to) do
       %Actor{} = group ->
-        case ActivityPub.announce(group, object, id, true, false) do
+        case Actions.Announce.announce(group, object, id, true, false) do
           {:ok, _activity, _object} ->
             Logger.info("Forwarded activity to external members of the group")
             :ok
 
-          _ ->
+          {:error, _err} ->
             Logger.info("Failed to forward activity to external members of the group")
             :error
         end
 
-      _ ->
+      nil ->
         :ok
     end
   end
@@ -198,6 +223,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
   Adds an id and a published data if they aren't there,
   also adds it to an included object
   """
+  @spec lazy_put_activity_defaults(map()) :: map()
   def lazy_put_activity_defaults(%{"object" => _object} = map) do
     if is_map(map["object"]) do
       object = lazy_put_object_defaults(map["object"])
@@ -214,6 +240,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
     Map.put_new_lazy(map, "published", &make_date/0)
   end
 
+  @spec get_actor(map()) :: String.t() | nil
   def get_actor(%{"actor" => actor}) when is_binary(actor) do
     actor
   end
@@ -241,6 +268,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
 
   Takes the actor or attributedTo attributes (considers only the first elem if they're an array)
   """
+  @spec origin_check?(String.t(), map()) :: boolean()
   def origin_check?(id, %{"type" => "Tombstone", "id" => tombstone_id}), do: id == tombstone_id
 
   def origin_check?(id, %{"actor" => actor, "attributedTo" => _attributed_to} = params)
@@ -282,6 +310,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
     compare_uris?(uri_1, uri_2)
   end
 
+  @spec compare_uris?(URI.t(), URI.t()) :: boolean()
   defp compare_uris?(%URI{} = id_uri, %URI{} = other_uri),
     do: id_uri.host == other_uri.host && id_uri.port == other_uri.port
 
@@ -311,7 +340,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
       {:ok, media} ->
         media
 
-      _ ->
+      {:error, _err} ->
         nil
     end
   end
@@ -509,7 +538,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
   @doc """
   Make add activity data
   """
-  @spec make_add_data(map(), map()) :: map()
+  @spec make_add_data(map(), map(), map()) :: map()
   def make_add_data(object, target, additional \\ %{}) do
     Logger.debug("Making add data")
     Logger.debug(inspect(object))
@@ -530,7 +559,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
   @doc """
   Make move activity data
   """
-  @spec make_add_data(map(), map()) :: map()
+  @spec make_move_data(map(), map(), map(), map()) :: map()
   def make_move_data(object, origin, target, additional \\ %{}) do
     Logger.debug("Making move data")
     Logger.debug(inspect(object))
@@ -554,6 +583,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
   @doc """
   Converts PEM encoded keys to a public key representation
   """
+  @spec pem_to_public_key(String.t()) :: {:RSAPublicKey, any(), any()}
   def pem_to_public_key(pem) do
     [key_code] = :public_key.pem_decode(pem)
     key = :public_key.pem_entry_decode(key_code)
@@ -567,6 +597,7 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
     end
   end
 
+  @spec pem_to_public_key_pem(String.t()) :: String.t()
   def pem_to_public_key_pem(pem) do
     public_key = pem_to_public_key(pem)
     public_key = :public_key.pem_entry_encode(:RSAPublicKey, public_key)

lib/federation/activity_stream.ex

@@ -3,5 +3,5 @@ defmodule Mobilizon.Federation.ActivityStream do
   The ActivityStream Type
   """
 
-  @type t :: map()
+  @type t :: %{String.t() => String.t() | list(String.t()) | map() | nil}
 end

lib/federation/activity_stream/converter/actor.ex

@@ -29,7 +29,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Actor do
   Converts an AP object data to our internal data structure.
   """
   @impl Converter
-  @spec as_to_model_data(map()) :: {:ok, map()}
+  @spec as_to_model_data(map()) :: map() | {:error, :actor_not_allowed_type}
   def as_to_model_data(%{"type" => type} = data) when type in @allowed_types do
     avatar =
       download_picture(get_in(data, ["icon", "url"]), get_in(data, ["icon", "name"]), "avatar")
@@ -64,7 +64,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Actor do
     }
   end
 
-  def as_to_model_data(_), do: :error
+  def as_to_model_data(_), do: {:error, :actor_not_allowed_type}
 
   @doc """
   Convert an actor struct to an ActivityStream representation.
@@ -135,7 +135,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Actor do
     end
   end
 
-  @spec download_picture(String.t() | nil, String.t(), String.t()) :: map()
+  @spec download_picture(String.t() | nil, String.t(), String.t()) :: map() | nil
   defp download_picture(nil, _name, _default_name), do: nil
 
   defp download_picture(url, name, default_name) do

lib/federation/activity_stream/converter/comment.ex

@@ -38,18 +38,15 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Comment do
   Converts an AP object data to our internal data structure.
   """
   @impl Converter
-  @spec as_to_model_data(map) :: {:ok, map} | {:error, any()}
+  @spec as_to_model_data(map) :: map | {:error, atom}
   def as_to_model_data(object) do
     Logger.debug("We're converting raw ActivityStream data to a comment entity")
     Logger.debug(inspect(object))
 
-    with {%Actor{id: actor_id, domain: actor_domain}, attributed_to} <-
+    tag_object = Map.get(object, "tag", [])
-           maybe_fetch_actor_and_attributed_to_id(object),
+
-         {:tags, tags} <- {:tags, fetch_tags(Map.get(object, "tag", []))},
+    case maybe_fetch_actor_and_attributed_to_id(object) do
-         {:mentions, mentions} <-
+      {:ok, %Actor{id: actor_id, domain: actor_domain}, attributed_to} ->
-           {:mentions, fetch_mentions(Map.get(object, "tag", []))},
-         discussion <-
-           Discussions.get_discussion_by_url(Map.get(object, "context")) do
         Logger.debug("Inserting full comment")
         Logger.debug(inspect(object))
 
@@ -64,9 +61,9 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Comment do
           in_reply_to_comment_id: nil,
           event_id: nil,
           uuid: object["uuid"],
-        discussion_id: if(is_nil(discussion), do: nil, else: discussion.id),
+          discussion_id: get_discussion_id(object),
-        tags: tags,
+          tags: fetch_tags(tag_object),
-        mentions: mentions,
+          mentions: fetch_mentions(tag_object),
           local: is_nil(actor_domain),
           visibility: if(Visibility.is_public?(object), do: :public, else: :private),
           published_at: object["published"],
@@ -81,9 +78,9 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Comment do
         Logger.debug("Converted object after fetching parents")
         Logger.debug(inspect(data))
         data
-    else
+
-      {:ok, %Actor{suspended: true}} ->
+      {:error, err} ->
-        :error
+        {:error, err}
     end
   end
 
@@ -94,9 +91,20 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Comment do
   """
   @impl Converter
   @spec model_to_as(CommentModel.t()) :: map
-  def model_to_as(%CommentModel{deleted_at: nil} = comment) do
+  def model_to_as(
+        %CommentModel{
+          deleted_at: nil,
+          attributed_to: attributed_to,
+          actor: %Actor{url: comment_actor_url}
+        } = comment
+      ) do
     to = determine_to(comment)
 
+    attributed_to =
+      if is_nil(attributed_to),
+        do: comment_actor_url,
+        else: Map.get(attributed_to, :url, comment_actor_url)
+
     object = %{
       "type" => "Note",
       "to" => to,
@@ -104,9 +112,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Comment do
       "content" => comment.text,
       "mediaType" => "text/html",
       "actor" => comment.actor.url,
-      "attributedTo" =>
+      "attributedTo" => attributed_to,
-        if(is_nil(comment.attributed_to), do: nil, else: comment.attributed_to.url) ||
-          comment.actor.url,
       "uuid" => comment.uuid,
       "id" => comment.url,
       "tag" => build_mentions(comment.mentions) ++ build_tags(comment.tags),
@@ -132,7 +138,6 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Comment do
   end
 
   @impl Converter
-  @spec model_to_as(CommentModel.t()) :: map
   def model_to_as(%CommentModel{} = comment) do
     Convertible.model_to_as(%TombstoneModel{
       uri: comment.url,
@@ -203,4 +208,13 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Comment do
       data
     end
   end
+
+  defp get_discussion_id(%{"context" => context}) do
+    case Discussions.get_discussion_by_url(context) do
+      %Discussion{id: discussion_id} -> discussion_id
+      nil -> nil
+    end
+  end
+
+  defp get_discussion_id(_object), do: nil
 end

lib/federation/activity_stream/converter/converter.ex

@@ -8,6 +8,6 @@ defmodule Mobilizon.Federation.ActivityStream.Converter do
 
   @type model_data :: map()
 
-  @callback as_to_model_data(as_data :: ActivityStream.t()) :: model_data()
+  @callback as_to_model_data(as_data :: ActivityStream.t()) :: model_data() | {:error, any()}
   @callback model_to_as(model :: struct()) :: ActivityStream.t()
 end

lib/federation/activity_stream/converter/discussion.ex

@@ -12,6 +12,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Discussion do
   alias Mobilizon.Federation.ActivityStream.{Converter, Convertible}
   alias Mobilizon.Federation.ActivityStream.Converter.Discussion, as: DiscussionConverter
   alias Mobilizon.Storage.Repo
+  import Mobilizon.Service.Guards, only: [is_valid_string: 1]
 
   require Logger
 
@@ -45,20 +46,28 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Discussion do
   end
 
   @impl Converter
-  @spec as_to_model_data(map) :: {:ok, map} | {:error, any()}
+  @spec as_to_model_data(map) :: map() | {:error, atom()}
-  def as_to_model_data(%{"type" => "Note", "name" => name} = object) when not is_nil(name) do
+  def as_to_model_data(%{"type" => "Note", "name" => name} = object) when is_valid_string(name) do
-    with creator_url <- Map.get(object, "actor"),
+    case extract_actors(object) do
-         {:ok, %Actor{id: creator_id, suspended: false}} <-
+      %{actor_id: actor_id, creator_id: creator_id} ->
+        %{actor_id: actor_id, creator_id: creator_id, title: name, url: object["id"]}
+
+      {:error, error} ->
+        {:error, error}
+    end
+  end
+
+  @spec extract_actors(map()) ::
+          %{actor_id: String.t(), creator_id: String.t()} | {:error, atom()}
+  defp extract_actors(%{"actor" => creator_url, "attributedTo" => actor_url} = _object)
+       when is_valid_string(creator_url) and is_valid_string(actor_url) do
+    with {:ok, %Actor{id: creator_id, suspended: false}} <-
            ActivityPubActor.get_or_fetch_actor_by_url(creator_url),
-         actor_url <- Map.get(object, "attributedTo"),
          {:ok, %Actor{id: actor_id, suspended: false}} <-
            ActivityPubActor.get_or_fetch_actor_by_url(actor_url) do
-      %{
+      %{actor_id: actor_id, creator_id: creator_id}
-        title: name,
+    else
-        actor_id: actor_id,
+      {:error, error} -> {:error, error}
-        creator_id: creator_id,
-        url: object["id"]
-      }
     end
   end
 end

lib/federation/activity_stream/converter/event.ex

@@ -45,19 +45,20 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Event do
   Converts an AP object data to our internal data structure.
   """
   @impl Converter
-  @spec as_to_model_data(map) :: {:ok, map()} | {:error, any()}
+  @spec as_to_model_data(map) :: map() | {:error, atom()}
   def as_to_model_data(object) do
-    with {%Actor{id: actor_id}, attributed_to} <-
+    case maybe_fetch_actor_and_attributed_to_id(object) do
-           maybe_fetch_actor_and_attributed_to_id(object),
+      {:ok, %Actor{id: actor_id}, attributed_to} ->
-         {:address, address_id} <-
+        address_id = get_address(object["location"])
-           {:address, get_address(object["location"])},
+        tags = fetch_tags(object["tag"])
-         {:tags, tags} <- {:tags, fetch_tags(object["tag"])},
+        mentions = fetch_mentions(object["tag"])
-         {:mentions, mentions} <- {:mentions, fetch_mentions(object["tag"])},
+        visibility = get_visibility(object)
-         {:visibility, visibility} <- {:visibility, get_visibility(object)},
+        options = get_options(object)
-         {:options, options} <- {:options, get_options(object)},
+        metadata = get_metdata(object)
-         {:metadata, metadata} <- {:metadata, get_metdata(object)},
+
-         [description: description, picture_id: picture_id, medias: medias] <-
+        [description: description, picture_id: picture_id, medias: medias] =
-           process_pictures(object, actor_id) do
+          process_pictures(object, actor_id)
+
         %{
           title: object["name"],
           description: description,
@@ -86,9 +87,9 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Event do
           publish_at: object["published"],
           language: object["inLanguage"]
         }
-    else
+
-      {:ok, %Actor{suspended: true}} ->
+      {:error, err} ->
-        :error
+        {:error, err}
     end
   end
 

lib/federation/activity_stream/converter/event_metadata.ex

@@ -4,9 +4,11 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.EventMetadata do
   """
 
   alias Mobilizon.Events.EventMetadata
+  alias Mobilizon.Federation.ActivityStream
 
   @property_value "PropertyValue"
 
+  @spec metadata_to_as(EventMetadata.t()) :: map()
   def metadata_to_as(%EventMetadata{type: :boolean, value: value, key: key})
       when value in ["true", "false"] do
     %{
@@ -47,6 +49,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.EventMetadata do
     )
   end
 
+  @spec as_to_metadata(ActivityStream.t()) :: map()
   def as_to_metadata(%{"type" => @property_value, "propertyID" => key, "value" => value})
       when is_boolean(value) do
     %{type: :boolean, key: key, value: to_string(value)}

lib/federation/activity_stream/converter/media.ex

@@ -6,6 +6,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Media do
   internal one, and back.
   """
 
+  alias Mobilizon.Federation.ActivityStream
   alias Mobilizon.Medias
   alias Mobilizon.Medias.Media, as: MediaModel
 
@@ -18,7 +19,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Media do
   @doc """
   Convert a media struct to an ActivityStream representation.
   """
-  @spec model_to_as(MediaModel.t()) :: map
+  @spec model_to_as(MediaModel.t()) :: ActivityStream.t()
   def model_to_as(%MediaModel{file: file}) do
     %{
       "type" => "Document",
@@ -31,29 +32,53 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Media do
   @doc """
   Save media data from raw data and return AS Link data.
   """
+  @spec find_or_create_media(map(), String.t() | integer()) ::
+          {:ok, MediaModel.t()} | {:error, atom() | String.t() | Ecto.Changeset.t()}
   def find_or_create_media(%{"type" => "Link", "href" => url}, actor_id),
-    do: find_or_create_media(url, actor_id)
+    do:
+      find_or_create_media(
+        %{"type" => "Document", "url" => url, "name" => "External media"},
+        actor_id
+      )
 
   def find_or_create_media(
         %{"type" => "Document", "url" => media_url, "name" => name},
         actor_id
       )
       when is_binary(media_url) do
-    with {:ok, %{body: body}} <- Tesla.get(media_url, opts: @http_options),
+    case upload_media(media_url, name) do
-         {:ok, %{url: url} = uploaded} <-
+      {:error, err} ->
-           Upload.store(%{body: body, name: name}),
+        {:error, err}
-         {:media_exists, nil} <- {:media_exists, Medias.get_media_by_url(url)} do
+
+      {:ok, %{url: url} = uploaded} ->
+        case Medias.get_media_by_url(url) do
+          %MediaModel{file: _file} = media ->
+            {:ok, media}
+
+          nil ->
             Medias.create_media(%{
               file: Map.take(uploaded, [:url, :name, :content_type, :size]),
               metadata: Map.take(uploaded, [:width, :height, :blurhash]),
               actor_id: actor_id
             })
-    else
+        end
-      {:media_exists, %MediaModel{file: _file} = media} ->
+    end
-        {:ok, media}
+  end
 
-      err ->
+  @spec upload_media(String.t(), String.t()) :: {:ok, map()} | {:error, atom() | String.t()}
-        err
+  defp upload_media(media_url, name) do
+    case Tesla.get(media_url, opts: @http_options) do
+      {:ok, %{body: body}} ->
+        case Upload.store(%{body: body, name: name}) do
+          {:ok, %{url: _url} = uploaded} ->
+            {:ok, uploaded}
+
+          {:error, err} ->
+            {:error, err}
+        end
+
+      {:error, err} ->
+        {:error, err}
     end
   end
 end

lib/federation/activity_stream/converter/member.ex

@@ -33,6 +33,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Member do
     }
   end
 
+  @spec as_to_model_data(map()) :: map()
   def as_to_model_data(%{
         "type" => "Member",
         "actor" => actor,

lib/federation/activity_stream/converter/post.ex

@@ -18,6 +18,8 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Post do
       process_pictures: 2
     ]
 
+  import Mobilizon.Service.Guards, only: [is_valid_string: 1]
+
   @behaviour Converter
 
   defimpl Convertible, for: Post do
@@ -63,15 +65,15 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Post do
   Converts an AP object data to our internal data structure.
   """
   @impl Converter
-  @spec as_to_model_data(map) :: {:ok, map} | {:error, any()}
+  @spec as_to_model_data(map) :: map() | {:error, any()}
   def as_to_model_data(
         %{"type" => "Article", "actor" => creator, "attributedTo" => group_uri} = object
       ) do
     with {:ok, %Actor{id: attributed_to_id} = group} <- get_actor(group_uri),
-         {:ok, %Actor{id: author_id}} <- get_actor(creator),
+         {:ok, %Actor{id: author_id}} <- get_actor(creator) do
-         {:visibility, visibility} <- {:visibility, get_visibility(object, group)},
+      [description: description, picture_id: picture_id, medias: medias] =
-         [description: description, picture_id: picture_id, medias: medias] <-
+        process_pictures(object, attributed_to_id)
-           process_pictures(object, attributed_to_id) do
+
       %{
         title: object["name"],
         body: description,
@@ -82,7 +84,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Post do
         publish_at: object["published"],
         picture_id: picture_id,
         medias: medias,
-        visibility: visibility,
+        visibility: get_visibility(object, group),
         draft: object["draft"] == true
       }
     else
@@ -92,11 +94,12 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Post do
   end
 
   @spec get_actor(String.t() | map() | nil) :: {:ok, Actor.t()} | {:error, String.t()}
-  defp get_actor(nil), do: {:error, "nil property found for actor data"}
+  defp get_actor(actor) when is_valid_string(actor),
-
-  defp get_actor(actor),
     do: actor |> Utils.get_url() |> ActivityPubActor.get_or_fetch_actor_by_url()
 
+  defp get_actor(_), do: {:error, "nil property found for actor data"}
+
+  @spec to_date(DateTime.t() | NaiveDateTime.t() | nil) :: String.t() | nil
   defp to_date(nil), do: nil
   defp to_date(%DateTime{} = date), do: DateTime.to_iso8601(date)
   defp to_date(%NaiveDateTime{} = date), do: NaiveDateTime.to_iso8601(date)

lib/federation/activity_stream/converter/resource.ex

@@ -56,18 +56,17 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Resource do
   Converts an AP object data to our internal data structure.
   """
   @impl Converter
-  @spec as_to_model_data(map) :: {:ok, map} | {:error, any()}
+  @spec as_to_model_data(map) :: map() | {:error, any()}
   def as_to_model_data(%{"type" => type, "actor" => creator, "attributedTo" => group} = object) do
     with {:ok, %Actor{id: actor_id, resources_url: resources_url}} <- get_actor(group),
-         {:ok, %Actor{id: creator_id}} <- get_actor(creator),
+         {:ok, %Actor{id: creator_id}} <- get_actor(creator) do
-         parent_id <- get_parent_id(object["context"], resources_url) do
       data = %{
         title: object["name"],
         summary: object["summary"],
         url: object["id"],
         actor_id: actor_id,
         creator_id: creator_id,
-        parent_id: parent_id,
+        parent_id: get_parent_id(object["context"], resources_url),
         published_at: object["published"]
       }
 

lib/federation/activity_stream/converter/todo.ex

@@ -47,14 +47,14 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Todo do
   Converts an AP object data to our internal data structure.
   """
   @impl Converter
-  @spec as_to_model_data(map) :: {:ok, map} | {:error, any()}
+  @spec as_to_model_data(map) :: map() | {:error, any()}
   def as_to_model_data(
         %{"type" => "Todo", "actor" => actor_url, "todoList" => todo_list_url} = object
       ) do
-    with {:ok, %Actor{id: creator_id} = _creator} <-
+    case ActivityPubActor.get_or_fetch_actor_by_url(actor_url) do
-           ActivityPubActor.get_or_fetch_actor_by_url(actor_url),
+      {:ok, %Actor{id: creator_id} = _creator} ->
-         {:todo_list, %TodoList{id: todo_list_id}} <-
+        case Todos.get_todo_list_by_url(todo_list_url) do
-           {:todo_list, Todos.get_todo_list_by_url(todo_list_url)} do
+          %TodoList{id: todo_list_id} ->
             %{
               title: object["name"],
               status: object["status"],
@@ -63,11 +63,22 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Todo do
               creator_id: creator_id,
               published_at: object["published"]
             }
-    else
+
-      {:todo_list, nil} ->
+          nil ->
-        with {:ok, %TodoList{}} <- ActivityPub.fetch_object_from_url(todo_list_url) do
+            case ActivityPub.fetch_object_from_url(todo_list_url) do
+              {:ok, _, %TodoList{}} ->
                 as_to_model_data(object)
-        end
+
+              {:ok, %TodoList{}} ->
+                as_to_model_data(object)
+
+              {:error, err} ->
+                {:error, err}
+            end
+        end
+
+      {:error, err} ->
+        {:error, err}
     end
   end
 end

lib/federation/activity_stream/converter/todo_list.ex

@@ -37,7 +37,7 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.TodoList do
   Converts an AP object data to our internal data structure.
   """
   @impl Converter
-  @spec as_to_model_data(map) :: {:ok, map} | {:error, any()}
+  @spec as_to_model_data(map) :: map() | {:error, :group_not_found}
   def as_to_model_data(%{"type" => "TodoList", "actor" => actor_url} = object) do
     case ActivityPubActor.get_or_fetch_actor_by_url(actor_url) do
       {:ok, %Actor{type: :Group, id: group_id} = _group} ->

lib/federation/activity_stream/converter/utils.ex

@@ -111,7 +111,6 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Utils do
     acc ++ [%{actor_id: actor_id}]
   end
 
-  @spec create_mention(map(), list()) :: list()
   defp create_mention(mention, acc) when is_map(mention) do
     with true <- mention["type"] == "Mention",
          {:ok, %Actor{id: actor_id}} <-
@@ -128,22 +127,34 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Utils do
     create_mention(mention, acc)
   end
 
-  @spec maybe_fetch_actor_and_attributed_to_id(map()) :: {Actor.t() | nil, Actor.t() | nil}
+  @spec maybe_fetch_actor_and_attributed_to_id(map()) ::
+          {:ok, Actor.t(), Actor.t() | nil} | {:error, atom()}
   def maybe_fetch_actor_and_attributed_to_id(%{
         "actor" => actor_url,
         "attributedTo" => attributed_to_url
       })
       when is_nil(attributed_to_url) do
-    {fetch_actor(actor_url), nil}
+    case fetch_actor(actor_url) do
+      {:ok, %Actor{} = actor} ->
+        {:ok, actor, nil}
+
+      {:error, err} ->
+        {:error, err}
+    end
   end
 
-  @spec maybe_fetch_actor_and_attributed_to_id(map()) :: {Actor.t() | nil, Actor.t() | nil}
   def maybe_fetch_actor_and_attributed_to_id(%{
         "actor" => actor_url,
         "attributedTo" => attributed_to_url
       })
       when is_nil(actor_url) do
-    {fetch_actor(attributed_to_url), nil}
+    case fetch_actor(attributed_to_url) do
+      {:ok, %Actor{} = actor} ->
+        {:ok, actor, nil}
+
+      {:error, err} ->
+        {:error, err}
+    end
   end
 
   # Only when both actor and attributedTo fields are both filled is when we can return both
@@ -152,9 +163,12 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Utils do
         "attributedTo" => attributed_to_url
       })
       when actor_url != attributed_to_url do
-    with actor <- fetch_actor(actor_url),
+    with {:ok, %Actor{} = actor} <- fetch_actor(actor_url),
-         attributed_to <- fetch_actor(attributed_to_url) do
+         {:ok, %Actor{} = attributed_to} <- fetch_actor(attributed_to_url) do
-      {actor, attributed_to}
+      {:ok, actor, attributed_to}
+    else
+      {:error, err} ->
+        {:error, err}
     end
   end
 
@@ -162,16 +176,25 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Utils do
   def maybe_fetch_actor_and_attributed_to_id(%{
         "attributedTo" => attributed_to_url
       }) do
-    {fetch_actor(attributed_to_url), nil}
+    case fetch_actor(attributed_to_url) do
+      {:ok, %Actor{} = attributed_to} -> {:ok, attributed_to, nil}
+      {:error, err} -> {:error, err}
+    end
   end
 
-  def maybe_fetch_actor_and_attributed_to_id(_), do: {nil, nil}
+  def maybe_fetch_actor_and_attributed_to_id(_), do: {:error, :no_actor_found}
 
-  @spec fetch_actor(String.t()) :: Actor.t()
+  @spec fetch_actor(String.t()) :: {:ok, Actor.t()} | {:error, atom()}
   defp fetch_actor(actor_url) do
-    with {:ok, %Actor{suspended: false} = actor} <-
+    case ActivityPubActor.get_or_fetch_actor_by_url(actor_url) do
-           ActivityPubActor.get_or_fetch_actor_by_url(actor_url) do
+      {:ok, %Actor{suspended: false} = actor} ->
-      actor
+        {:ok, actor}
+
+      {:ok, %Actor{suspended: true} = _actor} ->
+        {:error, :actor_suspended}
+
+      {:error, err} ->
+        {:error, err}
     end
   end
 
@@ -203,12 +226,17 @@ defmodule Mobilizon.Federation.ActivityStream.Converter.Utils do
       |> Map.new()
 
     picture_id =
-      with banner when is_map(banner) <- get_banner_picture(attachements),
+      case get_banner_picture(attachements) do
-           {:ok, %Media{id: picture_id}} <-
+        banner when is_map(banner) ->
-             MediaConverter.find_or_create_media(banner, actor_id) do
+          case MediaConverter.find_or_create_media(banner, actor_id) do
+            {:error, _err} ->
+              nil
+
+            {:ok, %Media{id: picture_id}} ->
               picture_id
-      else
+          end
-        _err ->
+
+        _ ->
           nil
       end
 

lib/federation/http_signatures/signature.ex

@@ -19,7 +19,7 @@ defmodule Mobilizon.Federation.HTTPSignatures.Signature do
 
   @spec key_id_to_actor_url(String.t()) :: String.t()
   def key_id_to_actor_url(key_id) do
-    %{path: path} =
+    %URI{path: path} =
       uri =
       key_id
       |> URI.parse()
@@ -29,7 +29,7 @@ defmodule Mobilizon.Federation.HTTPSignatures.Signature do
       if is_nil(path) do
         uri
       else
-        Map.put(uri, :path, String.trim_trailing(path, "/publickey"))
+        %URI{uri | path: String.trim_trailing(path, "/publickey")}
       end
 
     URI.to_string(uri)
@@ -78,15 +78,25 @@ defmodule Mobilizon.Federation.HTTPSignatures.Signature do
     end
   end
 
+  @spec fetch_public_key(Plug.Conn.t()) ::
+          {:ok, String.t()}
+          | {:error, :actor_fetch_error | :actor_not_fetchable | :pem_decode_error}
   def fetch_public_key(conn) do
     with %{"keyId" => kid} <- HTTPSignatures.signature_for_conn(conn),
          actor_id <- key_id_to_actor_url(kid),
          :ok <- Logger.debug("Fetching public key for #{actor_id}"),
          {:ok, public_key} <- get_public_key_for_url(actor_id) do
       {:ok, public_key}
+    else
+      {:error, err} ->
+        {:error, err}
     end
   end
 
+  @spec refetch_public_key(Plug.Conn.t()) ::
+          {:ok, String.t()}
+          | {:error, :actor_fetch_error | :actor_not_fetchable | :pem_decode_error,
+             :actor_is_local}
   def refetch_public_key(conn) do
     with %{"keyId" => kid} <- HTTPSignatures.signature_for_conn(conn),
          actor_id <- key_id_to_actor_url(kid),
@@ -94,9 +104,13 @@ defmodule Mobilizon.Federation.HTTPSignatures.Signature do
          {:ok, _actor} <- ActivityPubActor.make_actor_from_url(actor_id),
          {:ok, public_key} <- get_public_key_for_url(actor_id) do
       {:ok, public_key}
+    else
+      {:error, err} ->
+        {:error, err}
     end
   end
 
+  @spec sign(Actor.t(), map()) :: String.t() | {:error, :pem_decode_error} | no_return
   def sign(%Actor{domain: domain, keys: keys} = actor, headers) when is_nil(domain) do
     Logger.debug("Signing a payload on behalf of #{actor.url}")
     Logger.debug("headers")
@@ -112,14 +126,17 @@ defmodule Mobilizon.Federation.HTTPSignatures.Signature do
     raise ArgumentError, message: "Can't do a signature on remote actor #{url}"
   end
 
+  @spec generate_date_header :: String.t()
   def generate_date_header, do: generate_date_header(NaiveDateTime.utc_now())
 
   def generate_date_header(%NaiveDateTime{} = date) do
     Timex.format!(date, "{WDshort}, {0D} {Mshort} {YYYY} {h24}:{m}:{s} GMT")
   end
 
+  @spec generate_request_target(String.t(), String.t()) :: String.t()
   def generate_request_target(method, path), do: "#{method} #{path}"
 
+  @spec build_digest(String.t()) :: String.t()
   def build_digest(body) do
     "SHA-256=#{:sha256 |> :crypto.hash(body) |> Base.encode64()}"
   end

lib/federation/web_finger/web_finger.ex

@@ -19,11 +19,15 @@ defmodule Mobilizon.Federation.WebFinger do
   require Logger
   import SweetXml
 
+  @doc """
+  Returns the Web Host Metadata (for `/.well-known/host-meta`) representation for the instance, following RFC6414.
+  """
+  @spec host_meta :: String.t()
   def host_meta do
     base_url = Endpoint.url()
     %URI{host: host} = URI.parse(base_url)
 
-    {
+    XmlBuilder.to_doc({
       :XRD,
       %{
         xmlns: "http://docs.oasis-open.org/ns/xri/xrd-1.0",
@@ -43,10 +47,13 @@ defmodule Mobilizon.Federation.WebFinger do
           }
         }
       ]
-    }
+    })
-    |> XmlBuilder.to_doc()
   end
 
+  @doc """
+  Returns the Webfinger representation for the instance, following RFC7033.
+  """
+  @spec webfinger(String.t(), String.t()) :: {:ok, map} | {:error, :actor_not_found}
   def webfinger(resource, "JSON") do
     host = Endpoint.host()
     regex = ~r/(acct:)?(?<name>\w+)@#{host}/
@@ -61,15 +68,18 @@ defmodule Mobilizon.Federation.WebFinger do
             {:ok, represent_actor(actor, "JSON")}
 
           _e ->
-            {:error, "Couldn't find actor"}
+            {:error, :actor_not_found}
         end
     end
   end
 
-  @spec represent_actor(Actor.t()) :: struct()
+  @doc """
+  Return an `Mobilizon.Actors.Actor` Webfinger representation (as JSON)
+  """
+  @spec represent_actor(Actor.t()) :: map()
+  @spec represent_actor(Actor.t(), String.t()) :: map()
   def represent_actor(%Actor{} = actor), do: represent_actor(actor, "JSON")
 
-  @spec represent_actor(Actor.t(), String.t()) :: struct()
   def represent_actor(%Actor{} = actor, "JSON") do
     links =
       [
@@ -89,6 +99,7 @@ defmodule Mobilizon.Federation.WebFinger do
     }
   end
 
+  @spec maybe_add_avatar(list(map()), Actor.t()) :: list(map())
   defp maybe_add_avatar(data, %Actor{avatar: avatar}) when not is_nil(avatar) do
     data ++
       [
@@ -102,6 +113,7 @@ defmodule Mobilizon.Federation.WebFinger do
 
   defp maybe_add_avatar(data, _actor), do: data
 
+  @spec maybe_add_profile_page(list(map()), Actor.t()) :: list(map())
   defp maybe_add_profile_page(data, %Actor{type: :Group, url: url}) do
     data ++
       [
@@ -115,37 +127,76 @@ defmodule Mobilizon.Federation.WebFinger do
 
   defp maybe_add_profile_page(data, _actor), do: data
 
+  @type finger_errors ::
+          :host_not_found | :address_invalid | :http_error | :webfinger_information_not_json
+
   @doc """
   Finger an actor to retreive it's ActivityPub ID/URL
 
-  Fetches the Extensible Resource Descriptor endpoint `/.well-known/host-meta` to find the Webfinger endpoint (usually `/.well-known/webfinger?resource=`) with `find_webfinger_endpoint/1` and then performs a Webfinger query to get the ActivityPub ID associated to an actor.
+  Fetches the Extensible Resource Descriptor endpoint `/.well-known/host-meta` to find the Webfinger endpoint (usually `/.well-known/webfinger?resource=`) and then performs a Webfinger query to get the ActivityPub ID associated to an actor.
   """
-  @spec finger(String.t()) :: {:ok, String.t()} | {:error, atom()}
+  @spec finger(String.t()) ::
+          {:ok, String.t()}
+          | {:error, finger_errors}
   def finger(actor) do
     actor = String.trim_leading(actor, "@")
 
-    with address when is_binary(address) <- apply_webfinger_endpoint(actor),
+    case validate_endpoint(actor) do
-         false <- address_invalid(address),
+      {:ok, address} ->
-         {:ok, %{body: body, status: code}} when code in 200..299 <-
+        case fetch_webfinger_data(address) do
-           WebfingerClient.get(address),
+          {:ok, %{"url" => url}} ->
-         {:ok, %{"url" => url}} <- webfinger_from_json(body) do
             {:ok, url}
-    else
+
-      e ->
+          {:error, err} ->
-        Logger.debug("Couldn't finger #{actor}")
+            Logger.debug("Couldn't process webfinger data for #{actor}")
-        Logger.debug(inspect(e))
+            {:error, err}
-        {:error, e}
+        end
+
+      {:error, err} ->
+        Logger.debug("Couldn't find webfinger endpoint for #{actor}")
+        {:error, err}
     end
   end
 
-  @doc """
+  @spec fetch_webfinger_data(String.t()) ::
-  Fetches the Extensible Resource Descriptor endpoint `/.well-known/host-meta` to find the Webfinger endpoint (usually `/.well-known/webfinger?resource=`)
+          {:ok, map()} | {:error, :webfinger_information_not_json | :http_error}
-  """
+  defp fetch_webfinger_data(address) do
-  @spec find_webfinger_endpoint(String.t()) :: String.t()
+    case WebfingerClient.get(address) do
-  def find_webfinger_endpoint(domain) when is_binary(domain) do
+      {:ok, %{body: body, status: code}} when code in 200..299 ->
+        webfinger_from_json(body)
+
+      _ ->
+        {:error, :http_error}
+    end
+  end
+
+  @spec validate_endpoint(String.t()) ::
+          {:ok, String.t()} | {:error, :address_invalid | :host_not_found}
+  defp validate_endpoint(actor) do
+    case apply_webfinger_endpoint(actor) do
+      address when is_binary(address) ->
+        if address_invalid(address) do
+          {:error, :address_invalid}
+        else
+          {:ok, address}
+        end
+
+      _ ->
+        {:error, :host_not_found}
+    end
+  end
+
+  # Fetches the Extensible Resource Descriptor endpoint `/.well-known/host-meta`
+  # to find the Webfinger endpoint (usually `/.well-known/webfinger?resource=`)
+  @spec find_webfinger_endpoint(String.t()) ::
+          {:ok, String.t()} | {:error, :link_not_found} | {:error, any()}
+  defp find_webfinger_endpoint(domain) when is_binary(domain) do
     with {:ok, %{body: body}} <- fetch_document("http://#{domain}/.well-known/host-meta"),
          link_template when is_binary(link_template) <- find_link_from_template(body) do
       {:ok, link_template}
+    else
+      {:error, :link_not_found} -> {:error, :link_not_found}
+      {:error, error} -> {:error, error}
     end
   end
 

lib/federation/web_finger/xml_builder.ex

@@ -5,42 +5,54 @@
 
 defmodule Mobilizon.Federation.WebFinger.XmlBuilder do
   @moduledoc """
-  Builds XRD for WebFinger host_meta.
+  Extremely basic XML encoder. Builds XRD for WebFinger host_meta.
   """
 
-  def to_xml({tag, attributes, content}) do
+  @typep content :: list({tag :: atom(), attributes :: map()}) | String.t()
+  @typep document :: {tag :: atom(), attributes :: map(), content :: content}
+
+  @doc """
+  Return the XML representation for a document.
+  """
+  @spec to_doc(document :: document) :: String.t()
+  def to_doc(document), do: ~s(<?xml version="1.0" encoding="UTF-8"?>) <> to_xml(document)
+
+  @spec to_xml(document) :: String.t()
+  @spec to_xml({tag :: atom(), attributes :: map()}) :: String.t()
+  @spec to_xml({tag :: atom(), content :: content}) :: String.t()
+  @spec to_xml(content :: content) :: String.t()
+  defp to_xml({tag, attributes, content}) do
     open_tag = make_open_tag(tag, attributes)
     content_xml = to_xml(content)
 
     "<#{open_tag}>#{content_xml}</#{tag}>"
   end
 
-  def to_xml({tag, %{} = attributes}) do
+  defp to_xml({tag, %{} = attributes}) do
     open_tag = make_open_tag(tag, attributes)
 
     "<#{open_tag} />"
   end
 
-  def to_xml({tag, content}), do: to_xml({tag, %{}, content})
+  defp to_xml({tag, content}), do: to_xml({tag, %{}, content})
 
-  def to_xml(content) when is_binary(content), do: to_string(content)
+  defp to_xml(content) when is_binary(content), do: to_string(content)
 
-  def to_xml(content) when is_list(content) do
+  defp to_xml(content) when is_list(content) do
     content
     |> Enum.map(&to_xml/1)
     |> Enum.join()
   end
 
-  def to_xml(%NaiveDateTime{} = time), do: NaiveDateTime.to_iso8601(time)
+  defp to_xml(%NaiveDateTime{} = time), do: NaiveDateTime.to_iso8601(time)
-
-  def to_doc(content), do: ~s(<?xml version="1.0" encoding="UTF-8"?>) <> to_xml(content)
 
+  @spec make_open_tag(tag :: atom, attributes :: map()) :: String.t()
   defp make_open_tag(tag, attributes) do
     attributes_string =
       attributes
       |> Enum.map(fn {attribute, value} -> "#{attribute}=\"#{value}\"" end)
       |> Enum.join(" ")
 
-    [tag, attributes_string] |> Enum.join(" ") |> String.trim()
+    [to_string(tag), attributes_string] |> Enum.join(" ") |> String.trim()
   end
 end

lib/graphql/api/comments.ex

@@ -5,8 +5,7 @@ defmodule Mobilizon.GraphQL.API.Comments do
 
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Discussions.Comment
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity}
-  alias Mobilizon.Federation.ActivityPub.Activity
   alias Mobilizon.GraphQL.API.Utils
 
   @doc """
@@ -15,7 +14,7 @@ defmodule Mobilizon.GraphQL.API.Comments do
   @spec create_comment(map) :: {:ok, Activity.t(), Comment.t()} | any
   def create_comment(args) do
     args = extract_pictures_from_comment_body(args)
-    ActivityPub.create(:comment, args, true)
+    Actions.Create.create(:comment, args, true)
   end
 
   @doc """
@@ -24,7 +23,7 @@ defmodule Mobilizon.GraphQL.API.Comments do
   @spec update_comment(Comment.t(), map()) :: {:ok, Activity.t(), Comment.t()} | any
   def update_comment(%Comment{} = comment, args) do
     args = extract_pictures_from_comment_body(args)
-    ActivityPub.update(comment, args, true)
+    Actions.Update.update(comment, args, true)
   end
 
   @doc """
@@ -32,7 +31,7 @@ defmodule Mobilizon.GraphQL.API.Comments do
   """
   @spec delete_comment(Comment.t(), Actor.t()) :: {:ok, Activity.t(), Comment.t()} | any
   def delete_comment(%Comment{} = comment, %Actor{} = actor) do
-    ActivityPub.delete(comment, actor, true)
+    Actions.Delete.delete(comment, actor, true)
   end
 
   @doc """
@@ -42,7 +41,7 @@ defmodule Mobilizon.GraphQL.API.Comments do
   def create_discussion(args) do
     args = extract_pictures_from_comment_body(args)
 
-    ActivityPub.create(
+    Actions.Create.create(
       :discussion,
       args,
       true

lib/graphql/api/events.ex

@@ -6,8 +6,7 @@ defmodule Mobilizon.GraphQL.API.Events do
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Events.Event
 
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity, Utils}
-  alias Mobilizon.Federation.ActivityPub.{Activity, Utils}
   alias Mobilizon.GraphQL.API.Utils, as: APIUtils
 
   @doc """
@@ -15,15 +14,8 @@ defmodule Mobilizon.GraphQL.API.Events do
   """
   @spec create_event(map) :: {:ok, Activity.t(), Event.t()} | any
   def create_event(args) do
-    with organizer_actor <- Map.get(args, :organizer_actor),
-         args <- extract_pictures_from_event_body(args, organizer_actor),
-         args <-
-           Map.update(args, :picture, nil, fn picture ->
-             process_picture(picture, organizer_actor)
-           end) do
     # For now we don't federate drafts but it will be needed if we want to edit them as groups
-      ActivityPub.create(:event, args, should_federate(args))
+    Actions.Create.create(:event, prepare_args(args), should_federate(args))
-    end
   end
 
   @doc """
@@ -31,21 +23,26 @@ defmodule Mobilizon.GraphQL.API.Events do
   """
   @spec update_event(map, Event.t()) :: {:ok, Activity.t(), Event.t()} | any
   def update_event(args, %Event{} = event) do
-    with organizer_actor <- Map.get(args, :organizer_actor),
+    Actions.Update.update(event, prepare_args(args), should_federate(args))
-         args <- extract_pictures_from_event_body(args, organizer_actor),
-         args <-
-           Map.update(args, :picture, nil, fn picture ->
-             process_picture(picture, organizer_actor)
-           end) do
-      ActivityPub.update(event, args, should_federate(args))
-    end
   end
 
   @doc """
   Trigger the deletion of an event
   """
+  @spec delete_event(Event.t(), Actor.t(), boolean()) :: {:ok, Activity.t(), Entity.t()} | any()
   def delete_event(%Event{} = event, %Actor{} = actor, federate \\ true) do
-    ActivityPub.delete(event, actor, federate)
+    Actions.Delete.delete(event, actor, federate)
+  end
+
+  @spec prepare_args(map) :: map
+  defp prepare_args(args) do
+    organizer_actor = Map.get(args, :organizer_actor)
+
+    args
+    |> extract_pictures_from_event_body(organizer_actor)
+    |> Map.update(:picture, nil, fn picture ->
+      process_picture(picture, organizer_actor)
+    end)
   end
 
   defp process_picture(nil, _), do: nil
@@ -75,6 +72,7 @@ defmodule Mobilizon.GraphQL.API.Events do
 
   defp extract_pictures_from_event_body(args, _), do: args
 
+  @spec should_federate(map()) :: boolean
   defp should_federate(%{attributed_to_id: attributed_to_id}) when not is_nil(attributed_to_id),
     do: true
 

lib/graphql/api/follows.ex

@@ -6,73 +6,81 @@ defmodule Mobilizon.GraphQL.API.Follows do
   alias Mobilizon.Actors
   alias Mobilizon.Actors.{Actor, Follower}
 
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity}
-  alias Mobilizon.Federation.ActivityPub.Activity
 
   require Logger
 
+  @doc """
+  Make an actor (`follower`) follow another (`followed`).
+  """
+  @spec follow(follower :: Actor.t(), followed :: Actor.t()) ::
+          {:ok, Activity.t(), Mobilizon.Actors.Follower.t()}
+          | {:error, String.t()}
   def follow(%Actor{} = follower, %Actor{} = followed) do
-    case ActivityPub.follow(follower, followed) do
+    Actions.Follow.follow(follower, followed)
-      {:ok, activity, follow} ->
-        {:ok, activity, follow}
-
-      {:error, e} ->
-        Logger.warn("Error while following actor: #{inspect(e)}")
-        {:error, e}
-
-      e ->
-        Logger.warn("Error while following actor: #{inspect(e)}")
-        {:error, e}
-    end
   end
 
+  @doc """
+  Make an actor (`follower`) unfollow another (`followed`).
+  """
+  @spec unfollow(follower :: Actor.t(), followed :: Actor.t()) ::
+          {:ok, Activity.t(), Mobilizon.Actors.Follower.t()}
+          | {:error, String.t()}
   def unfollow(%Actor{} = follower, %Actor{} = followed) do
-    case ActivityPub.unfollow(follower, followed) do
+    Actions.Follow.unfollow(follower, followed)
-      {:ok, activity, follow} ->
-        {:ok, activity, follow}
-
-      e ->
-        Logger.warn("Error while unfollowing actor: #{inspect(e)}")
-        {:error, e}
-    end
   end
 
-  def accept(%Actor{} = follower, %Actor{} = followed) do
+  @doc """
-    Logger.debug("We're trying to accept a follow")
+  Make an actor (`followed`) accept the follow from another (`follower`).
+  """
+  @spec accept(follower :: Actor.t(), followed :: Actor.t()) ::
+          {:ok, Activity.t(), Mobilizon.Actors.Follower.t()}
+          | {:error, String.t()}
+  def accept(%Actor{url: follower_url} = follower, %Actor{url: followed_url} = followed) do
+    Logger.debug(
+      "We're trying to accept a follow: #{followed_url} is accepting #{follower_url} follow request."
+    )
 
-    with %Follower{approved: false} = follow <-
+    case Actors.is_following(follower, followed) do
-           Actors.is_following(follower, followed),
+      %Follower{approved: false} = follow ->
-         {:ok, %Activity{} = activity, %Follower{approved: true} = follow} <-
+        Actions.Accept.accept(
-           ActivityPub.accept(
           :follow,
           follow,
           true
-           ) do
+        )
-      {:ok, activity, follow}
+
-    else
       %Follower{approved: true} ->
         {:error, "Follow already accepted"}
+
+      nil ->
+        {:error, "Can't accept follow: #{follower_url} is not following #{followed_url}."}
     end
   end
 
-  def reject(%Actor{} = follower, %Actor{} = followed) do
+  @doc """
-    Logger.debug("We're trying to reject a follow")
+  Make an actor (`followed`) reject the follow from another (`follower`).
+  """
+  @spec reject(follower :: Actor.t(), followed :: Actor.t()) ::
+          {:ok, Activity.t(), Mobilizon.Actors.Follower.t()}
+          | {:error, String.t()}
+  def reject(%Actor{url: follower_url} = follower, %Actor{url: followed_url} = followed) do
+    Logger.debug(
+      "We're trying to reject a follow: #{followed_url} is rejecting #{follower_url} follow request."
+    )
 
-    with {:follower, %Follower{} = follow} <-
+    case Actors.is_following(follower, followed) do
-           {:follower, Actors.is_following(follower, followed)},
+      %Follower{approved: true} ->
-         {:ok, %Activity{} = activity, %Follower{} = follow} <-
+        {:error, "Follow already accepted"}
-           ActivityPub.reject(
+
+      %Follower{} = follow ->
+        Actions.Reject.reject(
           :follow,
           follow,
           true
-           ) do
+        )
-      {:ok, activity, follow}
-    else
-      {:follower, nil} ->
-        {:error, "Follow not found"}
 
-      {:follower, %Follower{approved: true}} ->
+      nil ->
-        {:error, "Follow already accepted"}
+        {:error, "Follow not found"}
     end
   end
 end

lib/graphql/api/groups.ex

@@ -6,39 +6,35 @@ defmodule Mobilizon.GraphQL.API.Groups do
   alias Mobilizon.Actors
   alias Mobilizon.Actors.Actor
 
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity}
-  alias Mobilizon.Federation.ActivityPub.Activity
   alias Mobilizon.Service.Formatter.HTML
 
   @doc """
   Create a group
   """
-  @spec create_group(map) :: {:ok, Activity.t(), Actor.t()} | any
+  @spec create_group(map) ::
+          {:ok, Activity.t(), Actor.t()}
+          | {:error, String.t() | Ecto.Changeset.t()}
   def create_group(args) do
-    with preferred_username <-
+    preferred_username =
-           args |> Map.get(:preferred_username) |> HTML.strip_tags() |> String.trim(),
+      args |> Map.get(:preferred_username) |> HTML.strip_tags() |> String.trim()
-         {:existing_group, nil} <-
+
-           {:existing_group, Actors.get_local_actor_by_name(preferred_username)},
+    args = args |> Map.put(:type, :Group)
-         args <- args |> Map.put(:type, :Group),
+
-         {:ok, %Activity{} = activity, %Actor{} = group} <-
+    case Actors.get_local_actor_by_name(preferred_username) do
-           ActivityPub.create(:actor, args, true, %{"actor" => args.creator_actor.url}) do
+      nil ->
-      {:ok, activity, group}
+        Actions.Create.create(:actor, args, true, %{"actor" => args.creator_actor.url})
-    else
+
-      {:existing_group, _} ->
+      %Actor{} ->
-        {:error, "A group with this name already exists"}
+        {:error, "A profile or group with that name already exists"}
     end
   end
 
-  @spec create_group(map) :: {:ok, Activity.t(), Actor.t()} | any
+  @spec update_group(map) ::
+          {:ok, Activity.t(), Actor.t()} | {:error, :group_not_found | Ecto.Changeset.t()}
   def update_group(%{id: id} = args) do
-    with {:existing_group, {:ok, %Actor{type: :Group} = group}} <-
+    with {:ok, %Actor{type: :Group} = group} <- Actors.get_group_by_actor_id(id) do
-           {:existing_group, Actors.get_group_by_actor_id(id)},
+      Actions.Update.update(group, args, true, %{"actor" => args.updater_actor.url})
-         {:ok, %Activity{} = activity, %Actor{} = group} <-
-           ActivityPub.update(group, args, true, %{"actor" => args.updater_actor.url}) do
-      {:ok, activity, group}
-    else
-      {:existing_group, _} ->
-        {:error, "A group with this name already exists"}
     end
   end
 end

lib/graphql/api/participations.ex

@@ -6,28 +6,27 @@ defmodule Mobilizon.GraphQL.API.Participations do
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Events
   alias Mobilizon.Events.{Event, Participant}
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity}
-  alias Mobilizon.Federation.ActivityPub.Activity
   alias Mobilizon.Service.Notifications.Scheduler
   alias Mobilizon.Web.Email.Participation
 
-  @spec join(Event.t(), Actor.t(), map()) :: {:ok, Activity.t(), Participant.t()}
+  @spec join(Event.t(), Actor.t(), map()) ::
+          {:ok, Activity.t(), Participant.t()} | {:error, :already_participant}
   def join(%Event{id: event_id} = event, %Actor{id: actor_id} = actor, args \\ %{}) do
-    with {:error, :participant_not_found} <-
+    case Mobilizon.Events.get_participant(event_id, actor_id, args) do
-           Mobilizon.Events.get_participant(event_id, actor_id, args),
+      {:ok, %Participant{}} ->
-         {:ok, activity, participant} <-
+        {:error, :already_participant}
-           ActivityPub.join(event, actor, Map.get(args, :local, true), %{metadata: args}) do
+
-      {:ok, activity, participant}
+      {:error, :participant_not_found} ->
+        Actions.Join.join(event, actor, Map.get(args, :local, true), %{metadata: args})
     end
   end
 
-  @spec leave(Event.t(), Actor.t()) :: {:ok, Activity.t(), Participant.t()}
+  @spec leave(Event.t(), Actor.t(), map()) ::
-  def leave(%Event{} = event, %Actor{} = actor, args \\ %{}) do
+          {:ok, Activity.t(), Participant.t()}
-    with {:ok, activity, participant} <-
+          | {:error, :is_only_organizer | :participant_not_found | Ecto.Changeset.t()}
-           ActivityPub.leave(event, actor, Map.get(args, :local, true), %{metadata: args}) do
+  def leave(%Event{} = event, %Actor{} = actor, args \\ %{}),
-      {:ok, activity, participant}
+    do: Actions.Leave.leave(event, actor, Map.get(args, :local, true), %{metadata: args})
-    end
-  end
 
   @doc """
   Update participation status
@@ -36,7 +35,6 @@ defmodule Mobilizon.GraphQL.API.Participations do
   def update(%Participant{} = participation, %Actor{} = moderator, :participant),
     do: accept(participation, moderator)
 
-  @spec update(Participant.t(), Actor.t(), atom()) :: {:ok, Activity.t(), Participant.t()}
   def update(%Participant{} = participation, %Actor{} = _moderator, :not_approved) do
     with {:ok, %Participant{} = participant} <-
            Events.update_participant(participation, %{role: :not_approved}) do
@@ -45,7 +43,6 @@ defmodule Mobilizon.GraphQL.API.Participations do
     end
   end
 
-  @spec update(Participant.t(), Actor.t(), atom()) :: {:ok, Activity.t(), Participant.t()}
   def update(%Participant{} = participation, %Actor{} = moderator, :rejected),
     do: reject(participation, moderator)
 
@@ -54,15 +51,18 @@ defmodule Mobilizon.GraphQL.API.Participations do
          %Participant{} = participation,
          %Actor{} = moderator
        ) do
-    with {:ok, activity, %Participant{role: :participant} = participation} <-
+    case Actions.Accept.accept(
-           ActivityPub.accept(
            :join,
            participation,
            true,
            %{"actor" => moderator.url}
-           ),
+         ) do
-         :ok <- Participation.send_emails_to_local_user(participation) do
+      {:ok, activity, %Participant{role: :participant} = participation} ->
+        Participation.send_emails_to_local_user(participation)
         {:ok, activity, participation}
+
+      {:error, err} ->
+        {:error, err}
     end
   end
 
@@ -72,7 +72,7 @@ defmodule Mobilizon.GraphQL.API.Participations do
          %Actor{} = moderator
        ) do
     with {:ok, activity, %Participant{role: :rejected} = participation} <-
-           ActivityPub.reject(
+           Actions.Reject.reject(
              :join,
              participation,
              true,

lib/graphql/api/reports.ex

@@ -9,48 +9,46 @@ defmodule Mobilizon.GraphQL.API.Reports do
   alias Mobilizon.Reports.{Note, Report, ReportStatus}
   alias Mobilizon.Users.User
 
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Activity}
-  alias Mobilizon.Federation.ActivityPub.Activity
 
   @doc """
   Create a report/flag on an actor, and optionally on an event or on comments.
   """
+  @spec report(map()) :: {:ok, Activity.t(), Report.t()} | {:error, Ecto.Changeset.t()}
   def report(args) do
-    case {:make_activity, ActivityPub.flag(args, Map.get(args, :forward, false) == true)} do
+    Actions.Flag.flag(args, Map.get(args, :forward, false) == true)
-      {:make_activity, {:ok, %Activity{} = activity, %Report{} = report}} ->
-        {:ok, activity, report}
-
-      {:make_activity, err} ->
-        {:error, err}
-    end
   end
 
   @doc """
   Update the state of a report
   """
+  @spec update_report_status(Actor.t(), Report.t(), ReportStatus.t()) ::
+          {:ok, Report.t()} | {:error, Ecto.Changeset.t() | String.t()}
   def update_report_status(%Actor{} = actor, %Report{} = report, state) do
-    with {:valid_state, true} <-
+    if ReportStatus.valid_value?(state) do
-           {:valid_state, ReportStatus.valid_value?(state)},
+      with {:ok, %Report{} = report} <- ReportsAction.update_report(report, %{"status" => state}) do
-         {:ok, report} <- ReportsAction.update_report(report, %{"status" => state}),
+        Admin.log_action(actor, "update", report)
-         {:ok, _} <- Admin.log_action(actor, "update", report) do
         {:ok, report}
+      end
     else
-      {:valid_state, false} -> {:error, "Unsupported state"}
+      {:error, "Unsupported state"}
     end
   end
 
   @doc """
   Create a note on a report
   """
-  @spec create_report_note(Report.t(), Actor.t(), String.t()) :: {:ok, Note.t()}
+  @spec create_report_note(Report.t(), Actor.t(), String.t()) ::
+          {:ok, Note.t()} | {:error, String.t() | Ecto.Changeset.t()}
   def create_report_note(
         %Report{id: report_id},
         %Actor{id: moderator_id, user_id: user_id} = moderator,
         content
       ) do
-    with %User{role: role} <- Users.get_user!(user_id),
+    %User{role: role} = Users.get_user!(user_id)
-         {:role, true} <- {:role, role in [:administrator, :moderator]},
+
-         {:ok, %Note{} = note} <-
+    if role in [:administrator, :moderator] do
+      with {:ok, %Note{} = note} <-
              Mobilizon.Reports.create_note(%{
                "report_id" => report_id,
                "moderator_id" => moderator_id,
@@ -58,8 +56,8 @@ defmodule Mobilizon.GraphQL.API.Reports do
              }),
            {:ok, _} <- Admin.log_action(moderator, "create", note) do
         {:ok, note}
+      end
     else
-      {:role, false} ->
       {:error, "You need to be a moderator or an administrator to create a note on a report"}
     end
   end
@@ -67,23 +65,25 @@ defmodule Mobilizon.GraphQL.API.Reports do
   @doc """
   Delete a report note
   """
-  @spec delete_report_note(Note.t(), Actor.t()) :: {:ok, Note.t()}
+  @spec delete_report_note(Note.t(), Actor.t()) ::
+          {:ok, Note.t()} | {:error, Ecto.Changeset.t() | String.t()}
   def delete_report_note(
         %Note{moderator_id: note_moderator_id} = note,
         %Actor{id: moderator_id, user_id: user_id} = moderator
       ) do
-    with {:same_actor, true} <- {:same_actor, note_moderator_id == moderator_id},
+    if note_moderator_id == moderator_id do
-         %User{role: role} <- Users.get_user!(user_id),
+      %User{role: role} = Users.get_user!(user_id)
-         {:role, true} <- {:role, role in [:administrator, :moderator]},
+
-         {:ok, %Note{} = note} <-
+      if role in [:administrator, :moderator] do
+        with {:ok, %Note{} = note} <-
                Mobilizon.Reports.delete_note(note),
              {:ok, _} <- Admin.log_action(moderator, "delete", note) do
           {:ok, note}
+        end
       else
-      {:role, false} ->
         {:error, "You need to be a moderator or an administrator to create a note on a report"}
-
+      end
-      {:same_actor, false} ->
+    else
       {:error, "You can only remove your own notes"}
     end
   end

lib/graphql/api/search.ex

@@ -59,8 +59,8 @@ defmodule Mobilizon.GraphQL.API.Search do
   @doc """
   Search events
   """
-  @spec search_events(String.t(), integer | nil, integer | nil) ::
+  @spec search_events(map(), integer | nil, integer | nil) ::
-          {:ok, Page.t()} | {:error, String.t()}
+          {:ok, Page.t()}
   def search_events(%{term: term} = args, page \\ 1, limit \\ 10) do
     term = String.trim(term)
 
@@ -78,6 +78,7 @@ defmodule Mobilizon.GraphQL.API.Search do
     end
   end
 
+  @spec interact(String.t()) :: {:ok, struct()} | {:error, :not_found}
   def interact(uri) do
     case ActivityPub.fetch_object_from_url(uri) do
       {:ok, object} ->

lib/graphql/api/utils.ex

@@ -10,7 +10,7 @@ defmodule Mobilizon.GraphQL.API.Utils do
   @doc """
   Creates HTML content from text and mentions
   """
-  @spec make_content_html(String.t(), list(), String.t()) :: String.t()
+  @spec make_content_html(String.t(), list(), String.t()) :: {String.t(), list(), list()}
   def make_content_html(text, additional_tags, content_type) do
     with {text, mentions, tags} <- format_input(text, content_type, []) do
       {text, mentions, additional_tags ++ Enum.map(tags, fn {_, tag} -> tag end)}

lib/graphql/error.ex

@@ -8,11 +8,19 @@ defmodule Mobilizon.GraphQL.Error do
   alias Mobilizon.Web.Gettext, as: GettextBackend
   import Mobilizon.Web.Gettext, only: [dgettext: 2]
 
+  @type t :: %{code: atom(), message: String.t(), status_code: pos_integer(), field: atom()}
+
   defstruct [:code, :message, :status_code, :field]
 
+  @type error :: {:error, any()} | {:error, any(), any(), any()} | atom()
+
+  @doc """
+  Normalize an error to return `t`.
+  """
   # Error Tuples
   # ------------
   # Regular errors
+  @spec normalize(error | list(error) | String.t() | any()) :: t()
   def normalize({:error, reason}) do
     handle(reason)
   end

lib/graphql/middleware/current_actor_provider.ex

@@ -0,0 +1,40 @@
+defmodule Mobilizon.GraphQL.Middleware.CurrentActorProvider do
+  @moduledoc """
+  Absinthe Error Handler
+  """
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Users
+  alias Mobilizon.Users.User
+
+  @behaviour Absinthe.Middleware
+
+  @impl Absinthe.Middleware
+  @spec call(Absinthe.Resolution.t(), any) :: Absinthe.Resolution.t()
+  def call(
+        %Absinthe.Resolution{context: %{current_user: %User{id: user_id} = user} = context} =
+          resolution,
+        _config
+      ) do
+    case Cachex.fetch(:default_actors, to_string(user_id), fn -> default(user) end) do
+      {status, %Actor{} = current_actor} when status in [:ok, :commit] ->
+        context = Map.put(context, :current_actor, current_actor)
+        %Absinthe.Resolution{resolution | context: context}
+
+      {_, nil} ->
+        resolution
+    end
+  end
+
+  def call(%Absinthe.Resolution{} = resolution, _config), do: resolution
+
+  @spec default(User.t()) :: {:commit, Actor.t()} | {:ignore, nil}
+  defp default(%User{} = user) do
+    case Users.get_actor_for_user(user) do
+      %Actor{} = actor ->
+        {:commit, actor}
+
+      nil ->
+        {:ignore, nil}
+    end
+  end
+end

lib/graphql/resolvers/activity.ex

@@ -4,7 +4,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Activity do
   """
 
   import Mobilizon.Users.Guards
-  alias Mobilizon.{Activities, Actors, Users}
+  alias Mobilizon.{Activities, Actors}
+  alias Mobilizon.Activities.Activity
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Service.Activity.Utils
   alias Mobilizon.Storage.Page
@@ -12,11 +13,12 @@ defmodule Mobilizon.GraphQL.Resolvers.Activity do
 
   require Logger
 
+  @spec group_activity(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Activity.t())} | {:error, :unauthorized | :unauthenticated}
   def group_activity(%Actor{type: :Group, id: group_id}, %{page: page, limit: limit} = args, %{
-        context: %{current_user: %User{role: role} = user}
+        context: %{current_user: %User{role: role}, current_actor: %Actor{id: actor_id}}
       }) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    if Actors.is_member?(actor_id, group_id) or is_moderator(role) do
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id) or is_moderator(role)} do
       %Page{total: total, elements: elements} =
         Activities.list_group_activities_for_member(
           group_id,
@@ -30,7 +32,6 @@ defmodule Mobilizon.GraphQL.Resolvers.Activity do
 
       {:ok, %Page{total: total, elements: elements}}
     else
-      {:member, false} ->
       {:error, :unauthorized}
     end
   end

lib/graphql/resolvers/actor.ex

@@ -4,15 +4,17 @@ defmodule Mobilizon.GraphQL.Resolvers.Actor do
   """
 
   import Mobilizon.Users.Guards
-  alias Mobilizon.{Actors, Admin, Users}
+  alias Mobilizon.{Actors, Admin}
   alias Mobilizon.Actors.Actor
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
   alias Mobilizon.Service.Workers.Background
   alias Mobilizon.Users.User
   import Mobilizon.Web.Gettext, only: [dgettext: 2]
 
   require Logger
 
+  @spec refresh_profile(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t()}
   def refresh_profile(_parent, %{id: id}, %{context: %{current_user: %User{role: role}}})
       when is_admin(role) do
     case Actors.get_actor(id) do
@@ -31,40 +33,38 @@ defmodule Mobilizon.GraphQL.Resolvers.Actor do
     end
   end
 
+  @spec suspend_profile(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t()}
   def suspend_profile(_parent, %{id: id}, %{
-        context: %{current_user: %User{role: role} = user}
+        context: %{
+          current_user: %User{role: role},
+          current_actor: %Actor{} = moderator_actor
+        }
       })
       when is_moderator(role) do
-    with {:moderator_actor, %Actor{} = moderator_actor} <-
+    case Actors.get_actor_with_preload(id) do
-           {:moderator_actor, Users.get_actor_for_user(user)},
-         %Actor{suspended: false} = actor <- Actors.get_actor_with_preload(id) do
-      case actor do
       # Suspend a group on this instance
-        %Actor{type: :Group, domain: nil} ->
+      %Actor{suspended: false, type: :Group, domain: nil} = actor ->
         Logger.debug("We're suspending a group on this very instance")
-          ActivityPub.delete(actor, moderator_actor, true, %{suspension: true})
+        Actions.Delete.delete(actor, moderator_actor, true, %{suspension: true})
         Admin.log_action(moderator_actor, "suspend", actor)
         {:ok, actor}
 
       # Delete a remote actor
-        %Actor{domain: domain} when not is_nil(domain) ->
+      %Actor{suspended: false, domain: domain} = actor when not is_nil(domain) ->
         Logger.debug("We're just deleting a remote instance")
         Actors.delete_actor(actor, suspension: true)
         Admin.log_action(moderator_actor, "suspend", actor)
         {:ok, actor}
 
-        %Actor{domain: nil} ->
+      %Actor{suspended: false, domain: nil} ->
         {:error, dgettext("errors", "No remote profile found with this ID")}
-      end
-    else
-      {:moderator_actor, nil} ->
-        {:error, dgettext("errors", "No profile found for the moderator user")}
 
       %Actor{suspended: true} ->
         {:error, dgettext("errors", "Profile already suspended")}
 
-      {:error, _} ->
+      nil ->
-        {:error, dgettext("errors", "Error while performing background task")}
+        {:error, dgettext("errors", "Profile not found")}
     end
   end
 
@@ -72,13 +72,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Actor do
     {:error, dgettext("errors", "Only moderators and administrators can suspend a profile")}
   end
 
+  @spec unsuspend_profile(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t()}
   def unsuspend_profile(_parent, %{id: id}, %{
-        context: %{current_user: %User{role: role} = user}
+        context: %{
+          current_user: %User{role: role},
+          current_actor: %Actor{} = moderator_actor
+        }
       })
       when is_moderator(role) do
-    with {:moderator_actor, %Actor{} = moderator_actor} <-
+    with %Actor{suspended: true} = actor <-
-           {:moderator_actor, Users.get_actor_for_user(user)},
-         %Actor{suspended: true} = actor <-
            Actors.get_actor_with_preload(id, true),
          {:delete_tombstones, {_, nil}} <-
            {:delete_tombstones, Mobilizon.Tombstone.delete_actor_tombstones(id)},

lib/graphql/resolvers/admin.ex

@@ -6,14 +6,13 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
   import Mobilizon.Users.Guards
 
   alias Mobilizon.{Actors, Admin, Config, Events}
-  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Actors.{Actor, Follower}
   alias Mobilizon.Admin.{ActionLog, Setting}
   alias Mobilizon.Cldr.Language
   alias Mobilizon.Config
   alias Mobilizon.Discussions.Comment
   alias Mobilizon.Events.Event
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Relay}
-  alias Mobilizon.Federation.ActivityPub.Relay
   alias Mobilizon.Reports.{Note, Report}
   alias Mobilizon.Service.Statistics
   alias Mobilizon.Storage.Page
@@ -21,6 +20,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
   import Mobilizon.Web.Gettext
   require Logger
 
+  @spec list_action_logs(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(ActionLog.t())} | {:error, String.t()}
   def list_action_logs(
         _parent,
         %{page: page, limit: limit},
@@ -38,10 +39,10 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
                          id: id,
                          inserted_at: inserted_at
                        } = action_log ->
-          with data when is_map(data) <-
+          target_type
-                 transform_action_log(String.to_existing_atom(target_type), action, action_log) do
+          |> String.to_existing_atom()
-            Map.merge(data, %{actor: actor, id: id, inserted_at: inserted_at})
+          |> transform_action_log(action, action_log)
-          end
+          |> Map.merge(%{actor: actor, id: id, inserted_at: inserted_at})
         end)
         |> Enum.filter(& &1)
 
@@ -53,6 +54,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
     {:error, dgettext("errors", "You need to be logged-in and a moderator to list action logs")}
   end
 
+  @spec transform_action_log(module(), atom(), ActionLog.t()) :: map()
   defp transform_action_log(
          Report,
          :update,
@@ -123,6 +125,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
   end
 
   # Changes are stored as %{"key" => "value"} so we need to convert them back as struct
+  @spec convert_changes_to_struct(module(), map()) :: struct()
   defp convert_changes_to_struct(struct, %{"report_id" => _report_id} = changes) do
     with data <- for({key, val} <- changes, into: %{}, do: {String.to_existing_atom(key), val}),
          data <- Map.put(data, :report, Mobilizon.Reports.get_report(data.report_id)) do
@@ -143,6 +146,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
   end
 
   # datetimes are not unserialized as DateTime/NaiveDateTime so we do it manually with changeset data
+  @spec process_eventual_type(Ecto.Changeset.t(), String.t(), String.t() | nil) ::
+          DateTime.t() | NaiveDateTime.t() | any()
   defp process_eventual_type(changeset, key, val) do
     cond do
       changeset[String.to_existing_atom(key)] == :utc_datetime and not is_nil(val) ->
@@ -158,6 +163,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
     end
   end
 
+  @spec get_list_of_languages(any(), any(), any()) :: {:ok, String.t()} | {:error, any()}
   def get_list_of_languages(_parent, %{codes: codes}, _resolution) when is_list(codes) do
     locale = Gettext.get_locale()
     locale = if Cldr.known_locale_name?(locale), do: locale, else: "en"
@@ -187,6 +193,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
     end
   end
 
+  @spec get_dashboard(any(), any(), Absinthe.Resolution.t()) ::
+          {:ok, map()} | {:error, String.t()}
   def get_dashboard(_parent, _args, %{context: %{current_user: %User{role: role}}})
       when is_admin(role) do
     last_public_event_published =
@@ -225,6 +233,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
      )}
   end
 
+  @spec get_settings(any(), any(), Absinthe.Resolution.t()) :: {:ok, map()} | {:error, String.t()}
   def get_settings(_parent, _args, %{
         context: %{current_user: %User{role: role}}
       })
@@ -237,6 +246,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
      dgettext("errors", "You need to be logged-in and an administrator to access admin settings")}
   end
 
+  @spec save_settings(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, map()} | {:error, String.t()}
   def save_settings(_parent, args, %{
         context: %{current_user: %User{role: role}}
       })
@@ -261,6 +272,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
      dgettext("errors", "You need to be logged-in and an administrator to save admin settings")}
   end
 
+  @spec list_relay_followers(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Follower.t())} | {:error, :unauthorized | :unauthenticated}
   def list_relay_followers(
         _parent,
         %{page: page, limit: limit},
@@ -283,6 +296,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
     {:error, :unauthenticated}
   end
 
+  @spec list_relay_followings(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Follower.t())} | {:error, :unauthorized | :unauthenticated}
   def list_relay_followings(
         _parent,
         %{page: page, limit: limit},
@@ -305,28 +320,34 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
     {:error, :unauthenticated}
   end
 
+  @spec create_relay(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Follower.t()} | {:error, any()}
   def create_relay(_parent, %{address: address}, %{context: %{current_user: %User{role: role}}})
       when is_admin(role) do
     case Relay.follow(address) do
       {:ok, _activity, follow} ->
         {:ok, follow}
 
-      {:error, err} when is_binary(err) ->
+      {:error, err} ->
         {:error, err}
     end
   end
 
+  @spec remove_relay(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Follower.t()} | {:error, any()}
   def remove_relay(_parent, %{address: address}, %{context: %{current_user: %User{role: role}}})
       when is_admin(role) do
     case Relay.unfollow(address) do
       {:ok, _activity, follow} ->
         {:ok, follow}
 
-      {:error, {:error, err}} when is_binary(err) ->
+      {:error, err} ->
         {:error, err}
     end
   end
 
+  @spec accept_subscription(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Follower.t()} | {:error, any()}
   def accept_subscription(
         _parent,
         %{address: address},
@@ -337,14 +358,13 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
       {:ok, _activity, follow} ->
         {:ok, follow}
 
-      {:error, {:error, err}} when is_binary(err) ->
+      {:error, err} ->
-        {:error, err}
-
-      {:error, err} when is_binary(err) ->
         {:error, err}
     end
   end
 
+  @spec reject_subscription(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Follower.t()} | {:error, any()}
   def reject_subscription(
         _parent,
         %{address: address},
@@ -355,15 +375,12 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
       {:ok, _activity, follow} ->
         {:ok, follow}
 
-      {:error, {:error, err}} when is_binary(err) ->
+      {:error, err} ->
-        {:error, err}
-
-      {:error, err} when is_binary(err) ->
         {:error, err}
     end
   end
 
-  @spec eventually_update_instance_actor(map()) :: :ok
+  @spec eventually_update_instance_actor(map()) :: :ok | {:error, :instance_actor_update_failure}
   defp eventually_update_instance_actor(admin_setting_args) do
     args = %{}
     new_instance_description = Map.get(admin_setting_args, :instance_description)
@@ -385,16 +402,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Admin do
         do: Map.put(args, :name, new_instance_name),
         else: args
 
-    with {:changes, true} <- {:changes, args != %{}},
+    if args != %{} do
-         %Actor{} = instance_actor <- Relay.get_actor(),
+      %Actor{} = instance_actor = Relay.get_actor()
-         {:ok, _activity, _actor} <- ActivityPub.update(instance_actor, args, true) do
+
-      :ok
+      case Actions.Update.update(instance_actor, args, true) do
-    else
+        {:ok, _activity, _actor} ->
-      {:changes, false} ->
           :ok
 
-      err ->
+        {:error, _err} ->
-        err
+          {:error, :instance_actor_update_failure}
+      end
+    else
+      :ok
     end
   end
 end

lib/graphql/resolvers/comment.ex

@@ -3,7 +3,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Comment do
   Handles the comment-related GraphQL calls.
   """
 
-  alias Mobilizon.{Actors, Admin, Discussions, Events, Users}
+  alias Mobilizon.{Actors, Admin, Discussions, Events}
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Discussions.Comment, as: CommentModel
   alias Mobilizon.Events.{Event, EventOptions}
@@ -14,61 +14,78 @@ defmodule Mobilizon.GraphQL.Resolvers.Comment do
 
   require Logger
 
+  @spec get_thread(any(), map(), Absinthe.Resolution.t()) :: {:ok, [CommentModel.t()]}
   def get_thread(_parent, %{id: thread_id}, _context) do
     {:ok, Discussions.get_thread_replies(thread_id)}
   end
 
+  @spec create_comment(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, CommentModel.t()} | {:error, :unauthorized | :not_found | any() | String.t()}
   def create_comment(
         _parent,
         %{event_id: event_id} = args,
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         }
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    case Events.get_event(event_id) do
-         {:find_event,
       {:ok,
        %Event{
          options: %EventOptions{comment_moderation: comment_moderation},
          organizer_actor_id: organizer_actor_id
-           }}} <-
+       }} ->
-           {:find_event, Events.get_event(event_id)},
+        if comment_moderation != :closed || actor_id == organizer_actor_id do
-         {:allowed, true} <-
+          args = Map.put(args, :actor_id, actor_id)
-           {:allowed, comment_moderation != :closed || actor_id == organizer_actor_id},
+
-         args <- Map.put(args, :actor_id, actor_id),
+          case Comments.create_comment(args) do
-         {:ok, _, %CommentModel{} = comment} <-
+            {:ok, _, %CommentModel{} = comment} ->
-           Comments.create_comment(args) do
               {:ok, comment}
-    else
+
             {:error, err} ->
               {:error, err}
-
+          end
-      {:allowed, false} ->
+        else
           {:error, :unauthorized}
         end
+
+      {:error, :event_not_found} ->
+        {:error, :not_found}
+    end
   end
 
   def create_comment(_parent, _args, _context) do
     {:error, dgettext("errors", "You are not allowed to create a comment if not connected")}
   end
 
+  @spec update_comment(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, CommentModel.t()} | {:error, :unauthorized | :not_found | any() | String.t()}
   def update_comment(
         _parent,
         %{text: text, comment_id: comment_id},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         }
       ) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    case Mobilizon.Discussions.get_comment_with_preload(comment_id) do
-         %CommentModel{actor_id: comment_actor_id} = comment <-
+      %CommentModel{actor_id: comment_actor_id} = comment ->
-           Mobilizon.Discussions.get_comment_with_preload(comment_id),
+        if actor_id == comment_actor_id do
-         true <- actor_id === comment_actor_id,
+          case Comments.update_comment(comment, %{text: text}) do
-         {:ok, _, %CommentModel{} = comment} <- Comments.update_comment(comment, %{text: text}) do
+            {:ok, _, %CommentModel{} = comment} ->
               {:ok, comment}
+
+            {:error, err} ->
+              {:error, err}
+          end
+        else
+          {:error, dgettext("errors", "You are not the comment creator")}
+        end
+
+      nil ->
+        {:error, :not_found}
     end
   end
 
@@ -81,13 +98,13 @@ defmodule Mobilizon.GraphQL.Resolvers.Comment do
         %{comment_id: comment_id},
         %{
           context: %{
-            current_user: %User{role: role} = user
+            current_user: %User{role: role},
+            current_actor: %Actor{id: actor_id} = actor
           }
         }
       ) do
-    with {:actor, %Actor{id: actor_id} = actor} <- {:actor, Users.get_actor_for_user(user)},
+    case Discussions.get_comment_with_preload(comment_id) do
-         %CommentModel{deleted_at: nil} = comment <-
+      %CommentModel{deleted_at: nil} = comment ->
-           Discussions.get_comment_with_preload(comment_id) do
         cond do
           {:comment_can_be_managed, true} == CommentModel.can_be_managed_by(comment, actor_id) ->
             do_delete_comment(comment, actor)
@@ -103,9 +120,12 @@ defmodule Mobilizon.GraphQL.Resolvers.Comment do
           true ->
             {:error, dgettext("errors", "You cannot delete this comment")}
         end
-    else
+
       %CommentModel{deleted_at: deleted_at} when not is_nil(deleted_at) ->
         {:error, dgettext("errors", "Comment is already deleted")}
+
+      nil ->
+        {:error, dgettext("errors", "Comment not found")}
     end
   end
 
@@ -113,10 +133,15 @@ defmodule Mobilizon.GraphQL.Resolvers.Comment do
     {:error, dgettext("errors", "You are not allowed to delete a comment if not connected")}
   end
 
+  @spec do_delete_comment(CommentModel.t(), Actor.t()) ::
+          {:ok, CommentModel.t()} | {:error, any()}
   defp do_delete_comment(%CommentModel{} = comment, %Actor{} = actor) do
-    with {:ok, _, %CommentModel{} = comment} <-
+    case Comments.delete_comment(comment, actor) do
-           Comments.delete_comment(comment, actor) do
+      {:ok, _, %CommentModel{} = comment} ->
         {:ok, comment}
+
+      {:error, err} ->
+        {:error, err}
     end
   end
 end

lib/graphql/resolvers/config.ex

@@ -8,6 +8,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Config do
   @doc """
   Gets config.
   """
+  @spec get_config(any(), map(), Absinthe.Resolution.t()) :: {:ok, map()}
   def get_config(_parent, _params, %{context: %{ip: ip}}) do
     geolix = Geolix.lookup(ip)
 
@@ -28,6 +29,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Config do
     {:ok, data}
   end
 
+  @spec terms(any(), map(), Absinthe.Resolution.t()) :: {:ok, map()}
   def terms(_parent, %{locale: locale}, _resolution) do
     type = Config.instance_terms_type()
 
@@ -41,6 +43,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Config do
     {:ok, %{body_html: body_html, type: type, url: url}}
   end
 
+  @spec privacy(any(), map(), Absinthe.Resolution.t()) :: {:ok, map()}
   def privacy(_parent, %{locale: locale}, _resolution) do
     type = Config.instance_privacy_type()
 
@@ -54,6 +57,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Config do
     {:ok, %{body_html: body_html, type: type, url: url}}
   end
 
+  @spec config_cache :: map()
   defp config_cache do
     case Cachex.fetch(:config, "full_config", fn _key ->
            case build_config_cache() do
@@ -62,10 +66,11 @@ defmodule Mobilizon.GraphQL.Resolvers.Config do
            end
          end) do
       {status, value} when status in [:ok, :commit] -> value
-      _err -> nil
+      _err -> %{}
     end
   end
 
+  @spec build_config_cache :: map()
   defp build_config_cache do
     %{
       name: Config.instance_name(),

lib/graphql/resolvers/discussion.ex

@@ -3,26 +3,27 @@ defmodule Mobilizon.GraphQL.Resolvers.Discussion do
   Handles the group-related GraphQL calls.
   """
 
-  alias Mobilizon.{Actors, Discussions, Users}
+  alias Mobilizon.{Actors, Discussions}
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Discussions.{Comment, Discussion}
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
   alias Mobilizon.GraphQL.API.Comments
   alias Mobilizon.Storage.Page
   alias Mobilizon.Users.User
   import Mobilizon.Web.Gettext
 
+  @spec find_discussions_for_actor(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Discussion.t())} | {:error, :unauthenticated}
   def find_discussions_for_actor(
         %Actor{id: group_id},
         %{page: page, limit: limit},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         }
       ) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    with {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          {:ok, %Actor{type: :Group} = group} <- Actors.get_group_by_actor_id(group_id) do
       {:ok, Discussions.find_discussions_for_actor(group, page, limit)}
     else
@@ -31,30 +32,42 @@ defmodule Mobilizon.GraphQL.Resolvers.Discussion do
     end
   end
 
-  def find_discussions_for_actor(%Actor{}, _args, _resolution) do
+  def find_discussions_for_actor(%Actor{}, _args, %{
+        context: %{
+          current_user: %User{}
+        }
+      }) do
     {:ok, %Page{total: 0, elements: []}}
   end
 
+  def find_discussions_for_actor(%Actor{}, _args, _resolution), do: {:error, :unauthenticated}
+
+  @spec get_discussion(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Discussion.t()} | {:error, :unauthorized | :discussion_not_found | String.t()}
   def get_discussion(_parent, %{id: id}, %{
         context: %{
-          current_user: %User{} = user
+          current_actor: %Actor{id: creator_id}
         }
       }) do
-    with {:actor, %Actor{id: creator_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    case Discussions.get_discussion(id) do
-         %Discussion{actor_id: actor_id} = discussion <-
+      %Discussion{actor_id: actor_id} = discussion ->
-           Discussions.get_discussion(id),
+        if Actors.is_member?(creator_id, actor_id) do
-         {:member, true} <- {:member, Actors.is_member?(creator_id, actor_id)} do
           {:ok, discussion}
+        else
+          {:error, :unauthorized}
+        end
+
+      nil ->
+        {:error, :discussion_not_found}
     end
   end
 
   def get_discussion(_parent, %{slug: slug}, %{
         context: %{
-          current_user: %User{} = user
+          current_actor: %Actor{id: creator_id}
         }
       }) do
-    with {:actor, %Actor{id: creator_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    with %Discussion{actor_id: actor_id} = discussion <-
-         %Discussion{actor_id: actor_id} = discussion <-
            Discussions.get_discussion_by_slug(slug),
          {:member, true} <- {:member, Actors.is_member?(creator_id, actor_id)} do
       {:ok, discussion}
@@ -76,6 +89,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Discussion do
   def get_discussion(_parent, _args, _resolution),
     do: {:error, dgettext("errors", "You need to be logged-in to access discussions")}
 
+  @spec get_comments_for_discussion(Discussion.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Discussion.t())}
   def get_comments_for_discussion(
         %Discussion{id: discussion_id},
         %{page: page, limit: limit},
@@ -84,48 +99,54 @@ defmodule Mobilizon.GraphQL.Resolvers.Discussion do
     {:ok, Discussions.get_comments_for_discussion(discussion_id, page, limit)}
   end
 
+  @spec create_discussion(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Discussion.t()}
+          | {:error, Ecto.Changeset.t() | String.t() | :unauthorized | :unauthenticated}
   def create_discussion(
         _parent,
         %{title: title, text: text, actor_id: group_id},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: creator_id}
           }
         }
       ) do
-    with {:actor, %Actor{id: creator_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    if Actors.is_member?(creator_id, group_id) do
-         {:member, true} <- {:member, Actors.is_member?(creator_id, group_id)},
+      case Comments.create_discussion(%{
-         {:ok, _activity, %Discussion{} = discussion} <-
-           Comments.create_discussion(%{
              title: title,
              text: text,
              actor_id: group_id,
              creator_id: creator_id,
              attributed_to_id: group_id
            }) do
+        {:ok, _activity, %Discussion{} = discussion} ->
           {:ok, discussion}
-    else
+
-      {:error, type, err, _} when type in [:discussion, :comment] ->
+        {:error, %Ecto.Changeset{} = err} ->
           {:error, err}
 
-      {:member, false} ->
+        {:error, _err} ->
+          {:error, dgettext("errors", "Error while creating a discussion")}
+      end
+    else
       {:error, :unauthorized}
     end
   end
 
   def create_discussion(_, _, _), do: {:error, :unauthenticated}
 
+  @spec reply_to_discussion(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Discussion.t()} | {:error, :discussion_not_found | :unauthenticated}
   def reply_to_discussion(
         _parent,
         %{text: text, discussion_id: discussion_id},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: creator_id}
           }
         }
       ) do
-    with {:actor, %Actor{id: creator_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    with {:no_discussion,
-         {:no_discussion,
           %Discussion{
             actor_id: actor_id,
             last_comment: %Comment{
@@ -155,22 +176,22 @@ defmodule Mobilizon.GraphQL.Resolvers.Discussion do
 
   def reply_to_discussion(_, _, _), do: {:error, :unauthenticated}
 
-  @spec update_discussion(map(), map(), map()) :: {:ok, Discussion.t()}
+  @spec update_discussion(map(), map(), map()) ::
+          {:ok, Discussion.t()} | {:error, :unauthorized | :unauthenticated}
   def update_discussion(
         _parent,
         %{title: title, discussion_id: discussion_id},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: creator_id}
           }
         }
       ) do
-    with {:actor, %Actor{id: creator_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    with {:no_discussion, %Discussion{actor_id: actor_id} = discussion} <-
-         {:no_discussion, %Discussion{actor_id: actor_id} = discussion} <-
            {:no_discussion, Discussions.get_discussion(discussion_id)},
          {:member, true} <- {:member, Actors.is_member?(creator_id, actor_id)},
          {:ok, _activity, %Discussion{} = discussion} <-
-           ActivityPub.update(
+           Actions.Update.update(
              discussion,
              %{
                title: title
@@ -185,17 +206,19 @@ defmodule Mobilizon.GraphQL.Resolvers.Discussion do
 
   def update_discussion(_, _, _), do: {:error, :unauthenticated}
 
+  @spec delete_discussion(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Discussion.t()} | {:error, String.t() | :unauthorized | :unauthenticated}
   def delete_discussion(_parent, %{discussion_id: discussion_id}, %{
         context: %{
-          current_user: %User{} = user
+          current_user: %User{},
+          current_actor: %Actor{id: creator_id} = actor
         }
       }) do
-    with {:actor, %Actor{id: creator_id} = actor} <- {:actor, Users.get_actor_for_user(user)},
+    with {:no_discussion, %Discussion{actor_id: actor_id} = discussion} <-
-         {:no_discussion, %Discussion{actor_id: actor_id} = discussion} <-
            {:no_discussion, Discussions.get_discussion(discussion_id)},
          {:member, true} <- {:member, Actors.is_member?(creator_id, actor_id)},
          {:ok, _activity, %Discussion{} = discussion} <-
-           ActivityPub.delete(discussion, actor) do
+           Actions.Delete.delete(discussion, actor) do
       {:ok, discussion}
     else
       {:no_discussion, _} ->

lib/graphql/resolvers/event.ex

@@ -3,7 +3,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
   Handles the event-related GraphQL calls.
   """
 
-  alias Mobilizon.{Actors, Admin, Events, Users}
+  alias Mobilizon.{Actors, Admin, Events}
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Config
   alias Mobilizon.Events.{Event, EventParticipantStats}
@@ -21,14 +21,17 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
   @event_max_limit 100
   @number_of_related_events 3
 
+  @spec organizer_for_event(Event.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t() | nil} | {:error, String.t()}
   def organizer_for_event(
         %Event{attributed_to_id: attributed_to_id, organizer_actor_id: organizer_actor_id},
         _args,
-        %{context: %{current_user: %User{role: user_role} = user}} = _resolution
+        %{
+          context: %{current_user: %User{role: user_role}, current_actor: %Actor{id: actor_id}}
+        } = _resolution
       )
       when not is_nil(attributed_to_id) do
     with %Actor{id: group_id} <- Actors.get_actor(attributed_to_id),
-         %Actor{id: actor_id} <- Users.get_actor_for_user(user),
          {:member, true} <-
            {:member, Actors.is_member?(actor_id, group_id) or is_moderator(user_role)},
          %Actor{} = actor <- Actors.get_actor(organizer_actor_id) do
@@ -61,6 +64,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
     end
   end
 
+  @spec list_events(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Event.t())} | {:error, :events_max_limit_reached}
   def list_events(
         _parent,
         %{page: page, limit: limit, order_by: order_by, direction: direction},
@@ -74,13 +79,13 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
     {:error, :events_max_limit_reached}
   end
 
+  @spec find_private_event(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Event.t()} | {:error, :event_not_found}
   defp find_private_event(
          _parent,
          %{uuid: uuid},
-         %{context: %{current_user: %User{} = user}} = _resolution
+         %{context: %{current_actor: %Actor{} = profile}} = _resolution
        ) do
-    %Actor{} = profile = Users.get_actor_for_user(user)
-
     case Events.get_event_by_uuid_with_preload(uuid) do
       # Event attributed to group
       %Event{attributed_to: %Actor{}} = event ->
@@ -107,6 +112,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
     {:error, :event_not_found}
   end
 
+  @spec find_event(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Event.t()} | {:error, :event_not_found}
   def find_event(parent, %{uuid: uuid} = args, %{context: context} = resolution) do
     with {:has_event, %Event{} = event} <-
            {:has_event, Events.get_public_event_by_uuid_with_preload(uuid)},
@@ -133,15 +140,15 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
   @doc """
   List participants for event (through an event request)
   """
+  @spec list_participants_for_event(Event.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Participant.t())} | {:error, String.t()}
   def list_participants_for_event(
         %Event{id: event_id} = event,
         %{page: page, limit: limit, roles: roles},
-        %{context: %{current_user: %User{} = user}} = _resolution
+        %{context: %{current_actor: %Actor{} = actor}} = _resolution
       ) do
-    with %Actor{} = actor <- Users.get_actor_for_user(user),
     # Check that moderator has right
-         {:event_can_be_managed, true} <-
+    if can_event_be_updated_by?(event, actor) do
-           {:event_can_be_managed, can_event_be_updated_by?(event, actor)} do
       roles =
         case roles do
           nil ->
@@ -160,7 +167,6 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
       participants = Events.list_participants_for_event(event_id, roles, page, limit)
       {:ok, participants}
     else
-      {:event_can_be_managed, _} ->
       {:error,
        dgettext("errors", "Provided profile doesn't have moderator permissions on this event")}
     end
@@ -170,6 +176,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
     {:ok, %{total: 0, elements: []}}
   end
 
+  @spec stats_participants(Event.t(), map(), Absinthe.Resolution.t()) :: {:ok, map()}
   def stats_participants(
         %Event{participant_stats: %EventParticipantStats{} = stats, id: event_id} = _event,
         _args,
@@ -202,6 +209,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
   @doc """
   List related events
   """
+  @spec list_related_events(Event.t(), map(), Absinthe.Resolution.t()) :: {:ok, list(Event.t())}
   def list_related_events(
         %Event{tags: tags, organizer_actor: organizer_actor, uuid: uuid},
         _args,
@@ -243,11 +251,14 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
     {:ok, events}
   end
 
+  @spec uniq_events(list(Event.t())) :: list(Event.t())
   defp uniq_events(events), do: Enum.uniq_by(events, fn event -> event.uuid end)
 
   @doc """
   Create an event
   """
+  @spec create_event(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Event.t()} | {:error, String.t() | Ecto.Changeset.t()}
   def create_event(
         _parent,
         %{organizer_actor_id: organizer_actor_id} = args,
@@ -287,15 +298,17 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
   @doc """
   Update an event
   """
+  @spec update_event(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Event.t()} | {:error, String.t() | Ecto.Changeset.t()}
   def update_event(
         _parent,
         %{event_id: event_id} = args,
-        %{context: %{current_user: %User{} = user}} = _resolution
+        %{context: %{current_user: %User{} = user, current_actor: %Actor{} = actor}} = _resolution
       ) do
     # See https://github.com/absinthe-graphql/absinthe/issues/490
-    with args <- Map.put(args, :options, args[:options] || %{}),
+    args = Map.put(args, :options, args[:options] || %{})
-         {:ok, %Event{} = event} <- Events.get_event_with_preload(event_id),
+
-         %Actor{} = actor <- Users.get_actor_for_user(user),
+    with {:ok, %Event{} = event} <- Events.get_event_with_preload(event_id),
          {:ok, args} <- verify_profile_change(args, event, user, actor),
          {:event_can_be_managed, true} <-
            {:event_can_be_managed, can_event_be_updated_by?(event, actor)},
@@ -319,7 +332,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
       {:new_actor, _} ->
         {:error, dgettext("errors", "You can't attribute this event to this profile.")}
 
-      {:error, _, %Ecto.Changeset{} = error, _} ->
+      {:error, %Ecto.Changeset{} = error} ->
         {:error, error}
     end
   end
@@ -331,13 +344,20 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
   @doc """
   Delete an event
   """
+  @spec delete_event(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Event.t()} | {:error, String.t() | Ecto.Changeset.t()}
   def delete_event(
         _parent,
         %{event_id: event_id},
-        %{context: %{current_user: %User{role: role} = user}}
+        %{
+          context: %{
+            current_user: %User{role: role},
+            current_actor: %Actor{id: actor_id} = actor
+          }
+        }
       ) do
-    with {:ok, %Event{local: is_local} = event} <- Events.get_event_with_preload(event_id),
+    case Events.get_event_with_preload(event_id) do
-         %Actor{id: actor_id} = actor <- Users.get_actor_for_user(user) do
+      {:ok, %Event{local: is_local} = event} ->
         cond do
           {:event_can_be_managed, true} ==
               {:event_can_be_managed, can_event_be_deleted_by?(event, actor)} ->
@@ -354,7 +374,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
           true ->
             {:error, dgettext("errors", "You cannot delete this event")}
         end
-    else
+
       {:error, :event_not_found} ->
         {:error, dgettext("errors", "Event not found")}
     end
@@ -364,6 +384,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
     {:error, dgettext("errors", "You need to be logged-in to delete an event")}
   end
 
+  @spec do_delete_event(Event.t(), Actor.t(), boolean()) :: {:ok, map()}
   defp do_delete_event(%Event{} = event, %Actor{} = actor, federate \\ true)
        when is_boolean(federate) do
     with {:ok, _activity, event} <- API.Events.delete_event(event, actor) do
@@ -371,6 +392,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
     end
   end
 
+  @spec is_organizer_group_member?(map()) :: boolean()
   defp is_organizer_group_member?(%{
          attributed_to_id: attributed_to_id,
          organizer_actor_id: organizer_actor_id
@@ -382,6 +404,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Event do
 
   defp is_organizer_group_member?(_), do: true
 
+  @spec verify_profile_change(map(), Event.t(), User.t(), Actor.t()) :: {:ok, map()}
   defp verify_profile_change(
          args,
          %Event{attributed_to: %Actor{}},

lib/graphql/resolvers/event/utils.ex

@@ -6,7 +6,10 @@ defmodule Mobilizon.GraphQL.Resolvers.Event.Utils do
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Events.Event
   alias Mobilizon.Federation.ActivityPub.Permission
+  import Mobilizon.Service.Guards, only: [is_valid_string: 1]
 
+  @spec can_event_be_updated_by?(%Event{id: String.t()}, Actor.t()) ::
+          boolean
   def can_event_be_updated_by?(
         %Event{attributed_to: %Actor{type: :Group}} = event,
         %Actor{} = actor_member
@@ -21,10 +24,13 @@ defmodule Mobilizon.GraphQL.Resolvers.Event.Utils do
     Event.can_be_managed_by?(event, actor_member_id)
   end
 
+  @spec can_event_be_deleted_by?(%Event{id: String.t(), url: String.t()}, Actor.t()) ::
+          boolean
   def can_event_be_deleted_by?(
-        %Event{attributed_to: %Actor{type: :Group}} = event,
+        %Event{attributed_to: %Actor{type: :Group}, id: event_id, url: event_url} = event,
         %Actor{} = actor_member
-      ) do
+      )
+      when is_valid_string(event_id) and is_valid_string(event_url) do
     Permission.can_delete_group_object?(actor_member, event)
   end
 

lib/graphql/resolvers/followers.ex

@@ -4,9 +4,9 @@ defmodule Mobilizon.GraphQL.Resolvers.Followers do
   """
 
   import Mobilizon.Users.Guards
-  alias Mobilizon.{Actors, Users}
+  alias Mobilizon.Actors
   alias Mobilizon.Actors.{Actor, Follower}
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
   alias Mobilizon.Storage.Page
   alias Mobilizon.Users.User
 
@@ -16,17 +16,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Followers do
         %{page: page, limit: limit} = args,
         %{
           context: %{
-            current_user: %User{role: user_role} = user
+            current_user: %User{role: user_role},
+            current_actor: %Actor{id: actor_id}
           }
         }
       ) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    if Actors.is_moderator?(actor_id, group_id) or is_moderator(user_role) do
-         {:member, true} <-
-           {:member, Actors.is_moderator?(actor_id, group_id) or is_moderator(user_role)} do
       {:ok,
        Actors.list_paginated_followers_for_actor(group, Map.get(args, :approved), page, limit)}
     else
-      _ -> {:error, :unauthorized}
+      {:error, :unauthorized}
     end
   end
 
@@ -35,19 +34,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Followers do
   @spec update_follower(any(), map(), map()) :: {:ok, Follower.t()} | {:error, any()}
   def update_follower(_, %{id: follower_id, approved: approved}, %{
         context: %{
-          current_user: %User{} = user
+          current_actor: %Actor{id: actor_id}
         }
       }) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    with %Follower{target_actor: %Actor{type: :Group, id: group_id}} = follower <-
-         %Follower{target_actor: %Actor{type: :Group, id: group_id}} = follower <-
            Actors.get_follower(follower_id),
          {:member, true} <-
            {:member, Actors.is_moderator?(actor_id, group_id)},
          {:ok, _activity, %Follower{} = follower} <-
            (if approved do
-              ActivityPub.accept(:follow, follower)
+              Actions.Accept.accept(:follow, follower)
             else
-              ActivityPub.reject(:follow, follower)
+              Actions.Reject.reject(:follow, follower)
             end) do
       {:ok, follower}
     else

lib/graphql/resolvers/group.ex

@@ -4,9 +4,9 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
   """
 
   import Mobilizon.Users.Guards
-  alias Mobilizon.{Actors, Events, Users}
+  alias Mobilizon.{Actors, Events}
   alias Mobilizon.Actors.{Actor, Member}
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
   alias Mobilizon.GraphQL.API
   alias Mobilizon.Users.User
@@ -15,6 +15,12 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
 
   require Logger
 
+  @spec find_group(
+          any,
+          %{:preferred_username => binary, optional(any) => any},
+          Absinthe.Resolution.t()
+        ) ::
+          {:error, :group_not_found} | {:ok, Actor.t()}
   @doc """
   Find a group
   """
@@ -23,34 +29,30 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
         %{preferred_username: name} = args,
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         }
       ) do
-    with {:group, {:ok, %Actor{id: group_id, suspended: false} = group}} <-
+    case ActivityPubActor.find_or_make_group_from_nickname(name) do
-           {:group, ActivityPubActor.find_or_make_group_from_nickname(name)},
+      {:ok, %Actor{id: group_id, suspended: false} = group} ->
-         {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+        if Actors.is_member?(actor_id, group_id) do
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)} do
           {:ok, group}
         else
-      {:member, false} ->
           find_group(parent, args, nil)
+        end
 
-      {:group, _} ->
+      {:error, _err} ->
         {:error, :group_not_found}
-
-      _ ->
-        {:error, :unknown}
     end
   end
 
   def find_group(_parent, %{preferred_username: name}, _resolution) do
-    with {:ok, %Actor{suspended: false} = actor} <-
+    case ActivityPubActor.find_or_make_group_from_nickname(name) do
-           ActivityPubActor.find_or_make_group_from_nickname(name),
+      {:ok, %Actor{suspended: false} = actor} ->
-         %Actor{} = actor <- restrict_fields_for_non_member_request(actor) do
+        %Actor{} = actor = restrict_fields_for_non_member_request(actor)
         {:ok, actor}
-    else
+
-      _ ->
+      {:error, _err} ->
         {:error, :group_not_found}
     end
   end
@@ -58,13 +60,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
   @doc """
   Get a group
   """
+  @spec get_group(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t()}
   def get_group(_parent, %{id: id}, %{context: %{current_user: %User{role: role}}}) do
-    with %Actor{type: :Group, suspended: suspended} = actor <-
+    case Actors.get_actor_with_preload(id, true) do
-           Actors.get_actor_with_preload(id, true),
+      %Actor{type: :Group, suspended: suspended} = actor ->
-         true <- suspended == false or is_moderator(role) do
+        if suspended == false or is_moderator(role) do
           {:ok, actor}
         else
-      _ ->
+          {:error, dgettext("errors", "Group with ID %{id} not found", id: id)}
+        end
+
+      nil ->
         {:error, dgettext("errors", "Group with ID %{id} not found", id: id)}
     end
   end
@@ -72,6 +79,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
   @doc """
   Lists all groups
   """
+  @spec list_groups(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Actor.t())} | {:error, String.t()}
   def list_groups(
         _parent,
         %{
@@ -96,6 +105,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
     do: {:error, dgettext("errors", "You may not list groups unless moderator.")}
 
   # TODO Move me to somewhere cleaner
+  @spec save_attached_pictures(map()) :: map()
   defp save_attached_pictures(args) do
     Enum.reduce([:avatar, :banner], args, fn key, args ->
       if is_map(args) && Map.has_key?(args, key) && !is_nil(args[key][:media]) do
@@ -114,17 +124,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
   @doc """
   Create a new group. The creator is automatically added as admin
   """
+  @spec create_group(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t()}
   def create_group(
         _parent,
         args,
         %{
           context: %{
-            current_user: user
+            current_actor: %Actor{id: creator_actor_id} = creator_actor
           }
         }
       ) do
-    with %Actor{id: creator_actor_id} = creator_actor <- Users.get_actor_for_user(user),
+    with args when is_map(args) <- Map.update(args, :preferred_username, "", &String.downcase/1),
-         args when is_map(args) <- Map.update(args, :preferred_username, "", &String.downcase/1),
          args when is_map(args) <- Map.put(args, :creator_actor, creator_actor),
          args when is_map(args) <- Map.put(args, :creator_actor_id, creator_actor_id),
          {:picture, args} when is_map(args) <- {:picture, save_attached_pictures(args)},
@@ -147,31 +158,34 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
   @doc """
   Update a group. The creator is automatically added as admin
   """
+  @spec update_group(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t()}
   def update_group(
         _parent,
         %{id: group_id} = args,
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{} = updater_actor
           }
         }
       ) do
-    with %Actor{} = updater_actor <- Users.get_actor_for_user(user),
+    if Actors.is_administrator?(updater_actor.id, group_id) do
-         {:administrator, true} <-
+      args = Map.put(args, :updater_actor, updater_actor)
-           {:administrator, Actors.is_administrator?(updater_actor.id, group_id)},
+
-         args when is_map(args) <- Map.put(args, :updater_actor, updater_actor),
+      case save_attached_pictures(args) do
-         {:picture, args} when is_map(args) <- {:picture, save_attached_pictures(args)},
+        {:error, :file_too_large} ->
-         {:ok, _activity, %Actor{type: :Group} = group} <-
-           API.Groups.update_group(args) do
-      {:ok, group}
-    else
-      {:picture, {:error, :file_too_large}} ->
           {:error, dgettext("errors", "The provided picture is too heavy")}
 
-      {:error, err} when is_binary(err) ->
+        map when is_map(map) ->
-        {:error, err}
+          case API.Groups.update_group(args) do
+            {:ok, _activity, %Actor{type: :Group} = group} ->
+              {:ok, group}
 
-      {:administrator, false} ->
+            {:error, _err} ->
+              {:error, dgettext("errors", "Failed to update the group")}
+          end
+      end
+    else
       {:error, dgettext("errors", "Profile is not administrator for the group")}
     end
   end
@@ -183,20 +197,21 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
   @doc """
   Delete an existing group
   """
+  @spec delete_group(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, %{id: integer()}} | {:error, String.t()}
   def delete_group(
         _parent,
         %{group_id: group_id},
         %{
           context: %{
-            current_user: user
+            current_actor: %Actor{id: actor_id} = actor
           }
         }
       ) do
-    with %Actor{id: actor_id} = actor <- Users.get_actor_for_user(user),
+    with {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
          {:ok, %Member{} = member} <- Actors.get_member(actor_id, group.id),
          {:is_admin, true} <- {:is_admin, Member.is_administrator(member)},
-         {:ok, _activity, group} <- ActivityPub.delete(group, actor, true) do
+         {:ok, _activity, group} <- Actions.Delete.delete(group, actor, true) do
       {:ok, %{id: group.id}}
     else
       {:error, :group_not_found} ->
@@ -218,16 +233,17 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
   @doc """
   Join an existing group
   """
+  @spec join_group(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Member.t()} | {:error, String.t()}
   def join_group(_parent, %{group_id: group_id} = args, %{
-        context: %{current_user: %User{} = user}
+        context: %{current_actor: %Actor{} = actor}
       }) do
-    with %Actor{} = actor <- Users.get_actor_for_user(user),
+    with {:ok, %Actor{type: :Group} = group} <-
-         {:ok, %Actor{type: :Group} = group} <-
            Actors.get_group_by_actor_id(group_id),
          {:error, :member_not_found} <- Actors.get_member(actor.id, group.id),
          {:is_able_to_join, true} <- {:is_able_to_join, Member.can_be_joined(group)},
          {:ok, _activity, %Member{} = member} <-
-           ActivityPub.join(group, actor, true, args) do
+           Actions.Join.join(group, actor, true, args) do
       {:ok, member}
     else
       {:error, :group_not_found} ->
@@ -248,18 +264,20 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
   @doc """
   Leave a existing group
   """
+  @spec leave_group(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Member.t()} | {:error, String.t()}
   def leave_group(
         _parent,
         %{group_id: group_id},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{} = actor
           }
         }
       ) do
-    with {:actor, %Actor{} = actor} <- {:actor, Users.get_actor_for_user(user)},
+    with {:group, %Actor{type: :Group} = group} <- {:group, Actors.get_actor(group_id)},
-         {:group, %Actor{type: :Group} = group} <- {:group, Actors.get_actor(group_id)},
+         {:ok, _activity, %Member{} = member} <-
-         {:ok, _activity, %Member{} = member} <- ActivityPub.leave(group, actor, true) do
+           Actions.Leave.leave(group, actor, true) do
       {:ok, member}
     else
       {:error, :member_not_found} ->
@@ -268,7 +286,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
       {:group, nil} ->
         {:error, dgettext("errors", "Group not found")}
 
-      {:is_not_only_admin, false} ->
+      {:error, :is_not_only_admin} ->
         {:error,
          dgettext("errors", "You can't leave this group because you are the only administrator")}
     end
@@ -278,6 +296,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
     {:error, dgettext("errors", "You need to be logged-in to leave a group")}
   end
 
+  @spec find_events_for_group(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Event.t())}
   def find_events_for_group(
         %Actor{id: group_id} = group,
         %{
@@ -286,13 +306,12 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
         } = args,
         %{
           context: %{
-            current_user: %User{role: user_role} = user
+            current_user: %User{role: user_role},
+            current_actor: %Actor{id: actor_id}
           }
         }
       ) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    if Actors.is_member?(actor_id, group_id) or is_moderator(user_role) do
-         {:member, true} <-
-           {:member, Actors.is_member?(actor_id, group_id) or is_moderator(user_role)} do
       # TODO : Handle public / restricted to group members events
       {:ok,
        Events.list_organized_events_for_group(
@@ -304,7 +323,6 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
          limit
        )}
     else
-      {:member, false} ->
       find_events_for_group(group, args, nil)
     end
   end
@@ -328,16 +346,15 @@ defmodule Mobilizon.GraphQL.Resolvers.Group do
      )}
   end
 
+  @spec restrict_fields_for_non_member_request(Actor.t()) :: Actor.t()
   defp restrict_fields_for_non_member_request(%Actor{} = group) do
-    Map.merge(
+    %Actor{
-      group,
+      group
-      %{
+      | followers: [],
-        followers: [],
         followings: [],
         organized_events: [],
         comments: [],
         feed_tokens: []
     }
-    )
   end
 end

lib/graphql/resolvers/media.ex

@@ -4,7 +4,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Media do
   """
 
   alias Mobilizon.Actors.Actor
-  alias Mobilizon.{Medias, Users}
+  alias Mobilizon.Medias
   alias Mobilizon.Medias.Media
   alias Mobilizon.Users.User
   import Mobilizon.Web.Gettext
@@ -44,10 +44,9 @@ defmodule Mobilizon.GraphQL.Resolvers.Media do
   def upload_media(
         _parent,
         %{file: %Plug.Upload{} = file} = args,
-        %{context: %{current_user: %User{} = user}}
+        %{context: %{current_actor: %Actor{id: actor_id}}}
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    with {:ok,
-         {:ok,
           %{
             name: _name,
             url: url,
@@ -94,6 +93,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Media do
     else
       {:media, nil} -> {:error, :not_found}
       {:is_owned, _} -> {:error, :unauthorized}
+      {:error, :enofile} -> {:error, "File not found"}
     end
   end
 

lib/graphql/resolvers/member.ex

@@ -4,9 +4,9 @@ defmodule Mobilizon.GraphQL.Resolvers.Member do
   """
 
   import Mobilizon.Users.Guards
-  alias Mobilizon.{Actors, Users}
+  alias Mobilizon.Actors
   alias Mobilizon.Actors.{Actor, Member}
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
   alias Mobilizon.Storage.Page
   alias Mobilizon.Users.User
@@ -17,16 +17,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Member do
 
   If actor requesting is not part of the group, we only return the number of members, not members
   """
+  @spec find_members_for_group(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Member.t())}
   def find_members_for_group(
         %Actor{id: group_id} = group,
         %{page: page, limit: limit, roles: roles},
         %{
-          context: %{current_user: %User{role: user_role} = user}
+          context: %{current_user: %User{role: user_role}, current_actor: %Actor{id: actor_id}}
         } = _resolution
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    if Actors.is_member?(actor_id, group_id) or is_moderator(user_role) do
-         {:member, true} <-
-           {:member, Actors.is_member?(actor_id, group_id) or is_moderator(user_role)} do
       roles =
         case roles do
           "" ->
@@ -42,27 +42,25 @@ defmodule Mobilizon.GraphQL.Resolvers.Member do
       %Page{} = page = Actors.list_members_for_group(group, roles, page, limit)
       {:ok, page}
     else
-      {:member, false} ->
       # Actor is not member of group, fallback to public
-        with %Page{} = page <- Actors.list_members_for_group(group) do
+      %Page{} = page = Actors.list_members_for_group(group)
       {:ok, %Page{page | elements: []}}
     end
   end
-  end
 
   def find_members_for_group(%Actor{} = group, _args, _resolution) do
-    with %Page{} = page <- Actors.list_members_for_group(group) do
+    %Page{} = page = Actors.list_members_for_group(group)
     {:ok, %Page{page | elements: []}}
   end
-  end
 
+  @spec invite_member(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Member.t()} | {:error, String.t()}
   def invite_member(
         _parent,
         %{group_id: group_id, target_actor_username: target_actor_username},
-        %{context: %{current_user: %User{} = user}}
+        %{context: %{current_actor: %Actor{id: actor_id} = actor}}
       ) do
-    with %Actor{id: actor_id} = actor <- Users.get_actor_for_user(user),
+    with {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
-         {:ok, %Actor{} = group} <- Actors.get_group_by_actor_id(group_id),
          {:has_rights_to_invite, {:ok, %Member{role: role}}}
          when role in [:moderator, :administrator, :creator] <-
            {:has_rights_to_invite, Actors.get_member(actor_id, group_id)},
@@ -73,7 +71,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Member do
             ActivityPubActor.find_or_make_actor_from_nickname(target_actor_username)},
          {:existant, true} <-
            {:existant, check_member_not_existant_or_rejected(target_actor_id, group.id)},
-         {:ok, _activity, %Member{} = member} <- ActivityPub.invite(group, actor, target_actor) do
+         {:ok, _activity, %Member{} = member} <-
+           Actions.Invite.invite(group, actor, target_actor) do
       {:ok, member}
     else
       {:error, :group_not_found} ->
@@ -97,13 +96,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Member do
     end
   end
 
-  def accept_invitation(_parent, %{id: member_id}, %{context: %{current_user: %User{} = user}}) do
+  @spec accept_invitation(any(), map(), Absinthe.Resolution.t()) ::
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+          {:ok, Member.t()} | {:error, String.t()}
-         %Member{actor: %Actor{id: member_actor_id}} = member <-
+  def accept_invitation(_parent, %{id: member_id}, %{
+        context: %{current_actor: %Actor{id: actor_id}}
+      }) do
+    with %Member{actor: %Actor{id: member_actor_id}} = member <-
            Actors.get_member(member_id),
-         {:is_same_actor, true} <- {:is_same_actor, member_actor_id === actor_id},
+         {:is_same_actor, true} <- {:is_same_actor, member_actor_id == actor_id},
          {:ok, _activity, %Member{} = member} <-
-           ActivityPub.accept(
+           Actions.Accept.accept(
              :invite,
              member,
              true
@@ -115,13 +117,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Member do
     end
   end
 
-  def reject_invitation(_parent, %{id: member_id}, %{context: %{current_user: %User{} = user}}) do
+  @spec reject_invitation(any(), map(), Absinthe.Resolution.t()) ::
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+          {:ok, Member.t()} | {:error, String.t()}
-         {:invitation_exists, %Member{actor: %Actor{id: member_actor_id}} = member} <-
+  def reject_invitation(_parent, %{id: member_id}, %{
+        context: %{current_actor: %Actor{id: actor_id}}
+      }) do
+    with {:invitation_exists, %Member{actor: %Actor{id: member_actor_id}} = member} <-
            {:invitation_exists, Actors.get_member(member_id)},
-         {:is_same_actor, true} <- {:is_same_actor, member_actor_id === actor_id},
+         {:is_same_actor, true} <- {:is_same_actor, member_actor_id == actor_id},
          {:ok, _activity, %Member{} = member} <-
-           ActivityPub.reject(
+           Actions.Reject.reject(
              :invite,
              member,
              true
@@ -136,19 +141,20 @@ defmodule Mobilizon.GraphQL.Resolvers.Member do
     end
   end
 
+  @spec update_member(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Member.t()} | {:error, String.t()}
   def update_member(_parent, %{member_id: member_id, role: role}, %{
-        context: %{current_user: %User{} = user}
+        context: %{current_actor: %Actor{} = moderator}
       }) do
-    with %Actor{} = moderator <- Users.get_actor_for_user(user),
+    with %Member{} = member <- Actors.get_member(member_id),
-         %Member{} = member <- Actors.get_member(member_id),
          {:ok, _activity, %Member{} = member} <-
-           ActivityPub.update(member, %{role: role}, true, %{moderator: moderator}) do
+           Actions.Update.update(member, %{role: role}, true, %{moderator: moderator}) do
       {:ok, member}
     else
-      {:has_rights_to_update_role, {:error, :member_not_found}} ->
+      {:error, :member_not_found} ->
         {:error, dgettext("errors", "You are not a moderator or admin for this group")}
 
-      {:is_only_admin, true} ->
+      {:error, :only_admin_left} ->
         {:error,
          dgettext(
            "errors",
@@ -160,16 +166,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Member do
   def update_member(_parent, _args, _resolution),
     do: {:error, "You must be logged-in to update a member"}
 
+  @spec remove_member(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Member.t()} | {:error, String.t()}
   def remove_member(_parent, %{member_id: member_id, group_id: group_id}, %{
-        context: %{current_user: %User{} = user}
+        context: %{current_actor: %Actor{id: moderator_id} = moderator}
       }) do
-    with %Actor{id: moderator_id} = moderator <- Users.get_actor_for_user(user),
+    with %Member{role: role} = member when role != :rejected <- Actors.get_member(member_id),
-         %Member{role: role} = member when role != :rejected <- Actors.get_member(member_id),
          %Actor{type: :Group} = group <- Actors.get_actor(group_id),
          {:has_rights_to_remove, {:ok, %Member{role: role}}}
          when role in [:moderator, :administrator, :creator] <-
            {:has_rights_to_remove, Actors.get_member(moderator_id, group_id)},
-         {:ok, _activity, %Member{}} <- ActivityPub.remove(member, group, moderator, true) do
+         {:ok, _activity, %Member{}} <-
+           Actions.Remove.remove(member, group, moderator, true) do
       {:ok, member}
     else
       %Member{role: :rejected} ->

lib/graphql/resolvers/participant.ex

@@ -2,7 +2,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Participant do
   @moduledoc """
   Handles the participation-related GraphQL calls.
   """
-  alias Mobilizon.{Actors, Config, Crypto, Events, Users}
+  alias Mobilizon.{Actors, Config, Crypto, Events}
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Events.{Event, Participant}
   alias Mobilizon.GraphQL.API.Participations
@@ -16,6 +16,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Participant do
   @doc """
   Join an event for an regular or anonymous actor
   """
+  @spec actor_join_event(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Participant.t()} | {:error, String.t()}
   def actor_join_event(
         _parent,
         %{actor_id: actor_id, event_id: event_id} = args,
@@ -117,7 +119,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Participant do
            |> Map.put(:actor, actor) do
       {:ok, participant}
     else
-      {:maximum_attendee_capacity, _} ->
+      {:error, :maximum_attendee_capacity_reached} ->
         {:error, dgettext("errors", "The event has already reached its maximum capacity")}
 
       {:has_event, _} ->
@@ -127,39 +129,53 @@ defmodule Mobilizon.GraphQL.Resolvers.Participant do
       {:error, :event_not_found} ->
         {:error, dgettext("errors", "Event id not found")}
 
-      {:ok, %Participant{}} ->
+      {:error, :already_participant} ->
         {:error, dgettext("errors", "You are already a participant of this event")}
     end
   end
 
+  @spec check_anonymous_participation(String.t(), String.t()) ::
+          {:ok, Event.t()} | {:error, String.t()}
+  defp check_anonymous_participation(actor_id, event_id) do
+    cond do
+      Config.anonymous_participation?() == false ->
+        {:error, dgettext("errors", "Anonymous participation is not enabled")}
+
+      to_string(Config.anonymous_actor_id()) != actor_id ->
+        {:error, dgettext("errors", "The anonymous actor ID is invalid")}
+
+      true ->
+        case Mobilizon.Events.get_event_with_preload(event_id) do
+          {:ok, %Event{} = event} ->
+            {:ok, event}
+
+          {:error, :event_not_found} ->
+            {:error,
+             dgettext("errors", "Event with this ID %{id} doesn't exist", id: inspect(event_id))}
+        end
+    end
+  end
+
   @doc """
   Leave an event for an anonymous actor
   """
+  @spec actor_leave_event(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, map()} | {:error, String.t()}
   def actor_leave_event(
         _parent,
         %{actor_id: actor_id, event_id: event_id, token: token},
         _resolution
       )
       when not is_nil(token) do
-    with {:anonymous_participation_enabled, true} <-
+    case check_anonymous_participation(actor_id, event_id) do
-           {:anonymous_participation_enabled, Config.anonymous_participation?()},
+      {:ok, %Event{} = event} ->
-         {:anonymous_actor_id, true} <-
+        %Actor{} = actor = Actors.get_actor_with_preload!(actor_id)
-           {:anonymous_actor_id, to_string(Config.anonymous_actor_id()) == actor_id},
+
-         {:has_event, {:ok, %Event{} = event}} <-
+        case Participations.leave(event, actor, %{local: false, cancellation_token: token}) do
-           {:has_event, Mobilizon.Events.get_event_with_preload(event_id)},
+          {:ok, _activity, %Participant{id: participant_id} = _participant} ->
-         %Actor{} = actor <- Actors.get_actor_with_preload(actor_id),
-         {:ok, _activity, %Participant{id: participant_id} = _participant} <-
-           Participations.leave(event, actor, %{local: false, cancellation_token: token}) do
             {:ok, %{event: %{id: event_id}, actor: %{id: actor_id}, id: participant_id}}
-    else
-      {:has_event, _} ->
-        {:error,
-         dgettext("errors", "Event with this ID %{id} doesn't exist", id: inspect(event_id))}
 
-      {:is_owned, nil} ->
+          {:error, :is_only_organizer} ->
-        {:error, dgettext("errors", "Profile is not owned by authenticated user")}
-
-      {:only_organizer, true} ->
             {:error,
              dgettext(
                "errors",
@@ -168,6 +184,10 @@ defmodule Mobilizon.GraphQL.Resolvers.Participant do
 
           {:error, :participant_not_found} ->
             {:error, dgettext("errors", "Participant not found")}
+
+          {:error, _err} ->
+            {:error, dgettext("errors", "Failed to leave the event")}
+        end
     end
   end
 
@@ -188,7 +208,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Participant do
       {:is_owned, nil} ->
         {:error, dgettext("errors", "Profile is not owned by authenticated user")}
 
-      {:only_organizer, true} ->
+      {:error, :is_only_organizer} ->
         {:error,
          dgettext(
            "errors",
@@ -204,19 +224,19 @@ defmodule Mobilizon.GraphQL.Resolvers.Participant do
     {:error, dgettext("errors", "You need to be logged-in to leave an event")}
   end
 
+  @spec update_participation(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Participation.t()} | {:error, String.t()}
   def update_participation(
         _parent,
         %{id: participation_id, role: new_role},
         %{
           context: %{
-            current_user: user
+            current_actor: %Actor{} = moderator_actor
           }
         }
       ) do
-    # Check that moderator provided is rightly authenticated
-    with %Actor{} = moderator_actor <- Users.get_actor_for_user(user),
     # Check that participation already exists
-         {:has_participation, %Participant{role: old_role, event_id: event_id} = participation} <-
+    with {:has_participation, %Participant{role: old_role, event_id: event_id} = participation} <-
            {:has_participation, Events.get_participant(participation_id)},
          {:same_role, false} <- {:same_role, new_role == old_role},
          # Check that moderator has right

lib/graphql/resolvers/person.ex

@@ -12,7 +12,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   alias Mobilizon.Users.User
   import Mobilizon.Web.Gettext
 
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
   require Logger
 
@@ -21,6 +21,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   @doc """
   Get a person
   """
+  @spec get_person(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t() | :unauthorized}
   def get_person(_parent, %{id: id}, %{context: %{current_user: %User{role: role}}}) do
     with %Actor{suspended: suspended} = actor <- Actors.get_actor_with_preload(id, true),
          true <- suspended == false or is_moderator(role) do
@@ -36,6 +38,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   @doc """
   Find a person
   """
+  @spec fetch_person(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t() | :unauthorized | :unauthenticated}
   def fetch_person(_parent, %{preferred_username: preferred_username}, %{
         context: %{current_user: %User{} = user}
       }) do
@@ -57,6 +61,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
 
   def fetch_person(_parent, _args, _resolution), do: {:error, :unauthenticated}
 
+  @spec list_persons(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Actor.t())} | {:error, :unauthorized | :unauthenticated}
   def list_persons(
         _parent,
         %{
@@ -91,8 +97,14 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   @doc """
   Returns the current actor for the currently logged-in user
   """
-  def get_current_person(_parent, _args, %{context: %{current_user: user}}) do
+  @spec get_current_person(any, any, Absinthe.Resolution.t()) ::
-    {:ok, Users.get_actor_for_user(user)}
+          {:error, :unauthenticated | :no_current_person} | {:ok, Actor.t()}
+  def get_current_person(_parent, _args, %{context: %{current_actor: %Actor{} = actor}}) do
+    {:ok, actor}
+  end
+
+  def get_current_person(_parent, _args, %{context: %{current_user: %User{}}}) do
+    {:error, :no_current_person}
   end
 
   def get_current_person(_parent, _args, _resolution) do
@@ -102,6 +114,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   @doc """
   Returns the list of identities for the logged-in user
   """
+  @spec identities(any, any, Absinthe.Resolution.t()) ::
+          {:error, :unauthenticated} | {:ok, list(Actor.t())}
   def identities(_parent, _args, %{context: %{current_user: user}}) do
     {:ok, Users.get_actors_for_user(user)}
   end
@@ -113,6 +127,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   @doc """
   This function is used to create more identities from an existing user
   """
+  @spec create_person(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t() | :unauthenticated}
   def create_person(
         _parent,
         %{preferred_username: _preferred_username} = args,
@@ -140,6 +156,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   @doc """
   This function is used to update an existing identity
   """
+  @spec update_person(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t() | :unauthenticated}
   def update_person(
         _parent,
         %{id: id} = args,
@@ -148,21 +166,24 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
     require Logger
     args = Map.put(args, :user_id, user.id)
 
-    with {:find_actor, %Actor{} = actor} <-
+    case owned_actor(user, id) do
-           {:find_actor, Actors.get_actor(id)},
+      {:ok, %Actor{} = actor} ->
-         {:is_owned, %Actor{}} <- User.owns_actor(user, actor.id),
+        case save_attached_pictures(args) do
-         {:picture, args} when is_map(args) <- {:picture, save_attached_pictures(args)},
+          args when is_map(args) ->
-         {:ok, _activity, %Actor{} = actor} <- ActivityPub.update(actor, args, true) do
+            case Actions.Update.update(actor, args, true) do
+              {:ok, _activity, %Actor{} = actor} ->
                 {:ok, actor}
-    else
+
-      {:picture, {:error, :file_too_large}} ->
+              {:error, err} ->
+                {:error, err}
+            end
+
+          {:error, :file_too_large} ->
             {:error, dgettext("errors", "The provided picture is too heavy")}
+        end
 
-      {:find_actor, nil} ->
+      {:error, err} ->
-        {:error, dgettext("errors", "Profile not found")}
+        {:error, err}
-
-      {:is_owned, nil} ->
-        {:error, dgettext("errors", "Profile is not owned by authenticated user")}
     end
   end
 
@@ -173,30 +194,27 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   @doc """
   This function is used to delete an existing identity
   """
+  @spec delete_person(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t() | :unauthenticated}
   def delete_person(
         _parent,
         %{id: id} = _args,
-        %{context: %{current_user: user}} = _resolution
+        %{context: %{current_user: %User{} = user}} = _resolution
       ) do
-    with {:find_actor, %Actor{} = actor} <-
+    case owned_actor(user, id) do
-           {:find_actor, Actors.get_actor(id)},
+      {:ok, %Actor{} = actor} ->
-         {:is_owned, %Actor{}} <- User.owns_actor(user, actor.id),
+        if last_identity?(user) do
-         {:last_identity, false} <- {:last_identity, last_identity?(user)},
-         {:last_admin, false} <- {:last_admin, last_admin_of_a_group?(actor.id)},
-         {:ok, actor} <- Actors.delete_actor(actor) do
-      {:ok, actor}
-    else
-      {:find_actor, nil} ->
-        {:error, dgettext("errors", "Profile not found")}
-
-      {:last_identity, true} ->
           {:error, dgettext("errors", "Cannot remove the last identity of a user")}
-
+        else
-      {:last_admin, true} ->
+          if last_admin_of_a_group?(actor.id) do
             {:error, dgettext("errors", "Cannot remove the last administrator of a group")}
+          else
+            Actors.delete_actor(actor)
+          end
+        end
 
-      {:is_owned, nil} ->
+      {:error, err} ->
-        {:error, dgettext("errors", "Profile is not owned by authenticated user")}
+        {:error, err}
     end
   end
 
@@ -204,20 +222,51 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
     {:error, :unauthenticated}
   end
 
+  @spec owned_actor(User.t(), integer() | String.t()) :: {:error, String.t()} | {:ok, Actor.t()}
+  defp owned_actor(%User{} = user, actor_id) do
+    with {:find_actor, %Actor{} = actor} <-
+           {:find_actor, Actors.get_actor(actor_id)},
+         {:is_owned, %Actor{}} <- User.owns_actor(user, actor.id) do
+      {:ok, actor}
+    else
+      {:find_actor, nil} ->
+        {:error, dgettext("errors", "Profile not found")}
+
+      {:is_owned, nil} ->
+        {:error, dgettext("errors", "Profile is not owned by authenticated user")}
+    end
+  end
+
+  @spec last_identity?(User.t()) :: boolean
   defp last_identity?(user) do
     length(Users.get_actors_for_user(user)) <= 1
   end
 
+  @spec save_attached_pictures(map()) :: map() | {:error, any()}
   defp save_attached_pictures(args) do
-    with args when is_map(args) <- save_attached_picture(args, :avatar),
+    case save_attached_picture(args, :avatar) do
-         args when is_map(args) <- save_attached_picture(args, :banner) do
+      {:error, err} ->
+        {:error, err}
+
+      args when is_map(args) ->
+        case save_attached_picture(args, :banner) do
+          {:error, err} ->
+            {:error, err}
+
+          args when is_map(args) ->
             args
         end
     end
+  end
 
+  @spec save_attached_picture(map(), :avatar | :banner) :: map() | {:error, any}
   defp save_attached_picture(args, key) do
     if Map.has_key?(args, key) && !is_nil(args[key][:media]) do
-      with media when is_map(media) <- save_picture(args[key][:media], key) do
+      case save_picture(args[key][:media], key) do
+        {:error, err} ->
+          {:error, err}
+
+        media when is_map(media) ->
           Map.put(args, key, media)
       end
     else
@@ -225,73 +274,82 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
     end
   end
 
+  @spec save_picture(map(), :avatar | :banner) :: {:ok, map()} | {:error, any()}
   defp save_picture(media, key) do
-    with {:ok, %{name: name, url: url, content_type: content_type, size: size}} <-
+    case Upload.store(media.file, type: key, description: media.alt) do
-           Upload.store(media.file, type: key, description: media.alt) do
+      {:ok, %{name: name, url: url, content_type: content_type, size: size}} ->
         %{"name" => name, "url" => url, "content_type" => content_type, "size" => size}
+
+      {:error, err} ->
+        {:error, err}
     end
   end
 
   @doc """
   This function is used to register a person afterwards the user has been created (but not activated)
   """
+  @spec register_person(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Actor.t()} | {:error, String.t()}
   def register_person(_parent, args, _resolution) do
     # When registering, email is assumed confirmed (unlike changing email)
-    with {:ok, %User{} = user} <- Users.get_user_by_email(args.email, unconfirmed: false),
+    case Users.get_user_by_email(args.email, unconfirmed: false) do
-         user_actor <- Users.get_actor_for_user(user),
+      {:ok, %User{} = user} ->
-         no_actor <- is_nil(user_actor),
+        if is_nil(Users.get_actor_for_user(user)) do
-         {:no_actor, true} <- {:no_actor, no_actor},
+          # No profile yet, we can create one
-         args <- Map.update(args, :preferred_username, "", &String.downcase/1),
+          case prepare_args(args, user) do
-         args <- Map.put(args, :user_id, user.id),
+            args when is_map(args) ->
-         {:picture, args} when is_map(args) <- {:picture, save_attached_pictures(args)},
+              Actors.new_person(args, true)
-         {:ok, %Actor{} = new_person} <- Actors.new_person(args, true) do
+
-      {:ok, new_person}
+            {:error, :file_too_large} ->
-    else
-      {:picture, {:error, :file_too_large}} ->
               {:error, dgettext("errors", "The provided picture is too heavy")}
 
+            {:error, _err} ->
+              {:error, dgettext("errors", "Error while uploading pictures")}
+          end
+        else
+          {:error, dgettext("errors", "You already have a profile for this user")}
+        end
+
       {:error, :user_not_found} ->
         {:error, dgettext("errors", "No user with this email was found")}
-
-      {:no_actor, _} ->
-        {:error, dgettext("errors", "You already have a profile for this user")}
-
-      {:error, %Ecto.Changeset{} = e} ->
-        {:error, e}
     end
   end
 
+  @spec prepare_args(map(), User.t()) :: map() | {:error, any()}
+  defp prepare_args(args, %User{} = user) do
+    args
+    |> Map.update(:preferred_username, "", &String.downcase/1)
+    |> Map.put(:user_id, user.id)
+    |> save_attached_pictures()
+  end
+
   @doc """
   Returns the participations, optionally restricted to an event
   """
+  @spec person_participations(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Participant.t())} | {:error, :unauthorized | String.t()}
   def person_participations(
         %Actor{id: actor_id} = person,
         %{event_id: event_id},
         %{context: %{current_user: %User{} = user}}
       ) do
-    with {:can_get_participations, true} <-
+    if user_can_access_person_details?(person, user) do
-           {:can_get_participations, user_can_access_person_details?(person, user)},
+      case Events.get_participant(event_id, actor_id) do
-         {:no_participant, {:ok, %Participant{} = participant}} <-
+        {:ok, %Participant{} = participant} -> {:ok, %Page{elements: [participant], total: 1}}
-           {:no_participant, Events.get_participant(event_id, actor_id)} do
+        {:error, :participant_not_found} -> {:ok, %Page{elements: [], total: 0}}
-      {:ok, %Page{elements: [participant], total: 1}}
+      end
     else
-      {:is_owned, nil} ->
+      {:error, :unauthorized}
-        {:error, dgettext("errors", "Profile is not owned by authenticated user")}
-
-      {:no_participant, _} ->
-        {:ok, %Page{elements: [], total: 0}}
     end
   end
 
   def person_participations(%Actor{} = person, %{page: page, limit: limit}, %{
         context: %{current_user: %User{} = user}
       }) do
-    with {:can_get_participations, true} <-
+    if user_can_access_person_details?(person, user) do
-           {:can_get_participations, user_can_access_person_details?(person, user)},
+      %Page{} = page = Events.list_event_participations_for_actor(person, page, limit)
-         %Page{} = page <- Events.list_event_participations_for_actor(person, page, limit) do
       {:ok, page}
     else
-      {:can_get_participations, false} ->
       {:error, dgettext("errors", "Profile is not owned by authenticated user")}
     end
   end
@@ -303,23 +361,22 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   def person_memberships(%Actor{id: actor_id} = person, %{group: group}, %{
         context: %{current_user: %User{} = user}
       }) do
-    with {:can_get_memberships, true} <-
+    if user_can_access_person_details?(person, user) do
-           {:can_get_memberships, user_can_access_person_details?(person, user)},
+      with {:group, %Actor{id: group_id}} <- {:group, Actors.get_actor_by_name(group, :Group)},
-         {:group, %Actor{id: group_id}} <- {:group, Actors.get_actor_by_name(group, :Group)},
+           {:ok, %Member{} = membership} <- Actors.get_member(actor_id, group_id) do
-         {:ok, %Member{} = membership} <- Actors.get_member(actor_id, group_id),
+        {:ok,
-         memberships <- %Page{
+         %Page{
            total: 1,
            elements: [Repo.preload(membership, [:actor, :parent, :invited_by])]
-         } do
+         }}
-      {:ok, memberships}
       else
         {:error, :member_not_found} ->
           {:ok, %Page{total: 0, elements: []}}
 
         {:group, nil} ->
           {:error, :group_not_found}
-
+      end
-      {:can_get_memberships, _} ->
+    else
       {:error, dgettext("errors", "Profile is not owned by authenticated user")}
     end
   end
@@ -341,6 +398,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
     end
   end
 
+  @spec user_for_person(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, User.t() | nil} | {:error, String.t() | nil}
   def user_for_person(%Actor{type: :Person, user_id: user_id}, _args, %{
         context: %{current_user: %User{role: role}}
       })
@@ -359,6 +418,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
 
   def user_for_person(_, _args, _resolution), do: {:error, nil}
 
+  @spec organized_events_for_person(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Event.t())} | {:error, :unauthorized}
   def organized_events_for_person(
         %Actor{} = person,
         %{page: page, limit: limit},
@@ -366,12 +427,10 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
           context: %{current_user: %User{} = user}
         }
       ) do
-    with {:can_get_events, true} <-
+    if user_can_access_person_details?(person, user) do
-           {:can_get_events, user_can_access_person_details?(person, user)},
+      %Page{} = page = Events.list_organized_events_for_actor(person, page, limit)
-         %Page{} = page <- Events.list_organized_events_for_actor(person, page, limit) do
       {:ok, page}
     else
-      {:can_get_events, false} ->
       {:error, :unauthorized}
     end
   end

lib/graphql/resolvers/post.ex

@@ -4,10 +4,9 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
   """
 
   import Mobilizon.Users.Guards
-  alias Mobilizon.{Actors, Posts, Users}
+  alias Mobilizon.{Actors, Posts}
   alias Mobilizon.Actors.Actor
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Permission, Utils}
-  alias Mobilizon.Federation.ActivityPub.{Permission, Utils}
   alias Mobilizon.Posts.Post
   alias Mobilizon.Storage.Page
   alias Mobilizon.Users.User
@@ -22,22 +21,21 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
 
   Returns only if actor requesting is a member of the group
   """
+  @spec find_posts_for_group(Actor.t(), map(), Absinthe.Resolution.t()) :: {:ok, Page.t(Post.t())}
   def find_posts_for_group(
         %Actor{id: group_id} = group,
         %{page: page, limit: limit} = args,
         %{
           context: %{
-            current_user: %User{role: user_role} = user
+            current_user: %User{role: user_role},
+            current_actor: %Actor{id: actor_id}
           }
         } = _resolution
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    if Actors.is_member?(actor_id, group_id) or is_moderator(user_role) do
-         {:member, true} <-
+      %Page{} = page = Posts.get_posts_for_group(group, page, limit)
-           {:member, Actors.is_member?(actor_id, group_id) or is_moderator(user_role)},
-         %Page{} = page <- Posts.get_posts_for_group(group, page, limit) do
       {:ok, page}
     else
-      {:member, _} ->
       find_posts_for_group(group, args, nil)
     end
   end
@@ -47,10 +45,9 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
         %{page: page, limit: limit},
         _resolution
       ) do
-    with %Page{} = page <- Posts.get_public_posts_for_group(group, page, limit) do
+    %Page{} = page = Posts.get_public_posts_for_group(group, page, limit)
     {:ok, page}
   end
-  end
 
   def find_posts_for_group(
         _group,
@@ -60,18 +57,19 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
     {:ok, %Page{total: 0, elements: []}}
   end
 
+  @spec get_post(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Post.t()} | {:error, :post_not_found}
   def get_post(
         parent,
         %{slug: slug},
         %{
           context: %{
-            current_user: %User{role: user_role} = user
+            current_user: %User{role: user_role},
+            current_actor: %Actor{} = current_profile
           }
         } = _resolution
       ) do
-    with {:current_actor, %Actor{} = current_profile} <-
+    with {:post, %Post{attributed_to: %Actor{}} = post} <-
-           {:current_actor, Users.get_actor_for_user(user)},
-         {:post, %Post{attributed_to: %Actor{}} = post} <-
            {:post, Posts.get_post_by_slug_with_preloads(slug)},
          {:member, true} <-
            {:member,
@@ -102,17 +100,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
     {:error, :post_not_found}
   end
 
+  @spec create_post(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Post.t()} | {:error, String.t()}
   def create_post(
         _parent,
         %{attributed_to_id: group_id} = args,
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         } = _resolution
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    with {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          %Actor{} = group <- Actors.get_actor(group_id),
          args <-
            Map.update(args, :picture, nil, fn picture ->
@@ -120,7 +119,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
            end),
          args <- extract_pictures_from_post_body(args, actor_id),
          {:ok, _, %Post{} = post} <-
-           ActivityPub.create(
+           Actions.Create.create(
              :post,
              args
              |> Map.put(:author_id, actor_id)
@@ -142,17 +141,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
     {:error, dgettext("errors", "You need to be logged-in to create posts")}
   end
 
+  @spec update_post(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Post.t()} | {:error, String.t()}
   def update_post(
         _parent,
         %{id: id} = args,
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id, url: actor_url}
           }
         } = _resolution
       ) do
     with {:uuid, {:ok, _uuid}} <- {:uuid, Ecto.UUID.cast(id)},
-         %Actor{id: actor_id, url: actor_url} <- Users.get_actor_for_user(user),
          {:post, %Post{attributed_to: %Actor{id: group_id} = group} = post} <-
            {:post, Posts.get_post_with_preloads(id)},
          args <-
@@ -162,7 +162,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
          args <- extract_pictures_from_post_body(args, actor_id),
          {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          {:ok, _, %Post{} = post} <-
-           ActivityPub.update(post, args, true, %{"actor" => actor_url}) do
+           Actions.Update.update(post, args, true, %{"actor" => actor_url}) do
       {:ok, post}
     else
       {:uuid, :error} ->
@@ -180,22 +180,23 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
     {:error, dgettext("errors", "You need to be logged-in to update posts")}
   end
 
+  @spec delete_post(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Post.t()} | {:error, String.t()}
   def delete_post(
         _parent,
         %{id: post_id},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id} = actor
           }
         } = _resolution
       ) do
     with {:uuid, {:ok, _uuid}} <- {:uuid, Ecto.UUID.cast(post_id)},
-         %Actor{id: actor_id} = actor <- Users.get_actor_for_user(user),
          {:post, %Post{attributed_to: %Actor{id: group_id}} = post} <-
            {:post, Posts.get_post_with_preloads(post_id)},
          {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          {:ok, _, %Post{} = post} <-
-           ActivityPub.delete(post, actor) do
+           Actions.Delete.delete(post, actor) do
       {:ok, post}
     else
       {:uuid, :error} ->
@@ -213,6 +214,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Post do
     {:error, dgettext("errors", "You need to be logged-in to delete posts")}
   end
 
+  @spec process_picture(map() | nil, Actor.t()) :: nil | map()
   defp process_picture(nil, _), do: nil
   defp process_picture(%{media_id: _picture_id} = args, _), do: args
 

lib/graphql/resolvers/push_subscription.ex

@@ -10,6 +10,8 @@ defmodule Mobilizon.GraphQL.Resolvers.PushSubscription do
   @doc """
   List all of an user's registered push subscriptions
   """
+  @spec list_user_push_subscriptions(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(PushSubscription.t())} | {:error, :unauthenticated}
   def list_user_push_subscriptions(_parent, %{page: page, limit: limit}, %{
         context: %{current_user: %User{id: user_id}}
       }) do
@@ -22,6 +24,8 @@ defmodule Mobilizon.GraphQL.Resolvers.PushSubscription do
   @doc """
   Register a push subscription
   """
+  @spec register_push_subscription(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, String.t()} | {:error, String.t()}
   def register_push_subscription(_parent, args, %{
         context: %{current_user: %User{id: user_id}}
       }) do

lib/graphql/resolvers/report.ex

@@ -5,7 +5,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Report do
 
   import Mobilizon.Users.Guards
 
-  alias Mobilizon.{Actors, Config, Reports, Users}
+  alias Mobilizon.{Actors, Config, Reports}
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Reports.{Note, Report}
   alias Mobilizon.Users.User
@@ -13,6 +13,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Report do
 
   alias Mobilizon.GraphQL.API
 
+  @spec list_reports(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Report.t())} | {:error, String.t()}
   def list_reports(
         _parent,
         %{page: page, limit: limit, status: status},
@@ -26,6 +28,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Report do
     {:error, dgettext("errors", "You need to be logged-in and a moderator to list reports")}
   end
 
+  @spec get_report(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Report.t()} | {:error, String.t()}
   def get_report(_parent, %{id: id}, %{context: %{current_user: %User{role: role}}})
       when is_moderator(role) do
     case Mobilizon.Reports.get_report(id) do
@@ -44,16 +48,17 @@ defmodule Mobilizon.GraphQL.Resolvers.Report do
   @doc """
   Create a report, either logged-in or anonymously
   """
+  @spec create_report(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Report.t()} | {:error, String.t()}
   def create_report(
         _parent,
         args,
-        %{context: %{current_user: %User{} = user}} = _resolution
+        %{context: %{current_actor: %Actor{id: reporter_id}}} = _resolution
       ) do
-    with %Actor{id: reporter_id} <- Users.get_actor_for_user(user),
+    case args |> Map.put(:reporter_id, reporter_id) |> API.Reports.report() do
-         {:ok, _, %Report{} = report} <-
+      {:ok, _, %Report{} = report} ->
-           args |> Map.put(:reporter_id, reporter_id) |> API.Reports.report() do
         {:ok, report}
-    else
+
       _error ->
         {:error, dgettext("errors", "Error while saving report")}
     end
@@ -81,14 +86,15 @@ defmodule Mobilizon.GraphQL.Resolvers.Report do
   @doc """
   Update a report's status
   """
+  @spec update_report(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Report.t()} | {:error, String.t()}
   def update_report(
         _parent,
         %{report_id: report_id, status: status},
-        %{context: %{current_user: %User{role: role} = user}}
+        %{context: %{current_user: %User{role: role}, current_actor: %Actor{} = actor}}
       )
       when is_moderator(role) do
-    with %Actor{} = actor <- Users.get_actor_for_user(user),
+    with %Report{} = report <- Mobilizon.Reports.get_report(report_id),
-         %Report{} = report <- Mobilizon.Reports.get_report(report_id),
          {:ok, %Report{} = report} <- API.Reports.update_report_status(actor, report, status) do
       {:ok, report}
     else
@@ -101,28 +107,28 @@ defmodule Mobilizon.GraphQL.Resolvers.Report do
     {:error, dgettext("errors", "You need to be logged-in and a moderator to update a report")}
   end
 
+  @spec create_report_note(any(), map(), Absinthe.Resolution.t()) :: {:ok, Note.t()}
   def create_report_note(
         _parent,
         %{report_id: report_id, content: content},
-        %{context: %{current_user: %User{role: role} = user}}
+        %{context: %{current_user: %User{role: role}, current_actor: %Actor{id: moderator_id}}}
       )
       when is_moderator(role) do
-    with %Actor{id: moderator_id} <- Users.get_actor_for_user(user),
+    with %Report{} = report <- Reports.get_report(report_id),
-         %Report{} = report <- Reports.get_report(report_id),
          %Actor{} = moderator <- Actors.get_local_actor_with_preload(moderator_id),
          {:ok, %Note{} = note} <- API.Reports.create_report_note(report, moderator, content) do
       {:ok, note}
     end
   end
 
+  @spec delete_report_note(any(), map(), Absinthe.Resolution.t()) :: {:ok, map()}
   def delete_report_note(
         _parent,
         %{note_id: note_id},
-        %{context: %{current_user: %User{role: role} = user}}
+        %{context: %{current_user: %User{role: role}, current_actor: %Actor{id: moderator_id}}}
       )
       when is_moderator(role) do
-    with %Actor{id: moderator_id} <- Users.get_actor_for_user(user),
+    with %Note{} = note <- Reports.get_note(note_id),
-         %Note{} = note <- Reports.get_note(note_id),
          %Actor{} = moderator <- Actors.get_local_actor_with_preload(moderator_id),
          {:ok, %Note{} = note} <- API.Reports.delete_report_note(note, moderator) do
       {:ok, %{id: note.id}}

lib/graphql/resolvers/resource.ex

@@ -3,9 +3,9 @@ defmodule Mobilizon.GraphQL.Resolvers.Resource do
   Handles the resources-related GraphQL calls
   """
 
-  alias Mobilizon.{Actors, Resources, Users}
+  alias Mobilizon.{Actors, Resources}
   alias Mobilizon.Actors.Actor
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
   alias Mobilizon.Resources.Resource
   alias Mobilizon.Resources.Resource.Metadata
   alias Mobilizon.Service.RichMedia.Parser
@@ -21,17 +21,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Resource do
 
   Returns only if actor requesting is a member of the group
   """
+  @spec find_resources_for_group(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Resource.t())}
   def find_resources_for_group(
         %Actor{id: group_id} = group,
         %{page: page, limit: limit},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         } = _resolution
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    with {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          %Page{} = page <- Resources.get_resources_for_group(group, page, limit) do
       {:ok, page}
     else
@@ -48,17 +49,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Resource do
     {:ok, %Page{total: 0, elements: []}}
   end
 
+  @spec find_resources_for_parent(Resource.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Resource.t())}
   def find_resources_for_parent(
         %Resource{actor_id: group_id} = parent,
         %{page: page, limit: limit},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         } = _resolution
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    with {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          %Page{} = page <- Resources.get_resources_for_folder(parent, page, limit) do
       {:ok, page}
     end
@@ -67,18 +69,18 @@ defmodule Mobilizon.GraphQL.Resolvers.Resource do
   def find_resources_for_parent(_parent, _args, _resolution),
     do: {:ok, %Page{total: 0, elements: []}}
 
+  @spec get_resource(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Resource.t()} | {:error, :group_not_found | :resource_not_found | String.t()}
   def get_resource(
         _parent,
         %{path: path, username: username},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         } = _resolution
       ) do
-    with {:current_actor, %Actor{id: actor_id}} <-
+    with {:group, %Actor{id: group_id}} <- {:group, Actors.get_actor_by_name(username, :Group)},
-           {:current_actor, Users.get_actor_for_user(user)},
-         {:group, %Actor{id: group_id}} <- {:group, Actors.get_actor_by_name(username, :Group)},
          {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          {:resource, %Resource{} = resource} <-
            {:resource, Resources.get_resource_by_group_and_path_with_preloads(group_id, path)} do
@@ -94,21 +96,22 @@ defmodule Mobilizon.GraphQL.Resolvers.Resource do
     {:error, dgettext("errors", "You need to be logged-in to access resources")}
   end
 
+  @spec create_resource(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Resource.t()} | {:error, String.t()}
   def create_resource(
         _parent,
         %{actor_id: group_id} = args,
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id}
           }
         } = _resolution
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    with {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          parent <- get_eventual_parent(args),
          {:own_check, true} <- {:own_check, check_resource_owned_by_group(parent, group_id)},
          {:ok, _, %Resource{} = resource} <-
-           ActivityPub.create(
+           Actions.Create.create(
              :resource,
              args
              |> Map.put(:actor_id, group_id)
@@ -133,50 +136,59 @@ defmodule Mobilizon.GraphQL.Resolvers.Resource do
     {:error, dgettext("errors", "You need to be logged-in to create resources")}
   end
 
+  @spec update_resource(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Resource.t()} | {:error, String.t()}
   def update_resource(
         _parent,
         %{id: resource_id} = args,
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id, url: actor_url}
           }
         } = _resolution
       ) do
-    with %Actor{id: actor_id, url: actor_url} <- Users.get_actor_for_user(user),
+    case Resources.get_resource_with_preloads(resource_id) do
-         {:resource, %Resource{actor_id: group_id} = resource} <-
+      %Resource{actor_id: group_id} = resource ->
-           {:resource, Resources.get_resource_with_preloads(resource_id)},
+        if Actors.is_member?(actor_id, group_id) do
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
+          case Actions.Update.update(resource, args, true, %{"actor" => actor_url}) do
-         {:ok, _, %Resource{} = resource} <-
+            {:ok, _, %Resource{} = resource} ->
-           ActivityPub.update(resource, args, true, %{"actor" => actor_url}) do
               {:ok, resource}
-    else
-      {:resource, _} ->
-        {:error, dgettext("errors", "Resource doesn't exist")}
 
-      {:member, _} ->
+            {:error, %Ecto.Changeset{} = err} ->
+              {:error, err}
+
+            {:error, err} when is_atom(err) ->
+              {:error, dgettext("errors", "Unknown error while updating resource")}
+          end
+        else
           {:error, dgettext("errors", "Profile is not member of group")}
         end
+
+      nil ->
+        {:error, dgettext("errors", "Resource doesn't exist")}
+    end
   end
 
   def update_resource(_parent, _args, _resolution) do
     {:error, dgettext("errors", "You need to be logged-in to update resources")}
   end
 
+  @spec delete_resource(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Resource.t()} | {:error, String.t()}
   def delete_resource(
         _parent,
         %{id: resource_id},
         %{
           context: %{
-            current_user: %User{} = user
+            current_actor: %Actor{id: actor_id} = actor
           }
         } = _resolution
       ) do
-    with %Actor{id: actor_id} = actor <- Users.get_actor_for_user(user),
+    with {:resource, %Resource{parent_id: _parent_id, actor_id: group_id} = resource} <-
-         {:resource, %Resource{parent_id: _parent_id, actor_id: group_id} = resource} <-
            {:resource, Resources.get_resource_with_preloads(resource_id)},
          {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          {:ok, _, %Resource{} = resource} <-
-           ActivityPub.delete(resource, actor) do
+           Actions.Delete.delete(resource, actor) do
       {:ok, resource}
     else
       {:resource, _} ->
@@ -191,6 +203,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Resource do
     {:error, dgettext("errors", "You need to be logged-in to delete resources")}
   end
 
+  @spec preview_resource_link(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Metadata.t()} | {:error, String.t() | :unknown_resource}
   def preview_resource_link(
         _parent,
         %{resource_url: resource_url},
@@ -218,6 +232,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Resource do
     {:error, dgettext("errors", "You need to be logged-in to view a resource preview")}
   end
 
+  @spec proxyify_pictures(Metadata.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, String.t() | nil} | {:error, String.t()}
   def proxyify_pictures(%Metadata{} = metadata, _args, %{
         definition: %{schema_node: %{name: name}}
       }) do

lib/graphql/resolvers/search.ex

@@ -2,12 +2,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Search do
   @moduledoc """
   Handles the event-related GraphQL calls
   """
-
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Events.Event
   alias Mobilizon.GraphQL.API.Search
+  alias Mobilizon.Storage.Page
 
   @doc """
   Search persons
   """
+  @spec search_persons(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Actor.t())} | {:error, String.t()}
   def search_persons(_parent, %{page: page, limit: limit} = args, _resolution) do
     Search.search_actors(Map.put(args, :minimum_visibility, :private), page, limit, :Person)
   end
@@ -15,6 +19,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Search do
   @doc """
   Search groups
   """
+  @spec search_groups(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Actor.t())} | {:error, String.t()}
   def search_groups(_parent, %{page: page, limit: limit} = args, _resolution) do
     Search.search_actors(args, page, limit, :Group)
   end
@@ -22,10 +28,13 @@ defmodule Mobilizon.GraphQL.Resolvers.Search do
   @doc """
   Search events
   """
+  @spec search_events(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Event.t())} | {:error, String.t()}
   def search_events(_parent, %{page: page, limit: limit} = args, _resolution) do
     Search.search_events(args, page, limit)
   end
 
+  @spec interact(any(), map(), Absinthe.Resolution.t()) :: {:ok, struct} | {:error, :not_found}
   def interact(_parent, %{uri: uri}, _resolution) do
     Search.interact(uri)
   end

lib/graphql/resolvers/statistics.ex

@@ -8,6 +8,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Statistics do
   @doc """
   Gets config.
   """
+  @spec get_statistics(any(), any(), any()) :: {:ok, map()}
   def get_statistics(_parent, _params, _context) do
     {:ok,
      %{

lib/graphql/resolvers/tag.ex

@@ -6,9 +6,12 @@ defmodule Mobilizon.GraphQL.Resolvers.Tag do
   alias Mobilizon.{Events, Posts}
   alias Mobilizon.Events.{Event, Tag}
   alias Mobilizon.Posts.Post
+  alias Mobilizon.Storage.Page
 
-  def list_tags(_parent, %{page: page, limit: limit}, _resolution) do
+  @spec list_tags(any(), map(), Absinthe.Resolution.t()) :: {:ok, Page.t(Tag.t())}
-    tags = Mobilizon.Events.list_tags(page, limit)
+  def list_tags(_parent, %{page: page, limit: limit} = args, _resolution) do
+    filter = Map.get(args, :filter)
+    tags = Mobilizon.Events.list_tags(filter, page, limit)
 
     {:ok, tags}
   end
@@ -18,6 +21,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Tag do
 
   From an event or a struct with an url
   """
+  @spec list_tags_for_event(Event.t(), map(), Absinthe.Resolution.t()) :: {:ok, list(Tag.t())}
   def list_tags_for_event(%Event{id: id}, _args, _resolution) do
     {:ok, Events.list_tags_for_event(id)}
   end
@@ -32,6 +36,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Tag do
   @doc """
   Retrieve the list of tags for a post
   """
+  @spec list_tags_for_post(Post.t(), map(), Absinthe.Resolution.t()) :: {:ok, list(Tag.t())}
   def list_tags_for_post(%Post{id: id}, _args, _resolution) do
     {:ok, Posts.list_tags_for_post(id)}
   end
@@ -49,9 +54,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Tag do
   @doc """
   Retrieve the list of related tags for a parent tag
   """
+  @spec list_tags_for_post(Tag.t(), map(), Absinthe.Resolution.t()) :: {:ok, list(Tag.t())}
   def get_related_tags(%Tag{} = tag, _args, _resolution) do
-    with tags <- Events.list_tag_neighbors(tag) do
+    {:ok, Events.list_tag_neighbors(tag)}
-      {:ok, tags}
-    end
   end
 end

lib/graphql/resolvers/todos.ex

@@ -3,12 +3,11 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
   Handles the todos related GraphQL calls
   """
 
-  alias Mobilizon.{Actors, Todos, Users}
+  alias Mobilizon.{Actors, Todos}
   alias Mobilizon.Actors.Actor
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.Actions
   alias Mobilizon.Storage.Page
   alias Mobilizon.Todos.{Todo, TodoList}
-  alias Mobilizon.Users.User
   import Mobilizon.Web.Gettext
 
   require Logger
@@ -18,15 +17,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
 
   Returns only if actor requesting is a member of the group
   """
+  @spec find_todo_lists_for_group(Actor.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(TodoList.t())}
   def find_todo_lists_for_group(
         %Actor{id: group_id} = group,
         _args,
         %{
-          context: %{current_user: %User{} = user}
+          context: %{current_actor: %Actor{id: actor_id}}
         } = _resolution
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    with {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          %Page{} = page <- Todos.get_todo_lists_for_group(group) do
       {:ok, page}
     else
@@ -41,15 +41,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
     {:ok, %Page{total: 0, elements: []}}
   end
 
+  @spec find_todo_lists_for_group(TodoList.t(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(Todo.t())} | {:error, String.t()}
   def find_todos_for_todo_list(
         %TodoList{actor_id: group_id} = todo_list,
         _args,
         %{
-          context: %{current_user: %User{} = user}
+          context: %{current_actor: %Actor{id: actor_id}}
         } = _resolution
       ) do
-    with %Actor{id: actor_id} <- Users.get_actor_for_user(user),
+    with {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          %Page{} = page <- Todos.get_todos_for_todo_list(todo_list) do
       {:ok, page}
     else
@@ -58,15 +59,16 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
     end
   end
 
+  @spec get_todo_list(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, TodoList.t()} | {:error, String.t()}
   def get_todo_list(
         _parent,
         %{id: todo_list_id},
         %{
-          context: %{current_user: %User{} = user}
+          context: %{current_actor: %Actor{id: actor_id}}
         } = _resolution
       ) do
-    with {:actor, %Actor{id: actor_id}} <- {:actor, Users.get_actor_for_user(user)},
+    with {:todo, %TodoList{actor_id: group_id} = todo} <-
-         {:todo, %TodoList{actor_id: group_id} = todo} <-
            {:todo, Todos.get_todo_list(todo_list_id)},
          {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)} do
       {:ok, todo}
@@ -82,19 +84,28 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
     end
   end
 
+  @spec create_todo_list(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, TodoList.t()} | {:error, String.t()}
   def create_todo_list(
         _parent,
         %{group_id: group_id} = args,
         %{
-          context: %{current_user: %User{} = user}
+          context: %{current_actor: %Actor{id: actor_id}}
         } = _resolution
       ) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    with {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
-         {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          {:ok, _, %TodoList{} = todo_list} <-
-           ActivityPub.create(:todo_list, Map.put(args, :actor_id, group_id), true, %{}) do
+           Actions.Create.create(
+             :todo_list,
+             Map.put(args, :actor_id, group_id),
+             true,
+             %{}
+           ) do
       {:ok, todo_list}
     else
+      {:actor, nil} ->
+        {:error, dgettext("errors", "No profile found for user")}
+
       {:member, _} ->
         {:error, dgettext("errors", "Profile is not member of group")}
     end
@@ -112,7 +123,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
   #          {:todo_list, Todos.get_todo_list(todo_list_id)},
   #        {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
   #        {:ok, _, %TodoList{} = todo} <-
-  #          ActivityPub.update_todo_list(todo_list, actor, true, %{}) do
+  #          Actions.Update.update_todo_list(todo_list, actor, true, %{}) do
   #     {:ok, todo}
   #   else
   #     {:todo_list, _} ->
@@ -135,7 +146,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
   #          {:todo_list, Todos.get_todo_list(todo_list_id)},
   #        {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
   #        {:ok, _, %TodoList{} = todo} <-
-  #          ActivityPub.delete_todo_list(todo_list, actor, true, %{}) do
+  #          Actions.Delete.delete_todo_list(todo_list, actor, true, %{}) do
   #     {:ok, todo}
   #   else
   #     {:todo_list, _} ->
@@ -146,15 +157,15 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
   #   end
   # end
 
+  @spec get_todo(any(), map(), Absinthe.Resolution.t()) :: {:ok, Todo.t()} | {:error, String.t()}
   def get_todo(
         _parent,
         %{id: todo_id},
         %{
-          context: %{current_user: %User{} = user}
+          context: %{current_actor: %Actor{id: actor_id}}
         } = _resolution
       ) do
-    with {:actor, %Actor{id: actor_id}} <- {:actor, Users.get_actor_for_user(user)},
+    with {:todo, %Todo{todo_list_id: todo_list_id} = todo} <-
-         {:todo, %Todo{todo_list_id: todo_list_id} = todo} <-
            {:todo, Todos.get_todo(todo_id)},
          {:todo_list, %TodoList{actor_id: group_id}} <-
            {:todo_list, Todos.get_todo_list(todo_list_id)},
@@ -172,21 +183,30 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
     end
   end
 
+  @spec create_todo(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Todo.t()} | {:error, String.t()}
   def create_todo(
         _parent,
         %{todo_list_id: todo_list_id} = args,
         %{
-          context: %{current_user: %User{} = user}
+          context: %{current_actor: %Actor{id: actor_id}}
         } = _resolution
       ) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    with {:todo_list, %TodoList{actor_id: group_id} = _todo_list} <-
-         {:todo_list, %TodoList{actor_id: group_id} = _todo_list} <-
            {:todo_list, Todos.get_todo_list(todo_list_id)},
          {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          {:ok, _, %Todo{} = todo} <-
-           ActivityPub.create(:todo, Map.put(args, :creator_id, actor_id), true, %{}) do
+           Actions.Create.create(
+             :todo,
+             Map.put(args, :creator_id, actor_id),
+             true,
+             %{}
+           ) do
       {:ok, todo}
     else
+      {:actor, nil} ->
+        {:error, dgettext("errors", "No profile found for user")}
+
       {:todo_list, _} ->
         {:error, dgettext("errors", "Todo list doesn't exist")}
 
@@ -195,23 +215,27 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
     end
   end
 
+  @spec update_todo(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Todo.t()} | {:error, String.t()}
   def update_todo(
         _parent,
         %{id: todo_id} = args,
         %{
-          context: %{current_user: %User{} = user}
+          context: %{current_actor: %Actor{id: actor_id}}
         } = _resolution
       ) do
-    with {:actor, %Actor{id: actor_id} = _actor} <- {:actor, Users.get_actor_for_user(user)},
+    with {:todo, %Todo{todo_list_id: todo_list_id} = todo} <-
-         {:todo, %Todo{todo_list_id: todo_list_id} = todo} <-
            {:todo, Todos.get_todo(todo_id)},
          {:todo_list, %TodoList{actor_id: group_id}} <-
            {:todo_list, Todos.get_todo_list(todo_list_id)},
          {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
          {:ok, _, %Todo{} = todo} <-
-           ActivityPub.update(todo, args, true, %{}) do
+           Actions.Update.update(todo, args, true, %{}) do
       {:ok, todo}
     else
+      {:actor, nil} ->
+        {:error, dgettext("errors", "No profile found for user")}
+
       {:todo_list, _} ->
         {:error, dgettext("errors", "Todo list doesn't exist")}
 
@@ -237,7 +261,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Todos do
   #          {:todo_list, Todos.get_todo_list(todo_list_id)},
   #        {:member, true} <- {:member, Actors.is_member?(actor_id, group_id)},
   #        {:ok, _, %Todo{} = todo} <-
-  #          ActivityPub.delete_todo(todo, actor, true, %{}) do
+  #          Actions.Delete.delete_todo(todo, actor, true, %{}) do
   #     {:ok, todo}
   #   else
   #     {:todo_list, _} ->

lib/graphql/resolvers/user.ex

@@ -7,8 +7,7 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
 
   alias Mobilizon.{Actors, Admin, Config, Events, Users}
   alias Mobilizon.Actors.Actor
-  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityPub.{Actions, Relay}
-  alias Mobilizon.Federation.ActivityPub.Relay
   alias Mobilizon.Service.Auth.Authenticator
   alias Mobilizon.Storage.{Page, Repo}
   alias Mobilizon.Users.{Setting, User}
@@ -21,6 +20,7 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   @doc """
   Find an user by its ID
   """
+  @spec find_user(any(), map(), Absinthe.Resolution.t()) :: {:ok, User.t()} | {:error, String.t()}
   def find_user(_parent, %{id: id}, %{context: %{current_user: %User{role: role}}})
       when is_moderator(role) do
     with {:ok, %User{} = user} <- Users.get_user_with_actors(id) do
@@ -31,6 +31,8 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   @doc """
   Return current logged-in user
   """
+  @spec get_current_user(any, map(), Absinthe.Resolution.t()) ::
+          {:error, :unauthenticated} | {:ok, Mobilizon.Users.User.t()}
   def get_current_user(_parent, _args, %{context: %{current_user: %User{} = user}}) do
     {:ok, user}
   end
@@ -42,6 +44,8 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   @doc """
   List instance users
   """
+  @spec list_users(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, Page.t(User.t())} | {:error, :unauthorized}
   def list_users(
         _parent,
         %{email: email, page: page, limit: limit, sort: sort, direction: direction},
@@ -58,6 +62,8 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   @doc """
   Login an user. Returns a token and the user
   """
+  @spec login_user(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, map()} | {:error, :user_not_found | String.t()}
   def login_user(_parent, %{email: email, password: password}, %{context: context}) do
     with {:ok,
           %{
@@ -65,9 +71,8 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
             refresh_token: _refresh_token,
             user: %User{} = user
           } = user_and_tokens} <- Authenticator.authenticate(email, password),
-         {:ok, %User{} = user} <- update_user_login_information(user, context),
+         {:ok, %User{} = user} <- update_user_login_information(user, context) do
-         user_and_tokens <- Map.put(user_and_tokens, :user, user) do
+      {:ok, %{user_and_tokens | user: user}}
-      {:ok, user_and_tokens}
     else
       {:error, :user_not_found} ->
         {:error, :user_not_found}
@@ -87,6 +92,8 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   @doc """
   Refresh a token
   """
+  @spec refresh_token(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, map()} | {:error, String.t()}
   def refresh_token(_parent, %{refresh_token: refresh_token}, _resolution) do
     with {:ok, user, _claims} <- Auth.Guardian.resource_from_token(refresh_token),
          {:ok, _old, {exchanged_token, _claims}} <-
@@ -105,6 +112,9 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
     {:error, dgettext("errors", "You need to have an existing token to get a refresh token")}
   end
 
+  @spec logout(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, String.t()}
+          | {:error, :token_not_found | :unable_to_logout | :unauthenticated | :invalid_argument}
   def logout(_parent, %{refresh_token: refresh_token}, %{context: %{current_user: %User{}}}) do
     with {:ok, _claims} <- Auth.Guardian.decode_and_verify(refresh_token, %{"typ" => "refresh"}),
          {:ok, _claims} <- Auth.Guardian.revoke(refresh_token) do
@@ -133,7 +143,7 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
     - create the user
     - send a validation email to the user
   """
-  @spec create_user(any, map, any) :: tuple
+  @spec create_user(any, %{email: String.t()}, any) :: {:ok, User.t()} | {:error, String.t()}
   def create_user(_parent, %{email: email} = args, _resolution) do
     with :registration_ok <- check_registration_config(email),
          :not_deny_listed <- check_registration_denylist(email),
@@ -160,20 +170,22 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
     end
   end
 
-  @spec check_registration_config(map) :: atom
+  @spec check_registration_config(String.t()) ::
+          :registration_ok | :registration_closed | :not_allowlisted
   defp check_registration_config(email) do
     cond do
       Config.instance_registrations_open?() ->
         :registration_ok
 
       Config.instance_registrations_allowlist?() ->
-        check_allow_listed_email?(email)
+        check_allow_listed_email(email)
 
       true ->
         :registration_closed
     end
   end
 
+  @spec check_registration_denylist(String.t()) :: :deny_listed | :not_deny_listed
   defp check_registration_denylist(email) do
     # Remove everything behind the +
     email = String.replace(email, ~r/(\+.*)(?=\@)/, "")
@@ -183,8 +195,8 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
       else: :not_deny_listed
   end
 
-  @spec check_allow_listed_email?(String.t()) :: :registration_ok | :not_allowlisted
+  @spec check_allow_listed_email(String.t()) :: :registration_ok | :not_allowlisted
-  defp check_allow_listed_email?(email) do
+  defp check_allow_listed_email(email) do
     if email_in_list(email, Config.instance_registrations_allowlist()),
       do: :registration_ok,
       else: :not_allowlisted
@@ -199,23 +211,29 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   @doc """
   Validate an user, get its actor and a token
   """
+  @spec validate_user(map(), %{token: String.t()}, map()) :: {:ok, map()} | {:error, String.t()}
   def validate_user(_parent, %{token: token}, _resolution) do
-    with {:check_confirmation_token, {:ok, %User{} = user}} <-
+    case Email.User.check_confirmation_token(token) do
-           {:check_confirmation_token, Email.User.check_confirmation_token(token)},
+      {:ok, %User{} = user} ->
-         {:get_actor, actor} <- {:get_actor, Users.get_actor_for_user(user)},
+        actor = Users.get_actor_for_user(user)
-         {:ok, %{access_token: access_token, refresh_token: refresh_token}} <-
+
-           Authenticator.generate_tokens(user) do
+        {:ok, %{access_token: access_token, refresh_token: refresh_token}} =
+          Authenticator.generate_tokens(user)
+
         {:ok,
          %{
            access_token: access_token,
            refresh_token: refresh_token,
            user: Map.put(user, :default_actor, actor)
          }}
-    else
-      error ->
-        Logger.info("Unable to validate user with token #{token}")
-        Logger.debug(inspect(error))
 
+      {:error, :invalid_token} ->
+        Logger.info("Invalid token #{token} to validate user")
+        {:error, dgettext("errors", "Unable to validate user")}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        Logger.info("Unable to validate user with token #{token}")
+        Logger.debug(inspect(err))
         {:error, dgettext("errors", "Unable to validate user")}
     end
   end
@@ -267,12 +285,25 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   @doc """
   Reset the password from an user
   """
+  @spec reset_password(map(), %{password: String.t(), token: String.t()}, map()) ::
+          {:ok, map()} | {:error, String.t()}
   def reset_password(_parent, %{password: password, token: token}, _resolution) do
-    with {:ok, %User{email: email} = user} <-
+    case Email.User.check_reset_password_token(password, token) do
-           Email.User.check_reset_password_token(password, token),
+      {:ok, %User{email: email} = user} ->
-         {:ok, %{access_token: access_token, refresh_token: refresh_token}} <-
+        {:ok, tokens} = Authenticator.authenticate(email, password)
-           Authenticator.authenticate(email, password) do
+        {:ok, Map.put(tokens, :user, user)}
-      {:ok, %{access_token: access_token, refresh_token: refresh_token, user: user}}
+
+      {:error, %Ecto.Changeset{errors: [password: {"registration.error.password_too_short", _}]}} ->
+        {:error,
+         gettext(
+           "The password you have choosen is too short. Please make sure your password contains at least 6 charaters."
+         )}
+
+      {:error, _err} ->
+        {:error,
+         gettext(
+           "The token you provided is invalid. Make sure that the URL is exactly the one provided inside the email you got."
+         )}
     end
   end
 
@@ -280,12 +311,12 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   def change_default_actor(
         _parent,
         %{preferred_username: username},
-        %{context: %{current_user: user}}
+        %{context: %{current_user: %User{id: user_id} = user}}
       ) do
-    with %Actor{id: actor_id} <- Actors.get_local_actor_by_name(username),
+    with %Actor{id: actor_id} = actor <- Actors.get_local_actor_by_name(username),
          {:user_actor, true} <-
            {:user_actor, actor_id in Enum.map(Users.get_actors_for_user(user), & &1.id)},
-         %User{} = user <- Users.update_user_default_actor(user.id, actor_id) do
+         %User{} = user <- Users.update_user_default_actor(user_id, actor) do
       {:ok, user}
     else
       {:user_actor, _} ->
@@ -369,6 +400,9 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
            |> Repo.update() do
       {:ok, user}
     else
+      {:can_change_password, false} ->
+        {:error, dgettext("errors", "You cannot change your password.")}
+
       {:current_password, _} ->
         {:error, dgettext("errors", "The current password is invalid")}
 
@@ -408,14 +442,18 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
 
       {:ok, user}
     else
-      {:current_password, _} ->
+      {:current_password, {:error, _}} ->
         {:error, dgettext("errors", "The password provided is invalid")}
 
       {:same_email, true} ->
         {:error, dgettext("errors", "The new email must be different")}
 
-      {:email_valid, _} ->
+      {:email_valid, false} ->
         {:error, dgettext("errors", "The new email doesn't seem to be valid")}
+
+      {:error, %Ecto.Changeset{} = err} ->
+        Logger.debug(inspect(err))
+        {:error, dgettext("errors", "Failed to update user email")}
     end
   end
 
@@ -423,30 +461,37 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
     {:error, dgettext("errors", "You need to be logged-in to change your email")}
   end
 
+  @spec validate_email(map(), %{token: String.t()}, map()) ::
+          {:ok, User.t()} | {:error, String.t()}
   def validate_email(_parent, %{token: token}, _resolution) do
-    with {:get, %User{} = user} <- {:get, Users.get_user_by_activation_token(token)},
+    case Users.get_user_by_activation_token(token) do
-         {:ok, %User{} = user} <- Users.validate_email(user) do
+      %User{} = user ->
+        case Users.validate_email(user) do
+          {:ok, %User{} = user} ->
             {:ok, user}
-    else
+
-      {:get, nil} ->
+          {:error, %Ecto.Changeset{} = err} ->
+            Logger.debug(inspect(err))
+            {:error, dgettext("errors", "Failed to validate user email")}
+        end
+
+      nil ->
         {:error, dgettext("errors", "Invalid activation token")}
     end
   end
 
   def delete_account(_parent, %{user_id: user_id}, %{
-        context: %{current_user: %User{role: role} = moderator_user}
+        context: %{
+          current_user: %User{role: role},
+          current_actor: %Actor{} = moderator_actor
+        }
       })
       when is_moderator(role) do
-    with {:moderator_actor, %Actor{} = moderator_actor} <-
+    with %User{disabled: false} = user <- Users.get_user(user_id),
-           {:moderator_actor, Users.get_actor_for_user(moderator_user)},
-         %User{disabled: false} = user <- Users.get_user(user_id),
          {:ok, %User{}} <-
            do_delete_account(%User{} = user, actor_performing: Relay.get_actor()) do
       Admin.log_action(moderator_actor, "delete", user)
     else
-      {:moderator_actor, nil} ->
-        {:error, dgettext("errors", "No profile found for the moderator user")}
-
       %User{disabled: true} ->
         {:error, dgettext("errors", "User already disabled")}
     end
@@ -488,7 +533,7 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
          :ok <-
            Enum.each(actors, fn actor ->
              actor_performing = Keyword.get(options, :actor_performing, actor)
-             ActivityPub.delete(actor, actor_performing, true)
+             Actions.Delete.delete(actor, actor_performing, true)
            end),
          # Delete user
          {:ok, user} <-
@@ -547,11 +592,16 @@ defmodule Mobilizon.GraphQL.Resolvers.User do
   def update_locale(_parent, %{locale: locale}, %{
         context: %{current_user: %User{locale: current_locale} = user}
       }) do
-    with true <- current_locale != locale,
+    if current_locale != locale do
-         {:ok, %User{} = updated_user} <- Users.update_user(user, %{locale: locale}) do
+      case Users.update_user(user, %{locale: locale}) do
+        {:ok, %User{} = updated_user} ->
           {:ok, updated_user}
+
+        {:error, %Ecto.Changeset{} = err} ->
+          Logger.debug(err)
+          {:error, dgettext("errors", "Error while updating locale")}
+      end
     else
-      false ->
       {:ok, user}
     end
   end

lib/graphql/resolvers/users/activity_settings.ex

@@ -4,10 +4,12 @@ defmodule Mobilizon.GraphQL.Resolvers.Users.ActivitySettings do
   """
 
   alias Mobilizon.Users
-  alias Mobilizon.Users.User
+  alias Mobilizon.Users.{ActivitySetting, User}
 
   require Logger
 
+  @spec user_activity_settings(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, list(ActivitySetting.t())} | {:error, :unauthenticated}
   def user_activity_settings(_parent, _args, %{context: %{current_user: %User{} = user}}) do
     {:ok, Users.activity_settings_for_user(user)}
   end
@@ -16,6 +18,8 @@ defmodule Mobilizon.GraphQL.Resolvers.Users.ActivitySettings do
     {:error, :unauthenticated}
   end
 
+  @spec upsert_user_activity_setting(any(), map(), Absinthe.Resolution.t()) ::
+          {:ok, ActivitySetting.t()} | {:error, :unauthenticated}
   def upsert_user_activity_setting(_parent, args, %{context: %{current_user: %User{id: user_id}}}) do
     Users.create_activity_setting(Map.put(args, :user_id, user_id))
   end