# Portions of this file are derived from Pleroma: # Copyright © 2017-2018 Pleroma Authors <https://pleroma.social> # SPDX-License-Identifier: AGPL-3.0-only # Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/pleroma/web/activity_pub/transmogrifier.ex defmodule Mobilizon.Service.ActivityPub.Transmogrifier do @moduledoc """ A module to handle coding from internal to wire ActivityPub and back. """ alias Mobilizon.Actors alias Mobilizon.Actors.{Actor, Follower} alias Mobilizon.Events alias Mobilizon.Events.{Event, Comment, Participant} alias Mobilizon.Service.ActivityPub alias Mobilizon.Service.ActivityPub.{Visibility, Utils} require Logger def get_actor(%{"actor" => actor}) when is_binary(actor) do actor end def get_actor(%{"actor" => actor}) when is_list(actor) do if is_binary(Enum.at(actor, 0)) do Enum.at(actor, 0) else Enum.find(actor, fn %{"type" => type} -> type in ["Person", "Service", "Application"] end) |> Map.get("id") end end def get_actor(%{"actor" => %{"id" => id}}) when is_bitstring(id) do id end def get_actor(%{"actor" => nil, "attributedTo" => actor}) when not is_nil(actor) do get_actor(%{"actor" => actor}) end @doc """ Modifies an incoming AP object (mastodon format) to our internal format. """ def fix_object(object) do object |> Map.put("actor", object["attributedTo"]) |> fix_attachments |> fix_in_reply_to # |> fix_tag end def fix_in_reply_to(%{"inReplyTo" => in_reply_to} = object) when not is_nil(in_reply_to) and is_bitstring(in_reply_to) do in_reply_to |> do_fix_in_reply_to(object) end def fix_in_reply_to(%{"inReplyTo" => in_reply_to} = object) when not is_nil(in_reply_to) and is_map(in_reply_to) do if is_bitstring(in_reply_to["id"]) do in_reply_to["id"] |> do_fix_in_reply_to(object) end end def fix_in_reply_to(%{"inReplyTo" => in_reply_to} = object) when not is_nil(in_reply_to) and is_list(in_reply_to) do if is_bitstring(Enum.at(in_reply_to, 0)) do in_reply_to |> Enum.at(0) |> do_fix_in_reply_to(object) end end def fix_in_reply_to(%{"inReplyTo" => in_reply_to} = object) when not is_nil(in_reply_to) do Logger.warn("inReplyTo ID seem incorrect: #{inspect(in_reply_to)}") do_fix_in_reply_to("", object) end def fix_in_reply_to(object), do: object def do_fix_in_reply_to(in_reply_to_id, object) do case fetch_obj_helper(in_reply_to_id) do {:ok, replied_object} -> object |> Map.put("inReplyTo", replied_object.url) {:error, {:error, :not_supported}} -> Logger.info("Object reply origin has not a supported type") object e -> Logger.warn("Couldn't fetch #{in_reply_to_id} #{inspect(e)}") object end end def fix_attachments(object) do attachments = (object["attachment"] || []) |> Enum.map(fn data -> url = [%{"type" => "Link", "mediaType" => data["mediaType"], "href" => data["url"]}] Map.put(data, "url", url) end) object |> Map.put("attachment", attachments) end def fix_tag(object) do tags = (object["tag"] || []) |> Enum.filter(fn data -> data["type"] == "Hashtag" and data["name"] end) |> Enum.map(fn data -> String.slice(data["name"], 1..-1) end) combined = (object["tag"] || []) ++ tags object |> Map.put("tag", combined) end def handle_incoming(%{"id" => nil}), do: :error def handle_incoming(%{"id" => ""}), do: :error def handle_incoming(%{"type" => "Flag"} = data) do with params <- Mobilizon.Service.ActivityPub.Converters.Flag.as_to_model(data) do params = %{ reporter_url: params["reporter"].url, reported_actor_url: params["reported"].url, comments_url: params["comments"] |> Enum.map(& &1.url), content: params["content"] || "", additional: %{ "cc" => [params["reported"].url] } } ActivityPub.flag(params) end end def handle_incoming(%{"type" => "Create", "object" => %{"type" => "Note"} = object} = data) do Logger.info("Handle incoming to create notes") with {:ok, %Actor{} = actor} <- ActivityPub.get_or_fetch_by_url(data["actor"]) do Logger.debug("found actor") Logger.debug(inspect(actor)) params = %{ to: data["to"], object: object |> fix_object, actor: actor, local: false, published: data["published"], additional: Map.take(data, [ "cc", "id" ]) } ActivityPub.create(params) end end def handle_incoming(%{"type" => "Create", "object" => %{"type" => "Event"} = object} = data) do Logger.info("Handle incoming to create event") with {:ok, %Actor{} = actor} <- ActivityPub.get_or_fetch_by_url(data["actor"]) do Logger.debug("found actor") Logger.debug(inspect(actor)) params = %{ to: data["to"], object: object |> fix_object, actor: actor, local: false, published: data["published"], additional: Map.take(data, [ "cc", "id" ]) } ActivityPub.create(params) end end def handle_incoming( %{"type" => "Follow", "object" => followed, "actor" => follower, "id" => id} = _data ) do with {:ok, %Actor{} = followed} <- ActivityPub.get_or_fetch_by_url(followed, true), {:ok, %Actor{} = follower} <- ActivityPub.get_or_fetch_by_url(follower), {:ok, activity, object} <- ActivityPub.follow(follower, followed, id, false) do {:ok, activity, object} else e -> Logger.warn("Unable to handle Follow activity #{inspect(e)}") :error end end def handle_incoming( %{ "type" => "Accept", "object" => accepted_object, "actor" => _actor, "id" => id } = data ) do with actor_url <- get_actor(data), {:ok, %Actor{} = actor} <- ActivityPub.get_or_fetch_by_url(actor_url), {:object_not_found, {:ok, activity, object}} <- {:object_not_found, do_handle_incoming_accept_following(accepted_object, actor) || do_handle_incoming_accept_join(accepted_object, actor)} do {:ok, activity, object} else {:object_not_found, nil} -> Logger.warn( "Unable to process Accept activity #{inspect(id)}. Object #{inspect(accepted_object)} wasn't found." ) :error e -> Logger.warn( "Unable to process Accept activity #{inspect(id)} for object #{inspect(accepted_object)} only returned #{ inspect(e) }" ) :error end end def handle_incoming( %{"type" => "Reject", "object" => rejected_object, "actor" => _actor, "id" => id} = data ) do with actor_url <- get_actor(data), {:ok, %Actor{} = actor} <- ActivityPub.get_or_fetch_by_url(actor_url), {:object_not_found, {:ok, activity, object}} <- {:object_not_found, do_handle_incoming_reject_following(rejected_object, actor) || do_handle_incoming_reject_join(rejected_object, actor)} do {:ok, activity, object} else {:object_not_found, nil} -> Logger.warn( "Unable to process Reject activity #{inspect(id)}. Object #{inspect(rejected_object)} wasn't found." ) :error e -> Logger.warn( "Unable to process Reject activity #{inspect(id)} for object #{inspect(rejected_object)} only returned #{ inspect(e) }" ) :error end end # # def handle_incoming( # %{"type" => "Like", "object" => object_id, "actor" => actor, "id" => id} = data # ) do # with %User{} = actor <- User.get_or_fetch_by_ap_id(actor), # {:ok, object} <- # fetch_obj_helper(object_id) || ActivityPub.fetch_object_from_id(object_id), # {:ok, activity, object} <- ActivityPub.like(actor, object, id, false) do # {:ok, activity} # else # _e -> :error # end # end # # def handle_incoming( %{"type" => "Announce", "object" => object_id, "actor" => _actor, "id" => id} = data ) do with actor <- get_actor(data), {:ok, %Actor{} = actor} <- ActivityPub.get_or_fetch_by_url(actor), {:ok, object} <- fetch_obj_helper_as_activity_streams(object_id), public <- Visibility.is_public?(data), {:ok, activity, object} <- ActivityPub.announce(actor, object, id, false, public) do {:ok, activity, object} else e -> Logger.debug(inspect(e)) :error end end def handle_incoming( %{"type" => "Update", "object" => %{"type" => object_type} = object, "actor" => _actor_id} = data ) when object_type in ["Person", "Group", "Application", "Service", "Organization"] do case Actors.get_actor_by_url(object["id"]) do {:ok, %Actor{url: actor_url}} -> ActivityPub.update(%{ local: false, to: data["to"] || [], cc: data["cc"] || [], object: object, actor: actor_url }) e -> Logger.debug(inspect(e)) :error end end def handle_incoming( %{"type" => "Update", "object" => %{"type" => "Event"} = object, "actor" => actor} = _update ) do with {:ok, %{"actor" => existing_organizer_actor_url} = existing_event_data} <- fetch_obj_helper_as_activity_streams(object), object <- Map.merge(existing_event_data, object), {:ok, %Actor{url: actor_url}} <- actor |> Utils.get_url() |> Actors.get_actor_by_url(), true <- Utils.get_url(existing_organizer_actor_url) == actor_url do ActivityPub.update(%{ local: false, to: object["to"] || [], cc: object["cc"] || [], object: object, actor: actor_url }) else e -> Logger.debug(inspect(e)) :error end end def handle_incoming( %{ "type" => "Undo", "object" => %{ "type" => "Announce", "object" => object_id, "id" => cancelled_activity_id }, "actor" => _actor, "id" => id } = data ) do with actor <- get_actor(data), {:ok, %Actor{} = actor} <- ActivityPub.get_or_fetch_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 {:ok, activity, object} else _e -> :error end end def handle_incoming( %{ "type" => "Undo", "object" => %{"type" => "Follow", "object" => followed}, "actor" => follower, "id" => id } = _data ) do with {:ok, %Actor{domain: nil} = followed} <- Actors.get_actor_by_url(followed), {:ok, %Actor{} = follower} <- Actors.get_actor_by_url(follower), {:ok, activity, object} <- ActivityPub.unfollow(follower, followed, id, false) do {:ok, activity, object} else e -> Logger.debug(inspect(e)) :error end end # TODO: We presently assume that any actor on the same origin domain as the object being # deleted has the rights to delete that object. A better way to validate whether or not # the object should be deleted is to refetch the object URI, which should return either # an error or a tombstone. This would allow us to verify that a deletion actually took # place. def handle_incoming( %{"type" => "Delete", "object" => object, "actor" => _actor, "id" => _id} = data ) do object_id = Utils.get_url(object) with actor <- get_actor(data), {:ok, %Actor{url: _actor_url}} <- Actors.get_actor_by_url(actor), {:ok, object} <- fetch_obj_helper(object_id), # TODO : Validate that DELETE comes indeed form right domain (see above) # :ok <- contain_origin(actor_url, object.data), {:ok, activity, object} <- ActivityPub.delete(object, false) do {:ok, activity, object} else e -> Logger.debug(inspect(e)) :error end end def handle_incoming( %{"type" => "Join", "object" => object, "actor" => _actor, "id" => _id} = data ) do with actor <- get_actor(data), {:ok, %Actor{url: _actor_url} = actor} <- Actors.get_actor_by_url(actor), {:ok, object} <- fetch_obj_helper(object), {:ok, activity, object} <- ActivityPub.join(object, actor, false) do {:ok, activity, object} else e -> Logger.debug(inspect(e)) :error end end def handle_incoming( %{"type" => "Leave", "object" => object, "actor" => actor, "id" => _id} = data ) do with actor <- get_actor(data), {:ok, %Actor{} = actor} <- Actors.get_actor_by_url(actor), {:ok, object} <- fetch_obj_helper(object), {:ok, activity, object} <- ActivityPub.leave(object, actor, false) do {:ok, activity, object} else {:only_organizer, true} -> Logger.warn( "Actor #{inspect(actor)} tried to leave event #{inspect(object)} but it was the only organizer so we didn't detach it" ) :error e -> Logger.error(inspect(e)) :error end end # # # TODO # # Accept # # Undo # # def handle_incoming( # %{ # "type" => "Undo", # "object" => %{"type" => "Like", "object" => object_id}, # "actor" => _actor, # "id" => id # } = data # ) do # with actor <- get_actor(data), # %Actor{} = actor <- ActivityPub.get_or_fetch_by_url(actor), # {:ok, object} <- fetch_obj_helper(object_id) || fetch_obj_helper(object_id), # {:ok, activity, _, _} <- ActivityPub.unlike(actor, object, id, false) do # {:ok, activity} # else # _e -> :error # end # end def handle_incoming(_) do Logger.info("Handing something not supported") {:error, :not_supported} end @doc """ Handle incoming `Accept` activities wrapping a `Follow` activity """ def do_handle_incoming_accept_following(follow_object, %Actor{} = actor) do with {:follow, {:ok, %Follower{approved: false, actor: follower, id: follow_id, target_actor: followed} = follow}} <- {:follow, get_follow(follow_object)}, {:same_actor, true} <- {:same_actor, actor.id == followed.id}, {:ok, activity, _} <- ActivityPub.accept( %{ to: [follower.url], actor: actor.url, object: follow_object, local: false }, "#{MobilizonWeb.Endpoint.url()}/accept/follow/#{follow_id}" ), {:ok, %Follower{approved: true}} <- Actors.update_follower(follow, %{"approved" => true}) do {:ok, activity, follow} else {:follow, _} -> Logger.debug( "Tried to handle an Accept activity but it's not containing a Follow activity" ) nil {:same_actor} -> {:error, "Actor who accepted the follow wasn't the target. Quite odd."} {:ok, %Follower{approved: true} = _follow} -> {:error, "Follow already accepted"} end end @doc """ Handle incoming `Reject` activities wrapping a `Follow` activity """ def do_handle_incoming_reject_following(follow_object, %Actor{} = actor) do with {:follow, {:ok, %Follower{approved: false, actor: follower, id: follow_id, target_actor: followed} = follow}} <- {:follow, get_follow(follow_object)}, {:same_actor, true} <- {:same_actor, actor.id == followed.id}, {:ok, activity, _} <- ActivityPub.reject( %{ to: [follower.url], actor: actor.url, object: follow_object, local: false }, "#{MobilizonWeb.Endpoint.url()}/reject/follow/#{follow_id}" ), {:ok, %Follower{}} <- Actors.delete_follower(follow) do {:ok, activity, follow} else {:follow, _} -> Logger.debug( "Tried to handle a Reject activity but it's not containing a Follow activity" ) nil {:same_actor} -> {:error, "Actor who rejected the follow wasn't the target. Quite odd."} {:ok, %Follower{approved: true} = _follow} -> {:error, "Follow already accepted"} end end @doc """ Handle incoming `Accept` activities wrapping a `Join` activity on an event """ def do_handle_incoming_accept_join(join_object, %Actor{} = actor_accepting) do with {:join_event, {:ok, %Participant{role: :not_approved, actor: actor, id: join_id, event: event} = participant}} <- {:join_event, get_participant(join_object)}, # TODO: The actor that accepts the Join activity may another one that the event organizer ? # Or maybe for groups it's the group that sends the Accept activity {:same_actor, true} <- {:same_actor, actor_accepting.id == event.organizer_actor_id}, {:ok, activity, _} <- ActivityPub.accept( %{ to: [actor.url], actor: actor_accepting.url, object: join_object, local: false }, "#{MobilizonWeb.Endpoint.url()}/accept/join/#{join_id}" ), {:ok, %Participant{role: :participant}} <- Events.update_participant(participant, %{"role" => :participant}) do {:ok, activity, participant} else {:join_event, {:ok, %Participant{role: :participant}}} -> Logger.debug( "Tried to handle an Accept activity on a Join activity with a event object but the participant is already validated" ) nil {:join_event, _err} -> Logger.debug( "Tried to handle an Accept activity but it's not containing a Join activity on a event" ) nil {:same_actor} -> {:error, "Actor who accepted the join wasn't the event organizer. Quite odd."} {:ok, %Participant{role: :participant} = _follow} -> {:error, "Participant"} end end @doc """ Handle incoming `Reject` activities wrapping a `Join` activity on an event """ def do_handle_incoming_reject_join(join_object, %Actor{} = actor_accepting) do with {:join_event, {:ok, %Participant{role: :not_approved, actor: actor, id: join_id, event: event} = participant}} <- {:join_event, get_participant(join_object)}, # TODO: The actor that accepts the Join activity may another one that the event organizer ? # Or maybe for groups it's the group that sends the Accept activity {:same_actor, true} <- {:same_actor, actor_accepting.id == event.organizer_actor_id}, {:ok, activity, _} <- ActivityPub.reject( %{ to: [actor.url], actor: actor_accepting.url, object: join_object, local: false }, "#{MobilizonWeb.Endpoint.url()}/reject/join/#{join_id}" ), {:ok, %Participant{}} <- Events.delete_participant(participant) do {:ok, activity, participant} else {:join_event, {:ok, %Participant{role: :participant}}} -> Logger.debug( "Tried to handle an Reject activity on a Join activity with a event object but the participant is already validated" ) nil {:join_event, _err} -> Logger.debug( "Tried to handle an Reject activity but it's not containing a Join activity on a event" ) nil {:same_actor} -> {:error, "Actor who rejected the join wasn't the event organizer. Quite odd."} {:ok, %Participant{role: :participant} = _follow} -> {:error, "Participant"} end end # TODO: Add do_handle_incoming_accept_join/1 on Groups defp get_follow(follow_object) do with follow_object_id when not is_nil(follow_object_id) <- Utils.get_url(follow_object), {:not_found, %Follower{} = follow} <- {:not_found, Actors.get_follower_by_url(follow_object_id)} do {:ok, follow} else {:not_found, _err} -> {:error, "Follow URL not found"} _ -> {:error, "ActivityPub ID not found in Accept Follow object"} end end defp get_participant(join_object) do with join_object_id when not is_nil(join_object_id) <- Utils.get_url(join_object), {:not_found, %Participant{} = participant} <- {:not_found, Events.get_participant_by_url(join_object_id)} do {:ok, participant} else {:not_found, _err} -> {:error, "Participant URL not found"} _ -> {:error, "ActivityPub ID not found in Accept Join object"} end end def set_reply_to_uri(%{"inReplyTo" => in_reply_to} = object) do with false <- String.starts_with?(in_reply_to, "http"), {:ok, replied_to_object} <- fetch_obj_helper(in_reply_to) do Map.put(object, "inReplyTo", replied_to_object["external_url"] || in_reply_to) else _e -> object end end def set_reply_to_uri(obj), do: obj # # # Prepares the object of an outgoing create activity. def prepare_object(object) do object # |> set_sensitive |> add_hashtags |> add_mention_tags # |> add_emoji_tags |> add_attributed_to # |> prepare_attachments |> set_reply_to_uri end @doc """ internal -> Mastodon """ def prepare_outgoing(%{"type" => "Create", "object" => %{"type" => "Note"} = object} = data) do Logger.debug("Prepare outgoing for a note creation") object = object |> prepare_object data = data |> Map.put("object", object) |> Map.merge(Utils.make_json_ld_header()) Logger.debug("Finished prepare outgoing for a note creation") {:ok, data} end def prepare_outgoing(%{"type" => _type} = data) do data = data |> Map.merge(Utils.make_json_ld_header()) {:ok, data} end # def prepare_outgoing(%Event{} = event) do # event = # event # |> Map.from_struct() # |> Map.drop([:__meta__]) # |> Map.put(:"@context", "https://www.w3.org/ns/activitystreams") # |> prepare_object # {:ok, event} # end # def prepare_outgoing(%Comment{} = comment) do # comment = # comment # |> Map.from_struct() # |> Map.drop([:__meta__]) # |> Map.put(:"@context", "https://www.w3.org/ns/activitystreams") # |> prepare_object # {:ok, comment} # end # # def maybe_fix_object_url(data) do # if is_binary(data["object"]) and not String.starts_with?(data["object"], "http") do # case ActivityPub.fetch_object_from_id(data["object"]) do # {:ok, relative_object} -> # if relative_object.data["external_url"] do # data = # data # |> Map.put("object", relative_object.data["external_url"]) # else # data # end # # e -> # Logger.error("Couldn't fetch #{data["object"]} #{inspect(e)}") # data # end # else # data # end # end # def add_hashtags(object) do tags = (object["tag"] || []) |> Enum.map(fn tag -> %{ "href" => MobilizonWeb.Endpoint.url() <> "/tags/#{tag}", "name" => "##{tag}", "type" => "Hashtag" } end) object |> Map.put("tag", tags) end def add_mention_tags(object) do recipients = (object["to"] ++ (object["cc"] || [])) -- ["https://www.w3.org/ns/activitystreams#Public"] mentions = recipients |> Enum.filter(& &1) |> Enum.map(fn url -> case Actors.get_actor_by_url(url) do {:ok, actor} -> actor _ -> nil end end) |> Enum.filter(& &1) |> Enum.map(fn actor -> %{"type" => "Mention", "href" => actor.url, "name" => "@#{actor.preferred_username}"} end) tags = object["tag"] || [] object |> Map.put("tag", tags ++ mentions) end # # # TODO: we should probably send mtime instead of unix epoch time for updated # def add_emoji_tags(object) do # tags = object["tag"] || [] # emoji = object["emoji"] || [] # # out = # emoji # |> Enum.map(fn {name, url} -> # %{ # "icon" => %{"url" => url, "type" => "Image"}, # "name" => ":" <> name <> ":", # "type" => "Emoji", # "updated" => "1970-01-01T00:00:00Z", # "id" => url # } # end) # # object # |> Map.put("tag", tags ++ out) # end # # # def set_sensitive(object) do # tags = object["tag"] || [] # Map.put(object, "sensitive", "nsfw" in tags) # end # def add_attributed_to(object) do attributed_to = object["attributedTo"] || object["actor"] object |> Map.put("attributedTo", attributed_to) end # # def prepare_attachments(object) do # attachments = # (object["attachment"] || []) # |> Enum.map(fn data -> # [%{"mediaType" => media_type, "href" => href} | _] = data["url"] # %{"url" => href, "mediaType" => media_type, "name" => data["name"], "type" => "Document"} # end) # # object # |> Map.put("attachment", attachments) # end @spec fetch_obj_helper(map() | String.t()) :: Event.t() | Comment.t() | Actor.t() | any() def fetch_obj_helper(object) do Logger.debug("Fetching object #{inspect(object)}") case object |> Utils.get_url() |> ActivityPub.fetch_object_from_url() do {:ok, object} -> {:ok, object} err -> Logger.info("Error while fetching #{inspect(object)}") {:error, err} end end def fetch_obj_helper_as_activity_streams(object) do with {:ok, object} <- fetch_obj_helper(object) do {:ok, Mobilizon.Service.ActivityPub.Convertible.model_to_as(object)} end end end