defmodule Eventos.Groups.Group.TitleSlug do
  @moduledoc """
  Slug generation for groups
  """
  alias Eventos.Groups.Group
  import Ecto.Query
  alias Eventos.Repo
  use EctoAutoslugField.Slug, from: :title, to: :slug

  def build_slug(sources, changeset) do
    slug = super(sources, changeset)
    build_unique_slug(slug, changeset)
  end

  defp build_unique_slug(slug, changeset) do
    query = from g in Group,
                 where: g.slug == ^slug

    case Repo.one(query) do
      nil -> slug
      _story ->
        slug
        |> Eventos.Slug.increment_slug()
        |> build_unique_slug(changeset)
    end
  end
end

defmodule Eventos.Groups.Group do
  @moduledoc """
  Represents a group
  """
  use Ecto.Schema
  import Ecto.Changeset
  alias Eventos.Groups.{Group, Member, Request}
  alias Eventos.Accounts.Account
  alias Eventos.Groups.Group.TitleSlug

  schema "groups" do
    field :description, :string
    field :suspended, :boolean, default: false
    field :title, :string
    field :slug, TitleSlug.Type
    field :uri, :string
    field :url, :string
    many_to_many :accounts, Account, join_through: Member
    has_many :requests, Request

    timestamps()
  end

  @doc false
  def changeset(%Group{} = group, attrs) do
    group
    |> cast(attrs, [:title, :description, :suspended, :url, :uri])
    |> validate_required([:title, :description, :suspended, :url, :uri])
    |> TitleSlug.maybe_generate_slug()
    |> TitleSlug.unique_constraint()
  end
end