# Pleroma: A lightweight social networking server
# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only

defmodule Pleroma.Activity do
  use Ecto.Schema

  alias Pleroma.Activity
  alias Pleroma.Activity.Queries
  alias Pleroma.Bookmark
  alias Pleroma.Notification
  alias Pleroma.Object
  alias Pleroma.Repo
  alias Pleroma.ReportNote
  alias Pleroma.ThreadMute
  alias Pleroma.User
  alias Pleroma.Web.ActivityPub.ActivityPub

  import Ecto.Changeset
  import Ecto.Query

  require Pleroma.Constants

  @type t :: %__MODULE__{}
  @type actor :: String.t()

  @primary_key {:id, FlakeId.Ecto.CompatType, autogenerate: true}

  schema "activities" do
    field(:data, :map)
    field(:local, :boolean, default: true)
    field(:actor, :string)
    field(:recipients, {:array, :string}, default: [])
    field(:thread_muted?, :boolean, virtual: true)

    # A field that can be used if you need to join some kind of other
    # id to order / paginate this field by
    field(:pagination_id, :string, virtual: true)

    # This is a fake relation,
    # do not use outside of with_preloaded_user_actor/with_joined_user_actor
    has_one(:user_actor, User, on_delete: :nothing, foreign_key: :id)
    # This is a fake relation, do not use outside of with_preloaded_bookmark/get_bookmark
    has_one(:bookmark, Bookmark)
    # This is a fake relation, do not use outside of with_preloaded_report_notes
    has_many(:report_notes, ReportNote)
    has_many(:notifications, Notification, on_delete: :delete_all)

    # Attention: this is a fake relation, don't try to preload it blindly and expect it to work!
    # The foreign key is embedded in a jsonb field.
    #
    # To use it, you probably want to do an inner join and a preload:
    #
    # ```
    # |> join(:inner, [activity], o in Object,
    #      on: fragment("(?->>'id') = COALESCE((?)->'object'->> 'id', (?)->>'object')",
    #        o.data, activity.data, activity.data))
    # |> preload([activity, object], [object: object])
    # ```
    #
    # As a convenience, Activity.with_preloaded_object() sets up an inner join and preload for the
    # typical case.
    has_one(:object, Object, on_delete: :nothing, foreign_key: :id)

    timestamps()
  end

  def with_joined_object(query, join_type \\ :inner) do
    join(query, join_type, [activity], o in Object,
      on:
        fragment(
          "(?->>'id') = COALESCE(?->'object'->>'id', ?->>'object')",
          o.data,
          activity.data,
          activity.data
        ),
      as: :object
    )
  end

  def with_preloaded_object(query, join_type \\ :inner) do
    query
    |> has_named_binding?(:object)
    |> if(do: query, else: with_joined_object(query, join_type))
    |> preload([activity, object: object], object: object)
  end

  # Note: applies to fake activities (ActivityPub.Utils.get_notified_from_object/1 etc.)
  def user_actor(%Activity{actor: nil}), do: nil

  def user_actor(%Activity{} = activity) do
    with %User{} <- activity.user_actor do
      activity.user_actor
    else
      _ -> User.get_cached_by_ap_id(activity.actor)
    end
  end

  def with_joined_user_actor(query, join_type \\ :inner) do
    join(query, join_type, [activity], u in User,
      on: u.ap_id == activity.actor,
      as: :user_actor
    )
  end

  def with_preloaded_user_actor(query, join_type \\ :inner) do
    query
    |> with_joined_user_actor(join_type)
    |> preload([activity, user_actor: user_actor], user_actor: user_actor)
  end

  def with_preloaded_bookmark(query, %User{} = user) do
    from([a] in query,
      left_join: b in Bookmark,
      on: b.user_id == ^user.id and b.activity_id == a.id,
      preload: [bookmark: b]
    )
  end

  def with_preloaded_bookmark(query, _), do: query

  def with_preloaded_report_notes(query) do
    from([a] in query,
      left_join: r in ReportNote,
      on: a.id == r.activity_id,
      preload: [report_notes: r]
    )
  end

  def with_preloaded_report_notes(query, _), do: query

  def with_set_thread_muted_field(query, %User{} = user) do
    from([a] in query,
      left_join: tm in ThreadMute,
      on: tm.user_id == ^user.id and tm.context == fragment("?->>'context'", a.data),
      as: :thread_mute,
      select: %Activity{a | thread_muted?: not is_nil(tm.id)}
    )
  end

  def with_set_thread_muted_field(query, _), do: query

  def get_by_ap_id(ap_id) do
    ap_id
    |> Queries.by_ap_id()
    |> Repo.one()
  end

  def get_bookmark(%Activity{} = activity, %User{} = user) do
    if Ecto.assoc_loaded?(activity.bookmark) do
      activity.bookmark
    else
      Bookmark.get(user.id, activity.id)
    end
  end

  def get_bookmark(_, _), do: nil

  def get_report(activity_id) do
    opts = %{
      type: "Flag",
      skip_preload: true,
      preload_report_notes: true
    }

    ActivityPub.fetch_activities_query([], opts)
    |> where(id: ^activity_id)
    |> Repo.one()
  end

  def change(struct, params \\ %{}) do
    struct
    |> cast(params, [:data, :recipients])
    |> validate_required([:data])
    |> unique_constraint(:ap_id, name: :activities_unique_apid_index)
  end

  def get_by_ap_id_with_object(ap_id) do
    ap_id
    |> Queries.by_ap_id()
    |> with_preloaded_object(:left)
    |> Repo.one()
  end

  @spec get_by_id(String.t()) :: Activity.t() | nil
  def get_by_id(id) do
    case FlakeId.flake_id?(id) do
      true ->
        Activity
        |> where([a], a.id == ^id)
        |> restrict_deactivated_users()
        |> Repo.one()

      _ ->
        nil
    end
  end

  def get_by_id_with_object(id) do
    Activity
    |> where(id: ^id)
    |> with_preloaded_object()
    |> Repo.one()
  end

  def all_by_ids_with_object(ids) do
    Activity
    |> where([a], a.id in ^ids)
    |> with_preloaded_object()
    |> Repo.all()
  end

  @doc """
  Accepts `ap_id` or list of `ap_id`.
  Returns a query.
  """
  @spec create_by_object_ap_id(String.t() | [String.t()]) :: Ecto.Queryable.t()
  def create_by_object_ap_id(ap_id) do
    ap_id
    |> Queries.by_object_id()
    |> Queries.by_type("Create")
  end

  def get_all_create_by_object_ap_id(ap_id) do
    ap_id
    |> create_by_object_ap_id()
    |> Repo.all()
  end

  def get_create_by_object_ap_id(ap_id) when is_binary(ap_id) do
    create_by_object_ap_id(ap_id)
    |> restrict_deactivated_users()
    |> Repo.one()
  end

  def get_create_by_object_ap_id(_), do: nil

  @doc """
  Accepts `ap_id` or list of `ap_id`.
  Returns a query.
  """
  @spec create_by_object_ap_id_with_object(String.t() | [String.t()]) :: Ecto.Queryable.t()
  def create_by_object_ap_id_with_object(ap_id) do
    ap_id
    |> create_by_object_ap_id()
    |> with_preloaded_object()
  end

  def get_create_by_object_ap_id_with_object(ap_id) when is_binary(ap_id) do
    ap_id
    |> create_by_object_ap_id_with_object()
    |> Repo.one()
  end

  def get_create_by_object_ap_id_with_object(_), do: nil

  defp get_in_reply_to_activity_from_object(%Object{data: %{"inReplyTo" => ap_id}}) do
    get_create_by_object_ap_id_with_object(ap_id)
  end

  defp get_in_reply_to_activity_from_object(_), do: nil

  def get_in_reply_to_activity(%Activity{} = activity) do
    get_in_reply_to_activity_from_object(Object.normalize(activity))
  end

  def normalize(obj) when is_map(obj), do: get_by_ap_id_with_object(obj["id"])
  def normalize(ap_id) when is_binary(ap_id), do: get_by_ap_id_with_object(ap_id)
  def normalize(_), do: nil

  def delete_all_by_object_ap_id(id) when is_binary(id) do
    id
    |> Queries.by_object_id()
    |> Queries.exclude_type("Delete")
    |> select([u], u)
    |> Repo.delete_all()
    |> elem(1)
    |> Enum.find(fn
      %{data: %{"type" => "Create", "object" => ap_id}} when is_binary(ap_id) -> ap_id == id
      %{data: %{"type" => "Create", "object" => %{"id" => ap_id}}} -> ap_id == id
      _ -> nil
    end)
    |> purge_web_resp_cache()
  end

  def delete_all_by_object_ap_id(_), do: nil

  defp purge_web_resp_cache(%Activity{} = activity) do
    %{path: path} = URI.parse(activity.data["id"])
    Cachex.del(:web_resp_cache, path)
    activity
  end

  defp purge_web_resp_cache(nil), do: nil

  def follow_accepted?(
        %Activity{data: %{"type" => "Follow", "object" => followed_ap_id}} = activity
      ) do
    with %User{} = follower <- Activity.user_actor(activity),
         %User{} = followed <- User.get_cached_by_ap_id(followed_ap_id) do
      Pleroma.FollowingRelationship.following?(follower, followed)
    else
      _ -> false
    end
  end

  def follow_accepted?(_), do: false

  def all_by_actor_and_id(actor, status_ids \\ [])
  def all_by_actor_and_id(_actor, []), do: []

  def all_by_actor_and_id(actor, status_ids) do
    Activity
    |> where([s], s.id in ^status_ids)
    |> where([s], s.actor == ^actor)
    |> Repo.all()
  end

  def follow_requests_for_actor(%User{ap_id: ap_id}) do
    ap_id
    |> Queries.by_object_id()
    |> Queries.by_type("Follow")
    |> where([a], fragment("? ->> 'state' = 'pending'", a.data))
  end

  def following_requests_for_actor(%User{ap_id: ap_id}) do
    Queries.by_type("Follow")
    |> where([a], fragment("?->>'state' = 'pending'", a.data))
    |> where([a], a.actor == ^ap_id)
    |> Repo.all()
  end

  def restrict_deactivated_users(query) do
    deactivated_users =
      from(u in User.Query.build(%{deactivated: true}), select: u.ap_id)
      |> Repo.all()

    Activity.Queries.exclude_authors(query, deactivated_users)
  end

  defdelegate search(user, query, options \\ []), to: Pleroma.Activity.Search

  def direct_conversation_id(activity, for_user) do
    alias Pleroma.Conversation.Participation

    with %{data: %{"context" => context}} when is_binary(context) <- activity,
         %Pleroma.Conversation{} = conversation <- Pleroma.Conversation.get_for_ap_id(context),
         %Participation{id: participation_id} <-
           Participation.for_user_and_conversation(for_user, conversation) do
      participation_id
    else
      _ -> nil
    end
  end

  @spec pinned_by_actor?(Activity.t()) :: boolean()
  def pinned_by_actor?(%Activity{} = activity) do
    actor = user_actor(activity)
    activity.id in actor.pinned_activities
  end

  def local_only?(activity) do
    recipients = Enum.concat(activity.data["to"], Map.get(activity.data, "cc", []))
    public = Pleroma.Constants.as_public()
    local = Pleroma.Constants.as_local_public()

    Enum.member?(recipients, local) and not Enum.member?(recipients, public)
  end
end