# Pleroma: A lightweight social networking server
# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only

defmodule Pleroma.Web.MastodonAPI.StatusController do
  use Pleroma.Web, :controller

  import Pleroma.Web.ControllerHelper,
    only: [try_render: 3, add_link_headers: 2]

  require Ecto.Query

  alias Pleroma.Activity
  alias Pleroma.Bookmark
  alias Pleroma.Object
  alias Pleroma.Repo
  alias Pleroma.Config
  alias Pleroma.ScheduledActivity
  alias Pleroma.User
  alias Pleroma.Web.ActivityPub.ActivityPub
  alias Pleroma.Web.ActivityPub.Visibility
  alias Pleroma.Web.CommonAPI
  alias Pleroma.Web.MastodonAPI.AccountView
  alias Pleroma.Web.MastodonAPI.ScheduledActivityView
  alias Pleroma.Web.OAuth.Token
  alias Pleroma.Web.Plugs.OAuthScopesPlug
  alias Pleroma.Web.Plugs.RateLimiter

  plug(Pleroma.Web.ApiSpec.CastAndValidate)

  plug(:skip_public_check when action in [:index, :show])

  @unauthenticated_access %{fallback: :proceed_unauthenticated, scopes: []}
  @cachex Pleroma.Config.get([:cachex, :provider], Cachex)

  plug(
    OAuthScopesPlug,
    %{@unauthenticated_access | scopes: ["read:statuses"]}
    when action in [
           :index,
           :show,
           :context,
           :translate
         ]
  )

  plug(
    OAuthScopesPlug,
    %{scopes: ["write:statuses"]}
    when action in [
           :create,
           :delete,
           :reblog,
           :unreblog
         ]
  )

  plug(OAuthScopesPlug, %{scopes: ["read:favourites"]} when action == :favourites)

  plug(
    OAuthScopesPlug,
    %{scopes: ["write:favourites"]} when action in [:favourite, :unfavourite]
  )

  plug(
    OAuthScopesPlug,
    %{scopes: ["write:mutes"]} when action in [:mute_conversation, :unmute_conversation]
  )

  plug(
    OAuthScopesPlug,
    %{@unauthenticated_access | scopes: ["read:accounts"]}
    when action in [:favourited_by, :reblogged_by]
  )

  plug(OAuthScopesPlug, %{scopes: ["write:accounts"]} when action in [:pin, :unpin])

  # Note: scope not present in Mastodon: read:bookmarks
  plug(OAuthScopesPlug, %{scopes: ["read:bookmarks"]} when action == :bookmarks)

  # Note: scope not present in Mastodon: write:bookmarks
  plug(
    OAuthScopesPlug,
    %{scopes: ["write:bookmarks"]} when action in [:bookmark, :unbookmark]
  )

  @rate_limited_status_actions ~w(reblog unreblog favourite unfavourite create delete)a

  plug(
    RateLimiter,
    [name: :status_id_action, bucket_name: "status_id_action:reblog_unreblog", params: [:id]]
    when action in ~w(reblog unreblog)a
  )

  plug(
    RateLimiter,
    [name: :status_id_action, bucket_name: "status_id_action:fav_unfav", params: [:id]]
    when action in ~w(favourite unfavourite)a
  )

  plug(RateLimiter, [name: :statuses_actions] when action in @rate_limited_status_actions)

  action_fallback(Pleroma.Web.MastodonAPI.FallbackController)

  defdelegate open_api_operation(action), to: Pleroma.Web.ApiSpec.StatusOperation

  @doc """
  GET `/api/v1/statuses?ids[]=1&ids[]=2`

  `ids` query param is required
  """
  def index(%{assigns: %{user: user}} = conn, %{ids: ids} = params) do
    limit = 100

    activities =
      ids
      |> Enum.take(limit)
      |> Activity.all_by_ids_with_object()
      |> Enum.filter(&Visibility.visible_for_user?(&1, user))

    render(conn, "index.json",
      activities: activities,
      for: user,
      as: :activity,
      with_muted: Map.get(params, :with_muted, false)
    )
  end

  @doc """
  POST /api/v1/statuses
  """
  # Creates a scheduled status when `scheduled_at` param is present and it's far enough
  def create(
        %{
          assigns: %{user: user},
          body_params: %{status: _, scheduled_at: scheduled_at} = params
        } = conn,
        _
      )
      when not is_nil(scheduled_at) do
    params =
      Map.put(params, :in_reply_to_status_id, params[:in_reply_to_id])
      |> put_application(conn)

    attrs = %{
      params: Map.new(params, fn {key, value} -> {to_string(key), value} end),
      scheduled_at: scheduled_at
    }

    with {:far_enough, true} <- {:far_enough, ScheduledActivity.far_enough?(scheduled_at)},
         {:ok, scheduled_activity} <- ScheduledActivity.create(user, attrs) do
      conn
      |> put_view(ScheduledActivityView)
      |> render("show.json", scheduled_activity: scheduled_activity)
    else
      {:far_enough, _} ->
        params = Map.drop(params, [:scheduled_at])
        create(%Plug.Conn{conn | body_params: params}, %{})

      error ->
        error
    end
  end

  # Creates a regular status
  def create(%{assigns: %{user: user}, body_params: %{status: _} = params} = conn, _) do
    params =
      Map.put(params, :in_reply_to_status_id, params[:in_reply_to_id])
      |> put_application(conn)

    with {:ok, activity} <- CommonAPI.post(user, params) do
      try_render(conn, "show.json",
        activity: activity,
        for: user,
        as: :activity,
        with_direct_conversation_id: true
      )
    else
      {:error, {:reject, message}} ->
        conn
        |> put_status(:unprocessable_entity)
        |> json(%{error: message})

      {:error, message} ->
        conn
        |> put_status(:unprocessable_entity)
        |> json(%{error: message})
    end
  end

  def create(%{assigns: %{user: _user}, body_params: %{media_ids: _} = params} = conn, _) do
    params = Map.put(params, :status, "")
    create(%Plug.Conn{conn | body_params: params}, %{})
  end

  @doc "GET /api/v1/statuses/:id"
  def show(%{assigns: %{user: user}} = conn, %{id: id} = params) do
    with %Activity{} = activity <- Activity.get_by_id_with_object(id),
         true <- Visibility.visible_for_user?(activity, user) do
      try_render(conn, "show.json",
        activity: activity,
        for: user,
        with_direct_conversation_id: true,
        with_muted: Map.get(params, :with_muted, false)
      )
    else
      _ -> {:error, :not_found}
    end
  end

  @doc "DELETE /api/v1/statuses/:id"
  def delete(%{assigns: %{user: user}} = conn, %{id: id}) do
    with %Activity{} = activity <- Activity.get_by_id_with_object(id),
         {:ok, %Activity{}} <- CommonAPI.delete(id, user) do
      try_render(conn, "show.json",
        activity: activity,
        for: user,
        with_direct_conversation_id: true,
        with_source: true
      )
    else
      _e -> {:error, :not_found}
    end
  end

  @doc "POST /api/v1/statuses/:id/reblog"
  def reblog(%{assigns: %{user: user}, body_params: params} = conn, %{id: ap_id_or_id}) do
    with {:ok, announce} <- CommonAPI.repeat(ap_id_or_id, user, params),
         %Activity{} = announce <- Activity.normalize(announce.data) do
      try_render(conn, "show.json", %{activity: announce, for: user, as: :activity})
    end
  end

  @doc "POST /api/v1/statuses/:id/unreblog"
  def unreblog(%{assigns: %{user: user}} = conn, %{id: activity_id}) do
    with {:ok, _unannounce} <- CommonAPI.unrepeat(activity_id, user),
         %Activity{} = activity <- Activity.get_by_id(activity_id) do
      try_render(conn, "show.json", %{activity: activity, for: user, as: :activity})
    end
  end

  @doc "POST /api/v1/statuses/:id/favourite"
  def favourite(%{assigns: %{user: user}} = conn, %{id: activity_id}) do
    with {:ok, _fav} <- CommonAPI.favorite(user, activity_id),
         %Activity{} = activity <- Activity.get_by_id(activity_id) do
      try_render(conn, "show.json", activity: activity, for: user, as: :activity)
    end
  end

  @doc "POST /api/v1/statuses/:id/unfavourite"
  def unfavourite(%{assigns: %{user: user}} = conn, %{id: activity_id}) do
    with {:ok, _unfav} <- CommonAPI.unfavorite(activity_id, user),
         %Activity{} = activity <- Activity.get_by_id(activity_id) do
      try_render(conn, "show.json", activity: activity, for: user, as: :activity)
    end
  end

  @doc "POST /api/v1/statuses/:id/pin"
  def pin(%{assigns: %{user: user}} = conn, %{id: ap_id_or_id}) do
    with {:ok, activity} <- CommonAPI.pin(ap_id_or_id, user) do
      try_render(conn, "show.json", activity: activity, for: user, as: :activity)
    else
      {:error, :pinned_statuses_limit_reached} ->
        {:error, "You have already pinned the maximum number of statuses"}

      {:error, :ownership_error} ->
        {:error, :unprocessable_entity, "Someone else's status cannot be pinned"}

      {:error, :visibility_error} ->
        {:error, :unprocessable_entity, "Non-public status cannot be pinned"}

      error ->
        error
    end
  end

  @doc "POST /api/v1/statuses/:id/unpin"
  def unpin(%{assigns: %{user: user}} = conn, %{id: ap_id_or_id}) do
    with {:ok, activity} <- CommonAPI.unpin(ap_id_or_id, user) do
      try_render(conn, "show.json", activity: activity, for: user, as: :activity)
    end
  end

  @doc "POST /api/v1/statuses/:id/bookmark"
  def bookmark(%{assigns: %{user: user}} = conn, %{id: id}) do
    with %Activity{} = activity <- Activity.get_by_id_with_object(id),
         %User{} = user <- User.get_cached_by_nickname(user.nickname),
         true <- Visibility.visible_for_user?(activity, user),
         {:ok, _bookmark} <- Bookmark.create(user.id, activity.id) do
      try_render(conn, "show.json", activity: activity, for: user, as: :activity)
    end
  end

  @doc "POST /api/v1/statuses/:id/unbookmark"
  def unbookmark(%{assigns: %{user: user}} = conn, %{id: id}) do
    with %Activity{} = activity <- Activity.get_by_id_with_object(id),
         %User{} = user <- User.get_cached_by_nickname(user.nickname),
         true <- Visibility.visible_for_user?(activity, user),
         {:ok, _bookmark} <- Bookmark.destroy(user.id, activity.id) do
      try_render(conn, "show.json", activity: activity, for: user, as: :activity)
    end
  end

  @doc "POST /api/v1/statuses/:id/mute"
  def mute_conversation(%{assigns: %{user: user}, body_params: params} = conn, %{id: id}) do
    with %Activity{} = activity <- Activity.get_by_id(id),
         {:ok, activity} <- CommonAPI.add_mute(user, activity, params) do
      try_render(conn, "show.json", activity: activity, for: user, as: :activity)
    end
  end

  @doc "POST /api/v1/statuses/:id/unmute"
  def unmute_conversation(%{assigns: %{user: user}} = conn, %{id: id}) do
    with %Activity{} = activity <- Activity.get_by_id(id),
         {:ok, activity} <- CommonAPI.remove_mute(user, activity) do
      try_render(conn, "show.json", activity: activity, for: user, as: :activity)
    end
  end

  @doc "GET /api/v1/statuses/:id/favourited_by"
  def favourited_by(%{assigns: %{user: user}} = conn, %{id: id}) do
    with true <- Pleroma.Config.get([:instance, :show_reactions]),
         %Activity{} = activity <- Activity.get_by_id_with_object(id),
         {:visible, true} <- {:visible, Visibility.visible_for_user?(activity, user)},
         %Object{data: %{"likes" => likes}} <- Object.normalize(activity, fetch: false) do
      users =
        User
        |> Ecto.Query.where([u], u.ap_id in ^likes)
        |> Repo.all()
        |> Enum.filter(&(not User.blocks?(user, &1)))

      conn
      |> put_view(AccountView)
      |> render("index.json", for: user, users: users, as: :user)
    else
      {:visible, false} -> {:error, :not_found}
      _ -> json(conn, [])
    end
  end

  @doc "GET /api/v1/statuses/:id/reblogged_by"
  def reblogged_by(%{assigns: %{user: user}} = conn, %{id: id}) do
    with %Activity{} = activity <- Activity.get_by_id_with_object(id),
         {:visible, true} <- {:visible, Visibility.visible_for_user?(activity, user)},
         %Object{data: %{"announcements" => announces, "id" => ap_id}} <-
           Object.normalize(activity, fetch: false) do
      announces =
        "Announce"
        |> Activity.Queries.by_type()
        |> Ecto.Query.where([a], a.actor in ^announces)
        # this is to use the index
        |> Activity.Queries.by_object_id(ap_id)
        |> Repo.all()
        |> Enum.filter(&Visibility.visible_for_user?(&1, user))
        |> Enum.map(& &1.actor)
        |> Enum.uniq()

      users =
        User
        |> Ecto.Query.where([u], u.ap_id in ^announces)
        |> Repo.all()
        |> Enum.filter(&(not User.blocks?(user, &1)))

      conn
      |> put_view(AccountView)
      |> render("index.json", for: user, users: users, as: :user)
    else
      {:visible, false} -> {:error, :not_found}
      _ -> json(conn, [])
    end
  end

  @doc "GET /api/v1/statuses/:id/context"
  def context(%{assigns: %{user: user}} = conn, %{id: id}) do
    with %Activity{} = activity <- Activity.get_by_id(id) do
      activities =
        activity.data["context"]
        |> ActivityPub.fetch_activities_for_context(%{
          blocking_user: user,
          user: user,
          exclude_id: activity.id
        })
        |> Enum.filter(fn activity -> Visibility.visible_for_user?(activity, user) end)

      render(conn, "context.json", activity: activity, activities: activities, user: user)
    end
  end

  @doc "GET /api/v1/favourites"
  def favourites(%{assigns: %{user: %User{} = user}} = conn, params) do
    activities = ActivityPub.fetch_favourites(user, params)

    conn
    |> add_link_headers(activities)
    |> render("index.json",
      activities: activities,
      for: user,
      as: :activity
    )
  end

  @doc "GET /api/v1/bookmarks"
  def bookmarks(%{assigns: %{user: user}} = conn, params) do
    user = User.get_cached_by_id(user.id)

    bookmarks =
      user.id
      |> Bookmark.for_user_query()
      |> Pleroma.Pagination.fetch_paginated(params)

    activities =
      bookmarks
      |> Enum.map(fn b -> Map.put(b.activity, :bookmark, Map.delete(b, :activity)) end)

    conn
    |> add_link_headers(bookmarks)
    |> render("index.json",
      activities: activities,
      for: user,
      as: :activity
    )
  end

  @doc "GET /api/v1/statuses/:id/translations/:language"
  def translate(%{assigns: %{user: user}} = conn, %{id: id, language: language}) do
    with {:enabled, true} <- {:enabled, Config.get([:translator, :enabled])},
         %Activity{} = activity <- Activity.get_by_id_with_object(id),
         {:visible, true} <- {:visible, Visibility.visible_for_user?(activity, user)},
         translation_module <- Config.get([:translator, :module]),
         {:ok, detected, translation} <-
           fetch_or_translate(
             activity.id,
             activity.object.data["content"],
             language,
             translation_module
           ) do
      json(conn, %{detected_language: detected, text: translation})
    else
      {:enabled, false} ->
        conn
        |> put_status(:bad_request)
        |> json(%{"error" => "Translation is not enabled"})

      {:visible, false} ->
        {:error, :not_found}

      e ->
        e
    end
  end

  defp fetch_or_translate(status_id, text, language, translation_module) do
    @cachex.fetch!(:user_cache, "translations:#{status_id}:#{language}", fn _ ->
      value = translation_module.translate(text, language)

      with {:ok, _, _} <- value do
        value
      else
        _ -> {:ignore, value}
      end
    end)
  end

  defp put_application(params, %{assigns: %{token: %Token{user: %User{} = user} = token}} = _conn) do
    if user.disclose_client do
      %{client_name: client_name, website: website} = Repo.preload(token, :app).app
      Map.put(params, :generator, %{type: "Application", name: client_name, url: website})
    else
      Map.put(params, :generator, nil)
    end
  end

  defp put_application(params, _), do: Map.put(params, :generator, nil)
end