defmodule Pleroma.Web.MastodonAPI.MastodonAPIController do
  use Pleroma.Web, :controller
  alias Pleroma.{Repo, Activity, User, Notification}
  alias Pleroma.Web.OAuth.App
  alias Pleroma.Web
  alias Pleroma.Web.MastodonAPI.{StatusView, AccountView}
  alias Pleroma.Web.ActivityPub.ActivityPub
  alias Pleroma.Web.TwitterAPI.TwitterAPI
  alias Pleroma.Web.CommonAPI
  import Ecto.Query
  import Logger

  def create_app(conn, params) do
    with cs <- App.register_changeset(%App{}, params) |> IO.inspect,
         {:ok, app} <- Repo.insert(cs) |> IO.inspect do
      res = %{
        id: app.id,
        client_id: app.client_id,
        client_secret: app.client_secret
      }

      json(conn, res)
    end
  end

  def verify_credentials(%{assigns: %{user: user}} = conn, params) do
    account = AccountView.render("account.json", %{user: user})
    json(conn, account)
  end

  def masto_instance(conn, _params) do
    response = %{
      uri: Web.base_url,
      title: Web.base_url,
      description: "A Pleroma instance, an alternative fediverse server",
      version: "Pleroma Dev"
    }

    json(conn, response)
  end

  defp add_link_headers(conn, method, activities) do
    last = List.last(activities)
    first = List.first(activities)
    if last do
      min = last.id
      max = first.id
      next_url = mastodon_api_url(Pleroma.Web.Endpoint, method, max_id: min)
      prev_url = mastodon_api_url(Pleroma.Web.Endpoint, method, since_id: max)
      conn
      |> put_resp_header("link", "<#{next_url}>; rel=\"next\", <#{prev_url}>; rel=\"prev\"")
    else
      conn
    end
  end

  def home_timeline(%{assigns: %{user: user}} = conn, params) do
    activities = ActivityPub.fetch_activities([user.ap_id | user.following], Map.put(params, "type", "Create"))
    |> Enum.reverse

    conn
    |> add_link_headers(:home_timeline, activities)
    |> render(StatusView, "index.json", %{activities: activities, for: user, as: :activity})
  end

  def public_timeline(%{assigns: %{user: user}} = conn, params) do
    params = params
    |> Map.put("type", "Create")
    |> Map.put("local_only", !!params["local"])

    activities = ActivityPub.fetch_public_activities(params)
    |> Enum.reverse

    conn
    |> add_link_headers(:public_timeline, activities)
    |> render(StatusView, "index.json", %{activities: activities, for: user, as: :activity})
  end

  def user_statuses(%{assigns: %{user: user}} = conn, params) do
    with %User{ap_id: ap_id} <- Repo.get(User, params["id"]) do
      params = params
      |> Map.put("type", "Create")
      |> Map.put("actor_id", ap_id)

      activities = ActivityPub.fetch_activities([], params)
      |> Enum.reverse

      render conn, StatusView, "index.json", %{activities: activities, for: user, as: :activity}
    end
  end

  def get_status(%{assigns: %{user: user}} = conn, %{"id" => id}) do
    with %Activity{} = activity <- Repo.get(Activity, id) do
      render conn, StatusView, "status.json", %{activity: activity, for: user}
    end
  end

  def get_context(%{assigns: %{user: user}} = conn, %{"id" => id}) do
    with %Activity{} = activity <- Repo.get(Activity, id),
         activities <- ActivityPub.fetch_activities_for_context(activity.data["object"]["context"]),
         activities <- activities |> Enum.filter(fn (%{id: aid}) -> to_string(aid) != to_string(id) end),
         grouped_activities <- Enum.group_by(activities, fn (%{id: id}) -> id < activity.id end) do
      result = %{
        ancestors: StatusView.render("index.json", for: user, activities: grouped_activities[true] || [], as: :activity) |> Enum.reverse,
        descendants: StatusView.render("index.json", for: user, activities: grouped_activities[false] || [], as: :activity) |> Enum.reverse,
      }

      json(conn, result)
    end
  end

  def post_status(%{assigns: %{user: user}} = conn, %{"status" => status} = params) do
    l = status |> String.trim |> String.length

    params = params
    |> Map.put("in_reply_to_status_id", params["in_reply_to_id"])

    if l > 0 && l < 5000 do
      {:ok, activity} = TwitterAPI.create_status(user, params)
      render conn, StatusView, "status.json", %{activity: activity, for: user, as: :activity}
    end
  end

  def delete_status(%{assigns: %{user: user}} = conn, %{"id" => id}) do
    with {:ok, %Activity{}} <- CommonAPI.delete(id, user) do
      json(conn, %{})
    else
      _e ->
        conn
        |> put_status(403)
        |> json(%{error: "Can't delete this post"})
    end
  end

  def reblog_status(%{assigns: %{user: user}} = conn, %{"id" => ap_id_or_id}) do
    with {:ok, _announce, %{data: %{"id" => id}}} = CommonAPI.repeat(ap_id_or_id, user),
         %Activity{} = activity <- Activity.get_create_activity_by_object_ap_id(id) do
      render conn, StatusView, "status.json", %{activity: activity, for: user, as: :activity}
    end
  end

  def fav_status(%{assigns: %{user: user}} = conn, %{"id" => ap_id_or_id}) do
    with {:ok, _fav, %{data: %{"id" => id}}} = CommonAPI.favorite(ap_id_or_id, user),
         %Activity{} = activity <- Activity.get_create_activity_by_object_ap_id(id) do
      render conn, StatusView, "status.json", %{activity: activity, for: user, as: :activity}
    end
  end

  def unfav_status(%{assigns: %{user: user}} = conn, %{"id" => ap_id_or_id}) do
    with {:ok, %{data: %{"id" => id}}} = CommonAPI.unfavorite(ap_id_or_id, user),
         %Activity{} = activity <- Activity.get_create_activity_by_object_ap_id(id) do
      render conn, StatusView, "status.json", %{activity: activity, for: user, as: :activity}
    end
  end

  def notifications(%{assigns: %{user: user}} = conn, params) do
    notifications = Notification.for_user(user, params)
    result = Enum.map(notifications, fn (%{id: id, activity: activity, inserted_at: created_at}) ->
      actor = User.get_cached_by_ap_id(activity.data["actor"])
      case activity.data["type"] do
        "Create" ->
          %{id: id, type: "mention", created_at: created_at, account: AccountView.render("account.json", %{user: actor}), status: StatusView.render("status.json", %{activity: activity})}
        "Like" ->
          liked_activity = Activity.get_create_activity_by_object_ap_id(activity.data["object"])
          %{id: id, type: "favourite", created_at: created_at, account: AccountView.render("account.json", %{user: actor}), status: StatusView.render("status.json", %{activity: liked_activity})}
        "Announce" ->
          announced_activity = Activity.get_create_activity_by_object_ap_id(activity.data["object"])
          %{id: id, type: "reblog", created_at: created_at, account: AccountView.render("account.json", %{user: actor}), status: StatusView.render("status.json", %{activity: announced_activity})}
        "Follow" ->
          %{id: id, type: "follow", created_at: created_at, account: AccountView.render("account.json", %{user: actor})}
        _ -> nil
      end
    end)
    |> Enum.filter(&(&1))

    conn
    |> add_link_headers(:notifications, notifications)
    |> json(result)
  end

  def relationships(%{assigns: %{user: user}} = conn, %{"id" => id}) do
    id = List.wrap(id)
    q = from u in User,
      where: u.id in ^id
    targets = Repo.all(q)
    render conn, AccountView, "relationships.json", %{user: user, targets: targets}
  end

  def empty_array(conn, _) do
    Logger.debug("Unimplemented, returning an empty array")
    json(conn, [])
  end
end