defmodule <%= @web_module %>.Oauth.AuthorizeController do
  @behaviour Boruta.Oauth.AuthorizeApplication

  use <%= @web_module %>, :controller

  alias Boruta.Oauth.AuthorizeResponse
  alias Boruta.Oauth.Error
  alias Boruta.Oauth.ResourceOwner
  alias <%= @web_module %>.OauthView

  def oauth_module, do: Application.get_env(:<%= @otp_app %>, :oauth_module)

  def authorize(%Plug.Conn{} = conn, _params) do
    current_user = conn.assigns[:current_user]
    conn = store_user_return_to(conn)

    authorize_response(
      conn,
      current_user
    )
  end

  defp authorize_response(conn, %_{} = current_user) do
    conn
    |> oauth_module().authorize(
      %ResourceOwner{sub: current_user.id, username: current_user.email},
      __MODULE__
    )
  end

  defp authorize_response(_conn, _params) do
    raise """
    Here occurs the login process. After login, user may be redirected
    to get_session(conn, :user_return_to)
    """
  end

  @impl Boruta.Oauth.AuthorizeApplication
  def authorize_success(
        conn,
        %AuthorizeResponse{} = response
      ) do
    redirect(conn, external: AuthorizeResponse.redirect_to_url(response))
  end

  @impl Boruta.Oauth.AuthorizeApplication
  def authorize_error(
        %Plug.Conn{},
        %Error{status: :unauthorized, error: :invalid_resource_owner}
      ) do
    raise """
    Here occurs the login process. After login, user may be redirected
    to get_session(conn, :user_return_to)
    """
  end

  def authorize_error(
        conn,
        %Error{
          error: error,
          error_description: error_description,
          format: format,
          redirect_uri: redirect_uri
        }
      )
      when not is_nil(format) do
    query = URI.encode_query(%{error: error, error_description: error_description})

    url =
      case format do
        :query -> "#{redirect_uri}?#{query}"
        :fragment -> "#{redirect_uri}##{query}"
      end

    conn
    |> redirect(external: url)
  end

  def authorize_error(
        conn,
        %Error{status: status, error: error, error_description: error_description}
      ) do
    conn
    |> put_status(status)
    |> put_view(OauthView)
    |> render("error.html", error: error, error_description: error_description)
  end

  @impl Boruta.Oauth.AuthorizeApplication
  def preauthorize_success(_conn, _response), do: :ok

  @impl Boruta.Oauth.AuthorizeApplication
  def preauthorize_error(_conn, _response), do: :ok

  defp store_user_return_to(conn) do
    conn
    |> put_session(
      :user_return_to,
      current_path(conn)
    )
  end
end