defmodule TwitchApi.SimpleServer.Callback do
  @moduledoc """
  This module provides the required logic for the callback endpoint
  """

  import Plug.Conn

  alias TwitchApi.OIDC

  @spec call(Plug.Conn.t()) :: Plug.Conn.t()
  def call(conn) do
    conn = fetch_query_params(conn)
    query_params = conn.query_params
    %{"state" => state} = query_params

    case Enum.member?(OIDC.get_state(), state) do
      false ->
        send_resp(conn, 200, "error")

      true ->
        OIDC.delete_from_state(state)
        OIDC.request_access_token(conn.query_params)
        send_resp(conn, 200, "ok")
    end
  end

  @spec callback_uri :: callback_uri :: binary
  def callback_uri do
    port = Application.get_env(:scrapped_twitch_api, :callback_port)
    uri = Application.get_env(:scrapped_twitch_api, :callback_uri)
    protocol = Application.get_env(:scrapped_twitch_api, :callback_protocol)

    "#{protocol}://#{uri}:#{port}/callback"
  end
end