if Code.ensure_loaded?(Plug) do
  defmodule WeChat.Plug.RefreshAccessToken do
    @moduledoc false

    use Plug.Builder

    plug(
      Plug.Parsers,
      parsers: [:urlencoded, :json],
      pass: ["text/*", "application/json"],
      json_decoder: Jason
    )

    require Logger

    def call(conn, opts) do
      conn = conn |> super(opts) |> fetch_query_params()
      adapter_storage = opts[:adapter_storage]
      body = conn.body_params

      result =
        case refresh(body, adapter_storage) do
          {:ok, token} ->
            %{"access_token" => token.access_token}

          {:error, %WeChat.Error{} = error} ->
            Logger.error(
              "refresh token occurs an error: #{inspect(error)} with body: #{inspect(body)}"
            )

            error
        end

      conn
      |> put_resp_content_type("application/json")
      |> send_resp(200, Jason.encode!(result))
      |> halt()
    end

    defp refresh(
           %{
             "appid" => appid,
             "authorizer_appid" => authorizer_appid,
             "access_token" => access_token
           },
           adapter_storage
         ) do
      comp_adapter_storage = adapter_storage[:component]
      comp_adapter_storage.refresh_access_token(appid, authorizer_appid, access_token, [])
    end

    defp refresh(%{"appid" => appid, "access_token" => access_token}, adapter_storage) do
      common_adapter_storage = adapter_storage[:common]
      common_adapter_storage.refresh_access_token(appid, access_token, [])
    end

    defp refresh(_, _) do
      {
        :error,
        %WeChat.Error{reason: :invalid_request}
      }
    end
  end
end