defmodule FreshbooksApiClient.Caller.HttpXml do
  @moduledoc """
  This module makes a request using HTTP and XML.

  It uses FreshbooksApiClient.Caller
  """

  @base_url "https://:subdomain.freshbooks.com/api/2.1/xml-in"

  use FreshbooksApiClient.Caller

  alias FreshbooksApiClient.Xml

  def run(method, params, opts \\ []) do
    response = method
      |> get_request_body(params)
      |> make_request(opts)

    case response do
      {:ok, %HTTPoison.Response{body: resp, status_code: 200}} ->
        {:ok, resp}
      {:ok, %HTTPoison.Response{body: resp, status_code: 401}} ->
        {:error, :unauthorized}
      {:ok, %HTTPoison.Error{reason: _}} -> {:error, :conn}
    end
  end

  defp get_request_body(method, params) do
    Xml.to_xml(method, params)
  end

  defp make_request(body, opts) do
    HTTPoison.post(request_url(), body, generate_headers())
  end

  defp generate_headers() do
    [auth_headers()]
  end

  defp content_headers() do
    {"Accept", "application/xml"}
  end

  defp auth_headers() do
    encoded = Base.encode64("#{FreshbooksApiClient.token()}:X")
    {"Authorization", "Basic #{encoded}"}
  end

  defp request_url(), do: request_url(FreshbooksApiClient.subdomain())
  defp request_url(subdomain) do
    String.replace(@base_url, ":subdomain", subdomain)
  end
end