defmodule Witaixir do
  use HTTPoison.Base

  @moduledoc """
  Documentation for Witaixir.
  """

  # public functions

  def get(path, query_string, client) do
    fetch(:get, build_url(path, query_string, client), authorization_header(client))
  end

  # HTTPoison overridden functions

  defp process_request_body(body), do: Poison.encode!(body)
  defp process_response_body(""), do: nil
  defp process_response_body(body), do: Poison.decode!(body)

  # private functions

  defp authorization_header(client, headers \\ []), do: headers ++ [{:Authorization, "Bearer #{client.token}"}]

  defp build_url(path, query_string, client) do
    build_host(client)
    |> build_path(path)
    |> build_query_string(query_string)
    |> build_version(client)
  end

  defp build_host(client), do: client.base_url
  defp build_path(url, path), do: url <> "/" <> path
  defp build_query_string(url, query_string \\ ""), do: url <> "?" <> query_string
  defp build_version(url, client), do: url <> "&v" <> client.version

  defp fetch(method, url, headers, body \\ ""), do: request(method, url, body, headers)

  defp process_response({:error, %HTTPoison.Error{reason: reason}}), do: { :error, reason }
  defp process_response({:ok, %HTTPoison.Response{status_code: 200, body: body}}), do: { :ok, body }
  defp process_response({:ok, %HTTPoison.Response{status_code: status_code, body: body}}), do: { :ok, status_code, body }
end