defmodule DoubleBypass.Assertions do
  use ExUnit.CaseTemplate

  def run(conn, params) do
    Enum.map(params, &assert_on(conn, &1))
    send_resp(conn, params)
  end

  defp assert_on(conn, {:path, path}), do: assert conn.request_path == path
  defp assert_on(conn, {:query, query}), do: assert conn.query_string == query
  defp assert_on(conn, {:method, method}), do: assert conn.method == method
  defp assert_on(conn, {:headers, headers}) do
    conn_headers = conn.req_headers |> Enum.into(%{})
    Enum.map(headers, fn({k, v}) ->
      assert conn_headers[k] == v
    end)
  end
  defp assert_on(conn, {:body, body}) when is_bitstring(body) do
    assert conn
          |> Plug.Conn.read_body
          |> elem(1) == body
  end
  defp assert_on(conn, {:body, body}) do
    assert conn
          |> Plug.Conn.read_body
          |> elem(1)
          |> Poison.decode! == body
  end
  defp assert_on(_conn, _), do: :noop

  defp send_resp(conn, params) do
    case params do
       %{response: response, status_code: status_code} when is_bitstring(response) -> Plug.Conn.resp(conn, status_code, response)
       %{response: response, status_code: status_code} -> Plug.Conn.resp(conn, status_code, Poison.encode!(response))
       %{status_code: status_code} -> Plug.Conn.resp(conn, status_code, "")
       %{response: response} when is_bitstring(response) -> Plug.Conn.resp(conn, 200, response)
       %{response: response} -> Plug.Conn.resp(conn, 200, Poison.encode!(response))
       _ -> Plug.Conn.resp(conn, 200, "")
    end
  end
end