defmodule Wobserver.Web.Router.Helper do
  @moduledoc ~S"""
  Helper methods for routers.
  """

  alias Plug.Conn

  @doc ~S"""
  Sends a JSON encoded response back to the client.

  The https status will be `200` or `500` if the given `data` can not be JSON encoded.

  The `conn` content type is set to `application/json`, only if the data could be encoded.
  """
  @spec send_json_resp(
    data :: atom | String.t | map | list,
    conn :: Plug.Conn.t
  ) :: Plug.Conn.t
  def send_json_resp(data, conn)

  def send_json_resp(:page_not_found, conn) do
    conn
    |> Conn.send_resp(404, "Page not Found")
  end

  def send_json_resp(data, conn) do
    case Poison.encode(data) do
      {:ok, json} ->
        conn
        |> Conn.put_resp_content_type("application/json")
        |> Conn.send_resp(200, json)
      _ ->
        conn
        |> Conn.send_resp(500, "Response could not be generated.")
    end
  end
end