defmodule Qrandom do
  @moduledoc """
  Client for QRNG service of Australian National University.
  """

  @api_url "https://qrng.anu.edu.au/API/jsonI.php?length=1&type=uint16"
  @max_uint16 65535

  @doc """
  Random integer number between 0-65535.
  """
  def int() do
    case HTTPoison.get(@api_url) do
      {:ok, %HTTPoison.Response{status_code: 200, body: body}} ->
        case Poison.decode(body) do
          {:ok, response} ->
            List.first(response["data"])
          _ ->
            {:error, "It's not possible to parse response from ANU QRNG API"}
        end
      _ ->
        {:error, "It's not possible to get a random number from ANU QRNG API"}
    end
  end

  @doc """
  Random float number between 0.0-1.0.
  """
  def float() do
    case int() do
      qint when is_integer(qint) -> qint / @max_uint16
      error -> error
    end
  end
end