API call with fallback

QRandom.rb

require 'rest-client'
require 'securerandom'

module QRandom
  MAX_NUMBER = 99999
  
  def self.next
    api_url = 'http://qrng.anu.edu.au/API/jsonI.php?type=uint16&length=2'
    
    RestClient.get(api_url) do |response, request, result, &block|
      response.code == 200 ? parse_response(response) : fallback_number(response)
    end
  end
  
  def self.parse_response(response)
    json = JSON.parse(response)
    
    if json["success"] == true && json["data"]
      json["data"].inject(:+) % MAX_NUMBER || fallback_number
    else
      fallback_number
    end
  end
  
  def self.fallback_number(response)
    puts "--- Fallback triggered ---"
    puts response.inspect
    SecureRandom.random_number(MAX_NUMBER)
  end
end

puts QRandom::next