FrankYan93/nanotwitter

require 'bunny'
require 'thread'
require 'json'
class NotificationClient
    attr_reader :reply_queue
    attr_accessor :response, :call_id
    attr_reader :lock, :condition

    def initialize(ch, server_queue)
        @ch = ch
        @x              = ch.default_exchange
        @server_queue   = server_queue
        @reply_queue    = ch.queue('', exclusive: true)
        @lock      = Mutex.new
        @condition = ConditionVariable.new
        that       = self

        @reply_queue.subscribe do |_delivery_info, properties, payload|
            if properties[:correlation_id] == that.call_id
                that.response = JSON.parse payload
                that.lock.synchronize { that.condition.signal }
            end
        end
    end

    def call(n)
        self.call_id = generate_uuid
        @x.publish(n.to_s,
                   routing_key: @server_queue,
                   correlation_id: call_id,
                   reply_to: @reply_queue.name)
        lock.synchronize { condition.wait(lock) }
        response
    end

    protected

    def generate_uuid
        # very naive but good enough for code
        # examples
        "#{rand}#{rand}#{rand}"
    end
end

def rpcClient sendHash#the producer
  conn = Bunny.new(ENV["RABBITMQ_BIGWIG_TX_URL"],automatically_recover: false)
  conn.start
  ch = conn.create_channel

    client = NotificationClient.new(ch, 'rpc_queue')
    print " [x] Requesting #{sendHash}\n"

    response = client.call(sendHash.to_json)
    puts " [.] Got #{response}"

    ch.close
    conn.close
end