#!/usr/bin/env node

var amqp = require('amqplib');

var when = require('when');

var conn = amqp.connect('amqp://localhost')

conn.then(createChannel).then(null, console.warn);

function createChannel(conn) {

return when(conn.createChannel().then(requestFib)).ensure(function() { conn.close(); });

}

function requestFib(ch) {

var answer = when.defer();

var correlationId = generateUuid();

function maybeAnswer(msg) {

if (msg.properties.correlationId === correlationId) {

answer.resolve(msg.content.toString());

}

}

var ok = ch.assertQueue('', {exclusive: true})

.then(function(qok) { return qok.queue; });

ok = ok.then(function(queue) {

return ch.consume(queue, maybeAnswer, {noAck: true})

.then(function() { return queue; });

});

ok = ok.then(function(queue) {

console.log(' [x] Requesting fib(30)');

ch.sendToQueue('rpc_queue', new Buffer('30'), {

correlationId: correlationId, replyTo: queue

});

return answer.promise;

});

return ok.then(function(fibN) {

console.log(' [.] Got %d', fibN);

});

}

function generateUuid() {

return Math.random().toString() + Math.random().toString() + Math.random().toString();

}