# Simple RabbitMQ intermediated peer-to-peer test. See
# <http://www.holygoat.co.uk/blog/entry/2009-09-17-1.
#
# Shared prologue.

import threading

from amqplib import client_0_8 as amqp

conn = amqp.Connection(host="localhost:5672", 
    userid="guest",
    password="guest",
    virtual_host="/", 
    insist=False)

chan = conn.channel()

consumertag = "consumer"

# Register a callback. This allows you to loop, consuming messages, blocking if
# there are none.
def recv_callback(msg):
     print 'Received: ' + msg.body

def keep_receiving():
    while True:
         chan.wait()


def queue_setup(agentname):
    # Declare your queues. If they already exist this is a no-op.
    chan.queue_declare(queue=agentname, 
            # durable = persists after server shutdown.
            durable=True,
            # exclusive = private queue.
            exclusive=False,
            # auto_delete = queue disappears when you disconnect.
            auto_delete=False)

    # Declare your exchange. Exchanges route messages to queues.
    # A direct exchange uses a string= tag check, and thus is quite fast.
    # Durable as with a queue.
    chan.exchange_declare(exchange="sorting_room", type="direct", durable=True,
            auto_delete=False,)

    # Link the queue to the exchange. Any messages arriving for "notifications"
    # will go to the agent's queue.
    chan.queue_bind(queue=agentname, exchange="sorting_room",
            routing_key="notifications")
    
    # Consume messages.
    chan.basic_consume(queue=agentname, no_ack=True,
            callback=recv_callback, consumer_tag=consumertag)
    
    threading.Thread(target=keep_receiving).start()


def notify_others(message_text):
    # Create your new message.
    msg = amqp.Message(message_text)

    # Mode 2 = message persists to disk, so this is reboot-safe.
    # Only works with durable queues.
    msg.properties["delivery_mode"] = 2

    # Send!
    chan.basic_publish(msg,exchange="sorting_room",routing_key="notifications")


def cleanup():
    # Cancel the registration and close everything. Do this when the agent
    # shuts down.
    chan.basic_cancel(consumertag)
    chan.close()
    conn.close()


# On each agent:
# all.queue_setup("agent1")
# all.queue_setup("agent2")
#
# Now send a message:
# all.notify_others("Hello, world! (Agent 1)")