'''
Created on 06.03.2016

@author: wn
'''


import Queue
import threading
from logger import Logger


class BrokerException(Exception): pass

class BrokerDuplicateIdException(BrokerException): pass

class BrokerNotSubscribedException(BrokerException): pass

class BrokerOverflowException(BrokerException): pass



class Broker(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
        self.setDaemon(True)
        self.outQueues = {}
        self.inQueue = Queue.Queue()

    def run(self):
	while True:
	    try:
            	item = self.inQueue.get(True, None)
		Logger.log("got an item")
            	for (n, q) in self.outQueues.iteritems():
                    Logger.log("passed to %s" % n)
                    q.put_nowait(item) 
            except Queue.Full:
                pass

    def getInQueue(self):
        return self.inQueue
        
    def subscribe(self, name):
        if self.outQueues.has_key(name):
            raise BrokerDuplicateIdException()
        self.outQueues[name] = Queue.Queue()
        return self.outQueues[name]
    
    def unsubscribe(self, name):
        try:
            del self.outQueues[name]
        except KeyError:
            raise BrokerNotSubscribedException