# -*- coding: utf-8 -*-
import select
import socket
import threading
import random
from Queue import Queue, Empty

MAGIC_PACKET = ""
for i in xrange(50):
	MAGIC_PACKET += chr(random.randrange(ord('a'),ord('z')))



def split_args(txt):
	SA_S0, SA_QUOT = range(2)
	split_args_state = SA_S0
	# FSM:
	#
	#   else
	#    ,--.
	#    |  V    " 
	#    `-(S0)----->(QUOT)
	#        ^         |
	#        `---------´
	#             "
	#
	args = []
	current = u""
	for i in xrange(len(txt)):
		c = txt[i]
		if   split_args_state==SA_S0:
			if c=='"':
				split_args_state = SA_QUOT
				args.append(current)
				current = u""
			elif c in " \t\n":
				if len(current)!=0:
					args.append(current)
					current = u""
			else:
				current += c
		elif split_args_state==SA_QUOT: 
			if c=='"':
				split_args_state = SA_S0
			else:
				current += c
		else:
			assert False
	if len(current)!=0:
		args.append(current)
	return args
	

def get_local_ip():
    def udp_listening_server():
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.bind(('<broadcast>', 8888))
        s.setblocking(0)
        while True:
            result = select.select([s],[],[])
            msg, address = result[0][0].recvfrom(1024)
            msg = unicode(msg)
            if msg == MAGIC_PACKET:
                break
        queue.put(address)

    queue = Queue()
    thread = threading.Thread(target=udp_listening_server)
    thread.queue = queue
    thread.start()
    s2 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s2.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
    waiting = True
    while waiting:
        s2.sendto(bytes(MAGIC_PACKET), ('<broadcast>', 8888))
        try:
            address = queue.get(False)
        except Empty:
            pass
        else:
            waiting = False
    return address[0]