# -*- coding: utf-8 -*-
from copy import deepcopy, copy
from pdb import set_trace as st

from os import fork, pipe, read, write, close, fdopen
from sys import exit

from socket import *
from select import poll, POLLIN, POLLPRI, POLLHUP, POLLERR, POLLOUT

import Queue

from time import sleep

import sys
reload(sys)
sys.setdefaultencoding('utf8')

HOST = None
PORT = 4500
# Keep up with the queues of outgoing messages
message_queues = {}

# poll flags
READ_ONLY = POLLIN | POLLPRI | POLLHUP | POLLERR
READ_WRITE = READ_ONLY | POLLOUT

for res in  getaddrinfo(HOST, PORT, AF_INET, SOCK_STREAM):
    af, socktype, proto, canonname, sa = res

    # create server socket and binding it to address
    server = socket(af, socktype, proto)
    server.bind(sa)
    server.listen(5)
    server.setblocking(0)

    # Map file descriptors to socket objects
    fd_to_socket = { server.fileno(): server,
                   }

poller = poll()
poller.register(server, READ_ONLY)

while 1:
    events = poller.poll(100)

    for fd, flag in events:
        s  = fd_to_socket[fd]

        # some checks
        if flag & (POLLIN | POLLPRI):
            if s is server:                         # new connection
                connection, client_addr = s.accept()
                print "Connected ", client_addr
                connection.setblocking(0)
                fd_to_socket[ connection.fileno() ] = connection

                poller.register(connection, READ_ONLY)

                message_queues[connection] = Queue.Queue()

            else:                                   # reading new data
                data = s.recv(1024)
                if data:
                    print "From %s received:\n'%s'\n" % (s, data)
                    poller.modify(s, READ_WRITE)
                else:                               # empty string, client disconnecting
                    print "Closing connection %s after reading no data"
                    poller.unregister(s)
                    s.close()

                    del message_queues[s]
        elif flag & POLLHUP:                        # client dirty hangup connection
            print "Clossing connection from %s after HANGUP" % s.getpeername()
            poller.unregister(s)
            s.close()

            # del message_queues
            del message_queues[s]

        elif flag & POLLOUT:                        # ready send data to client
            try:
                # st()
                next_msg = message_queues[s].get_nowait()
            except Queue.Empty:
                # no writable data, so stop monitoring this connection for write
                poller.modify(s, READ_ONLY)
                print "Nothing to send to %s" % str(s.getpeername())
            else:
                print "Send %s to %s" % (next_msg, s.getpeername())
                s.send(next_msg)

        elif flag & POLLERR:                        # closing connection on some error
            print "Clossing connection from %s after Exception" % s.getpeername()
            poller.unregister(s)
            s.close()

            del message_queues[s]

    # conn, addr = server.accept()
    # print "Connected ", addr