#!/usr/bin/env python

import random

from zope.interface import implements

from twisted.cred import portal, checkers
from twisted.spread import pb
from twisted.internet import reactor


class MyServer:

    # emulate crash when server send data to client
    crash_server_to_client = False

    def __init__(self):
        self.last_responses = {}  # indexed by name


class MyRealm:
    implements(portal.IRealm)
    def requestAvatar(self, avatarID, mind, *interfaces):
        assert pb.IPerspective in interfaces
        avatar = User(avatarID)
        avatar.server = self.server
        return pb.IPerspective, avatar, lambda: None


class User(pb.Avatar):

    def __init__(self, name):
        self.name = name

    def perspectiveMessageReceived(self, *args, **kwargs):
        '''Save last response.'''
        response = pb.Avatar.perspectiveMessageReceived(self, *args, **kwargs)
        self.server.last_responses[self.name] = response  # save last response

        if self.server.crash_server_to_client:
            self.server.crash_server_to_client = False  # emulate one error
            raise NotImplementedError

        return response

    def perspective_get_data(self):
        r = random.randint(0, 100)

        print '%s: !!!SEND %d' % (self.name, r)

        return r

    def perspective_get_last_response(self):
        last_response = self.server.last_responses[self.name]
        print 'return last response: %s' % last_response
        return last_response


realm = MyRealm()
realm.server = MyServer()
checker = checkers.InMemoryUsernamePasswordDatabaseDontUse()
checker.addUser('alice', '1234')
p = portal.Portal(realm, [checker])

reactor.listenTCP(8800, pb.PBServerFactory(p))
reactor.run()