#!/usr/bin/env python3

# Slixmpp: The Slick XMPP Library
# Copyright (C) 2010  Nathanael C. Fritz
# This file is part of Slixmpp.
# See the file LICENSE for copying permission.

import logging
from getpass import getpass
from argparse import ArgumentParser

import slixmpp

import ssl
from slixmpp.xmlstream import cert


class GTalkBot(slixmpp.ClientXMPP):

    """
    A demonstration of using Slixmpp with accounts from a Google Apps
    account with a custom domain, because it requires custom certificate
    validation.
    """

    def __init__(self, jid, password):
        slixmpp.ClientXMPP.__init__(self, jid, password)

        # The session_start event will be triggered when
        # the bot establishes its connection with the server
        # and the XML streams are ready for use. We want to
        # listen for this event so that we we can initialize
        # our roster.
        self.add_event_handler("session_start", self.start)

        # The message event is triggered whenever a message
        # stanza is received. Be aware that that includes
        # MUC messages and error messages.
        self.add_event_handler("message", self.message)

        # Using a Google Apps custom domain, the certificate
        # does not contain the custom domain, just the GTalk
        # server name. So we will need to process invalid
        # certifcates ourselves and check that it really
        # is from Google.
        self.add_event_handler("ssl_invalid_cert", self.invalid_cert)

    def invalid_cert(self, pem_cert):
        der_cert = ssl.PEM_cert_to_DER_cert(pem_cert)
        try:
            cert.verify('talk.google.com', der_cert)
            logging.debug("CERT: Found GTalk certificate")
        except cert.CertificateError as err:
            logging.error(err.message)
            self.disconnect()

    async def start(self, event):
        """
        Process the session_start event.

        Typical actions for the session_start event are
        requesting the roster and broadcasting an initial
        presence stanza.

        Arguments:
            event -- An empty dictionary. The session_start
                     event does not provide any additional
                     data.
        """
        self.send_presence()
        await self.get_roster()

    def message(self, msg):
        """
        Process incoming message stanzas. Be aware that this also
        includes MUC messages and error messages. It is usually
        a good idea to check the messages's type before processing
        or sending replies.

        Arguments:
            msg -- The received message stanza. See the documentation
                   for stanza objects and the Message stanza to see
                   how it may be used.
        """
        if msg['type'] in ('chat', 'normal'):
            msg.reply("Thanks for sending\n%(body)s" % msg).send()


if __name__ == '__main__':
    # Setup the command line arguments.
    parser = ArgumentParser()

    # Output verbosity options.
    parser.add_argument("-q", "--quiet", help="set logging to ERROR",
                        action="store_const", dest="loglevel",
                        const=logging.ERROR, default=logging.INFO)
    parser.add_argument("-d", "--debug", help="set logging to DEBUG",
                        action="store_const", dest="loglevel",
                        const=logging.DEBUG, default=logging.INFO)

    # JID and password options.
    parser.add_argument("-j", "--jid", dest="jid",
                        help="JID to use")
    parser.add_argument("-p", "--password", dest="password",
                        help="password to use")

    args = parser.parse_args()

    # Setup logging.
    logging.basicConfig(level=args.loglevel,
                        format='%(levelname)-8s %(message)s')

    if args.jid is None:
        args.jid = input("Username: ")
    if args.password is None:
        args.password = getpass("Password: ")

    # Setup the GTalkBot and register plugins. Note that while plugins may
    # have interdependencies, the order in which you register them does
    # not matter.
    xmpp = GTalkBot(args.jid, args.password)
    xmpp.register_plugin('xep_0030') # Service Discovery
    xmpp.register_plugin('xep_0004') # Data Forms
    xmpp.register_plugin('xep_0060') # PubSub
    xmpp.register_plugin('xep_0199') # XMPP Ping

    # Connect to the XMPP server and start processing XMPP stanzas.
    xmpp.connect()
    xmpp.process()
