Telegram Bot: Welcome new user

import json
import logging
import urllib
import urllib2

from google.appengine.api import urlfetch
from google.appengine.ext import ndb
import webapp2

TOKEN = 'YOUR_BOT_TOKEN_HERE'

BASE_URL = 'https://api.telegram.org/bot' + TOKEN + '/'


# ================================

class EnableStatus(ndb.Model):
    # key name: str(chat_id)
    enabled = ndb.BooleanProperty(indexed=False, default=False)


# ================================

def setEnabled(chat_id, yes):
    es = EnableStatus.get_or_insert(str(chat_id))
    es.enabled = yes
    es.put()

def getEnabled(chat_id):
    es = EnableStatus.get_by_id(str(chat_id))
    if es:
        return es.enabled
    return False

# ================================

class MeHandler(webapp2.RequestHandler):
    def get(self):
        urlfetch.set_default_fetch_deadline(60)
        self.response.write(json.dumps(json.load(urllib2.urlopen(BASE_URL + 'getMe'))))


class GetUpdatesHandler(webapp2.RequestHandler):
    def get(self):
        urlfetch.set_default_fetch_deadline(60)
        self.response.write(json.dumps(json.load(urllib2.urlopen(BASE_URL + 'getUpdates'))))


class SetWebhookHandler(webapp2.RequestHandler):
    def get(self):
        urlfetch.set_default_fetch_deadline(60)
        url = self.request.get('url')
        if url:
            self.response.write(json.dumps(json.load(urllib2.urlopen(BASE_URL + 'setWebhook', urllib.urlencode({'url': url})))))

class WebhookHandler(webapp2.RequestHandler):
    def post(self):
        urlfetch.set_default_fetch_deadline(60)
        body = json.loads(self.request.body)
        logging.info('request body:')
        logging.info(body)
        self.response.write(json.dumps(body))

        update_id = body['update_id']
        message = body['message']
        message_id = message.get('message_id')
        date = message.get('date')
        text = message.get('text')
        fr = message.get('from')
        chat = message['chat']
        chat_id = chat['id']

        def reply(msg):
            resp = urllib2.urlopen(BASE_URL + 'sendMessage', urllib.urlencode({
                'chat_id': str(chat_id),
                'text': msg,
                'disable_web_page_preview': 'true',
                'reply_to_message_id': str(message_id),
            })).read()
            logging.info('send response:')
            logging.info(resp)

        def send(msg):
            resp = urllib2.urlopen(BASE_URL + 'sendMessage', urllib.urlencode({
                'chat_id': str(chat_id),
                'text': msg,
            })).read()
            logging.info('send msg:')
            logging.info(resp)

        if 'new_chat_participant' in message:
            new_user = message.get('new_chat_participant')
            send('Welcome {0}!'.format(new_user['username']))

        if not text:
            logging.info('no text')
            return

        if text.startswith('/'):
            if text == '/start':
                reply('Bot enabled')
                setEnabled(chat_id, True)
            elif text == '/stop':
                reply('Bot disabled')
                setEnabled(chat_id, False)
            elif text == '/getChatId':
                reply(str(chat_id))
            else:
                reply('What command?')

        # CUSTOMIZE FROM HERE

        elif 'who are you' in text:
            reply('telebot starter kit, created by yukuku: https://github.com/yukuku/telebot')
        elif 'what time' in text:
            reply('look at the top-right corner of your screen!')
        else:
            if getEnabled(chat_id):
                resp1 = json.load(urllib2.urlopen('http://www.simsimi.com/requestChat?lc=en&ft=1.0&req=' + urllib.quote_plus(text.encode('utf-8'))))
                back = resp1.get('res')
                if not back:
                    reply('okay...')
                elif 'I HAVE NO RESPONSE' in back:
                    reply('you said something with no meaning')
                else:
                    reply(back)
            else:
                logging.info('not enabled for chat_id {}'.format(chat_id))


class TestMessage(webapp2.RequestHandler):
    def get(self):
        resp = urllib2.urlopen(BASE_URL + 'sendMessage', urllib.urlencode({
            'chat_id': str(1337), # REPLACE 1337 WITH YOUR CHAT ID
            'text': 'Hi there! Test test test!'
        })).read()

app = webapp2.WSGIApplication([
    ('/me', MeHandler),
    ('/updates', GetUpdatesHandler),
    ('/set_webhook', SetWebhookHandler),
    ('/webhook', WebhookHandler),
    ('/testmsg', TestMessage),
], debug=True)