handler.py

import json
import telegram
import os
import logging
import serverlessHandlers.HandleMessage as messageHandler

# Logging is cool!
logger = logging.getLogger()
if logger.handlers:
	for handler in logger.handlers:
		logger.removeHandler(handler)
logging.basicConfig(level=logging.INFO)

OK_RESPONSE = {
	'statusCode': 200,
	'headers': {'Content-Type': 'application/json'},
	'body': json.dumps('ok')
}
ERROR_RESPONSE = {
	'statusCode': 400,
	'body': json.dumps('Oops, something went wrong!')
}


def configure_telegram():
	"""
	Configures the bot with a Telegram Token.

	Returns a bot instance.
	"""

	TELEGRAM_TOKEN = os.environ.get('TELEGRAM_TOKEN')
	if not TELEGRAM_TOKEN:
		logger.error('The TELEGRAM_TOKEN must be set')
		raise NotImplementedError

	return telegram.Bot(TELEGRAM_TOKEN)


def webhook(event, context):
	"""
	Runs the Telegram webhook.
	"""

	bot = configure_telegram()
	logger.info('Event: {}'.format(event))

	if event.get('httpMethod') == 'POST' and event.get('body'):
		logger.info('Message received')
		update = telegram.Update.de_json(json.loads(event.get('body')), bot)
		chat_id = update.message.chat.id
		text = update.message.text
		message_id = update.message.message_id
		user_firstname = update.message.from_user.first_name

		# Entry point for incoming messages
		messageHandler.HandleMessage(bot, chat_id, text, message_id, user_firstname)

		return OK_RESPONSE

	return ERROR_RESPONSE


def set_webhook(event, context):
	"""
	Sets the Telegram bot webhook.
	"""

	logger.info('Event: {}'.format(event))
	bot = configure_telegram()
	url = 'https://{}/{}/'.format(
		event.get('headers').get('Host'),
		event.get('requestContext').get('stage'),
	)
	webhook = bot.set_webhook(url)

	if webhook:
		return OK_RESPONSE

	return ERROR_RESPONSE