#!/usr/bin/env python
# -*- coding: utf-8 -*-

# This is a simple echo bot using decorators and webhook with CherryPy
# It echoes any incoming text messages and does not use the polling method.

import cherrypy
import telebot
import logging


API_TOKEN = '<api_token>'

WEBHOOK_HOST = '<ip/host where the bot is running>'
WEBHOOK_PORT = 8443  # 443, 80, 88 or 8443 (port need to be 'open')
WEBHOOK_LISTEN = '0.0.0.0'  # In some VPS you may need to put here the IP addr

WEBHOOK_SSL_CERT = './webhook_cert.pem'  # Path to the ssl certificate
WEBHOOK_SSL_PRIV = './webhook_pkey.pem'  # Path to the ssl private key

# Quick'n'dirty SSL certificate generation:
#
# openssl genrsa -out webhook_pkey.pem 2048
# openssl req -new -x509 -days 3650 -key webhook_pkey.pem -out webhook_cert.pem
#
# When asked for "Common Name (e.g. server FQDN or YOUR name)" you should reply
# with the same value in you put in WEBHOOK_HOST

WEBHOOK_URL_BASE = "https://%s:%s" % (WEBHOOK_HOST, WEBHOOK_PORT)
WEBHOOK_URL_PATH = "/%s/" % (API_TOKEN)


logger = telebot.logger
telebot.logger.setLevel(logging.INFO)

bot = telebot.TeleBot(API_TOKEN)


# WebhookServer, process webhook calls
class WebhookServer(object):
    @cherrypy.expose
    def index(self):
        if 'content-length' in cherrypy.request.headers and \
           'content-type' in cherrypy.request.headers and \
           cherrypy.request.headers['content-type'] == 'application/json':
            length = int(cherrypy.request.headers['content-length'])
            json_string = cherrypy.request.body.read(length).decode("utf-8")
            update = telebot.types.Update.de_json(json_string)
            bot.process_new_messages([update.message])
            return ''
        else:
            raise cherrypy.HTTPError(403)


# Handle '/start' and '/help'
@bot.message_handler(commands=['help', 'start'])
def send_welcome(message):
    bot.reply_to(message,
                 ("Hi there, I am EchoBot.\n"
                  "I am here to echo your kind words back to you."))


# Handle all other messages
@bot.message_handler(func=lambda message: True, content_types=['text'])
def echo_message(message):
    bot.reply_to(message, message.text)


# Remove webhook, it fails sometimes the set if there is a previous webhook
bot.remove_webhook()

# Set webhook
bot.set_webhook(url=WEBHOOK_URL_BASE+WEBHOOK_URL_PATH,
                certificate=open(WEBHOOK_SSL_CERT, 'r'))

# Start cherrypy server
cherrypy.config.update({
    'server.socket_host': WEBHOOK_LISTEN,
    'server.socket_port': WEBHOOK_PORT,
    'server.ssl_module': 'builtin',
    'server.ssl_certificate': WEBHOOK_SSL_CERT,
    'server.ssl_private_key': WEBHOOK_SSL_PRIV
})

cherrypy.quickstart(WebhookServer(), WEBHOOK_URL_PATH, {'/': {}})