#!/usr/bin/env python3
# encoding=utf-8

'''
MessageQueue usage example with @queuedmessage decorator.
Provide your bot token with `TOKEN` environment variable or list it in
file `token.txt`
'''

import telegram.bot
from telegram.ext import messagequeue as mq


class MQBot(telegram.bot.Bot):
    '''A subclass of Bot which delegates send method handling to MQ'''
    def __init__(self, *args, is_queued_def=True, mqueue=None, **kwargs):
        super(MQBot, self).__init__(*args, **kwargs)
        # below 2 attributes should be provided for decorator usage
        self._is_messages_queued_default = is_queued_def
        self._msg_queue = mqueue or mq.MessageQueue()

    def __del__(self):
        try:
            self._msg_queue.stop()
        except:
            pass

    @mq.queuedmessage
    def send_message(self, *args, **kwargs):
        '''Wrapped method would accept new `queued` and `isgroup`
        OPTIONAL arguments'''
        return super(MQBot, self).send_message(*args, **kwargs)


if __name__ == '__main__':
    from telegram import ParseMode
    from telegram.ext import MessageHandler, Filters, CommandHandler
    from telegram.utils.request import Request
    import os
    token = os.environ.get('TOKEN') or open('token.txt').read().strip()
    # for test purposes limit global throughput to 3 messages per 3 seconds
    q = mq.MessageQueue(all_burst_limit=3, all_time_limit_ms=3000)
    # set connection pool size for bot 
    request = Request(con_pool_size=8)
    testbot = MQBot(token, request=request, mqueue=q)
    upd = telegram.ext.updater.Updater(bot=testbot, use_context=True)


    def show_bug(update, context):
        """
        The dot in "Hello, World." should raise an exception
        because it is unescaped.
        """
        context.bot.send_message(
            chat_id=update.effective_chat.id,
            text="Hello, World.",
            parse_mode=ParseMode.MARKDOWN_V2
        )

    def start(update, context):
        context.bot.send_message(
            chat_id=update.effective_chat.id,
            text=r"Hello, World\.",
            parse_mode=ParseMode.MARKDOWN_V2
        )

    upd.dispatcher.add_handler(CommandHandler("start", start))

    upd.dispatcher.add_handler(CommandHandler("bug", show_bug))
    upd.start_polling()