import telebot
import os
import logging
import traceback
import sys
from telebot.async_telebot import AsyncTeleBot
from persistence import UserRepository

class CommandHandler:
    async def handle(self, message: telebot.types.Message):
        pass

class TelegramBot:
    __bot: AsyncTeleBot
    __userRepository: UserRepository

    def __init__(self, userRepository: UserRepository):
        self.__userRepository = userRepository

        # Check token in environment variables
        if "TELEBOT_BOT_TOKEN" not in os.environ:
            raise AssertionError("Please configure TELEBOT_BOT_TOKEN as environment variables")

        self.__bot = telebot.async_telebot.AsyncTeleBot(
            token=os.environ["TELEBOT_BOT_TOKEN"],
            exception_handler=ExceptionHandler())
    
    async def run(self):
        await self.__bot.polling() 
    
    def register_command_handler(self, command: str, command_handler: CommandHandler):
        self.__bot.register_message_handler(
            command_handler.handle, 
            commands=[ command ])
    
    async def send_message_to_all(self, message_text: str):
        for user in self.__userRepository.getAllUsers():
            try:
                await self.__bot.send_message(
                    user[0],
                    message_text,
                    parse_mode='MarkdownV2'
                )
            except Exception as error:
                if 'bot was kicked from the group chat' in str(error):
                    self.__userRepository.removeChat(user[0])
    
    async def reply(self, message, message_text):
        await self.__bot.reply_to(
            message,
            message_text,
            parse_mode='MarkdownV2')

class ExceptionHandler(telebot.ExceptionHandler):
    def handle(self, exception):
        logging.error('Exception happened: {}'.format(str(exception)))
        print(traceback.format_exc())
        sys.exit('Exiting with telebot exception')
        return True