import logging
import traceback
from concurrent.futures.thread import ThreadPoolExecutor
from multiprocessing.pool import ThreadPool

import sentry_sdk
from django.core.cache import cache
from django.core.management import BaseCommand
from telegram import TelegramError, Update
from telegram.error import TimedOut
from telegram.ext import CallbackContext

from bots.models import TelegramBot


class Command(BaseCommand):
    def handle(self, *args, **options):
        pool = ThreadPool(8)

        def error_handler(update: Update, ctx: CallbackContext):
            sentry_sdk.capture_exception(ctx.error)
            logging.exception('Exception while processing update', exc_info=ctx.error)

        initialized = False
        dispatchers = []

        def check_updates(dispatcher):
            try:
                updates = dispatcher.bot.get_updates(dispatcher.last_update_id)
            except TimedOut:
                return
            except TelegramError as e:
                sentry_sdk.capture_exception(e)
                traceback.print_exc()
                updates = []

            for update in updates:
                pool.apply_async(dispatcher.process_update, (update,))
                dispatcher.last_update_id = update.update_id + 1

        while True:
            try:
                if not initialized or cache.get('bots_reset'):
                    logging.warning('Reloading dispatchers')
                    dispatchers = []
                    for bot in TelegramBot.objects.filter(active=True):
                        try:
                            dispatcher = bot.build_dispatcher(error_handler)
                            dispatcher.last_update_id = 0
                            dispatchers.append(dispatcher)
                        except TelegramError:
                            pass
                    cache.delete('bots_reset')
                    initialized = True

                with ThreadPoolExecutor() as executor:
                    for dispatcher in dispatchers:
                        executor.submit(check_updates, dispatcher)
            except KeyboardInterrupt:
                pool.terminate()
                pool.join()
                return
            except Exception as e:
                sentry_sdk.capture_exception(e)
                traceback.print_exc()