import logging
import signal
import sys

from telegram.ext import (
    Application,
    CallbackQueryHandler,
    CommandHandler,
    MessageHandler,
    filters,
)

from bot.config import BOT_TOKEN, LOG_LEVEL
from bot.handlers import (
    handle_callback,
    handle_snooze_input,
    help_command,
    list_reminders,
    reminder_conv_handler,
    start,
)
from bot.models import init_db
from bot.scheduler import init_scheduler, shutdown_scheduler

logging.basicConfig(
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
    level=getattr(logging, LOG_LEVEL, logging.INFO),
)
logger = logging.getLogger(__name__)


def main() -> None:
    # Initialize database
    init_db()
    logger.info("Database initialized")

    # Build application
    app = Application.builder().token(BOT_TOKEN).build()

    # Initialize scheduler
    init_scheduler(app.bot)

    # Register handlers (group=0)
    app.add_handler(CommandHandler("start", start))
    app.add_handler(CommandHandler("help", help_command))
    app.add_handler(MessageHandler(filters.Regex("^❓ 帮助$"), help_command))

    app.add_handler(reminder_conv_handler)

    app.add_handler(CommandHandler("list", list_reminders))
    app.add_handler(MessageHandler(filters.Regex("^📋 我的提醒$"), list_reminders))

    app.add_handler(CallbackQueryHandler(handle_callback))

    # Snooze minutes input in group=1, after ConversationHandler.
    # handle_snooze_input checks user_data and returns early if not waiting for input.
    app.add_handler(
        MessageHandler(filters.TEXT & ~filters.COMMAND, handle_snooze_input),
        group=1,
    )

    # Graceful shutdown
    def signal_handler(sig, frame):
        logger.info("Shutting down...")
        shutdown_scheduler()
        sys.exit(0)

    signal.signal(signal.SIGINT, signal_handler)
    signal.signal(signal.SIGTERM, signal_handler)

    # Start bot
    logger.info("Bot started")
    app.run_polling(allowed_updates=["message", "callback_query"])


if __name__ == "__main__":
    main()