"""
Main entry point for ROA2WEB Telegram Bot

This bot provides access to the ROA2WEB ERP system through Telegram
using direct command handlers for financial data queries.
"""

import asyncio
import logging
import os
from pathlib import Path
from dotenv import load_dotenv
# Note: uvicorn and threading removed - internal API now served via main.py

# ============================================================================
# LOAD ENVIRONMENT VARIABLES FIRST - BEFORE ANY APP IMPORTS
# ============================================================================
# This ensures all modules can access environment variables at import time
env_path = Path(__file__).parent.parent / '.env'
load_dotenv(env_path)

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

# Import database initialization
from backend.modules.telegram.db import (
    init_database,
    cleanup_expired_codes,
    cleanup_expired_sessions,
    cleanup_expired_email_codes
)

# Import bot handlers
from backend.modules.telegram.bot.handlers import (
    start_command,
    help_command,
    clear_command,
    companies_command,
    unlink_command,
    selectcompany_command,
    dashboard_command,
    sold_command,
    facturi_command,
    trezorerie_command,
    # FAZA 3: New command handlers with button interface
    menu_command,
    trezorerie_casa_command,
    trezorerie_banca_command,
    clienti_command,
    furnizori_command,
    evolutie_command,
    # FAZA 6: Cache management commands
    clearcache_command,
    togglecache_command,
    # Text message handlers
    handle_text_message,
    # FAZA 4: Callback and error handlers
    button_callback,
    error_handler
)

# Import email authentication handler
from backend.modules.telegram.bot.email_handlers import email_login_handler

# Note: internal_api import removed - now served via main.py at /api/telegram/internal/*

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger(__name__)

# Environment variables (already loaded above)
TELEGRAM_BOT_TOKEN = os.getenv('TELEGRAM_BOT_TOKEN')
BACKEND_URL = os.getenv('BACKEND_URL', 'http://localhost:8000')
# Note: INTERNAL_API_PORT removed - internal API now served via main.py


# ============================================================================
# TELEGRAM BOT SETUP
# ============================================================================

def create_telegram_application() -> Application:
    """
    Create and configure the Telegram bot application.

    Returns:
        Application: Configured Telegram application
    """
    logger.info("Creating Telegram application...")

    # Create application
    application = Application.builder().token(TELEGRAM_BOT_TOKEN).build()

    # Register email authentication conversation handler (must be before other handlers)
    application.add_handler(email_login_handler)

    # Register essential command handlers
    application.add_handler(CommandHandler("start", start_command))
    application.add_handler(CommandHandler("menu", menu_command))
    application.add_handler(CommandHandler("help", help_command))
    application.add_handler(CommandHandler("unlink", unlink_command))

    # =========================================================================
    # LEGACY COMMAND HANDLERS (kept for backwards compatibility, hidden from help)
    # =========================================================================
    # NOTE: These commands are redundant with the button interface.
    # They're kept for users who already know them, but we push buttons in help.
    # Consider removing completely if migration is successful.

    application.add_handler(CommandHandler("clear", clear_command))
    application.add_handler(CommandHandler("companies", companies_command))
    application.add_handler(CommandHandler("selectcompany", selectcompany_command))
    application.add_handler(CommandHandler("dashboard", dashboard_command))
    application.add_handler(CommandHandler("sold", sold_command))
    application.add_handler(CommandHandler("facturi", facturi_command))
    application.add_handler(CommandHandler("trezorerie", trezorerie_command))
    application.add_handler(CommandHandler("trezorerie_casa", trezorerie_casa_command))
    application.add_handler(CommandHandler("trezorerie_banca", trezorerie_banca_command))
    application.add_handler(CommandHandler("clienti", clienti_command))
    application.add_handler(CommandHandler("furnizori", furnizori_command))
    application.add_handler(CommandHandler("evolutie", evolutie_command))

    # FAZA 6: Cache management commands
    application.add_handler(CommandHandler("clearcache", clearcache_command))
    application.add_handler(CommandHandler("togglecache", togglecache_command))

    # Text message handler (for direct code input and future NLP)
    # IMPORTANT: This must be registered BEFORE CallbackQueryHandler
    # filters.TEXT & ~filters.COMMAND ensures we only process non-command text messages
    application.add_handler(MessageHandler(
        filters.TEXT & ~filters.COMMAND,
        handle_text_message
    ))

    # FAZA 4: Register callback query handler (for inline buttons)
    application.add_handler(CallbackQueryHandler(button_callback))

    # Register error handler
    application.add_error_handler(error_handler)

    logger.info("Telegram application configured with all handlers")

    return application


# ============================================================================
# STARTUP/SHUTDOWN
# ============================================================================
# Note: Internal API server removed - now served via main.py at /api/telegram/internal/*

async def startup():
    """
    Initialize the bot application on startup.
    """
    logger.info("🚀 ROA2WEB Telegram Bot - Starting up...")

    # Initialize database
    try:
        logger.info("Initializing SQLite database...")
        await init_database()
        logger.info("✅ Database initialized successfully")
    except Exception as e:
        logger.error(f"❌ Failed to initialize database: {e}")
        raise

    # Cleanup expired data
    try:
        logger.info("Cleaning up expired data...")
        expired_codes = await cleanup_expired_codes()
        expired_sessions = await cleanup_expired_sessions()
        expired_email_codes = await cleanup_expired_email_codes()
        logger.info(f"✅ Cleanup complete: {expired_codes} codes, {expired_sessions} sessions, {expired_email_codes} email codes removed")
    except Exception as e:
        logger.warning(f"⚠️ Cleanup failed (non-critical): {e}")

    logger.info("✅ Startup complete")


async def shutdown():
    """
    Clean up resources on shutdown.
    """
    logger.info("👋 ROA2WEB Telegram Bot - Shutting down...")
    logger.info("✅ Shutdown complete")


async def scheduled_cleanup():
    """
    Background task to periodically clean up expired data.
    Runs every hour to remove expired auth codes, sessions, and email codes.
    """
    while True:
        try:
            await asyncio.sleep(3600)  # Sleep for 1 hour
            logger.info("🧹 Running scheduled cleanup...")
            expired_codes = await cleanup_expired_codes()
            expired_sessions = await cleanup_expired_sessions()
            expired_email_codes = await cleanup_expired_email_codes()
            logger.info(f"✅ Scheduled cleanup: {expired_codes} codes, {expired_sessions} sessions, {expired_email_codes} email codes removed")
        except Exception as e:
            logger.error(f"❌ Error in scheduled cleanup: {e}")


# ============================================================================
# MAIN APPLICATION
# ============================================================================

async def main():
    """
    Main application entry point.

    Runs both the Telegram bot and internal API server concurrently.
    """
    try:
        # Run startup
        await startup()

        # Create Telegram application
        telegram_app = create_telegram_application()

        # Note: Internal API server removed - now served via main.py

        # Start scheduled cleanup task in background
        cleanup_task = asyncio.create_task(scheduled_cleanup())
        logger.info("✅ Scheduled cleanup task started")

        # Initialize and start Telegram bot
        logger.info("🤖 Starting Telegram bot polling...")
        await telegram_app.initialize()
        await telegram_app.start()
        await telegram_app.updater.start_polling(
            drop_pending_updates=True,
            poll_interval=0,        # No delay between polls
            timeout=30              # Long poll timeout 30 seconds (reduces requests from ~6/min to ~2/min)
        )

        logger.info("✅ Telegram bot is now running and polling for updates")
        logger.info(f"📱 Bot ready to receive messages at @{(await telegram_app.bot.get_me()).username}")
        logger.info("🎯 Bot is operational with direct command handlers!")

        # Keep running until interrupted
        await asyncio.Event().wait()

    except KeyboardInterrupt:
        logger.info("⚠️ Received interrupt signal")
    except Exception as e:
        logger.error(f"❌ Fatal error: {e}", exc_info=True)
        raise
    finally:
        # Stop Telegram bot gracefully
        try:
            if 'telegram_app' in locals():
                logger.info("Stopping Telegram bot...")
                await telegram_app.updater.stop()
                await telegram_app.stop()
                await telegram_app.shutdown()
                logger.info("✅ Telegram bot stopped")
        except Exception as e:
            logger.error(f"Error stopping Telegram bot: {e}")

        await shutdown()


# ============================================================================
# ENTRY POINT
# ============================================================================

if __name__ == "__main__":
    # Check required environment variables
    if not os.getenv('TELEGRAM_BOT_TOKEN'):
        logger.error("❌ TELEGRAM_BOT_TOKEN is required")
        logger.error("Please set it in .env file")
        exit(1)

    # Display startup banner
    logger.info("=" * 60)
    logger.info("  ROA2WEB TELEGRAM BOT")
    logger.info("  Financial ERP Assistant with Direct Commands")
    logger.info("=" * 60)

    # Run the main application
    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        logger.info("👋 Application stopped by user")
    except Exception as e:
        logger.error(f"❌ Application failed: {e}", exc_info=True)
        exit(1)