#!/usr/bin/env python3
"""
Main entry point for the Thailand Water Monitor system
"""

import argparse
import asyncio
import sys
import signal
from datetime import datetime
from typing import Optional

from .config import Config
from .water_scraper_v3 import EnhancedWaterMonitorScraper
from .logging_config import setup_logging, get_logger
from .exceptions import ConfigurationError, DatabaseConnectionError
from .metrics import get_metrics_collector

logger = get_logger(__name__)

def setup_signal_handlers(scraper: Optional[EnhancedWaterMonitorScraper] = None):
    """Setup signal handlers for graceful shutdown"""
    def signal_handler(signum, frame):
        logger.info(f"Received signal {signum}, shutting down gracefully...")
        if scraper:
            logger.info("Stopping scraper...")
        sys.exit(0)
    
    signal.signal(signal.SIGINT, signal_handler)
    signal.signal(signal.SIGTERM, signal_handler)

def run_test_cycle():
    """Run a single test cycle"""
    logger.info("Running test cycle...")
    
    try:
        # Validate configuration
        Config.validate_config()
        
        # Initialize scraper
        db_config = Config.get_database_config()
        scraper = EnhancedWaterMonitorScraper(db_config)
        
        # Run single scraping cycle
        result = scraper.run_scraping_cycle()
        
        if result:
            logger.info("✅ Test cycle completed successfully")
            
            # Show some statistics
            latest_data = scraper.get_latest_data(5)
            if latest_data:
                logger.info(f"Latest data points: {len(latest_data)}")
                for data in latest_data[:3]:  # Show first 3
                    logger.info(f"  • {data['station_code']}: {data['water_level']:.2f}m, {data['discharge']:.1f} cms")
        else:
            logger.warning("⚠️ Test cycle completed but no new data was found")
        
        return True
        
    except Exception as e:
        logger.error(f"❌ Test cycle failed: {e}")
        return False

def run_continuous_monitoring():
    """Run continuous monitoring with scheduling"""
    logger.info("Starting continuous monitoring...")
    
    try:
        # Validate configuration
        Config.validate_config()
        
        # Initialize scraper
        db_config = Config.get_database_config()
        scraper = EnhancedWaterMonitorScraper(db_config)
        
        # Setup signal handlers
        setup_signal_handlers(scraper)
        
        logger.info(f"Monitoring started with {Config.SCRAPING_INTERVAL_HOURS}h interval")
        logger.info("Press Ctrl+C to stop")
        
        # Run initial cycle
        logger.info("Running initial data collection...")
        scraper.run_scraping_cycle()
        
        # Start scheduled monitoring
        import schedule
        
        schedule.every(Config.SCRAPING_INTERVAL_HOURS).hours.do(scraper.run_scraping_cycle)
        
        while True:
            schedule.run_pending()
            time.sleep(60)  # Check every minute
            
    except KeyboardInterrupt:
        logger.info("Monitoring stopped by user")
    except Exception as e:
        logger.error(f"Monitoring failed: {e}")
        return False
    
    return True

def run_gap_filling(days_back: int):
    """Run gap filling for missing data"""
    logger.info(f"Checking for data gaps in the last {days_back} days...")
    
    try:
        # Validate configuration
        Config.validate_config()
        
        # Initialize scraper
        db_config = Config.get_database_config()
        scraper = EnhancedWaterMonitorScraper(db_config)
        
        # Fill gaps
        filled_count = scraper.fill_data_gaps(days_back)
        
        if filled_count > 0:
            logger.info(f"✅ Filled {filled_count} missing data points")
        else:
            logger.info("✅ No data gaps found")
        
        return True
        
    except Exception as e:
        logger.error(f"❌ Gap filling failed: {e}")
        return False

def run_data_update(days_back: int):
    """Update existing data with latest values"""
    logger.info(f"Updating existing data for the last {days_back} days...")
    
    try:
        # Validate configuration
        Config.validate_config()
        
        # Initialize scraper
        db_config = Config.get_database_config()
        scraper = EnhancedWaterMonitorScraper(db_config)
        
        # Update data
        updated_count = scraper.update_existing_data(days_back)
        
        if updated_count > 0:
            logger.info(f"✅ Updated {updated_count} data points")
        else:
            logger.info("✅ No data updates needed")
        
        return True
        
    except Exception as e:
        logger.error(f"❌ Data update failed: {e}")
        return False

def run_web_api():
    """Run the FastAPI web interface"""
    logger.info("Starting web API server...")
    
    try:
        import uvicorn
        from .web_api import app
        
        # Validate configuration
        Config.validate_config()
        
        # Run the server
        uvicorn.run(
            app,
            host="0.0.0.0",
            port=8000,
            log_config=None  # Use our custom logging
        )
        
    except ImportError:
        logger.error("FastAPI not installed. Run: pip install fastapi uvicorn")
        return False
    except Exception as e:
        logger.error(f"Web API failed: {e}")
        return False

def show_status():
    """Show current system status"""
    logger.info("=== Northern Thailand Ping River Monitor Status ===")
    
    try:
        # Show configuration
        Config.print_settings()
        
        # Test database connection
        logger.info("\n=== Database Connection Test ===")
        db_config = Config.get_database_config()
        scraper = EnhancedWaterMonitorScraper(db_config)
        
        if scraper.db_adapter:
            logger.info("✅ Database connection successful")
            
            # Show latest data
            latest_data = scraper.get_latest_data(3)
            if latest_data:
                logger.info(f"\n=== Latest Data ({len(latest_data)} points) ===")
                for data in latest_data:
                    timestamp = data['timestamp']
                    if isinstance(timestamp, str):
                        timestamp = datetime.fromisoformat(timestamp.replace('Z', '+00:00'))
                    logger.info(f"  • {data['station_code']} ({timestamp}): {data['water_level']:.2f}m")
            else:
                logger.info("No data found in database")
        else:
            logger.error("❌ Database connection failed")
        
        # Show metrics if available
        metrics_collector = get_metrics_collector()
        metrics = metrics_collector.get_all_metrics()
        
        if any(metrics.values()):
            logger.info("\n=== Metrics Summary ===")
            for metric_type, values in metrics.items():
                if values:
                    logger.info(f"{metric_type.title()}: {len(values)} metrics")
        
        return True
        
    except Exception as e:
        logger.error(f"Status check failed: {e}")
        return False

def main():
    """Main entry point"""
    parser = argparse.ArgumentParser(
        description="Northern Thailand Ping River Monitor",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Examples:
  %(prog)s --test                    # Run single test cycle
  %(prog)s                          # Run continuous monitoring
  %(prog)s --web-api                # Start web API server
  %(prog)s --fill-gaps 7            # Fill missing data for last 7 days
  %(prog)s --update-data 2          # Update existing data for last 2 days
  %(prog)s --status                 # Show system status
        """
    )
    
    parser.add_argument(
        "--test", 
        action="store_true",
        help="Run a single test cycle"
    )
    
    parser.add_argument(
        "--web-api",
        action="store_true", 
        help="Start the web API server"
    )
    
    parser.add_argument(
        "--fill-gaps",
        type=int,
        metavar="DAYS",
        help="Fill missing data gaps for the specified number of days back"
    )
    
    parser.add_argument(
        "--update-data",
        type=int,
        metavar="DAYS", 
        help="Update existing data for the specified number of days back"
    )
    
    parser.add_argument(
        "--status",
        action="store_true",
        help="Show current system status"
    )
    
    parser.add_argument(
        "--log-level",
        choices=["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"],
        default=Config.LOG_LEVEL,
        help="Set logging level"
    )
    
    parser.add_argument(
        "--log-file",
        default=Config.LOG_FILE,
        help="Log file path"
    )
    
    args = parser.parse_args()
    
    # Setup logging
    setup_logging(
        log_level=args.log_level,
        log_file=args.log_file,
        enable_console=True,
        enable_colors=True
    )
    
    logger.info("🏔️ Northern Thailand Ping River Monitor starting...")
    logger.info(f"Version: 3.1.3")
    logger.info(f"Log level: {args.log_level}")
    
    try:
        success = False
        
        if args.test:
            success = run_test_cycle()
        elif args.web_api:
            success = run_web_api()
        elif args.fill_gaps is not None:
            success = run_gap_filling(args.fill_gaps)
        elif args.update_data is not None:
            success = run_data_update(args.update_data)
        elif args.status:
            success = show_status()
        else:
            success = run_continuous_monitoring()
        
        if success:
            logger.info("✅ Operation completed successfully")
            sys.exit(0)
        else:
            logger.error("❌ Operation failed")
            sys.exit(1)
            
    except ConfigurationError as e:
        logger.error(f"Configuration error: {e}")
        sys.exit(1)
    except KeyboardInterrupt:
        logger.info("Operation cancelled by user")
        sys.exit(0)
    except Exception as e:
        logger.error(f"Unexpected error: {e}")
        sys.exit(1)

if __name__ == "__main__":
    main()