"""
Startup script for Face Verification System
"""

import os
import sys
import logging
from pathlib import Path

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


def check_dependencies():
    """Check if all required dependencies are installed"""
    required_packages = [
        'fastapi',
        'uvicorn',
        'cv2',
        'numpy',
        'pydantic'
    ]
    
    missing_packages = []
    
    for package in required_packages:
        try:
            if package == 'cv2':
                import cv2
            else:
                __import__(package)
            logger.info(f"✓ {package} installed")
        except ImportError:
            missing_packages.append(package)
            logger.error(f"✗ {package} not installed")
    
    if missing_packages:
        logger.error(f"Missing packages: {', '.join(missing_packages)}")
        logger.info("Install with: pip install -r requirements.txt")
        return False
    
    return True


def check_optional_dependencies():
    """Check optional face recognition libraries"""
    optional_packages = {
        'deepface': 'DeepFace',
        'face_recognition': 'face_recognition',
        'insightface': 'InsightFace'
    }
    
    available = []
    
    for package, name in optional_packages.items():
        try:
            __import__(package)
            available.append(name)
            logger.info(f"✓ {name} available")
        except ImportError:
            logger.warning(f"⚠ {name} not available (will use fallback)")
    
    if not available:
        logger.warning("No advanced face recognition library found. Using custom fallback.")
        logger.info("For better accuracy, install: pip install deepface face-recognition")
    else:
        logger.info(f"Using: {', '.join(available)}")


def create_directories():
    """Create necessary directories"""
    directories = ['uploads', 'temp', 'models']
    
    for directory in directories:
        Path(directory).mkdir(exist_ok=True)
        logger.info(f"✓ Directory created/verified: {directory}")


def download_models():
    """Download face detection models if not present"""
    try:
        import urllib.request
        
        models_dir = Path('models')
        models_dir.mkdir(exist_ok=True)
        
        # DNN face detection model files
        prototxt_url = "https://raw.githubusercontent.com/opencv/opencv/master/samples/dnn/face_detector/deploy.prototxt"
        model_url = "https://raw.githubusercontent.com/opencv/opencv_3rdparty/dnn_samples_face_detector_20170830/res10_300x300_ssd_iter_140000.caffemodel"
        
        prototxt_path = models_dir / "deploy.prototxt"
        model_path = models_dir / "res10_300x300_ssd_iter_140000.caffemodel"
        
        # Download prototxt
        if not prototxt_path.exists():
            logger.info("Downloading face detection prototxt...")
            urllib.request.urlretrieve(prototxt_url, prototxt_path)
            logger.info("✓ Prototxt downloaded")
        else:
            logger.info("✓ Prototxt already exists")
        
        # Download model (this is large, ~10MB)
        if not model_path.exists():
            logger.info("Downloading face detection model (this may take a while)...")
            urllib.request.urlretrieve(model_url, model_path)
            logger.info("✓ Model downloaded")
        else:
            logger.info("✓ Model already exists")
        
        return True
        
    except Exception as e:
        logger.warning(f"Could not download models: {e}")
        logger.info("Will use Haar Cascade fallback (built-in to OpenCV)")
        return False


def main():
    """Main startup function"""
    logger.info("=" * 60)
    logger.info("🚀 Face Verification System - Startup")
    logger.info("=" * 60)
    
    # Check dependencies
    logger.info("\n1. Checking dependencies...")
    if not check_dependencies():
        logger.error("❌ Dependency check failed")
        sys.exit(1)
    
    # Check optional dependencies
    logger.info("\n2. Checking optional dependencies...")
    check_optional_dependencies()
    
    # Create directories
    logger.info("\n3. Creating directories...")
    create_directories()
    
    # Download models
    logger.info("\n4. Checking face detection models...")
    download_models()
    
    # Set environment variables
    port = int(os.getenv('PORT', 7860))
    host = os.getenv('HOST', '0.0.0.0')
    
    logger.info("\n" + "=" * 60)
    logger.info("✓ Startup checks complete!")
    logger.info(f"Starting server on {host}:{port}")
    logger.info("=" * 60 + "\n")
    
    # Start the application
    import uvicorn
    from app import app
    
    uvicorn.run(
        app,
        host=host,
        port=port,
        log_level="info",
        access_log=True
    )


if __name__ == "__main__":
    main()