import os
import json
import logging
from datetime import datetime, timedelta
from flask import Flask, request, jsonify
from recommender import recommend_products
from flask_cors import CORS

# --- Configure Logging ---
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
    handlers=[
        logging.FileHandler('app.log'),
        logging.StreamHandler()
    ]
)
logger = logging.getLogger(__name__)

# --- Initialize Flask App and CORS ---

app = Flask(__name__)
CORS(app, resources={r"/api/*": {"origins": "*"}}) 

@app.route('/recommend/<int:user_id>', methods=['GET'])
def get_recommendations(user_id):
    logger.info(f"=== RECOMMENDATION REQUEST START ===")
    logger.info(f"Input - User ID: {user_id}")
    logger.info(f"Request method: {request.method}")
    logger.info(f"Request headers: {dict(request.headers)}")
    logger.info(f"Request args: {dict(request.args)}")
    
    try:
        # Get optional parameters
        top_n = request.args.get('top_n', default=5, type=int)
        logger.info(f"Parameters - top_n: {top_n}")
        
        logger.info("Calling recommend_products function...")
        recommendations = recommend_products(user_id, top_n)
        
        response_data = {
            "user_id": user_id,
            "recommendations": recommendations,
            "total_recommendations": len(recommendations),
            "timestamp": datetime.now().isoformat()
        }
        
        logger.info(f"Success - Generated {len(recommendations)} recommendations for user {user_id}")
        logger.info(f"Output - Response data keys: {list(response_data.keys())}")
        logger.info(f"Output - Recommendation IDs: {[r.get('id') for r in recommendations if isinstance(r, dict)]}")
        logger.info(f"=== RECOMMENDATION REQUEST END ===")
        
        return jsonify(response_data)
        
    except Exception as e:
        logger.error(f"=== RECOMMENDATION REQUEST FAILED ===")
        logger.error(f"Error type: {type(e).__name__}")
        logger.error(f"Error message: {str(e)}")
        logger.exception("Full traceback:")
        
        error_response = {
            "error": str(e),
            "user_id": user_id,
            "timestamp": datetime.now().isoformat()
        }
        
        logger.error(f"Returning error response: {error_response}")
        return jsonify(error_response), 500

@app.route('/health', methods=['GET'])
def health_check():
    logger.info("=== HEALTH CHECK REQUEST ===")
    response = {
        "status": "healthy",
        "timestamp": datetime.now().isoformat(),
        "service": "recommendation-api"
    }
    logger.info(f"Health check response: {response}")
    return jsonify(response)

@app.errorhandler(404)
def not_found(error):
    logger.warning(f"404 Error - Path: {request.path}, Method: {request.method}")
    return jsonify({"error": "Endpoint not found"}), 404

@app.errorhandler(500)
def internal_error(error):
    logger.error(f"500 Error - Path: {request.path}, Method: {request.method}")
    logger.exception("Internal server error:")
    return jsonify({"error": "Internal server error"}), 500

# -----------------------------------------------------------------------------
# SERVER EXECUTION
# -----------------------------------------------------------------------------

if __name__ == '__main__':
    port = int(os.environ.get("PORT", 7860))
    debug_mode = os.environ.get("FLASK_DEBUG", "False").lower() == "true"
    
    logger.info(f"=== STARTING RECOMMENDATION SERVER ===")
    logger.info(f"Debug mode: {debug_mode}")
    logger.info(f"Port: {port}")
    logger.info(f"Environment variables: PORT={os.environ.get('PORT')}, FLASK_DEBUG={os.environ.get('FLASK_DEBUG')}")
    
    if not debug_mode:
        logger.info("Using Waitress server for production")
        from waitress import serve
        serve(app, host="0.0.0.0", port=port)
    else:
        logger.info("Using Flask development server")
        app.run(debug=True, host="0.0.0.0", port=port)