import time
import json
from datetime import datetime
from functools import wraps

class PerformanceMonitor:
    def __init__(self):
        self.metrics = {
            "total_requests": 0,
            "successful_requests": 0,
            "failed_requests": 0,
            "average_response_time": 0,
            "last_request_time": None,
            "uptime_start": datetime.now().isoformat()
        }
        
    def log_request(self, func):
        """Decorator to monitor function performance"""
        @wraps(func)
        def wrapper(*args, **kwargs):
            start_time = time.time()
            self.metrics["total_requests"] += 1
            self.metrics["last_request_time"] = datetime.now().isoformat()
            
            try:
                result = func(*args, **kwargs)
                self.metrics["successful_requests"] += 1
                
                # Calculate response time
                response_time = time.time() - start_time
                self._update_average_response_time(response_time)
                
                return result
                
            except Exception as e:
                self.metrics["failed_requests"] += 1
                raise e
                
        return wrapper
        
    def _update_average_response_time(self, new_time):
        """Update running average of response times"""
        current_avg = self.metrics["average_response_time"]
        total_successful = self.metrics["successful_requests"]
        
        if total_successful == 1:
            self.metrics["average_response_time"] = new_time
        else:
            self.metrics["average_response_time"] = (
                (current_avg * (total_successful - 1) + new_time) / total_successful
            )
    
    def get_metrics(self):
        """Get current performance metrics"""
        success_rate = 0
        if self.metrics["total_requests"] > 0:
            success_rate = (
                self.metrics["successful_requests"] / self.metrics["total_requests"]
            ) * 100
            
        return {
            **self.metrics,
            "success_rate_percent": round(success_rate, 2),
            "average_response_time_seconds": round(self.metrics["average_response_time"], 2)
        }
    
    def get_health_status(self):
        """Get overall health status"""
        metrics = self.get_metrics()
        
        if metrics["success_rate_percent"] >= 95 and metrics["average_response_time_seconds"] < 10:
            return "🟢 Healthy"
        elif metrics["success_rate_percent"] >= 80 and metrics["average_response_time_seconds"] < 15:
            return "🟡 Degraded"
        else:
            return "🔴 Unhealthy"

# Global monitor instance
monitor = PerformanceMonitor()

# Usage example for your main app:
# @monitor.log_request
# def process_test_lifecycle(selected_story_id, custom_story=""):
#     # Your existing function code
#     pass