"""
Simple rate limiter for API requests.
"""

import time
from collections import defaultdict
from typing import Dict


class RateLimiter:
    """Simple rate limiter implementation"""
    
    def __init__(self, requests_per_minute: int = 100, burst_size: int = 20):
        self.requests_per_minute = requests_per_minute
        self.burst_size = burst_size
        self.requests: Dict[str, list] = defaultdict(list)
    
    def is_allowed(self, client_id: str) -> bool:
        """Check if request is allowed for client"""
        now = time.time()
        minute_ago = now - 60
        
        # Clean old requests
        self.requests[client_id] = [
            req_time for req_time in self.requests[client_id] 
            if req_time > minute_ago
        ]
        
        # Check rate limit
        if len(self.requests[client_id]) >= self.requests_per_minute:
            return False
        
        # Add current request
        self.requests[client_id].append(now)
        return True
    
    def get_client_stats(self, client_id: str) -> Dict:
        """Get rate limiting stats for a specific client"""
        now = time.time()
        minute_ago = now - 60
        
        # Clean old requests
        self.requests[client_id] = [
            req_time for req_time in self.requests[client_id] 
            if req_time > minute_ago
        ]
        
        current_requests = len(self.requests[client_id])
        remaining_tokens = max(0, self.requests_per_minute - current_requests)
        
        # Calculate reset time (next minute boundary)
        reset_time = int(now) + (60 - int(now) % 60)
        
        return {
            'client_id': client_id,
            'current_requests': current_requests,
            'remaining_tokens': remaining_tokens,
            'requests_per_minute': self.requests_per_minute,
            'reset_time': reset_time,
            'window_start': minute_ago,
            'window_end': now
        }
    
    def get_global_stats(self) -> Dict:
        """Get global rate limiting statistics"""
        now = time.time()
        minute_ago = now - 60
        
        total_clients = len(self.requests)
        total_requests = 0
        active_clients = 0
        
        for client_id in list(self.requests.keys()):
            # Clean old requests
            self.requests[client_id] = [
                req_time for req_time in self.requests[client_id] 
                if req_time > minute_ago
            ]
            
            client_requests = len(self.requests[client_id])
            total_requests += client_requests
            
            if client_requests > 0:
                active_clients += 1
            
            # Remove clients with no recent requests
            if client_requests == 0:
                del self.requests[client_id]
        
        return {
            'total_clients': total_clients,
            'active_clients': active_clients,
            'total_requests_last_minute': total_requests,
            'requests_per_minute_limit': self.requests_per_minute,
            'burst_size': self.burst_size,
            'window_duration': 60
        }