utils/rate_limiter.py

from fastapi import Request, HTTPException
from db.receipt_repository import ReceiptRepository

class RateLimiter:
    def __init__(self, max_requests: int = 5):
        self.max_requests = max_requests
        self.repository = ReceiptRepository()
    
    async def check_rate_limit(self, request: Request):
        """
        Check if the client has exceeded the rate limit
        """
        client_ip = request.client.host
        
        # Get the current submission count for this IP
        submission_count = self.repository.get_submission_count(client_ip)
        
        # If they've exceeded the limit, raise an exception
        if submission_count > self.max_requests:
            raise HTTPException(
                status_code=429,
                detail=f"Rate limit exceeded. Maximum {self.max_requests} receipts per hour."
            )
        
        return client_ip