app/utils/rate_limiter.py

from fastapi import HTTPException, Request
from redis import Redis
from ..core.config import settings
import time

class RateLimiter:
    def __init__(self, redis_client: Redis):
        self.redis = redis_client
        self.rate_limit = 100  # requests
        self.time_window = 60  # seconds

    async def check_rate_limit(self, request: Request):
        client_ip = request.client.host
        key = f"rate_limit:{client_ip}"
        
        current = int(time.time())
        window_start = current - self.time_window
        
        pipeline = self.redis.pipeline()
        pipeline.zremrangebyscore(key, 0, window_start)
        pipeline.zadd(key, {str(current): current})
        pipeline.zcard(key)
        pipeline.expire(key, self.time_window)
        _, _, request_count, _ = pipeline.execute()
        
        if request_count > self.rate_limit:
            raise HTTPException(
                status_code=429,
                detail="Too many requests. Please try again later."
            )

rate_limiter = RateLimiter(Redis(
    host=settings.REDIS_HOST,
    port=settings.REDIS_PORT,
    decode_responses=True
))