import time
from collections import defaultdict

from fastapi import HTTPException, Request
from starlette.middleware.base import BaseHTTPMiddleware


class RateLimitMiddleware(BaseHTTPMiddleware):
    def __init__(self, app, max_requests: int = 60, window_seconds: int = 60):
        super().__init__(app)
        self.max_requests = max_requests
        self.window_seconds = window_seconds
        self.requests: dict[str, list[float]] = defaultdict(list)

    async def dispatch(self, request: Request, call_next):
        if request.url.path in ("/api/health", "/static/", "/"):
            return await call_next(request)

        client_ip = request.client.host if request.client else "unknown"
        now = time.monotonic()
        cutoff = now - self.window_seconds

        self.requests[client_ip] = [t for t in self.requests[client_ip] if t > cutoff]

        if len(self.requests[client_ip]) >= self.max_requests:
            raise HTTPException(status_code=429, detail="Rate limit exceeded")

        self.requests[client_ip].append(now)
        return await call_next(request)