from __future__ import annotations

import time
from collections import defaultdict, deque
from threading import Lock


class RateLimiter:
    """In-memory sliding window limiter (per process). Good enough for single-replica / dev."""

    def __init__(self) -> None:
        self._hits: dict[str, deque[float]] = defaultdict(deque)
        self._lock = Lock()

    def allow(self, key: str, limit: int, window_seconds: int = 60) -> bool:
        if limit <= 0:
            return True
        now = time.monotonic()
        with self._lock:
            q = self._hits[key]
            while q and now - q[0] > window_seconds:
                q.popleft()
            if len(q) >= limit:
                return False
            q.append(now)
            return True


rate_limiter = RateLimiter()