from __future__ import annotations

import asyncio
import time
from collections import deque


class RateLimiter:
    def __init__(self, requests_per_second: float = 1.0) -> None:
        self._min_interval = 1.0 / requests_per_second
        self._timestamps: deque[float] = deque()
        self._lock = asyncio.Lock()

    async def acquire(self) -> None:
        async with self._lock:
            now = time.monotonic()
            while self._timestamps and self._timestamps[0] <= now - self._min_interval:
                self._timestamps.popleft()

            if self._timestamps:
                wait_time = self._timestamps[0] + self._min_interval - now
                if wait_time > 0:
                    await asyncio.sleep(wait_time)

            self._timestamps.append(time.monotonic())