import asyncio
import time


class InMemoryTokenBlacklist:
    def __init__(self) -> None:
        self._items: dict[str, float] = {}
        self._lock = asyncio.Lock()

    async def add(self, token: str, ttl: int) -> None:
        now = time.time()
        async with self._lock:
            self._cleanup(now)
            self._items[token] = now + ttl

    async def has(self, token: str) -> bool:
        now = time.time()
        async with self._lock:
            self._cleanup(now)
            return token in self._items

    def _cleanup(self, now: float) -> None:
        expired = [token for token, expires_at in self._items.items() if expires_at <= now]
        for token in expired:
            self._items.pop(token, None)