"""Redis 客户端(单例)。用于:
- 翻译缓存
- 翻译字符配额(月度)
- 限流(后续)
"""
from __future__ import annotations

import redis.asyncio as redis_async

from app.config import settings

_pool: redis_async.Redis | None = None


def get_redis() -> redis_async.Redis:
    global _pool
    if _pool is None:
        _pool = redis_async.from_url(
            settings.redis_url,
            encoding="utf-8",
            decode_responses=True,
            max_connections=20,
        )
    return _pool


async def close_redis() -> None:
    global _pool
    if _pool is not None:
        await _pool.aclose()
        _pool = None