"""
Redis 客户端管理
"""
import redis.asyncio as aioredis
from typing import Optional
from app.core.config import settings
import logging

logger = logging.getLogger(__name__)

# Redis 客户端实例
redis_client: aioredis.Redis = None


async def init_redis():
    """初始化 Redis 连接"""
    global redis_client
    try:
        redis_client = await aioredis.from_url(
            settings.REDIS_URL,
            encoding="utf-8",
            decode_responses=True,
            max_connections=10
        )
        # 测试连接
        await redis_client.ping()
        logger.info("Redis connected successfully")
    except Exception as e:
        logger.error(f"Redis connection failed: {e}")
        raise


async def close_redis():
    """关闭 Redis 连接"""
    global redis_client
    if redis_client:
        await redis_client.close()
        logger.info("Redis connection closed")


def get_redis() -> aioredis.Redis:
    """获取 Redis 客户端"""
    return redis_client


# Token 缓存相关操作
class TokenCache:
    """Token 缓存管理"""

    TOKEN_PREFIX = "token:"
    USER_TOKEN_PREFIX = "user_tokens:"

    @staticmethod
    async def save_token(user_id: int, token: str, expire_seconds: int = 86400):
        """
        保存 token 到 Redis
        :param user_id: 用户ID
        :param token: JWT token
        :param expire_seconds: 过期时间（秒），默认24小时
        """
        redis = get_redis()

        # 保存 token -> user_id 映射
        token_key = f"{TokenCache.TOKEN_PREFIX}{token}"
        await redis.setex(token_key, expire_seconds, str(user_id))

        # 保存 user_id -> tokens 集合（支持多设备登录）
        user_tokens_key = f"{TokenCache.USER_TOKEN_PREFIX}{user_id}"
        await redis.sadd(user_tokens_key, token)
        await redis.expire(user_tokens_key, expire_seconds)

        logger.info(f"Token saved for user {user_id}, expires in {expire_seconds}s")

    @staticmethod
    async def get_user_id(token: str) -> Optional[int]:
        """
        根据 token 获取用户ID
        :param token: JWT token
        :return: 用户ID 或 None
        """
        redis = get_redis()
        token_key = f"{TokenCache.TOKEN_PREFIX}{token}"
        user_id_str = await redis.get(token_key)

        if user_id_str:
            return int(user_id_str)
        return None

    @staticmethod
    async def delete_token(token: str):
        """
        删除指定 token
        :param token: JWT token
        """
        redis = get_redis()

        # 获取 user_id
        token_key = f"{TokenCache.TOKEN_PREFIX}{token}"
        user_id_str = await redis.get(token_key)

        if user_id_str:
            user_id = int(user_id_str)

            # 从用户 tokens 集合中移除
            user_tokens_key = f"{TokenCache.USER_TOKEN_PREFIX}{user_id}"
            await redis.srem(user_tokens_key, token)

        # 删除 token
        await redis.delete(token_key)
        logger.info(f"Token deleted: {token[:20]}...")

    @staticmethod
    async def delete_user_all_tokens(user_id: int):
        """
        删除用户的所有 token（用于强制登出）
        :param user_id: 用户ID
        """
        redis = get_redis()
        user_tokens_key = f"{TokenCache.USER_TOKEN_PREFIX}{user_id}"

        # 获取所有 tokens
        tokens = await redis.smembers(user_tokens_key)

        # 删除所有 token
        for token in tokens:
            token_key = f"{TokenCache.TOKEN_PREFIX}{token}"
            await redis.delete(token_key)

        # 删除集合
        await redis.delete(user_tokens_key)
        logger.info(f"All tokens deleted for user {user_id}")

    @staticmethod
    async def extend_token(token: str, expire_seconds: int = 86400):
        """
        延长 token 有效期（用于 token 刷新）
        :param token: JWT token
        :param expire_seconds: 延长的过期时间（秒）
        """
        redis = get_redis()
        token_key = f"{TokenCache.TOKEN_PREFIX}{token}"

        # 延长过期时间
        await redis.expire(token_key, expire_seconds)

        # 获取 user_id 并延长用户 tokens 集合过期时间
        user_id_str = await redis.get(token_key)
        if user_id_str:
            user_tokens_key = f"{TokenCache.USER_TOKEN_PREFIX}{user_id_str}"
            await redis.expire(user_tokens_key, expire_seconds)

        logger.info(f"Token extended: {token[:20]}...")