"""
Redis客户端模块
"""
import redis
import json
import logging
from typing import Optional, List, Any
from app.config import settings

logger = logging.getLogger(__name__)


class RedisClient:
    """Redis客户端"""
    
    _instance: Optional['RedisClient'] = None
    _client: Optional[redis.Redis] = None
    
    def __new__(cls):
        if cls._instance is None:
            cls._instance = super().__new__(cls)
        return cls._instance
    
    def __init__(self):
        if self._client is None:
            try:
                self._client = redis.from_url(
                    settings.REDIS_URL,
                    decode_responses=True
                )
                logger.info("Redis连接成功")
            except Exception as e:
                logger.warning(f"Redis连接失败: {str(e)}")
                self._client = None
    
    def is_connected(self) -> bool:
        """检查Redis是否连接"""
        if self._client is None:
            return False
        try:
            self._client.ping()
            return True
        except:
            return False
    
    def get(self, key: str) -> Optional[Any]:
        """获取缓存"""
        if not self.is_connected():
            return None
        try:
            value = self._client.get(key)
            if value:
                return json.loads(value)
            return None
        except Exception as e:
            logger.error(f"Redis获取失败: {str(e)}")
            return None
    
    def set(self, key: str, value: Any, expire: int = None) -> bool:
        """设置缓存"""
        if not self.is_connected():
            return False
        try:
            self._client.set(key, json.dumps(value), ex=expire)
            return True
        except Exception as e:
            logger.error(f"Redis设置失败: {str(e)}")
            return False
    
    def delete(self, key: str) -> bool:
        """删除缓存"""
        if not self.is_connected():
            return False
        try:
            self._client.delete(key)
            return True
        except Exception as e:
            logger.error(f"Redis删除失败: {str(e)}")
            return False
    
    def exists(self, key: str) -> bool:
        """检查键是否存在"""
        if not self.is_connected():
            return False
        try:
            return self._client.exists(key) > 0
        except Exception as e:
            logger.error(f"Redis检查失败: {str(e)}")
            return False


redis_client = RedisClient()