"""
Redis 连接管理模块

实现 Redis 连接池管理、健康检查和降级处理。
提供异步客户端（用于 async 路由）和同步客户端（用于同步依赖/中间件）。
需求引用: 4.1, 4.6
"""
from typing import Optional
from redis import asyncio as aioredis
import redis as sync_redis
import os
import logging

logger = logging.getLogger(__name__)


class RedisManager:
    """Redis 连接管理器"""

    def __init__(self):
        self.redis: Optional[aioredis.Redis] = None          # 异步客户端
        self._sync_redis: Optional[sync_redis.Redis] = None  # 同步客户端
        self._connected = False
        self._sync_connected = False

    async def connect(self) -> bool:
        """建立异步 Redis 连接"""
        if self._connected and self.redis:
            return True

        redis_url = os.getenv("REDIS_URL", "redis://192.168.0.3:6379")
        redis_password = os.getenv("REDIS_PASSWORD", "")
        pool_size = int(os.getenv("REDIS_POOL_SIZE", "50"))

        try:
            self.redis = await aioredis.from_url(
                redis_url,
                password=redis_password if redis_password else None,
                encoding="utf-8",
                decode_responses=True,
                max_connections=pool_size
            )
            await self.redis.ping()
            self._connected = True
            logger.info(f"Redis 异步连接成功: {redis_url}")

            # 同时建立同步连接（供同步代码使用）
            self._init_sync_client(redis_url, redis_password, pool_size)
            return True
        except Exception as e:
            logger.warning(f"Redis 连接失败，系统将降级运行: {e}")
            self.redis = None
            self._connected = False
            return False

    def _init_sync_client(self, redis_url: str, password: str, pool_size: int):
        """初始化同步 Redis 客户端"""
        try:
            self._sync_redis = sync_redis.from_url(
                redis_url,
                password=password if password else None,
                encoding="utf-8",
                decode_responses=True,
                max_connections=max(10, pool_size // 5),  # 同步连接池小一些
            )
            self._sync_redis.ping()
            self._sync_connected = True
            logger.info("Redis 同步连接成功")
        except Exception as e:
            logger.warning(f"Redis 同步连接失败: {e}")
            self._sync_redis = None
            self._sync_connected = False

    async def close(self):
        """关闭 Redis 连接"""
        if self.redis:
            try:
                await self.redis.close()
                logger.info("Redis 异步连接已关闭")
            except Exception as e:
                logger.warning(f"关闭 Redis 异步连接时出错: {e}")
            finally:
                self.redis = None
                self._connected = False

        if self._sync_redis:
            try:
                self._sync_redis.close()
            except Exception:
                pass
            finally:
                self._sync_redis = None
                self._sync_connected = False

    async def health_check(self) -> bool:
        """健康检查"""
        if not self.redis:
            return False
        try:
            await self.redis.ping()
            return True
        except Exception as e:
            logger.warning(f"Redis 健康检查失败: {e}")
            return False

    def get_client(self) -> Optional[aioredis.Redis]:
        """获取异步 Redis 客户端（用于 async 路由和服务）"""
        if self._connected and self.redis:
            return self.redis
        return None

    def get_sync_client(self) -> Optional[sync_redis.Redis]:
        """获取同步 Redis 客户端（用于同步依赖、中间件）"""
        if self._sync_connected and self._sync_redis:
            return self._sync_redis
        return None

    @property
    def is_connected(self) -> bool:
        return self._connected


# 全局单例
redis_manager = RedisManager()