# -*- coding: utf-8 -*-
import logging
import mysql.connector.pooling
import redis
from typing import Optional


class DBConnectionManager:
    """数据库连接管理器，负责管理MySQL和Redis连接池"""
    
    _instance = None
    
    @classmethod
    def get_instance(cls, mysql_config=None, redis_config=None):
        """获取单例实例
        
        Args:
            mysql_config: MySQL配置
            redis_config: Redis配置
            
        Returns:
            DBConnectionManager实例
        """
        if cls._instance is None:
            cls._instance = cls(mysql_config, redis_config)
        elif mysql_config or redis_config:
            # 如果已经有实例但又传入了配置，则更新配置
            if mysql_config and not cls._instance.mysql_pool:
                cls._instance.init_mysql_pool(mysql_config)
            if redis_config and not cls._instance.redis_pool:
                cls._instance.init_redis_pool(redis_config)
        return cls._instance
    
    def __init__(self, mysql_config=None, redis_config=None):
        """初始化数据库连接管理器
        
        Args:
            mysql_config: MySQL配置
            redis_config: Redis配置
        """
        # 防止直接实例化
        if DBConnectionManager._instance is not None:
            return
            
        self.mysql_pool = None
        self.redis_pool = None
        
        # 初始化MySQL连接池
        if mysql_config:
            self.init_mysql_pool(mysql_config)
        
        # 初始化Redis连接池
        if redis_config:
            self.init_redis_pool(redis_config)
            
    def get_mysql_connection(self):
        """获取MySQL连接"""
        if not self.mysql_pool:
            raise Exception("MySQL连接池未初始化")
        return self.mysql_pool.get_connection()
    
    def get_redis_connection(self):
        """获取Redis连接"""
        if not self.redis_pool:
            raise Exception("Redis连接池未初始化")
        return redis.Redis(connection_pool=self.redis_pool)