import pymysql
from typing import List, Dict, Any
from config import MYSQL_CONFIG

class MySQLClient:
    """MySQL客户端类"""
    
    def __init__(self):
        self.connection = None
    
    def connect(self):
        """建立数据库连接"""
        try:
            self.connection = pymysql.connect(
                host=MYSQL_CONFIG["host"],
                port=MYSQL_CONFIG["port"],
                user=MYSQL_CONFIG["user"],
                password=MYSQL_CONFIG["password"],
                database=MYSQL_CONFIG["database"],
                charset=MYSQL_CONFIG["charset"],
                cursorclass=pymysql.cursors.DictCursor
            )
            print(f"MySQL数据库连接成功 - {MYSQL_CONFIG['host']}:{MYSQL_CONFIG['port']}/{MYSQL_CONFIG['database']}")
            return True
        except Exception as e:
            print(f"MySQL数据库连接失败: {e}")
            return False
    
    def execute_query(self, sql: str, params: tuple = None) -> List[Dict[str, Any]]:
        """执行查询语句"""
        if not self.connection and not self.connect():
            return []
        
        try:
            with self.connection.cursor() as cursor:
                cursor.execute(sql, params)
                return cursor.fetchall()
        except Exception as e:
            print(f"执行查询失败: {e}")
            return []
    
    def execute_update(self, sql: str, params: tuple = None) -> int:
        """执行更新语句（INSERT, UPDATE, DELETE）"""
        if not self.connection and not self.connect():
            return 0
        
        try:
            with self.connection.cursor() as cursor:
                result = cursor.execute(sql, params)
                self.connection.commit()
                print(f"执行更新成功，影响行数: {result}")
                return result
        except Exception as e:
            print(f"执行更新失败: {e}")
            self.connection.rollback()
            return 0
    
    def is_connected(self) -> bool:
        """检查数据库连接状态"""
        if not self.connection:
            return False
        try:
            self.connection.ping(reconnect=True)
            return True
        except:
            return False

# 创建全局MySQL客户端实例
mysql_client = MySQLClient()