from .mysql_conn import MySQLConnection


# 全局 MySQL 客户端实例
_global_mysql_client = None

def init_global_mysql_client(host: str = None, port: int = None, 
                           user: str = None, password: str = None, 
                           database: str = None, charset: str = None,
                           pool_size: int = None, **kwargs) -> None:
    """
    初始化全局 MySQL 客户端
    
    Args:
        host: MySQL 主机地址
        port: MySQL 端口号
        user: MySQL 用户名
        password: MySQL 密码
        database: 数据库名称
        charset: 字符集
        pool_size: 连接池大小
        **kwargs: 其他 MySQL 连接参数
    """
    global _global_mysql_client
    if _global_mysql_client is None:
        _global_mysql_client = MySQLConnection(
            host=host, port=port, user=user, password=password, 
            database=database, charset=charset, pool_size=pool_size, **kwargs
        )


def get_global_mysql_client() -> MySQLConnection:
    """
    获取全局 MySQL 客户端实例
    
    Returns:
        MySQL SQL 执行器实例
    """
    global _global_mysql_client
    if _global_mysql_client is None:
        raise RuntimeError("Global MySQL client has not been initialized. Call init_global_mysql_client() first.")
    return _global_mysql_client


def close_global_mysql_client() -> None:
    """
    关闭全局 MySQL 客户端
    """
    global _global_mysql_client
    if _global_mysql_client is not None:
        _global_mysql_client.close()
        _global_mysql_client = None