"""
数据库连接服务模块
提供统一的数据库连接接口
"""
from sqlalchemy import create_engine
from urllib.parse import quote_plus
import logging

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)


def create_db_connection(host, port, database, username, password):
    """
    创建数据库连接
    
    Args:
        host: 数据库主机地址
        port: 端口
        database: 数据库名
        username: 用户名
        password: 密码
    
    Returns:
        SQLAlchemy engine对象
    """
    try:
        # 对密码进行URL编码，处理特殊字符
        encoded_password = quote_plus(password)
        
        # 构建连接字符串
        connection_string = f'mysql+pymysql://{username}:{encoded_password}@{host}:{port}/{database}'
        
        # 创建引擎
        engine = create_engine(
            connection_string,
            pool_pre_ping=True,  # 连接池预检
            pool_recycle=3600,   # 连接回收时间
            echo=False
        )
        
        logger.info(f"Database connection created successfully: {host}:{port}/{database}")
        return engine
        
    except Exception as e:
        logger.error(f"Failed to create database connection: {e}")
        raise