from datetime import datetime
import time
from typing import Optional

class CommonUtils:
    """工具类"""
    
    @staticmethod
    def generate_order_id(prefix: str) -> str:
        """
        生成订单号
        :param prefix: 订单前缀，如 M(商品订单)、P(支付订单)、D(配送订单)
        :return: 15位订单号：前缀(1位) + 日期(8位) + 时间戳(6位)
        """
        now = datetime.now()
        date_str = now.strftime('%Y%m%d')
        # 取时间戳后6位
        timestamp = str(int(time.time() * 1000))[-6:]
        return f"{prefix}{date_str}{timestamp}"
    
    @staticmethod
    def generate_verify_code() -> str:
        """
        生成核销码
        :return: 16位数字核销码：日期(8位) + 时间戳(8位)
        """
        now = datetime.now()
        date_str = now.strftime('%Y%m%d')
        timestamp = str(int(time.time() * 1000))[-8:]
        return f"{date_str}{timestamp}"