APP推送平台优惠卷

# 发放优惠券
def issue_coupon(user_id, coupon_code, discount_amount, expiration_date):
    # 将优惠券信息存入数据库
    coupon = {
        'user_id': user_id,
        'coupon_code': coupon_code,
        'discount_amount': discount_amount,
        'expiration_date': expiration_date
    }
    save_to_database(coupon)

# 使用优惠券
def use_coupon(user_id, order_total):
    coupon = get_coupon_by_user_id(user_id)
    if coupon and not is_expired(coupon['expiration_date']):
        if order_total >= coupon['discount_amount']:
            final_amount = order_total - coupon['discount_amount']
            apply_discount_to_order(user_id, final_amount)
            mark_coupon_as_used(coupon['coupon_code'])
        else:
            return "订单金额不足，无法使用优惠券"
    else:
        return "优惠券已过期或不存在"

# 辅助函数
def save_to_database(coupon):
    # 实现数据库保存逻辑
    pass

def get_coupon_by_user_id(user_id):
    # 实现从数据库获取优惠券逻辑
    pass

def is_expired(expiration_date):
    # 判断优惠券是否过期
    return datetime.now() > expiration_date

def apply_discount_to_order(user_id, final_amount):
    # 实现应用折扣到订单逻辑
    pass

def mark_coupon_as_used(coupon_code):
    # 实现标记优惠券已使用逻辑
    pass