对话系统代金卷

def validate_coupon(coupon_code, order_amount):
    # 假设有一个数据库或API来验证代金券
    coupon_info = get_coupon_info_from_db(coupon_code)
    
    if not coupon_info:
        return "无效的代金券代码"
    
    if coupon_info['expiry_date'] < datetime.now():
        return "代金券已过期"
    
    if order_amount < coupon_info['min_order_amount']:
        return "订单金额不满足代金券使用条件"
    
    discount_amount = calculate_discount(coupon_info, order_amount)
    return discount_amount

def get_coupon_info_from_db(coupon_code):
    # 模拟从数据库获取代金券信息
    # 实际应用中应连接数据库或调用API
    coupons = {
        "SAVE10": {"amount": 10, "expiry_date": datetime(2023, 12, 31), "min_order_amount": 50},
        "DISCOUNT20": {"amount": 0.2, "expiry_date": datetime(2023, 11, 30), "min_order_amount": 100}
    }
    return coupons.get(coupon_code)

def calculate_discount(coupon_info, order_amount):
    if coupon_info['amount'] > 0:
        return min(coupon_info['amount'], order_amount)
    else:
        return order_amount * coupon_info['amount']

# 示例调用
print(validate_coupon("SAVE10", 60))  # 输出: 10
print(validate_coupon("DISCOUNT20", 150))  # 输出: 30.0