安全专家服务代金卷

class Voucher:
    def __init__(self, code, amount, expiry_date, service_restriction=None):
        self.code = code
        self.amount = amount
        self.expiry_date = expiry_date
        self.service_restriction = service_restriction

    def is_valid(self):
        return datetime.now() < self.expiry_date

    def apply_discount(self, service_cost):
        if self.is_valid() and (not self.service_restriction or self.service_restriction == current_service):
            return max(service_cost - self.amount, 0)
        return service_cost

# 使用示例
current_service = "Web Security Audit"
voucher = Voucher(code="SEC2023", amount=50, expiry_date=datetime(2023, 12, 31), service_restriction="Web Security Audit")
service_cost = 200
final_cost = voucher.apply_discount(service_cost)
print(f"Final cost after applying voucher: ${final_cost}")