金融运营管控平台优惠活动

class Promotion:
    def __init__(self, code, discount_rate):
        self.code = code
        self.discount_rate = discount_rate

class Customer:
    def __init__(self, name, balance):
        self.name = name
        self.balance = balance
        self.promotions = []

    def add_promotion(self, promotion):
        self.promotions.append(promotion)

    def apply_promotion(self, purchase_amount):
        total_discount = 0
        for promo in self.promotions:
            total_discount += purchase_amount * promo.discount_rate
        final_amount = purchase_amount - total_discount
        if final_amount < 0:
            final_amount = 0
        self.balance -= final_amount
        return final_amount

# 示例使用
promo = Promotion("SAVE10", 0.1)
customer = Customer("Alice", 1000)
customer.add_promotion(promo)
final_payment = customer.apply_promotion(500)
print(f"Final payment after discount: {final_payment}")