package main

import "fmt"

/*
实例
汤宝宝家有一台咖啡机，他会自动给美式咖啡加奶和糖...
*/

type Drink interface {
	GetPrice() float64
	cost()
}

type Coffee struct {
	name  string
	Price float64
}

func (c *Coffee) GetPrice() float64 {
	return c.Price
}

func (c *Coffee) cost() {
	fmt.Printf("一杯%s咖啡，价格%.2f元。\n", c.name, c.Price)
}

type Maker struct {
	wrappedDrink Drink
	milkPrice    float64
	sugarPrice   float64
}

func (m *Maker) GetPrice() float64 {
	return m.wrappedDrink.GetPrice()
}

func (m *Maker) cost() {
	m.wrappedDrink.cost()
	fmt.Printf("加了奶和糖，总价%.2f元。\n",
		m.wrappedDrink.GetPrice()+m.milkPrice+m.sugarPrice)
}

func main() {
	fmt.Println("============= 装饰器模式 =============")

	var coffee, newCoffee Drink

	fmt.Println("自己泡杯咖啡")
	coffee = &Coffee{
		name:  "美式",
		Price: 10.0,
	}
	coffee.cost()

	fmt.Println("\n用咖啡机泡杯咖啡")
	newCoffee = &Maker{
		wrappedDrink: coffee,
		milkPrice:    1.0,
		sugarPrice:   1.0,
	}
	newCoffee.cost()

	fmt.Println()
	fmt.Println("=========== 装饰器模式结束 ===========")
}