<?php
/**
 * Description of StrategyDemo
 * 策略模式
 * @author jm
 */
class StrategyDemo
{
    //put your code here
    public static function main()
    {
        $price = 100;
//        $discount = new Discount7();//由外部客户端选择策略，不论什么策略都提供最终计算价格
        $discount = new DiscountFactory(7);//结合工厂
        echo "原价：".$price."，最终价格：".$discount->count($price)."\n";
        
    }
}

interface IDiscount{
    public function count($price);
}

class Discount9 implements IDiscount{
    public function count($price){
        return $price * 0.9;
    }
}

class Discount7 implements IDiscount{
    public function count($price){
        return $price * 0.7;
    }    
}
class Discount5 implements IDiscount{
    public function count($price){
        return $price * 0.5;
    }    
}

class DiscountFactory{
    private $_discount = null;
    public function __construct($discountInt)
    {
        switch ($discountInt) {
            case 5:
                $this->_discount =  new Discount5();
                break;                
            case 7:
                $this->_discount =  new Discount7();
                break;                
            case 9:
                $this->_discount =  new Discount9();
                break;
            default:
                return null;
        }
    }
    public function count($price){
        return $this->_discount->count($price);
    }
}

StrategyDemo::main();