【策略模式】不同的時間用不同的規則--優先考慮策略模式

記錄策略模式，與簡單工廠模式相互結合，降低代碼之間的耦合

案列：超市收銀軟體系統，需求：滿減，打折。。。各種優惠活動

5個類

1. CountP
2. Count
3. Rabate
4. Ret
5. Cash

/**
 * 父類
 */
abstract class CountP {
    abstract public function getCash($money);
}

/**
 * Class Count
 * @package Home\Driver\Sum
 * 正常計算類
 */
class Count extends CountP {
    public function getCash($money)
    {
        return $money;
    }
}

/**
 * Class Rabate
 * @package Home\Driver\Sum
 * 打折計算類
 */
class Rabate extends CountP {
    public $d = 1;

    public function __construct($dis)
    {
        $this->d = $dis;
    }

    public function getCash($money)
    {
        return $money * $this->d;
    }
}

/**
 * Class Ret
 * @package Home\Driver\Sum
 * 滿減計算類
 */
class Ret extends CountP {
    public $moneyCondition = 0;
    public $moneyReturn = 0;

    public function __construct($moneyCondition,$moneyReturn)
    {
        $this->moneyCondition = $moneyCondition;
        $this->moneyReturn = $moneyReturn;
    }

    public function getCash($money)
    {
        if($money>=$this->moneyCondition){
            $money = $money-floor($money/$this->moneyCondition)*$this->moneyReturn;
        }
        return $money;
    }
}

/**
 * Class Cash
 * @package Home\Driver
 * 工廠類
 */
class Cash{
    public $obj = null;

    public function __construct($type)
    {
        switch ($type){
            case '正常收費':
                $this->obj = new Count();
                break;
            case '8折':
                $this->obj = new Rabate(0.8);
                break;
            case '滿300減100':
                $this->obj = new Ret(300,100);
                break;
            default:
                throw_exception('類型錯誤');
                break;
        }
    }

    public function getAcceptCash($money){
        return $this->obj->getCash($money);
    }
}

/**
 * Class SumController
 * @package Home\Controller
 * 客戶端
 */
class SumController extends Controller {

    public function index(){
        $countSum = new Cash('滿300減100');
        $count = $countSum->getAcceptCash(400);
        echo $count;
    }
}