hemall.terabimsoft.com.cn/app/frontend/modules/order/discount/BaseDiscount.php

<?php
/**
 * Created by PhpStorm.
 * User: shenyang
 * Date: 2018/5/23
 * Time: 下午3:55
 */

namespace app\frontend\modules\order\discount;

use app\frontend\models\order\PreOrderDiscount;
use app\frontend\modules\order\models\PreOrder;

abstract class BaseDiscount
{
    /**
     * @var PreOrder
     */
    protected $order;
    /**
     * 优惠名
     * @var string
     */
    protected $name;
    /**
     * 是否不显示优惠多少金额
     * @var int
     */
    protected $no_show = 0;
    /**
     * 优惠码
     * @var
     */
    protected $code;
    /**
     * @var float
     */
    private $amount;

    public function __construct(PreOrder $order)
    {
        $this->order = $order;
    }
    public function getCode()
    {
        return $this->code;
    }

    public function getName()
    {
        return $this->name;
    }

    /**
     * @return bool
     */
    public function calculated()
    {
        return isset($this->amount);
    }

    public function preSave()
    {
        return true;
    }


    /**
     * 获取总金额
     * @return float
     */
    public function getAmount()
    {
        if (isset($this->amount)) {
            return $this->amount;
        }


        $this->amount = $this->_getAmount();
        if($this->amount && $this->preSave()){
            // 将抵扣总金额保存在订单优惠信息表中
            //统一算法记录金额保存算法为：四舍六入五成双
            $preOrderDiscount = new PreOrderDiscount([
                'discount_code' => $this->code,
                'amount' => round($this->amount,2,PHP_ROUND_HALF_EVEN),
                'name' => $this->getName(),
                'no_show' => $this->no_show
            ]);
            $preOrderDiscount->setOrder($this->order);
        }
        return $this->amount;
    }

    /**
     * 获取金额
     * @return int
     */
    abstract protected function _getAmount();

}