api/app/controller/Shop.php

<?php
/**
 * Created by PhpStorm.
 * User: yancheng<cheng@love.xiaoyan.me>
 * Date: 2020/12/10
 * Time: 20:35
 */

namespace app\controller;


use app\BaseController;
use app\middleware\LoginCheck;
use app\model\Carts;
use app\model\Goods;
use app\model\Order;
use app\model\OrderGoods;
use think\response\Json;
use think\facade\Db;

class Shop extends BaseController
{
    protected $middleware = [
        LoginCheck::class
    ];
    public function addToCart(int $goodsId = null,int $count = null){
        if(empty($goodsId) || empty($count)){
            return $this->fail('参数goodsId,count都必须填写');
        }
        $goods = (new Goods())->find($goodsId);
        if(empty($goods) || $goods->status != 1){
            return $this->fail('商品不存在或者已被下架');
        }
        $cart = new Carts();
        $uid = $this->getUserId();
        $cart = $cart->where('uid',$uid)
            ->where('goods_id',$goodsId)
            ->findOrEmpty();
            
        if($cart->isEmpty()){
            $cart->uid = $uid;
            $cart->goods_id = $goodsId;
            $cart->count = $count;
        }else{
            $cart->count += $count;
        }
        if($cart->count > $goods->stock){
            return $this->fail('库存不足');
        }
        $cart->add_price = $goods->sell_price;
        if($cart->save()){
            return $this->success();
        }
        return $this->fail('添加购物车失败');
    }

    /**
     * @return Json
     */
    public function queryCart(){
        $goods = (new Carts())->queryByUid($this->getUserId());
        $goods = $this->buildGoodsData($goods->toArray());
        return json($goods);
    }
    public function removeCart($id = null){
        if(empty($id)){
            return $this->fail('参数 id 必须填写');
        }
        Carts::destroy($id);
        return $this->success();
    }
    
    public function updateCart($id = null,$count = null){
        if(empty($id) || empty($count)){
            return $this->fail('参数 id ,count 都必须填写');
        }
        if($count < 0){
            return $this->fail('你是想我给你钱吗?count必须大于0');
        }
        $cart = new Carts();
        $cart = $cart->find($id);
        if(empty($cart)){
            return $this->fail('购物车不存在这个商品');
        }
        if($cart->uid != $this->getUserId()){
            return $this->fail('非法操作(不是你的数据)');
        }
        $goods = (new Goods())->find($cart->goods_id);
        if($count > $goods->stock){
            return $this->fail('库存不足');
        }
        $cart->count = $count;
        if($cart->save()){
            return $this->success($cart->toArray());
        }
        return $this->fail('添加购物车失败');
    }

    public function checkout($ids)
    {
        $cart = new Carts();
        $carts = $cart->where('uid',$this->getUserId())->where('id','in',$ids)->select();
        if($carts->count() == 0){
            return $this->fail('结算失败:没有找到待结算商品');
        }
        Db::startTrans();
        try{
            $order = new Order();
            $order->uid = $this->getUserId();
            $order->amount = 0;
            $order->paid = 0;

            if($order->save()){
                $totalAmount = 0;
                foreach ($carts as $c){
                    $g = (new Goods())->find($c->goods_id);
                    if(empty($g)){
                        continue;
                    }
                    if($g->stock < $c->count){
                        throw new \Exception('库存不足');
                    }
                    $g->stock -= $c->count;
                    $g->sell_count += $c->count;
                    $totalAmount += $g->sell_price * $c->count; // 累加商品价格
                    OrderGoods::create([
                        'order_id'  =>  $order->id,
                        'goods_id' =>  $c->goods_id,
                        'amount' =>  $g->sell_price,
                        'count' =>  $c->count,
                    ]);
                    $c->delete();
                    $g->save();
                }
                $order->amount = $totalAmount;
                if($order->save()){
                    
                    Db::commit();
                    return \json($order);
                }
            }
        }catch (\Exception $e){
            Db::rollback();
            return $this->fail('结算失败:'.$e->getMessage());
        }
        return $this->fail('结算失败');
    }
    
    
    public function queryOrder(){
        $or = new Order();
        $orders = $or->queryByUid($this->getUserId());
        foreach ($orders as $o){
            $o->goods = $this->buildGoodsData($or->getOrderGoods($o->id)->toArray());
        }
        return json($orders);
    }
}