用户界面 - 使用优惠券下单

paulfzy · Dec 23, 2018 · d74735f · d74735f
1 parent 7dc64dc
commit d74735f
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Showing 7 changed files with 110 additions and 22 deletions.
diff --git a/app/Exceptions/CouponCodeUnavailableException.php b/app/Exceptions/CouponCodeUnavailableException.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace App\Exceptions;
+
+use Illuminate\Http\Request;
+use Exception;
+
+class CouponCodeUnavailableException extends Exception
+{
+    public function __construct($message, int $code = 403)
+    {
+        parent::__construct($message, $code);
+    }
+
+    // 当这个异常被触发时，会调用 render 方法来输出给用户
+    public function render(Request $request)
+    {
+        // 如果用户通过 Api 请求，则返回 JSON 格式的错误信息
+        if ($request->expectsJson()) {
+            return response()->json(['msg' => $this->message], $this->code);
+        }
+        // 否则返回上一页并带上错误信息
+        return redirect()->back()->withErrors(['coupon_code' => $this->message]);
+    }
+}
diff --git a/app/Exceptions/Handler.php b/app/Exceptions/Handler.php
@@ -14,6 +14,7 @@ class Handler extends ExceptionHandler
      */
     protected $dontReport = [
         InvalidRequestException::class,
+        CouponCodeUnavailableException::class,
     ];
 
     /**

diff --git a/app/Http/Controllers/CouponCodesController.php b/app/Http/Controllers/CouponCodesController.php
@@ -2,34 +2,18 @@
 
 namespace App\Http\Controllers;
 
+use App\Exceptions\CouponCodeUnavailableException;
 use App\Models\CouponCode;
-use Carbon\Carbon;
 
 class CouponCodesController extends Controller
 {
     public function show($code)
     {
-        // 判断优惠券是否存在
         if (!$record = CouponCode::where('code', $code)->first()) {
-            abort(404);
+            throw new CouponCodeUnavailableException('优惠券不存在');
         }
 
-        // 如果优惠券没有启用，则等同于优惠券不存在
-        if (!$record->enabled) {
-            abort(404);
-        }
-
-        if ($record->total - $record->used <= 0) {
-            return response()->json(['msg' => '该优惠券已被兑完'], 403);
-        }
-
-        if ($record->not_before && $record->not_before->gt(Carbon::now())) {
-            return response()->json(['msg' => '该优惠券现在还不能使用'], 403);
-        }
-
-        if ($record->not_after && $record->not_after->lt(Carbon::now())) {
-            return response()->json(['msg' => '该优惠券已过期'], 403);
-        }
+        $record->checkAvailable();
 
         return $record;
     }

diff --git a/app/Http/Controllers/OrdersController.php b/app/Http/Controllers/OrdersController.php
@@ -3,10 +3,12 @@
 namespace App\Http\Controllers;
 
 use App\Events\OrderReviewed;
+use App\Exceptions\CouponCodeUnavailableException;
 use App\Exceptions\InvalidRequestException;
 use App\Http\Requests\ApplyRefundRequest;
 use App\Http\Requests\OrderRequest;
 use App\Http\Requests\SendReviewRequest;
+use App\Models\CouponCode;
 use App\Models\UserAddress;
 use App\Models\Order;
 use Carbon\Carbon;
@@ -19,8 +21,17 @@ public function store(OrderRequest $request, OrderService $orderService)
     {
         $user    = $request->user();
         $address = UserAddress::find($request->input('address_id'));
+        $coupon  = null;
 
-        return $orderService->store($user, $address, $request->input('remark'), $request->input('items'));
+        // 如果用户提交了优惠码
+        if ($code = $request->input('coupon_code')) {
+            $coupon = CouponCode::where('code', $code)->first();
+            if (!$coupon) {
+                throw new CouponCodeUnavailableException('优惠券不存在');
+            }
+        }
+        // 参数中加入 $coupon 变量
+        return $orderService->store($user, $address, $request->input('remark'), $request->input('items'), $coupon);
     }
 
     public function index(Request $request)

diff --git a/app/Models/CouponCode.php b/app/Models/CouponCode.php
@@ -2,6 +2,8 @@
 
 namespace App\Models;
 
+use App\Exceptions\CouponCodeUnavailableException;
+use Carbon\Carbon;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Support\Str;
 
@@ -50,6 +52,51 @@ public function getDescriptionAttribute()
         return $str.'减'.str_replace('.00', '', $this->value);
     }
 
+    public function checkAvailable($orderAmount = null)
+    {
+        if (!$this->enabled) {
+            throw new CouponCodeUnavailableException('优惠券不存在');
+        }
+
+        if ($this->total - $this->used <= 0) {
+            throw new CouponCodeUnavailableException('该优惠券已被兑完');
+        }
+
+        if ($this->not_before && $this->not_before->gt(Carbon::now())) {
+            throw new CouponCodeUnavailableException('该优惠券现在还不能使用');
+        }
+
+        if ($this->not_after && $this->not_after->lt(Carbon::now())) {
+            throw new CouponCodeUnavailableException('该优惠券已过期');
+        }
+
+        if (!is_null($orderAmount) && $orderAmount < $this->min_amount) {
+            throw new CouponCodeUnavailableException('订单金额不满足该优惠券最低金额');
+        }
+    }
+
+    public function getAdjustedPrice($orderAmount)
+    {
+        // 固定金额
+        if ($this->type === self::TYPE_FIXED) {
+            // 为了保证系统健壮性，我们需要订单金额最少为 0.01 元
+            return max(0.01, $orderAmount - $this->value);
+        }
+
+        return number_format($orderAmount * (100 - $this->value) / 100, 2, '.', '');
+    }
+
+    public function changeUsed($increase = true)
+    {
+        // 传入 true 代表新增用量，否则是减少用量
+        if ($increase) {
+            // 与检查 SKU 库存类似，这里需要检查当前用量是否已经超过总量
+            return $this->newQuery()->where('id', $this->id)->where('used', '<', $this->total)->increment('used');
+        } else {
+            return $this->decrement('used');
+        }
+    }
+
     public static function findAvailableCode($length = 16)
     {
         do {

diff --git a/app/Services/OrderService.php b/app/Services/OrderService.php
@@ -9,13 +9,20 @@
 use App\Exceptions\InvalidRequestException;
 use App\Jobs\CloseOrder;
 use Carbon\Carbon;
+use App\Models\CouponCode;
+use App\Exceptions\CouponCodeUnavailableException;
 
 class OrderService
 {
-    public function store(User $user, UserAddress $address, $remark, $items)
+    public function store(User $user, UserAddress $address, $remark, $items, CouponCode $coupon = null)
     {
+        // 如果传入了优惠券，则先检查是否可用
+        if ($coupon) {
+            // 但此时我们还没有计算出订单总金额，因此先不校验
+            $coupon->checkAvailable();
+        }
         // 开启一个数据库事务
-        $order = \DB::transaction(function () use ($user, $address, $remark, $items) {
+        $order = \DB::transaction(function () use ($user, $address, $remark, $items, $coupon) {
             // 更新此地址的最后使用时间
             $address->update(['last_used_at' => Carbon::now()]);
             // 创建一个订单
@@ -51,6 +58,18 @@ public function store(User $user, UserAddress $address, $remark, $items)
                     throw new InvalidRequestException('该商品库存不足');
                 }
             }
+            if ($coupon) {
+                // 总金额已经计算出来了，检查是否符合优惠券规则
+                $coupon->checkAvailable($totalAmount);
+                // 把订单金额修改为优惠后的金额
+                $totalAmount = $coupon->getAdjustedPrice($totalAmount);
+                // 将订单与优惠券关联
+                $order->couponCode()->associate($coupon);
+                // 增加优惠券的用量，需判断返回值
+                if ($coupon->changeUsed() <= 0) {
+                    throw new CouponCodeUnavailableException('该优惠券已被兑完');
+                }
+            }
             // 更新订单总金额
             $order->update(['total_amount' => $totalAmount]);
 

diff --git a/resources/views/cart/index.blade.php b/resources/views/cart/index.blade.php
@@ -142,6 +142,7 @@
           address_id: $('#order-form').find('select[name=address]').val(),
           items: [],
           remark: $('#order-form').find('textarea[name=remark]').val(),
+          coupon_code: $('input[name=coupon_code]').val(), // 从优惠码输入框中获取优惠码
         };
         // 遍历 <table> 标签内所有带有 data-id 属性的 <tr> 标签，也就是每一个购物车中的商品 SKU
         $('table tr[data-id]').each(function () {
-Original file line number
+Diff line change
@@ Expand Up / @@ -14,6 +14,7 @@ class Handler extends ExceptionHandler @@
          */
         protected $dontReport = [
             InvalidRequestException::class,
+            CouponCodeUnavailableException::class,
         ];
         /**
@@ Expand Down @@