update refund process

app/Services/CouponService.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace App\Services;
+
+use App\Models\Coupon;
+use App\Models\Order;
+use Illuminate\Support\Facades\DB;
+
+class CouponService
+{
+    public $order;
+
+    public function __construct($code)
+    {
+        $this->coupon = Coupon::where('code', $code)->first();
+        if (!$this->coupon) {
+            abort(500, '优惠券无效');
+        }
+        if ($this->coupon->limit_use <= 0 && $this->coupon->limit_use !== NULL) {
+            abort(500, '优惠券已无可用次数');
+        }
+        if (time() < $this->coupon->started_at) {
+            abort(500, '优惠券还未到可用时间');
+        }
+        if (time() > $this->coupon->ended_at) {
+            abort(500, '优惠券已过期');
+        }
+    }
+
+    public function use(Order $order)
+    {
+        switch ($this->coupon->type) {
+            case 1:
+                $order->discount_amount = $this->coupon->value;
+                break;
+            case 2:
+                $order->discount_amount = $order->total_amount * ($this->coupon->value / 100);
+                break;
+        }
+        if ($this->coupon->limit_use !== NULL) {
+            $this->coupon->limit_use = $this->coupon->limit_use - 1;
+            if (!$this->coupon->save()) {
+                return false;
+            }
+        }
+        return true;
+    }
+}