vip会员支持补差升级

app/Services/VipPaymentService.php

@@ -35,8 +35,26 @@ class VipPaymentService
      */
     public function createLocalOrder(User $user, VipLevel $vipLevel): VipPaymentOrder
     {
-        if ((float) $vipLevel->price <= 0) {
-            throw new RuntimeException('当前 VIP 等级未设置在线支付价格，暂不支持直接购买。');
+        $currentVip = $user->isVip() ? $user->vipLevel : null;
+        $isUpgrade = $currentVip && $vipLevel->isHigherThan($currentVip);
+
+        // 如果已经是该等级或更高级别，且不是永久会员续费（逻辑上续费应该用原价，但此处 user 需求是升级补差价）
+        // 这里我们主要处理补差价升级逻辑。
+        $price = $isUpgrade
+            ? $vipLevel->getUpgradePrice($currentVip)
+            : (float) $vipLevel->price;
+
+        if ($price < 0.01) {
+            // 如果差价极小或为 0（例如同级或降级），抛出异常或根据业务逻辑处理
+            if ($isUpgrade) {
+                throw new RuntimeException('当前等级差价不足 0.01 元，无法发起升级。');
+            }
+            if ($user->vip_level_id === $vipLevel->id) {
+                // 续费逻辑保持原价
+                $price = (float) $vipLevel->price;
+            } else {
+                throw new RuntimeException('不支持降级购买会员。');
+            }
         }
 
         return VipPaymentOrder::create([
@@ -45,13 +63,15 @@ class VipPaymentService
             'user_id' => $user->id,
             'vip_level_id' => $vipLevel->id,
             'status' => 'created',
-            'amount' => $vipLevel->price,
-            'subject' => '购买 VIP 会员 - '.$vipLevel->name,
+            'amount' => $price,
+            'subject' => ($isUpgrade ? '【升级】' : '购买') . ' VIP 会员 - ' . $vipLevel->name,
             'provider' => 'alipay',
             'vip_name' => $vipLevel->name,
             'vip_duration_days' => (int) $vipLevel->duration_days,
             'meta' => [
                 'username' => $user->username,
+                'is_upgrade' => $isUpgrade,
+                'old_vip_level_id' => $currentVip?->id,
             ],
         ]);
     }
@@ -188,7 +208,11 @@ class VipPaymentService
             if (! $lockedOrder->isVipOpened()) {
                 // 只在首次成功支付时开通会员，防止重复回调导致会员时长重复叠加。
                 $user = User::query()->lockForUpdate()->findOrFail($lockedOrder->user_id);
-                $this->vipService->grantVip($user, $lockedOrder->vip_level_id, (int) $lockedOrder->vip_duration_days);
+                
+                // 从 meta 中提取是否是升级
+                $isUpgrade = (bool) ($lockedOrder->meta['is_upgrade'] ?? false);
+                
+                $this->vipService->grantVip($user, $lockedOrder->vip_level_id, (int) $lockedOrder->vip_duration_days, $isUpgrade);
 
                 $lockedOrder->update([
                     'opened_vip_at' => now(),