feat: support refund

backend/app/http/posts.go

@@ -2,6 +2,7 @@ package http
 
 import (
 	_ "embed"
+	"fmt"
 	"strconv"
 	"time"
 
@@ -272,13 +273,22 @@ func (ctl *posts) Buy(ctx fiber.Ctx, id int64, user *model.Users) (*wechat.JSAPI
 		return nil, errors.Wrap(err, "订单创建失败")
 	}
 
+	payPrice := post.Price * int64(post.Discount) / 100
 	prePayResp, err := ctl.wepay.V3TransactionJsapi(ctx.Context(), func(bm *wepay.BodyMap) {
 		bm.
 			Expire(30 * time.Minute).
 			Description(post.Title).
 			OutTradeNo(order.OrderNo).
 			Payer(user.OpenID).
-			CNYAmount(post.Price * int64(post.Discount) / 100)
+			CNYAmount(payPrice).
+			Detail([]wepay.GoodsInfo{
+				{
+					GoodsName:       post.Title,
+					UnitPrice:       payPrice,
+					MerchantGoodsID: fmt.Sprintf("%d", post.ID),
+					Quantity:        1,
+				},
+			})
 	})
 	if err != nil {
 		log.Errorf("wepay.V3TransactionJsapi err: %v", err)