feat: add post buy count

backend/app/http/posts.go

@@ -14,6 +14,7 @@ import (
 	"github.com/gofiber/fiber/v3"
 	"github.com/gofiber/fiber/v3/log"
 	"github.com/pkg/errors"
+	"github.com/samber/lo"
 )
 
 type ListQuery struct {
@@ -25,6 +26,11 @@ type posts struct {
 	wepay *wepay.Client
 }
 
+type PostItem struct {
+	model.Posts
+	BoughtCount int64 `json:"bought_count"`
+}
+
 // List posts
 // @Router			/api/posts [get]
 // @Bind pagination query
@@ -32,11 +38,34 @@ type posts struct {
 // @Bind user local
 func (ctl *posts) List(ctx fiber.Ctx, pagination *requests.Pagination, query *ListQuery, user *model.Users) (*requests.Pager, error) {
 	cond := models.Posts.BuildConditionWithKey(query.Keyword)
-	return models.Posts.List(ctx.Context(), pagination, cond, func(item model.Posts) model.Posts {
+	pager, err := models.Posts.List(ctx.Context(), pagination, cond, func(item model.Posts) model.Posts {
 		item.Assets = fields.ToJson([]fields.MediaAsset{})
 		item.Content = ""
 		return item
 	})
+
+	postIds := lo.Map(pager.Items.([]model.Posts), func(item model.Posts, _ int) int64 {
+		return item.ID
+	})
+	if len(postIds) > 0 {
+		postCntMap, err := models.Posts.BoughtStatistics(ctx.Context(), postIds)
+		if err != nil {
+			return pager, err
+		}
+
+		items := lo.Map(pager.Items.([]model.Posts), func(item model.Posts, _ int) PostItem {
+			cnt := int64(0)
+			if v, ok := postCntMap[item.ID]; ok {
+				cnt = v
+			}
+
+			return PostItem{Posts: item, BoughtCount: cnt}
+		})
+
+		pager.Items = items
+	}
+
+	return pager, err
 }
 
 // Show