feat: add bought check

backend/app/http/posts.go

@@ -51,6 +51,11 @@ func (ctl *posts) List(ctx fiber.Ctx, pagination *requests.Pagination, query *Li
 
 	postIds := lo.Map(pager.Items.([]model.Posts), func(item model.Posts, _ int) int64 { return item.ID })
 	if len(postIds) > 0 {
+		userBoughtIds, err := models.Users.BatchCheckHasBought(ctx.Context(), user.ID, postIds)
+		if err != nil {
+			log.WithError(err).Errorf("BatchCheckHasBought err: %v", err)
+		}
+
 		items := lo.FilterMap(pager.Items.([]model.Posts), func(item model.Posts, _ int) (PostItem, bool) {
 			medias, err := models.Posts.GetMediaByIds(ctx.Context(), item.HeadImages.Data)
 			if err != nil {
@@ -67,6 +72,8 @@ func (ctl *posts) List(ctx fiber.Ctx, pagination *requests.Pagination, query *Li
 				return url, true
 			})
 
+			_, bought := userBoughtIds[item.ID]
+
 			return PostItem{
 				ID:          item.ID,
 				Title:       item.Title,
@@ -77,6 +84,7 @@ func (ctl *posts) List(ctx fiber.Ctx, pagination *requests.Pagination, query *Li
 				Likes:       item.Likes,
 				Tags:        item.Tags.Data,
 				HeadImages:  mediaUrls,
+				Bought:      bought,
 			}, true
 		})
 

backend/app/models/users.go

@@ -322,6 +322,29 @@ func (m *usersModel) GetUsersMapByIDs(ctx context.Context, ids []int64) (map[int
 	}), nil
 }
 
+func (m *usersModel) BatchCheckHasBought(ctx context.Context, userID int64, postIDs []int64) (map[int64]bool, error) {
+	tbl := table.UserPosts
+	stmt := tbl.SELECT(tbl.PostID.AS("post_id")).WHERE(
+		tbl.UserID.EQ(Int64(userID)).AND(
+			tbl.PostID.IN(lo.Map(postIDs, func(id int64, _ int) Expression { return Int64(id) })...),
+		),
+	)
+
+	var userPosts []struct {
+		PostID int64
+	}
+	if err := stmt.QueryContext(ctx, db, &userPosts); err != nil {
+		m.log.Errorf("error querying user posts: %v", err)
+		return nil, err
+	}
+
+	result := make(map[int64]bool)
+	for _, post := range userPosts {
+		result[post.PostID] = true
+	}
+	return result, nil
+}
+
 // HasBought
 func (m *usersModel) HasBought(ctx context.Context, userID, postID int64) (bool, error) {
 	tbl := table.UserPosts