refactor: improve search user collections logic to handle optional keyword

frontend/src/network/network.ts

@@ -730,7 +730,10 @@ class Network {
     );
   }
 
-  async listUserCollections(username: string, page: number = 1): Promise<PageResponse<Collection>> {
+  async listUserCollections(
+    username: string,
+    page: number = 1,
+  ): Promise<PageResponse<Collection>> {
     return this._callApi(() =>
       axios.get(`${this.apiBaseUrl}/collection/list`, {
         params: { username, page },
@@ -776,10 +779,11 @@ class Network {
   async searchUserCollections(
     username: string,
     keyword: string,
+    excludedRID?: number,
   ): Promise<Response<Collection[]>> {
     return this._callApi(() =>
       axios.get(`${this.apiBaseUrl}/collection/search`, {
-        params: { username, keyword },
+        params: { username, keyword, excludedRID },
       }),
     );
   }

server/api/collection.go

@@ -195,14 +195,21 @@ func handleRemoveResourceFromCollection(c fiber.Ctx) error {
 
 func handleSearchUserCollections(c fiber.Ctx) error {
 	keyword := c.Query("keyword", "")
-	if keyword == "" {
-		return model.NewRequestError("keyword is required")
-	}
+	// if keyword == "" {
+	// 	return model.NewRequestError("keyword is required")
+	// }
 	username := c.Query("username", "")
 	if username == "" {
 		return model.NewRequestError("username is required")
 	}
-	cols, err := service.SearchUserCollections(username, keyword)
+	excludedRIDStr := c.Query("excludedRID", "")
+	var excludedRID uint = 0
+	if excludedRIDStr != "" {
+		if rid, err := strconv.Atoi(excludedRIDStr); err == nil && rid > 0 {
+			excludedRID = uint(rid)
+		}
+	}
+	cols, err := service.SearchUserCollections(username, keyword, excludedRID)
 	if err != nil {
 		return err
 	}

server/dao/collection.go

@@ -15,11 +15,11 @@ func CreateCollection(uid uint, title string, article string, images []uint) (mo
 			Article: article,
 		}
 
-		if err := tx.Create(collection).Error; err != nil {
+		if err := tx.Create(&collection).Error; err != nil {
 			return err
 		}
 
-		if err := tx.Model(collection).Association("Images").Replace(images); err != nil {
+		if err := tx.Model(&collection).Association("Images").Replace(images); err != nil {
 			return err
 		}
 
@@ -176,14 +176,27 @@ func ListCollectionResources(collectionID uint, page int, pageSize int) ([]*mode
 }
 
 // SearchUserCollections searches for collections by user ID and keyword limited to 10 results.
-func SearchUserCollections(uid uint, keyword string) ([]*model.Collection, error) {
+// excludedRID: if >0, only return collections not containing this resource.
+func SearchUserCollections(uid uint, keyword string, excludedRID uint) ([]*model.Collection, error) {
 	var collections []*model.Collection
 
-	if err := db.
-		Model(&model.Collection{}).
+	query := db.Model(&model.Collection{}).
+		Where("user_id = ?", uid)
+
+	if keyword != "" {
+		query = query.Where("title LIKE ?", "%"+keyword+"%")
+	}
+
+	if excludedRID > 0 {
+		// Use LEFT JOIN with IS NULL for better performance
+		query = query.
+			Joins("LEFT JOIN collection_resources cr ON collections.id = cr.collection_id AND cr.resource_id = ?", excludedRID).
+			Where("cr.collection_id IS NULL")
+	}
+
+	if err := query.
 		Preload("Images").
 		Preload("Resources").
-		Where("user_id = ? AND title LIKE ?", uid, "%"+keyword+"%").
 		Limit(10).
 		Find(&collections).Error; err != nil {
 		return nil, err

server/service/collection.go

@@ -134,8 +134,9 @@ func ListCollectionResources(collectionID uint, page int) ([]*model.ResourceView
 }
 
 // Search user collections by keyword, limited to 10 results.
-func SearchUserCollections(username string, keyword string) ([]*model.CollectionView, error) {
-	if username == "" || keyword == "" {
+// excludedRID: if >0, only return collections not containing this resource.
+func SearchUserCollections(username string, keyword string, excludedRID uint) ([]*model.CollectionView, error) {
+	if username == "" {
 		return nil, errors.New("invalid parameters")
 	}
 	user, err := dao.GetUserByUsername(username)
@@ -143,7 +144,7 @@ func SearchUserCollections(username string, keyword string) ([]*model.Collection
 		return nil, err
 	}
 	uid := user.ID
-	collections, err := dao.SearchUserCollections(uid, keyword)
+	collections, err := dao.SearchUserCollections(uid, keyword, excludedRID)
 	if err != nil {
 		return nil, err
 	}