feat(tags): upsert note tags

persistence/repositories/tag_repository.go

@@ -48,3 +48,36 @@ func (r *tagRepository) Upsert(names []string) error {
 
 	return tx.Commit()
 }
+
+func (r *tagRepository) UpsertNoteTags(noteID int64, tagIDs []int64) error {
+	if len(tagIDs) == 0 {
+		return nil
+	}
+
+	tx, err := r.db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	placeholders := make([]string, 0, len(tagIDs))
+	args := make([]any, 0, len(tagIDs))
+
+	for _, tagID := range tagIDs {
+		placeholders = append(placeholders, "(?, ?)")
+		args = append(args, noteID, tagID)
+	}
+
+	query := "WITH input(note_id, tag_id) AS (VALUES " +
+		strings.Join(placeholders, ",") +
+		") INSERT INTO note_tags(note_id, tag_id) " +
+		"SELECT note_id, tag_id FROM input " +
+		"ON CONFLICT(note_id, tag_id) DO NOTHING" +
+		"SELECT note_id, tag_id FROM input;"
+
+	if _, err := tx.Exec(query, args...); err != nil {
+		return err
+	}
+
+	return tx.Commit()
+}