feat: tag system

internal/service/note.go

@@ -4,6 +4,7 @@ import (
 	"donniemarko/internal/note"
 	"donniemarko/internal/storage"
 	"sort"
+	"strings"
 )
 
 type NotesService struct {
@@ -91,3 +92,33 @@ func (s *NotesService) GetNoteByHash(hash string) (*note.Note, error) {
 func (s *NotesService) GetNotes() []*note.Note {
 	return s.storage.GetAll()
 }
+
+func (s *NotesService) AddTag(noteID, tag string) error {
+	tag = normalizeTag(tag)
+	if tag == "" {
+		return nil
+	}
+
+	if _, err := s.storage.Get(noteID); err != nil {
+		return err
+	}
+
+	return s.storage.AddTag(noteID, tag)
+}
+
+func (s *NotesService) RemoveTag(noteID, tag string) error {
+	tag = normalizeTag(tag)
+	if tag == "" {
+		return nil
+	}
+
+	if _, err := s.storage.Get(noteID); err != nil {
+		return err
+	}
+
+	return s.storage.RemoveTag(noteID, tag)
+}
+
+func normalizeTag(tag string) string {
+	return strings.ToLower(strings.TrimSpace(tag))
+}