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))
+}

internal/service/note_test.go

@@ -46,3 +46,31 @@ func TestQueryNotes_WithSearch(t *testing.T) {
 		t.Error("wrong note returned")
 	}
 }
+
+func TestTags_NormalizationAndRemove(t *testing.T) {
+	err := service.AddTag("test1", "  Go  ")
+	if err != nil {
+		t.Fatalf("add tag: %v", err)
+	}
+
+	n, err := service.GetNoteByHash("test1")
+	if err != nil {
+		t.Fatalf("get note: %v", err)
+	}
+	if len(n.Tags) != 1 || n.Tags[0] != "go" {
+		t.Fatalf("expected normalized tag, got %+v", n.Tags)
+	}
+
+	err = service.RemoveTag("test1", "GO")
+	if err != nil {
+		t.Fatalf("remove tag: %v", err)
+	}
+
+	n, err = service.GetNoteByHash("test1")
+	if err != nil {
+		t.Fatalf("get note: %v", err)
+	}
+	if len(n.Tags) != 0 {
+		t.Fatalf("expected tag to be removed, got %+v", n.Tags)
+	}
+}