Fix Track model to match Python reference

- R128: changed from JSONR128 float64 to R128 struct with i, tp, important_secs fields
  (Python R128 is an object, not a number)
- StorageID -> StorageDir with json tag storage_dir (Python API uses storage_dir)
- Lyrics: replaced TrackLyricsInfo with Lyrics (from supplement/lyrics.py) and
  TrackLyricsInfo (from track/lyrics_info.py with has_available_sync_lyrics,
  has_available_text_lyrics fields)
- Track.Lyrics field now maps to lyrics_info JSON key with TrackLyricsInfo type

internal/models/base.go

@@ -111,33 +111,69 @@ func (id JSONID) String() string {
 	return string(id)
 }
 
-// JSONR128 is a flexible R128 loudness normalization value that accepts both JSON numbers and objects.
-// The Yandex Music API sometimes returns r128 as a number (e.g., -23.5) and sometimes
-// as an object (e.g., {"value": -23.5}). JSONR128 accepts both and stores as float64.
-type JSONR128 float64
+// R128 represents EBU R 128 loudness normalization parameters.
+// The Yandex Music API returns this either as a number (e.g., -23.5) or as an object
+// with fields i, tp, important_secs.
+type R128 struct {
+	BaseModel
+	I              float64 `json:"i"`
+	Tp             float64 `json:"tp"`
+	ImportantSecs  int     `json:"important_secs"`
+}
 
 // UnmarshalJSON implements json.Unmarshaler, accepting both JSON numbers and objects.
-func (r *JSONR128) UnmarshalJSON(data []byte) error {
-	// Try float64 first
+func (r *R128) UnmarshalJSON(data []byte) error {
+	// Try float64 first (API sometimes returns just a number)
 	var f float64
 	if err := json.Unmarshal(data, &f); err == nil {
-		*r = JSONR128(f)
+		r.I = f
+		r.Tp = 0
+		r.ImportantSecs = 0
 		return nil
 	}
-	// Try object with "value" key
+	// Try object with fields i, tp, important_secs
 	var obj struct {
-		Value float64 `json:"value"`
+		I              float64 `json:"i"`
+		Tp             float64 `json:"tp"`
+		ImportantSecs  int     `json:"important_secs"`
 	}
-	if err := json.Unmarshal(data, &obj); err == nil {
-		*r = JSONR128(obj.Value)
-		return nil
+	if err := json.Unmarshal(data, &obj); err != nil {
+		return err
 	}
-	// Default to 0 if neither format works
-	*r = 0
+	r.I = obj.I
+	r.Tp = obj.Tp
+	r.ImportantSecs = obj.ImportantSecs
 	return nil
 }
 
-// Float64 returns the R128 value as a float64.
-func (r JSONR128) Float64() float64 {
-	return float64(r)
+// Float64 returns the integrated loudness (i) value as a float64.
+func (r R128) Float64() float64 {
+	return r.I
+}
+
+// DeJSON deserializes an R128 from JSON data.
+func (r *R128) DeJSON(data []byte, c ClientInterface) (Model, error) {
+	r128 := &R128{BaseModel: *NewBaseModel(c)}
+	if err := r128.UnmarshalJSON(data); err != nil {
+		return nil, err
+	}
+	return r128, nil
+}
+
+// DeList deserializes a list of R128 from JSON data.
+func (r *R128) DeList(data []byte, c ClientInterface) ([]Model, error) {
+	var rawList []json.RawMessage
+	if err := json.Unmarshal(data, &rawList); err != nil {
+		return nil, err
+	}
+
+	result := make([]Model, 0, len(rawList))
+	for _, item := range rawList {
+		r128 := &R128{BaseModel: *NewBaseModel(c)}
+		if err := r128.UnmarshalJSON(item); err != nil {
+			continue
+		}
+		result = append(result, r128)
+	}
+	return result, nil
 }

internal/models/track.go

@@ -11,7 +11,7 @@ type Track struct {
 	ID                       JSONID           `json:"id"`
 	Title                    string           `json:"title"`
 	DurationMs               int              `json:"duration_ms"`
-	StorageID                string           `json:"storage_id"`
+	StorageDir               string           `json:"storage_dir"`
 	CoverURI                 string           `json:"cover_uri"`
 	Artists                  []Artist         `json:"artists"`
 	Albums                   []Album          `json:"albums"`
@@ -20,11 +20,11 @@ type Track struct {
 	Explicit                 bool             `json:"explicit"`
 	Available                bool             `json:"available"`
 	AvailableForPremiumUsers bool             `json:"available_for_premium_users"`
-	R128                     JSONR128         `json:"r128"`
+	R128                     *R128            `json:"r128"`
 	TrackSharingFlag         string           `json:"track_sharing_flag"`
 	Major                    *Major           `json:"major"`
-	Lyrics                   *TrackLyricsInfo `json:"lyrics"`
-	SimilarTracks            []Track          `json:"similar_tracks"`
+	LyricsInfo               *TrackLyricsInfo `json:"lyrics_info"`
+	SimilarTracks            []Track        `json:"similar_tracks"`
 	DownloadInfo             []DownloadInfo   `json:"download_info"`
 }
 
@@ -47,8 +47,8 @@ func (t *Track) DeJSON(data []byte, c ClientInterface) (Model, error) {
 	if v, ok := raw["duration_ms"]; ok {
 		json.Unmarshal(v, &track.DurationMs)
 	}
-	if v, ok := raw["storage_id"]; ok {
-		json.Unmarshal(v, &track.StorageID)
+	if v, ok := raw["storage_dir"]; ok {
+		json.Unmarshal(v, &track.StorageDir)
 	}
 	if v, ok := raw["cover_uri"]; ok {
 		json.Unmarshal(v, &track.CoverURI)
@@ -94,10 +94,10 @@ func (t *Track) DeJSON(data []byte, c ClientInterface) (Model, error) {
 			track.Major = &major
 		}
 	}
-	if v, ok := raw["lyrics"]; ok {
+	if v, ok := raw["lyrics_info"]; ok {
 		var lyrics TrackLyricsInfo
 		if err := json.Unmarshal(v, &lyrics); err == nil {
-			track.Lyrics = &lyrics
+			track.LyricsInfo = &lyrics
 		}
 	}
 	if v, ok := raw["similar_tracks"]; ok {
@@ -154,15 +154,119 @@ type Major struct {
 	Description string `json:"description"`
 }
 
-// TrackLyricsInfo represents minimal lyrics info for a track.
-type TrackLyricsInfo struct {
-	ID        JSONID `json:"id"`
-	Text      string `json:"text"`
-	Major     *Major `json:"major"`
-	Available bool   `json:"available"`
-	HasText   bool   `json:"has_text"`
+// Lyrics represents track lyrics from supplement endpoint.
+type Lyrics struct {
+	BaseModel
+	ID              JSONID `json:"id"`
+	Text            string `json:"lyrics"`
+	FullLyrics      string `json:"full_lyrics"`
+	HasRights       bool   `json:"has_rights"`
+	ShowTranslation bool   `json:"show_translation"`
+	TextLanguage    string `json:"text_language"`
+	URL             string `json:"url"`
+	Major           *Major `json:"major"`
 }
 
+// DeJSON deserializes Lyrics from JSON data.
+func (l *Lyrics) DeJSON(data []byte, c ClientInterface) (Model, error) {
+	var raw map[string]json.RawMessage
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return nil, err
+	}
+
+	lyrics := &Lyrics{BaseModel: *NewBaseModel(c)}
+
+	if v, ok := raw["id"]; ok {
+		json.Unmarshal(v, &lyrics.ID)
+	}
+	if v, ok := raw["lyrics"]; ok {
+		json.Unmarshal(v, &lyrics.Text)
+	}
+	if v, ok := raw["full_lyrics"]; ok {
+		json.Unmarshal(v, &lyrics.FullLyrics)
+	}
+	if v, ok := raw["has_rights"]; ok {
+		json.Unmarshal(v, &lyrics.HasRights)
+	}
+	if v, ok := raw["show_translation"]; ok {
+		json.Unmarshal(v, &lyrics.ShowTranslation)
+	}
+	if v, ok := raw["text_language"]; ok {
+		json.Unmarshal(v, &lyrics.TextLanguage)
+	}
+	if v, ok := raw["url"]; ok {
+		json.Unmarshal(v, &lyrics.URL)
+	}
+	if v, ok := raw["major"]; ok {
+		var major Major
+		json.Unmarshal(v, &major)
+		lyrics.Major = &major
+	}
+
+	return lyrics, nil
+}
+
+// DeList deserializes a list of Lyrics from JSON data.
+func (l *Lyrics) DeList(data []byte, c ClientInterface) ([]Model, error) {
+	var rawList []json.RawMessage
+	if err := json.Unmarshal(data, &rawList); err != nil {
+		return nil, err
+	}
+
+	result := make([]Model, 0, len(rawList))
+	for _, item := range rawList {
+		lyrics := &Lyrics{BaseModel: *NewBaseModel(c)}
+		if err := json.Unmarshal(item, lyrics); err != nil {
+			continue
+		}
+		result = append(result, lyrics)
+	}
+	return result, nil
+}
+
+// TrackLyricsInfo represents lyrics availability info for a track.
+type TrackLyricsInfo struct {
+	BaseModel
+	HasAvailableSyncLyrics  bool `json:"has_available_sync_lyrics"`
+	HasAvailableTextLyrics  bool `json:"has_available_text_lyrics"`
+}
+
+// DeJSON deserializes TrackLyricsInfo from JSON data.
+func (tli *TrackLyricsInfo) DeJSON(data []byte, c ClientInterface) (Model, error) {
+	var raw map[string]json.RawMessage
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return nil, err
+	}
+
+	info := &TrackLyricsInfo{BaseModel: *NewBaseModel(c)}
+
+	if v, ok := raw["has_available_sync_lyrics"]; ok {
+		json.Unmarshal(v, &info.HasAvailableSyncLyrics)
+	}
+	if v, ok := raw["has_available_text_lyrics"]; ok {
+		json.Unmarshal(v, &info.HasAvailableTextLyrics)
+	}
+
+	return info, nil
+}
+
+// DeList deserializes a list of TrackLyricsInfo from JSON data.
+func (tli *TrackLyricsInfo) DeList(data []byte, c ClientInterface) ([]Model, error) {
+	var rawList []json.RawMessage
+	if err := json.Unmarshal(data, &rawList); err != nil {
+		return nil, err
+	}
+
+	result := make([]Model, 0, len(rawList))
+	for _, item := range rawList {
+		info := &TrackLyricsInfo{BaseModel: *NewBaseModel(c)}
+		if err := json.Unmarshal(item, info); err != nil {
+			continue
+		}
+		result = append(result, info)
+	}
+	return result, nil
+}
 // DownloadInfo represents file download info for a track.
 type DownloadInfo struct {
 	Quality         string `json:"quality"`

internal/models/track_short.go

@@ -11,7 +11,7 @@ type TrackShort struct {
 	ID                       JSONID            `json:"id"`
 	Title                    string            `json:"title"`
 	DurationMs               int               `json:"duration_ms"`
-	StorageID                string            `json:"storage_id"`
+	StorageDir               string            `json:"storage_dir"`
 	CoverURI                 string            `json:"cover_uri"`
 	Artists                  []Artist          `json:"artists"`
 	Albums                   []Album           `json:"albums"`
@@ -20,7 +20,7 @@ type TrackShort struct {
 	Explicit                 bool              `json:"explicit"`
 	Available                bool              `json:"available"`
 	AvailableForPremiumUsers bool              `json:"available_for_premium_users"`
-	R128                     JSONR128          `json:"r128"`
+	R128                     *R128             `json:"r128"`
 	TrackSharingFlag         string            `json:"track_sharing_flag"`
 	Major                    *Major            `json:"major"`
 	Lyrics                   *SupplementLyrics `json:"lyrics"`
@@ -51,8 +51,8 @@ func (t *TrackShort) DeJSON(data []byte, c ClientInterface) (Model, error) {
 	if v, ok := raw["duration_ms"]; ok {
 		json.Unmarshal(v, &track.DurationMs)
 	}
-	if v, ok := raw["storage_id"]; ok {
-		json.Unmarshal(v, &track.StorageID)
+	if v, ok := raw["storage_dir"]; ok {
+		json.Unmarshal(v, &track.StorageDir)
 	}
 	if v, ok := raw["cover_uri"]; ok {
 		json.Unmarshal(v, &track.CoverURI)

internal/models/track_test.go

@@ -43,7 +43,7 @@ func TestTrack_DeJSON(t *testing.T) {
 		"id": "123",
 		"title": "Test Track",
 		"duration_ms": 180000,
-		"storage_id": "456",
+		"storage_dir": "456",
 		"cover_uri": "https://example.com/cover.jpg",
 		"genre": "rock",
 		"version": "album",
@@ -55,7 +55,7 @@ func TestTrack_DeJSON(t *testing.T) {
 		"artists": [{"id": "1", "name": "Artist 1", "cover_uri": "https://example.com/artist.jpg"}],
 		"albums": [{"id": "789", "title": "Test Album", "cover_uri": "https://example.com/album.jpg", "year": 2023}],
 		"major": {"id": "major1", "name": "Major Label", "description": "Big label"},
-		"lyrics": {"id": "lyr1", "text": "Test lyrics", "available": true, "has_text": true}
+		"lyrics_info": {"has_available_sync_lyrics": true, "has_available_text_lyrics": true}
 	}`)
 
 	track := &Track{BaseModel: *NewBaseModel(client)}
@@ -80,8 +80,8 @@ func TestTrack_DeJSON(t *testing.T) {
 	if resultTrack.Major == nil || resultTrack.Major.Name != "Major Label" {
 		t.Errorf("Expected Major 'Major Label'")
 	}
-	if resultTrack.Lyrics == nil || resultTrack.Lyrics.Text != "Test lyrics" {
-		t.Errorf("Expected Lyrics 'Test lyrics'")
+	if resultTrack.LyricsInfo == nil || resultTrack.LyricsInfo.HasAvailableSyncLyrics != true {
+		t.Errorf("Expected LyricsInfo.HasAvailableSyncLyrics true")
 	}
 }