Refactor: comprehensive cleanup and modularization

- Extracted common JSON parsing helpers into internal/jsonutil
- Removed duplicated helper functions from provider packages
- Removed dead code in internal/app/app.go and downloader.go
- Replaced deprecated strings.Title with jsonutil.TitleCase
- Added graceful shutdown with signal handling in main.go
- Split monolithic cmd/rip/main.go into args.go, helpers.go, lastfm.go, search.go

internal/app/app.go

@@ -18,6 +18,7 @@ import (
 	"streamrip-go/internal/config"
 	"streamrip-go/internal/domain/media"
 	"streamrip-go/internal/download"
+	"streamrip-go/internal/jsonutil"
 	"streamrip-go/internal/naming"
 	"streamrip-go/internal/provider"
 	deezerprovider "streamrip-go/internal/provider/deezer"
@@ -259,7 +260,7 @@ func (m *Main) AddMixedPlaylistByTrackRefs(ctx context.Context, playlistID, play
 
 func (m *Main) ripCollection(ctx context.Context, p provider.Client, source, kind, id string, meta map[string]any) error {
 	name := titleFromMetadata(meta, id)
-	if n := stringFromAny(meta["name"]); n != "" {
+	if n := jsonutil.StringFromAny(meta["name"]); n != "" {
 		name = n
 	}
 
@@ -327,18 +328,18 @@ func (m *Main) ripVideo(ctx context.Context, p provider.Client, source, videoID
 }
 
 func buildCollectionAlbum(id string, meta map[string]any) collectionAlbum {
-	trackCount := intFromAny(meta["tracks_count"])
+	trackCount := jsonutil.IntFromAny(meta["tracks_count"])
 	if trackCount == 0 {
-		trackCount = intFromAny(meta["numberOfTracks"])
+		trackCount = jsonutil.IntFromAny(meta["numberOfTracks"])
 	}
 	return collectionAlbum{
 		ID:          id,
 		Meta:        meta,
 		Title:       titleFromMetadata(meta, id),
-		AlbumArtist: nestedString(meta, "artist", "name"),
-		BitDepth:    intFromAny(meta["maximum_bit_depth"]),
-		Sampling:    floatFromAny(meta["maximum_sampling_rate"]),
-		Explicit:    boolFromAny(meta["parental_warning"]),
+		AlbumArtist: jsonutil.NestedString(meta, "artist", "name"),
+		BitDepth:    jsonutil.IntFromAny(meta["maximum_bit_depth"]),
+		Sampling:    jsonutil.FloatFromAny(meta["maximum_sampling_rate"]),
+		Explicit:    jsonutil.BoolFromAny(meta["parental_warning"]),
 		TrackCount:  trackCount,
 	}
 }
@@ -459,10 +460,10 @@ func extractAlbumIDs(meta map[string]any) []string {
 		if !ok {
 			continue
 		}
-		id := stringFromAny(itm["id"])
+		id := jsonutil.StringFromAny(itm["id"])
 		if id == "" {
 			if nested, ok := itm["album"].(map[string]any); ok {
-				id = stringFromAny(nested["id"])
+				id = jsonutil.StringFromAny(nested["id"])
 			}
 		}
 		if id == "" {
@@ -517,23 +518,23 @@ func (m *Main) ripAlbum(ctx context.Context, p provider.Client, source, albumID
 	}
 
 	albumTitle := titleFromMetadata(albumMeta, albumID)
-	albumArtist := nestedString(albumMeta, "artist", "name")
+	albumArtist := jsonutil.NestedString(albumMeta, "artist", "name")
 	if albumArtist == "" {
 		albumArtist = "Unknown"
 	}
-	releaseDate := stringFromAny(albumMeta["release_date_original"])
+	releaseDate := jsonutil.StringFromAny(albumMeta["release_date_original"])
 	if releaseDate == "" {
-		releaseDate = stringFromAny(albumMeta["release_date"])
+		releaseDate = jsonutil.StringFromAny(albumMeta["release_date"])
 	}
 	if releaseDate == "" {
-		releaseDate = stringFromAny(albumMeta["releaseDate"])
+		releaseDate = jsonutil.StringFromAny(albumMeta["releaseDate"])
 	}
 	if releaseDate == "" {
-		releaseDate = stringFromAny(albumMeta["streamStartDate"])
+		releaseDate = jsonutil.StringFromAny(albumMeta["streamStartDate"])
 	}
 	year := naming.YearFromDate(releaseDate)
-	bitDepth := intFromAny(albumMeta["maximum_bit_depth"])
-	sampling := stringFromAny(albumMeta["maximum_sampling_rate"])
+	bitDepth := jsonutil.IntFromAny(albumMeta["maximum_bit_depth"])
+	sampling := jsonutil.StringFromAny(albumMeta["maximum_sampling_rate"])
 	if bitDepth == 0 || sampling == "" {
 		fallbackBitDepth, fallbackSampling := m.qualityProfileForSource(source)
 		if bitDepth == 0 {
@@ -564,7 +565,7 @@ func (m *Main) ripAlbum(ctx context.Context, p provider.Client, source, albumID
 		if !ok {
 			continue
 		}
-		id := stringFromAny(itm["id"])
+		id := jsonutil.StringFromAny(itm["id"])
 		if id != "" {
 			trackIDs = append(trackIDs, id)
 		}
@@ -573,9 +574,9 @@ func (m *Main) ripAlbum(ctx context.Context, p provider.Client, source, albumID
 	folder := m.albumFolderPath(source, albumID, albumTitle, albumArtist, year, bitDepth, sampling)
 	artRes, _ := artwork.Prepare(ctx, m.DL, folder, albumMeta, m.Config.Session.Artwork, false)
 	total := len(trackIDs)
-	discTotal := intFromAny(albumMeta["media_count"])
+	discTotal := jsonutil.IntFromAny(albumMeta["media_count"])
 	if discTotal == 0 {
-		discTotal = intFromAny(albumMeta["numberOfVolumes"])
+		discTotal = jsonutil.IntFromAny(albumMeta["numberOfVolumes"])
 	}
 	m.logf("Album: %s (%d tracks)\n", albumTitle, total)
 	failures := 0
@@ -631,12 +632,12 @@ func (m *Main) ripPlaylist(ctx context.Context, p provider.Client, source, playl
 	}
 
 	name := titleFromMetadata(playlistMeta, playlistID)
-	if n := stringFromAny(playlistMeta["name"]); n != "" {
+	if n := jsonutil.StringFromAny(playlistMeta["name"]); n != "" {
 		name = n
 	}
 	base := m.Config.Session.Downloads.Folder
 	if m.Config.Session.Downloads.SourceSubdirectories {
-		base = filepath.Join(base, strings.Title(source))
+		base = filepath.Join(base, jsonutil.TitleCase(source))
 	}
 	folder := filepath.Join(base, naming.CleanName(name, naming.Config{
 		RestrictCharacters: m.Config.Session.Filepaths.RestrictCharacters,
@@ -665,9 +666,9 @@ func (m *Main) ripPlaylist(ctx context.Context, p provider.Client, source, playl
 		if !ok {
 			continue
 		}
-		id := stringFromAny(itm["id"])
+		id := jsonutil.StringFromAny(itm["id"])
 		if id == "" {
-			id = stringFromAny(itm["track_id"])
+			id = jsonutil.StringFromAny(itm["track_id"])
 		}
 		if id != "" {
 			ids = append(ids, id)
@@ -806,11 +807,9 @@ func (m *Main) requireSourceDownloadAuth(source string) error {
 }
 
 func (m *Main) ripTrack(ctx context.Context, p provider.Client, source, id, fallbackTitle string, opts ripTrackOptions) error {
-	alreadyDownloaded, err := m.Store.IsDownloaded(ctx, source, id)
-	if err == nil && alreadyDownloaded {
-		if m.IgnoreDB {
-			alreadyDownloaded = false
-		} else {
+	if !m.IgnoreDB {
+		alreadyDownloaded, err := m.Store.IsDownloaded(ctx, source, id)
+		if err == nil && alreadyDownloaded {
 			if opts.total > 0 {
 				m.logf("[%d/%d] skip (already downloaded) id=%s\n", opts.index, opts.total, id)
 			} else {
@@ -820,19 +819,6 @@ func (m *Main) ripTrack(ctx context.Context, p provider.Client, source, id, fall
 		}
 	}
 
-	if m.IgnoreDB {
-		alreadyDownloaded = false
-	}
-
-	if alreadyDownloaded {
-		if opts.total > 0 {
-			m.logf("[%d/%d] skip (already downloaded) id=%s\n", opts.index, opts.total, id)
-		} else {
-			m.logf("skip (already downloaded) id=%s\n", id)
-		}
-		return nil
-	}
-
 	meta, err := p.GetMetadata(ctx, id, "track")
 	if err != nil {
 		_ = m.Store.MarkFailed(ctx, source, "track", id)
@@ -970,7 +956,7 @@ func (m *Main) qualityProfileForSource(source string) (int, string) {
 func (m *Main) albumFolderPath(source, albumID, albumTitle, albumArtist, year string, bitDepth int, samplingRate string) string {
 	base := m.Config.Session.Downloads.Folder
 	if m.Config.Session.Downloads.SourceSubdirectories {
-		base = filepath.Join(base, strings.Title(source))
+		base = filepath.Join(base, jsonutil.TitleCase(source))
 	}
 
 	vals := map[string]string{
@@ -995,34 +981,34 @@ func (m *Main) albumFolderPath(source, albumID, albumTitle, albumArtist, year st
 func (m *Main) trackOutputPath(source, id, title, ext string, trackMeta map[string]any, albumFolder string, albumDiscTotal int) string {
 	base := m.Config.Session.Downloads.Folder
 	if m.Config.Session.Downloads.SourceSubdirectories {
-		base = filepath.Join(base, strings.Title(source))
+		base = filepath.Join(base, jsonutil.TitleCase(source))
 	}
 
 	if albumFolder == "" && m.Config.Session.Filepaths.AddSinglesToFolder {
-		albumTitle := nestedString(trackMeta, "album", "title")
-		albumID := nestedString(trackMeta, "album", "id")
+		albumTitle := jsonutil.NestedString(trackMeta, "album", "title")
+		albumID := jsonutil.NestedString(trackMeta, "album", "id")
 		if albumID == "" {
 			albumID = id
 		}
-		albumArtist := nestedString(trackMeta, "album", "artist", "name")
+		albumArtist := jsonutil.NestedString(trackMeta, "album", "artist", "name")
 		if albumArtist == "" {
-			albumArtist = nestedString(trackMeta, "performer", "name")
+			albumArtist = jsonutil.NestedString(trackMeta, "performer", "name")
 		}
-		albumYear := naming.YearFromDate(stringFromAny(trackMeta["release_date_original"]))
+		albumYear := naming.YearFromDate(jsonutil.StringFromAny(trackMeta["release_date_original"]))
 		if albumYear == "Unknown" {
-			albumYear = naming.YearFromDate(stringFromAny(trackMeta["release_date"]))
+			albumYear = naming.YearFromDate(jsonutil.StringFromAny(trackMeta["release_date"]))
 		}
-		albumFolder = m.albumFolderPath(source, albumID, albumTitle, albumArtist, albumYear, intFromAny(trackMeta["maximum_bit_depth"]), stringFromAny(trackMeta["maximum_sampling_rate"]))
+		albumFolder = m.albumFolderPath(source, albumID, albumTitle, albumArtist, albumYear, jsonutil.IntFromAny(trackMeta["maximum_bit_depth"]), jsonutil.StringFromAny(trackMeta["maximum_sampling_rate"]))
 	}
 	if albumFolder != "" {
 		base = albumFolder
 		if m.Config.Session.Downloads.DiscSubdirectories && albumDiscTotal > 1 {
-			discNumber := intFromAny(trackMeta["media_number"])
+			discNumber := jsonutil.IntFromAny(trackMeta["media_number"])
 			if discNumber == 0 {
-				discNumber = intFromAny(trackMeta["volumeNumber"])
+				discNumber = jsonutil.IntFromAny(trackMeta["volumeNumber"])
 			}
 			if discNumber == 0 {
-				discNumber = intFromAny(trackMeta["disk_number"])
+				discNumber = jsonutil.IntFromAny(trackMeta["disk_number"])
 			}
 			if discNumber == 0 {
 				discNumber = 1
@@ -1033,19 +1019,19 @@ func (m *Main) trackOutputPath(source, id, title, ext string, trackMeta map[stri
 		}
 	}
 
-	trackNumber := intFromAny(trackMeta["track_number"])
+	trackNumber := jsonutil.IntFromAny(trackMeta["track_number"])
 	if trackNumber == 0 {
-		trackNumber = intFromAny(trackMeta["trackNumber"])
+		trackNumber = jsonutil.IntFromAny(trackMeta["trackNumber"])
 	}
 	explicit := ""
-	if boolFromAny(trackMeta["parental_warning"]) || boolFromAny(trackMeta["explicit"]) {
+	if jsonutil.BoolFromAny(trackMeta["parental_warning"]) || jsonutil.BoolFromAny(trackMeta["explicit"]) {
 		explicit = " (Explicit)"
 	}
-	artist := nestedString(trackMeta, "performer", "name")
+	artist := jsonutil.NestedString(trackMeta, "performer", "name")
 	if artist == "" {
-		artist = nestedString(trackMeta, "artist", "name")
+		artist = jsonutil.NestedString(trackMeta, "artist", "name")
 	}
-	albumArtist := nestedString(trackMeta, "album", "artist", "name")
+	albumArtist := jsonutil.NestedString(trackMeta, "album", "artist", "name")
 	if albumArtist == "" {
 		albumArtist = artist
 	}
@@ -1073,7 +1059,7 @@ func (m *Main) videoOutputPath(source, id, title, ext string) string {
 	}
 	base := m.Config.Session.Downloads.Folder
 	if m.Config.Session.Downloads.SourceSubdirectories {
-		base = filepath.Join(base, strings.Title(source))
+		base = filepath.Join(base, jsonutil.TitleCase(source))
 	}
 	fileName := naming.CleanName(title, naming.Config{
 		RestrictCharacters: m.Config.Session.Filepaths.RestrictCharacters,
@@ -1088,7 +1074,7 @@ func (m *Main) videoOutputPath(source, id, title, ext string) string {
 func titleFromMetadata(meta map[string]any, fallback string) string {
 	if title, ok := meta["title"].(string); ok {
 		title = strings.TrimSpace(title)
-		version := strings.TrimSpace(stringFromAny(meta["version"]))
+		version := strings.TrimSpace(jsonutil.StringFromAny(meta["version"]))
 		if version != "" {
 			return title + " (" + version + ")"
 		}
@@ -1099,70 +1085,8 @@ func titleFromMetadata(meta map[string]any, fallback string) string {
 	return fallback
 }
 
-func nestedString(v map[string]any, keys ...string) string {
-	return stringFromAny(nestedAny(v, keys...))
-}
-
-func nestedAny(v map[string]any, keys ...string) any {
-	cur := any(v)
-	for _, key := range keys {
-		m, ok := cur.(map[string]any)
-		if !ok {
-			return nil
-		}
-		cur = m[key]
-	}
-	return cur
-}
-
-func stringFromAny(v any) string {
-	switch t := v.(type) {
-	case string:
-		return t
-	case float64:
-		return strconv.FormatFloat(t, 'f', -1, 64)
-	case int64:
-		return strconv.FormatInt(t, 10)
-	case int:
-		return strconv.Itoa(t)
-	default:
-		return ""
-	}
-}
-
-func intFromAny(v any) int {
-	switch t := v.(type) {
-	case int:
-		return t
-	case int64:
-		return int(t)
-	case float64:
-		return int(t)
-	default:
-		return 0
-	}
-}
-
-func floatFromAny(v any) float64 {
-	switch t := v.(type) {
-	case float64:
-		return t
-	case int:
-		return float64(t)
-	case int64:
-		return float64(t)
-	default:
-		return 0
-	}
-}
-
-func boolFromAny(v any) bool {
-	b, _ := v.(bool)
-	return b
-}
-
 func replaygainGainFromAny(v any) string {
-	s := strings.TrimSpace(stringFromAny(v))
+	s := strings.TrimSpace(jsonutil.StringFromAny(v))
 	if s == "" {
 		return ""
 	}
@@ -1183,7 +1107,7 @@ func replaygainGainFromAny(v any) string {
 }
 
 func replaygainPeakFromAny(v any) string {
-	return strings.TrimSpace(stringFromAny(v))
+	return strings.TrimSpace(jsonutil.StringFromAny(v))
 }
 
 func trackMetaAlbum(trackMeta map[string]any) map[string]any {
@@ -1195,53 +1119,53 @@ func trackMetaAlbum(trackMeta map[string]any) map[string]any {
 }
 
 func buildTagMetadata(trackMeta map[string]any, title, source, trackID string, opts ripTrackOptions) tag.Metadata {
-	artist := nestedString(trackMeta, "performer", "name")
+	artist := jsonutil.NestedString(trackMeta, "performer", "name")
 	if artist == "" {
-		artist = nestedString(trackMeta, "artist", "name")
+		artist = jsonutil.NestedString(trackMeta, "artist", "name")
 	}
-	albumArtist := nestedString(trackMeta, "album", "artist", "name")
+	albumArtist := jsonutil.NestedString(trackMeta, "album", "artist", "name")
 	if albumArtist == "" {
 		albumArtist = artist
 	}
 	if strings.TrimSpace(opts.albumArtist) != "" {
 		albumArtist = strings.TrimSpace(opts.albumArtist)
 	}
-	trackNumber := intFromAny(trackMeta["track_number"])
+	trackNumber := jsonutil.IntFromAny(trackMeta["track_number"])
 	if trackNumber == 0 {
-		trackNumber = intFromAny(trackMeta["trackNumber"])
+		trackNumber = jsonutil.IntFromAny(trackMeta["trackNumber"])
 	}
-	discNumber := intFromAny(trackMeta["media_number"])
+	discNumber := jsonutil.IntFromAny(trackMeta["media_number"])
 	if discNumber == 0 {
-		discNumber = intFromAny(trackMeta["volumeNumber"])
+		discNumber = jsonutil.IntFromAny(trackMeta["volumeNumber"])
 	}
 	if discNumber == 0 {
-		discNumber = intFromAny(trackMeta["disk_number"])
+		discNumber = jsonutil.IntFromAny(trackMeta["disk_number"])
 	}
-	date := stringFromAny(trackMeta["release_date_original"])
+	date := jsonutil.StringFromAny(trackMeta["release_date_original"])
 	if date == "" {
-		date = stringFromAny(trackMeta["release_date"])
+		date = jsonutil.StringFromAny(trackMeta["release_date"])
 	}
 	if date == "" {
-		date = stringFromAny(trackMeta["streamStartDate"])
+		date = jsonutil.StringFromAny(trackMeta["streamStartDate"])
 	}
-	album := nestedString(trackMeta, "album", "title")
+	album := jsonutil.NestedString(trackMeta, "album", "title")
 	if album == "" {
-		album = stringFromAny(trackMeta["title"])
+		album = jsonutil.StringFromAny(trackMeta["title"])
 	}
-	trackTotal := intFromAny(trackMeta["tracks_count"])
+	trackTotal := jsonutil.IntFromAny(trackMeta["tracks_count"])
 	if trackTotal == 0 {
-		trackTotal = intFromAny(trackMeta["numberOfTracks"])
+		trackTotal = jsonutil.IntFromAny(trackMeta["numberOfTracks"])
 	}
 	if trackTotal == 0 {
-		trackTotal = intFromAny(trackMeta["track_total"])
+		trackTotal = jsonutil.IntFromAny(trackMeta["track_total"])
 	}
 	if opts.forPlaylist && opts.total > 0 {
 		trackTotal = opts.total
 	}
 
-	discTotal := intFromAny(trackMeta["media_count"])
+	discTotal := jsonutil.IntFromAny(trackMeta["media_count"])
 	if discTotal == 0 {
-		discTotal = intFromAny(trackMeta["numberOfVolumes"])
+		discTotal = jsonutil.IntFromAny(trackMeta["numberOfVolumes"])
 	}
 	if discTotal == 0 && opts.albumDiscTotal > 0 {
 		discTotal = opts.albumDiscTotal
@@ -1253,15 +1177,15 @@ func buildTagMetadata(trackMeta map[string]any, title, source, trackID string, o
 		discNumber = 1
 	}
 
-	genre := nestedString(trackMeta, "genre", "name")
+	genre := jsonutil.NestedString(trackMeta, "genre", "name")
 	if genre == "" {
-		genre = stringFromAny(trackMeta["genre"])
+		genre = jsonutil.StringFromAny(trackMeta["genre"])
 	}
 
-	comment := stringFromAny(trackMeta["comment"])
-	description := stringFromAny(trackMeta["description"])
-	lyrics := stringFromAny(trackMeta["lyrics"])
-	if lrc := stringFromAny(trackMeta["lyrics_synced"]); lrc != "" {
+	comment := jsonutil.StringFromAny(trackMeta["comment"])
+	description := jsonutil.StringFromAny(trackMeta["description"])
+	lyrics := jsonutil.StringFromAny(trackMeta["lyrics"])
+	if lrc := jsonutil.StringFromAny(trackMeta["lyrics_synced"]); lrc != "" {
 		lyrics = lrc
 	}
 	trackGain := replaygainGainFromAny(trackMeta["replaygain_track_gain"])
@@ -1273,7 +1197,7 @@ func buildTagMetadata(trackMeta map[string]any, title, source, trackID string, o
 	}
 	albumGain := replaygainGainFromAny(trackMeta["replaygain_album_gain"])
 	if albumGain == "" {
-		albumGain = replaygainGainFromAny(nestedAny(trackMeta, "album", "replaygain_album_gain"))
+		albumGain = replaygainGainFromAny(jsonutil.NestedAny(trackMeta, "album", "replaygain_album_gain"))
 	}
 	trackPeak := replaygainPeakFromAny(trackMeta["replaygain_track_peak"])
 	if trackPeak == "" {
@@ -1281,22 +1205,22 @@ func buildTagMetadata(trackMeta map[string]any, title, source, trackID string, o
 	}
 	albumPeak := replaygainPeakFromAny(trackMeta["replaygain_album_peak"])
 	if albumPeak == "" {
-		albumPeak = replaygainPeakFromAny(nestedAny(trackMeta, "album", "replaygain_album_peak"))
+		albumPeak = replaygainPeakFromAny(jsonutil.NestedAny(trackMeta, "album", "replaygain_album_peak"))
 	}
 
-	sourceAlbumID := nestedString(trackMeta, "album", "id")
+	sourceAlbumID := jsonutil.NestedString(trackMeta, "album", "id")
 	if sourceAlbumID == "" {
-		sourceAlbumID = stringFromAny(trackMeta["source_album_id"])
+		sourceAlbumID = jsonutil.StringFromAny(trackMeta["source_album_id"])
 	}
-	sourceArtistID := nestedString(trackMeta, "artist", "id")
+	sourceArtistID := jsonutil.NestedString(trackMeta, "artist", "id")
 	if sourceArtistID == "" {
-		sourceArtistID = nestedString(trackMeta, "performer", "id")
+		sourceArtistID = jsonutil.NestedString(trackMeta, "performer", "id")
 	}
 	if sourceArtistID == "" {
-		sourceArtistID = stringFromAny(trackMeta["source_artist_id"])
+		sourceArtistID = jsonutil.StringFromAny(trackMeta["source_artist_id"])
 	}
 	sourceTrackID := trackID
-	if v := stringFromAny(trackMeta["source_track_id"]); v != "" {
+	if v := jsonutil.StringFromAny(trackMeta["source_track_id"]); v != "" {
 		sourceTrackID = v
 	}
 
@@ -1314,8 +1238,8 @@ func buildTagMetadata(trackMeta map[string]any, title, source, trackID string, o
 		Comment:             comment,
 		Description:         description,
 		Lyrics:              lyrics,
-		Copyright:           stringFromAny(trackMeta["copyright"]),
-		ISRC:                stringFromAny(trackMeta["isrc"]),
+		Copyright:           jsonutil.StringFromAny(trackMeta["copyright"]),
+		ISRC:                jsonutil.StringFromAny(trackMeta["isrc"]),
 		ReplaygainTrackGain: trackGain,
 		ReplaygainAlbumGain: albumGain,
 		ReplaygainTrackPeak: trackPeak,