feat(subsonic): change frequent album list to use total time played per album instead of play count. (#331)

Co-authored-by: Brian Doherty <brian@mediaserver.dohertyfamily.me>

db/migrations.go

@@ -54,6 +54,7 @@ func (db *DB) Migrate(ctx MigrationContext) error {
 		construct(ctx, "202207251148", migrateStarRating),
 		construct(ctx, "202211111057", migratePlaylistsQueuesToFullID),
 		construct(ctx, "202304221528", migratePlaylistsToM3U),
+		construct(ctx, "202305301718", migratePlayCountToLength),
 	}
 
 	return gormigrate.
@@ -516,3 +517,19 @@ func migratePlaylistsToM3U(tx *gorm.DB, ctx MigrationContext) error {
 
 	return nil
 }
+
+func migratePlayCountToLength(tx *gorm.DB, _ MigrationContext) error {
+	// As a best guess, we set length played so far as length of album * current count / number of tracks in album
+	step := tx.Exec(`
+		UPDATE plays SET length=
+		((SELECT SUM(length) FROM tracks WHERE tracks.album_id=plays.album_id)*plays.count/
+		 (SELECT COUNT(*) FROM tracks WHERE tracks.album_id=plays.album_id));
+	`)
+	if err := step.Error; err != nil {
+		return fmt.Errorf("calculate length: %w", err)
+	}
+	
+	return nil
+}
+
+

db/model.go

@@ -190,6 +190,7 @@ type Play struct {
 	AlbumID int       `gorm:"not null; index" sql:"default: null; type:int REFERENCES albums(id) ON DELETE CASCADE"`
 	Time    time.Time `sql:"default: null"`
 	Count   int
+	Length	int
 }
 
 type Album struct {

server/ctrlsubsonic/handlers_by_folder.go

@@ -150,7 +150,7 @@ func (c *Controller) ServeGetAlbumList(r *http.Request) *spec.Response {
 			JOIN plays
 			ON albums.id=plays.album_id AND plays.user_id=?`,
 			user.ID)
-		q = q.Order("plays.count DESC")
+		q = q.Order("plays.length DESC")
 	case "newest":
 		q = q.Order("created_at DESC")
 	case "random":

server/ctrlsubsonic/handlers_by_tags.go

@@ -162,7 +162,7 @@ func (c *Controller) ServeGetAlbumListTwo(r *http.Request) *spec.Response {
 	case "frequent":
 		user := r.Context().Value(CtxUser).(*db.User)
 		q = q.Joins("JOIN plays ON albums.id=plays.album_id AND plays.user_id=?", user.ID)
-		q = q.Order("plays.count DESC")
+		q = q.Order("plays.length DESC")
 	case "newest":
 		q = q.Order("created_at DESC")
 	case "random":

server/ctrlsubsonic/handlers_common.go

@@ -69,7 +69,7 @@ func (c *Controller) ServeScrobble(r *http.Request) *spec.Response {
 	optStamp := params.GetOrTime("time", time.Now())
 	optSubmission := params.GetOrBool("submission", true)
 
-	if err := streamUpdateStats(c.DB, user.ID, track.Album.ID, optStamp); err != nil {
+	if err := streamUpdateStats(c.DB, user.ID, track, optStamp); err != nil {
 		return spec.NewError(0, "error updating stats: %v", err)
 	}
 

server/ctrlsubsonic/handlers_raw.go

@@ -58,19 +58,20 @@ func streamGetTransPrefProfile(dbc *db.DB, userID int, client string) (mime stri
 
 var errUnknownMediaType = fmt.Errorf("media type is unknown")
 
-func streamUpdateStats(dbc *db.DB, userID, albumID int, playTime time.Time) error {
+func streamUpdateStats(dbc *db.DB, userID int, track *db.Track, playTime time.Time) error {
 	var play db.Play
 	err := dbc.
-		Where("album_id=? AND user_id=?", albumID, userID).
+		Where("album_id=? AND user_id=?", track.AlbumID, userID).
 		First(&play).
 		Error
 	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
 		return fmt.Errorf("find stat: %w", err)
 	}
 
-	play.AlbumID = albumID
+	play.AlbumID = track.AlbumID
 	play.UserID = userID
 	play.Count++ // for getAlbumList?type=frequent
+	play.Length += track.Length
 	if playTime.After(play.Time) {
 		play.Time = playTime // for getAlbumList?type=recent
 	}
@@ -269,7 +270,7 @@ func (c *Controller) ServeStream(w http.ResponseWriter, r *http.Request) *spec.R
 
 	if track, ok := audioFile.(*db.Track); ok && track.Album != nil {
 		defer func() {
-			if err := streamUpdateStats(c.DB, user.ID, track.Album.ID, time.Now()); err != nil {
+			if err := streamUpdateStats(c.DB, user.ID, track, time.Now()); err != nil {
 				log.Printf("error updating track status: %v", err)
 			}
 		}()