Add player state persistence

app/src/main/kotlin/it/vfsfitvnm/vimusic/Database.kt

@@ -2,6 +2,8 @@ package it.vfsfitvnm.vimusic
 
 import android.content.Context
 import android.database.Cursor
+import android.os.Parcel
+import androidx.media3.common.MediaItem
 import androidx.room.*
 import androidx.room.migration.AutoMigrationSpec
 import it.vfsfitvnm.vimusic.models.*
@@ -115,6 +117,15 @@ interface Database {
     @RewriteQueriesToDropUnusedColumns
     @Query("SELECT * FROM Info JOIN SongWithAuthors ON Info.id = SongWithAuthors.authorInfoId JOIN Song ON SongWithAuthors.songId = Song.id WHERE browseId = :artistId ORDER BY Song.ROWID DESC")
     fun artistSongs(artistId: String): Flow<List<SongWithInfo>>
+
+    @Insert(onConflict = OnConflictStrategy.ABORT)
+    fun insertQueue(queuedMediaItems: List<QueuedMediaItem>)
+
+    @Query("SELECT * FROM QueuedMediaItem")
+    fun queue(): List<QueuedMediaItem>
+
+    @Query("DELETE FROM QueuedMediaItem")
+    fun clearQueue()
 }
 
 @androidx.room.Database(
@@ -125,19 +136,22 @@ interface Database {
         Info::class,
         SongWithAuthors::class,
         SearchQuery::class,
+        QueuedMediaItem::class,
     ],
     views = [
         SortedSongInPlaylist::class
     ],
-    version = 5,
+    version = 6,
     exportSchema = true,
     autoMigrations = [
         AutoMigration(from = 1, to = 2),
         AutoMigration(from = 2, to = 3),
         AutoMigration(from = 3, to = 4, spec = DatabaseInitializer.From3To4Migration::class),
         AutoMigration(from = 4, to = 5),
+        AutoMigration(from = 5, to = 6),
     ],
 )
+@TypeConverters(Converters::class)
 abstract class DatabaseInitializer protected constructor() : RoomDatabase() {
     abstract val database: Database
 
@@ -145,7 +159,7 @@ abstract class DatabaseInitializer protected constructor() : RoomDatabase() {
         lateinit var Instance: DatabaseInitializer
 
         context(Context)
-        operator fun invoke() {
+                operator fun invoke() {
             if (!::Instance.isInitialized) {
                 Instance = Room
                     .databaseBuilder(this@Context, DatabaseInitializer::class.java, "data.db")
@@ -158,6 +172,38 @@ abstract class DatabaseInitializer protected constructor() : RoomDatabase() {
     class From3To4Migration : AutoMigrationSpec
 }
 
+@TypeConverters
+object Converters {
+    @TypeConverter
+    fun mediaItemFromByteArray(value: ByteArray?): MediaItem? {
+        return value?.let { byteArray ->
+            runCatching {
+                val parcel = Parcel.obtain()
+                parcel.unmarshall(byteArray, 0, byteArray.size)
+                parcel.setDataPosition(0)
+
+                val bundle = parcel.readBundle(MediaItem::class.java.classLoader)
+                parcel.recycle()
+
+                bundle?.let(MediaItem.CREATOR::fromBundle)
+            }.getOrNull()
+        }
+    }
+
+    @TypeConverter
+    fun mediaItemToByteArray(mediaItem: MediaItem?): ByteArray? {
+        return mediaItem?.toBundle()?.let { persistableBundle ->
+            val parcel = Parcel.obtain()
+            parcel.writeBundle(persistableBundle)
+
+            val bytes = parcel.marshall()
+            parcel.recycle()
+
+            bytes
+        }
+    }
+}
+
 val Database.internal: RoomDatabase
     get() = DatabaseInitializer.Instance
 

app/src/main/kotlin/it/vfsfitvnm/vimusic/models/QueuedMediaItem.kt

@@ -0,0 +1,14 @@
+package it.vfsfitvnm.vimusic.models
+
+
+import androidx.media3.common.MediaItem
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+@Entity
+class QueuedMediaItem(
+    @PrimaryKey(autoGenerate = true) val id: Long = 0,
+    @ColumnInfo(typeAffinity = ColumnInfo.BLOB) val mediaItem: MediaItem,
+    var position: Long?
+)

app/src/main/kotlin/it/vfsfitvnm/vimusic/services/PlayerService.kt

@@ -41,6 +41,7 @@ import it.vfsfitvnm.vimusic.Database
 import it.vfsfitvnm.vimusic.MainActivity
 import it.vfsfitvnm.vimusic.R
 import it.vfsfitvnm.vimusic.internal
+import it.vfsfitvnm.vimusic.models.QueuedMediaItem
 import it.vfsfitvnm.vimusic.utils.*
 import it.vfsfitvnm.youtubemusic.Outcome
 import it.vfsfitvnm.youtubemusic.models.NavigationEndpoint
@@ -139,7 +140,35 @@ class PlayerService : Service(), Player.Listener, PlaybackStatsListener.Callback
         player.addListener(this)
         player.addAnalyticsListener(PlaybackStatsListener(false, this))
 
-        mediaSession = MediaSessionCompat(this, "PlayerService")
+        if (preferences.persistentQueue) {
+            coroutineScope.launch(Dispatchers.IO) {
+                val queuedSong = Database.queue()
+                Database.clearQueue()
+
+                if (queuedSong.isEmpty()) return@launch
+
+                val index = queuedSong.indexOfFirst { it.position != null }.coerceAtLeast(0)
+
+                withContext(Dispatchers.Main) {
+                    player.setMediaItems(
+                        queuedSong
+                            .map(QueuedMediaItem::mediaItem)
+                            .map { mediaItem ->
+                                mediaItem.buildUpon()
+                                    .setUri(mediaItem.mediaId)
+                                    .setCustomCacheKey(mediaItem.mediaId)
+                                    .build()
+                            },
+                        true
+                    )
+                    player.seekTo(index, queuedSong[index].position ?: 0)
+                    player.playWhenReady = false
+                    player.prepare()
+                }
+            }
+        }
+
+        mediaSession = MediaSessionCompat(baseContext, "PlayerService")
         mediaSession.setCallback(SessionCallback(player))
         mediaSession.setPlaybackState(stateBuilder.build())
         mediaSession.isActive = true
@@ -161,6 +190,24 @@ class PlayerService : Service(), Player.Listener, PlaybackStatsListener.Callback
     }
 
     override fun onDestroy() {
+        if (preferences.persistentQueue) {
+            val mediaItems = player.currentTimeline.mediaItems
+            val mediaItemIndex = player.currentMediaItemIndex
+            val mediaItemPosition = player.currentPosition
+
+            Database.internal.queryExecutor.execute {
+                Database.clearQueue()
+                Database.insertQueue(
+                    mediaItems.mapIndexed { index, mediaItem ->
+                        QueuedMediaItem(
+                            mediaItem = mediaItem,
+                            position = if (index == mediaItemIndex) mediaItemPosition else null
+                        )
+                    }
+                )
+            }
+        }
+
         player.removeListener(this)
         player.stop()
         player.release()

app/src/main/kotlin/it/vfsfitvnm/vimusic/ui/screens/settings/PlayerSettingsScreen.kt

@@ -239,6 +239,15 @@ fun PlayerSettingsScreen() {
                     }
                 )
 
+                SwitchSettingEntry(
+                    title = "Persistent queue",
+                    text = "Save and restore playing songs",
+                    isChecked = preferences.persistentQueue,
+                    onCheckedChange = {
+                        preferences.persistentQueue = it
+                    }
+                )
+
                 SettingsEntry(
                     title = "Equalizer",
                     text = "Interact with the system equalizer",

app/src/main/kotlin/it/vfsfitvnm/vimusic/utils/Preferences.kt

@@ -26,6 +26,7 @@ class Preferences(holder: SharedPreferences) : SharedPreferences by holder {
     var exoPlayerDiskCacheMaxSizeBytes by preference("exoPlayerDiskCacheMaxSizeBytes", 512L * 1024 * 1024)
     var skipSilence by preference("skipSilence", false)
     var volumeNormalization by preference("volumeNormalization", true)
+    var persistentQueue by preference("persistentQueue", false)
 }
 
 val Context.preferences: Preferences