music: enable runtime rescanning [#72]

Finally enable runtime rescanning, opening the door for a ton of new
features and automatic rescanning later on.

More work needs to be done on making the shared mutable state in-app
safer to use.

app/src/main/java/org/oxycblt/auxio/music/Indexer.kt

@@ -68,6 +68,10 @@ class Indexer {
     val isIndeterminate: Boolean
         get() = lastResponse == null && indexingState == null
 
+    /** Whether this instance is actively indexing or not. */
+    val isIndexing: Boolean
+        get() = indexingState != null
+
     /** Register a [Controller] with this instance. */
     fun registerController(controller: Controller) {
         if (BuildConfig.DEBUG && this.controller != null) {

app/src/main/java/org/oxycblt/auxio/music/IndexerService.kt

@@ -21,12 +21,16 @@ import android.app.Service
 import android.content.Intent
 import android.os.IBinder
 import androidx.core.app.ServiceCompat
+import coil.imageLoader
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.cancel
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import org.oxycblt.auxio.IntegerTable
+import org.oxycblt.auxio.playback.state.PlaybackStateDatabase
+import org.oxycblt.auxio.playback.state.PlaybackStateManager
 import org.oxycblt.auxio.util.logD
 
 /**
@@ -46,7 +50,9 @@ class IndexerService : Service(), Indexer.Controller {
 
     private val serviceJob = Job()
     private val indexScope = CoroutineScope(serviceJob + Dispatchers.IO)
-    private val updateScope = CoroutineScope(serviceJob + Dispatchers.IO)
+    private val updateScope = CoroutineScope(serviceJob + Dispatchers.Main)
+
+    private val playbackManager = PlaybackStateManager.getInstance()
 
     private var isForeground = false
     private lateinit var notification: IndexerNotification
@@ -80,6 +86,11 @@ class IndexerService : Service(), Indexer.Controller {
     }
 
     override fun onStartIndexing() {
+        if (indexer.isIndexing) {
+            indexer.cancelLast()
+            indexScope.cancel()
+        }
+
         indexScope.launch { indexer.index(this@IndexerService) }
     }
 
@@ -90,16 +101,23 @@ class IndexerService : Service(), Indexer.Controller {
                     state.response.library != musicStore.library) {
                     logD("Applying new library")
 
+                    val newLibrary = state.response.library
+
                     // Load was completed successfully, so apply the new library if we
                     // have not already. Only when we are done updating the library will
                     // the service stop it's foreground state.
                     updateScope.launch {
-                        // TODO: Update PlaybackStateManager here 
+                        imageLoader.memoryCache?.clear()
 
-                        withContext(Dispatchers.Main) {
+                        if (musicStore.library != null) {
-                            musicStore.updateLibrary(state.response.library)
+                            // This is a new library, so we need to make sure the playback state
+                            // is coherent.
+                            playbackManager.sanitize(
+                                PlaybackStateDatabase.getInstance(this@IndexerService), newLibrary)
                         }
 
+                        withContext(Dispatchers.Main) { musicStore.updateLibrary(newLibrary) }
+
                         stopForegroundSession()
                     }
                 } else {

app/src/main/java/org/oxycblt/auxio/music/MusicStore.kt

@@ -83,6 +83,7 @@ class MusicStore private constructor() {
             }
 
         fun sanitize(song: Song) = songs.find { it.id == song.id }
+        fun sanitize(songs: List<Song>) = songs.mapNotNull { sanitize(it) }
         fun sanitize(album: Album) = albums.find { it.id == album.id }
         fun sanitize(artist: Artist) = artists.find { it.id == artist.id }
         fun sanitize(genre: Genre) = genres.find { it.id == genre.id }

app/src/main/java/org/oxycblt/auxio/music/dirs/MusicDirsDialog.kt

@@ -25,17 +25,18 @@ import android.view.LayoutInflater
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AlertDialog
 import androidx.core.view.isVisible
+import androidx.fragment.app.activityViewModels
 import org.oxycblt.auxio.BuildConfig
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.DialogMusicDirsBinding
 import org.oxycblt.auxio.music.Directory
+import org.oxycblt.auxio.music.IndexerViewModel
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.settings.Settings
 import org.oxycblt.auxio.ui.fragment.ViewBindingDialogFragment
 import org.oxycblt.auxio.util.androidActivityViewModels
 import org.oxycblt.auxio.util.context
 import org.oxycblt.auxio.util.getSystemServiceSafe
-import org.oxycblt.auxio.util.hardRestart
 import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.util.showToast
 
@@ -46,6 +47,7 @@ import org.oxycblt.auxio.util.showToast
 class MusicDirsDialog :
     ViewBindingDialogFragment<DialogMusicDirsBinding>(), MusicDirAdapter.Listener {
     private val playbackModel: PlaybackViewModel by androidActivityViewModels()
+    private val indexerModel: IndexerViewModel by activityViewModels()
 
     private val dirAdapter = MusicDirAdapter(this)
     private val settings: Settings by lifecycleObject { binding -> Settings(binding.context) }
@@ -85,7 +87,7 @@ class MusicDirsDialog :
                 if (dirs.dirs != dirAdapter.data.currentList ||
                     dirs.shouldInclude != isInclude(requireBinding())) {
                     logD("Committing changes")
-                    saveAndRestart()
+                    saveAndDismiss()
                 } else {
                     logD("Dropping changes")
                     dismiss()
@@ -186,10 +188,10 @@ class MusicDirsDialog :
     private fun isInclude(binding: DialogMusicDirsBinding) =
         binding.folderModeGroup.checkedButtonId == R.id.dirs_mode_include
 
-    private fun saveAndRestart() {
+    private fun saveAndDismiss() {
         settings.setMusicDirs(MusicDirs(dirAdapter.data.currentList, isInclude(requireBinding())))
-
+        indexerModel.reindex()
-        playbackModel.savePlaybackState(requireContext()) { requireContext().hardRestart() }
+        dismiss()
     }
 
     private fun requireStorageManager(): StorageManager {

app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateManager.kt

@@ -45,6 +45,8 @@ import org.oxycblt.auxio.util.logW
  *
  * All access should be done with [PlaybackStateManager.getInstance].
  * @author OxygenCobalt
+ *
+ * TODO: Replace synchronized calls with annotation
  */
 class PlaybackStateManager private constructor() {
     private val musicStore = MusicStore.getInstance()
@@ -361,12 +363,11 @@ class PlaybackStateManager private constructor() {
      * **Seek** to a [positionMs].
      * @param positionMs The position to seek to in millis.
      */
+    @Synchronized
     fun seekTo(positionMs: Long) {
-        synchronized(this) {
+        this.positionMs = positionMs
-            this.positionMs = positionMs
+        controller?.seekTo(positionMs)
-            controller?.seekTo(positionMs)
+        notifyPositionChanged()
-            notifyPositionChanged()
-        }
     }
 
     /** Rewind to the beginning of a song. */
@@ -377,34 +378,8 @@ class PlaybackStateManager private constructor() {
     /** Restore the state from the [database] */
     suspend fun restoreState(database: PlaybackStateDatabase) {
         val library = musicStore.library ?: return
-        val start: Long
+        withContext(Dispatchers.IO) { readImpl(database, library) }?.let(::restoreImpl)
-        val state: PlaybackStateDatabase.SavedState?
+        isInitialized = true
-
-        logD("Getting state from DB")
-
-        withContext(Dispatchers.IO) {
-            start = System.currentTimeMillis()
-            state = database.read(library)
-        }
-
-        logD("State read completed successfully in ${System.currentTimeMillis() - start}ms")
-
-        synchronized(this) {
-            if (state != null) {
-                index = state.index
-                parent = state.parent
-                _queue = state.queue.toMutableList()
-                repeatMode = state.repeatMode
-                isShuffled = state.isShuffled
-
-                notifyNewPlayback()
-                seekTo(state.positionMs)
-                notifyRepeatModeChanged()
-                notifyShuffledChanged()
-            }
-
-            isInitialized = true
-        }
     }
 
     /** Save the current state to the [database]. */
@@ -412,23 +387,66 @@ class PlaybackStateManager private constructor() {
         logD("Saving state to DB")
 
         // Pack the entire state and save it to the database.
-        withContext(Dispatchers.IO) {
+        withContext(Dispatchers.IO) { saveImpl(database) }
-            val start = System.currentTimeMillis()
+    }
 
-            database.write(
+    suspend fun sanitize(database: PlaybackStateDatabase, newLibrary: MusicStore.Library) {
-                synchronized(this) {
+        // Since we need to sanitize the state and re-save it for consistency, take the
-                    PlaybackStateDatabase.SavedState(
+        // easy way out and just write a new state and restore from it. Don't really care.
-                        index = index,
+        logD("Sanitizing state")
-                        parent = parent,
+        isPlaying = false
-                        queue = _queue,
+        val state =
-                        positionMs = positionMs,
+            withContext(Dispatchers.IO) {
-                        isShuffled = isShuffled,
+                saveImpl(database)
-                        repeatMode = repeatMode)
+                readImpl(database, newLibrary)
-                })
+            }
 
-            this@PlaybackStateManager.logD(
+        state?.let(::restoreImpl)
-                "State save completed successfully in ${System.currentTimeMillis() - start}ms")
+    }
-        }
+
+    private fun readImpl(
+        database: PlaybackStateDatabase,
+        library: MusicStore.Library
+    ): PlaybackStateDatabase.SavedState? {
+        logD("Getting state from DB")
+
+        val start: Long = System.currentTimeMillis()
+        val state: PlaybackStateDatabase.SavedState? = database.read(library)
+
+        logD("State read completed successfully in ${System.currentTimeMillis() - start}ms")
+
+        return state
+    }
+
+    @Synchronized
+    private fun restoreImpl(state: PlaybackStateDatabase.SavedState) {
+        index = state.index
+        parent = state.parent
+        _queue = state.queue.toMutableList()
+        repeatMode = state.repeatMode
+        isShuffled = state.isShuffled
+
+        notifyNewPlayback()
+        seekTo(state.positionMs)
+        notifyRepeatModeChanged()
+        notifyShuffledChanged()
+    }
+
+    @Synchronized
+    private fun saveImpl(database: PlaybackStateDatabase) {
+        val start = System.currentTimeMillis()
+
+        database.write(
+            PlaybackStateDatabase.SavedState(
+                index = index,
+                parent = parent,
+                queue = _queue,
+                positionMs = positionMs,
+                isShuffled = isShuffled,
+                repeatMode = repeatMode))
+
+        this@PlaybackStateManager.logD(
+            "State save completed successfully in ${System.currentTimeMillis() - start}ms")
     }
 
     // --- CALLBACKS ---

app/src/main/java/org/oxycblt/auxio/playback/system/PlaybackService.kt

@@ -24,7 +24,6 @@ import android.content.Intent
 import android.content.IntentFilter
 import android.media.AudioManager
 import android.os.IBinder
-import android.support.v4.media.MediaMetadataCompat
 import androidx.core.app.ServiceCompat
 import com.google.android.exoplayer2.C
 import com.google.android.exoplayer2.ExoPlayer
@@ -273,10 +272,6 @@ class PlaybackService :
 
     override fun onPostNotification(notification: NotificationComponent) {
         if (hasPlayed && playbackManager.song != null) {
-            logD(
-                mediaSessionComponent.mediaSession.controller.metadata.getText(
-                    MediaMetadataCompat.METADATA_KEY_TITLE))
-
             if (!isForeground) {
                 startForeground(IntegerTable.PLAYBACK_NOTIFICATION_CODE, notification.build())
                 isForeground = true

app/src/main/java/org/oxycblt/auxio/settings/SettingsListFragment.kt

@@ -22,6 +22,7 @@ import android.view.View
 import androidx.annotation.DrawableRes
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.core.view.updatePadding
+import androidx.fragment.app.activityViewModels
 import androidx.preference.Preference
 import androidx.preference.PreferenceCategory
 import androidx.preference.PreferenceFragmentCompat
@@ -30,6 +31,7 @@ import androidx.recyclerview.widget.RecyclerView
 import coil.Coil
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.home.tabs.TabCustomizeDialog
+import org.oxycblt.auxio.music.IndexerViewModel
 import org.oxycblt.auxio.music.dirs.MusicDirsDialog
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.playback.replaygain.PreAmpCustomizeDialog
@@ -38,7 +40,6 @@ import org.oxycblt.auxio.settings.ui.IntListPreferenceDialog
 import org.oxycblt.auxio.settings.ui.WrappedDialogPreference
 import org.oxycblt.auxio.ui.accent.AccentCustomizeDialog
 import org.oxycblt.auxio.util.androidActivityViewModels
-import org.oxycblt.auxio.util.hardRestart
 import org.oxycblt.auxio.util.isNight
 import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.util.logEOrThrow
@@ -56,6 +57,7 @@ import org.oxycblt.auxio.util.systemBarInsetsCompat
 @Suppress("UNUSED")
 class SettingsListFragment : PreferenceFragmentCompat() {
     private val playbackModel: PlaybackViewModel by androidActivityViewModels()
+    private val indexerModel: IndexerViewModel by activityViewModels()
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
@@ -123,7 +125,7 @@ class SettingsListFragment : PreferenceFragmentCompat() {
                 }
             }
             getString(R.string.set_key_reindex) -> {
-                playbackModel.savePlaybackState(requireContext()) { context?.hardRestart() }
+                indexerModel.reindex()
             }
             else -> return super.onPreferenceTreeClick(preference)
         }

app/src/main/java/org/oxycblt/auxio/util/ContextUtil.kt

@@ -237,14 +237,3 @@ fun Context.newBroadcastPendingIntent(what: String): PendingIntent =
         Intent(what).setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY),
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) PendingIntent.FLAG_IMMUTABLE else 0)
 
-/** Hard-restarts the app. Useful for forcing the app to reload music. */
-fun Context.hardRestart() {
-    // Instead of having to do a ton of cleanup and horrible code changes
-    // to restart this application non-destructively, I just restart the UI task [There is only
-    // one, after all] and then kill the application using exitProcess. Works well enough.
-    val intent =
-        Intent(applicationContext, MainActivity::class.java)
-            .setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK)
-    startActivity(intent)
-    exitProcess(0)
-}