musikr: restructure loader into pipeline

app/src/main/java/org/oxycblt/auxio/detail/SongDetailDialog.kt

@@ -34,9 +34,9 @@ import org.oxycblt.auxio.detail.list.SongPropertyAdapter
 import org.oxycblt.auxio.list.adapter.UpdateInstructions
 import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.musikr.tag.Name
-import org.oxycblt.auxio.musikr.metadata.AudioProperties
 import org.oxycblt.auxio.music.resolveNames
+import org.oxycblt.auxio.musikr.metadata.AudioProperties
+import org.oxycblt.auxio.musikr.tag.Name
 import org.oxycblt.auxio.playback.formatDurationMs
 import org.oxycblt.auxio.playback.replaygain.formatDb
 import org.oxycblt.auxio.ui.ViewBindingMaterialDialogFragment

app/src/main/java/org/oxycblt/auxio/home/HomeFragment.kt

@@ -65,8 +65,8 @@ import org.oxycblt.auxio.music.MusicViewModel
 import org.oxycblt.auxio.music.Playlist
 import org.oxycblt.auxio.music.PlaylistDecision
 import org.oxycblt.auxio.music.PlaylistMessage
-import org.oxycblt.auxio.musikr.playlist.m3u.M3U
 import org.oxycblt.auxio.musikr.IndexingProgress
+import org.oxycblt.auxio.musikr.playlist.m3u.M3U
 import org.oxycblt.auxio.playback.PlaybackDecision
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.util.collect

app/src/main/java/org/oxycblt/auxio/image/coil/Components.kt

@@ -43,8 +43,8 @@ import kotlinx.coroutines.withContext
 import okio.FileSystem
 import okio.buffer
 import okio.source
-import org.oxycblt.auxio.musikr.cover.Cover
 import org.oxycblt.auxio.image.stack.CoverRetriever
+import org.oxycblt.auxio.musikr.cover.Cover
 
 class CoverKeyer @Inject constructor() : Keyer<Cover> {
     override fun key(data: Cover, options: Options) = "${data.key}&${options.size}"

app/src/main/java/org/oxycblt/auxio/image/stack/CoverRetriever.kt

@@ -20,9 +20,9 @@ package org.oxycblt.auxio.image.stack
 
 import java.io.InputStream
 import javax.inject.Inject
+import org.oxycblt.auxio.image.stack.extractor.CoverExtractor
 import org.oxycblt.auxio.musikr.cover.Cover
 import org.oxycblt.auxio.musikr.cover.CoverCache
-import org.oxycblt.auxio.image.stack.extractor.CoverExtractor
 import timber.log.Timber
 
 interface CoverRetriever {

app/src/main/java/org/oxycblt/auxio/image/stack/extractor/CoverExtractor.kt

@@ -35,6 +35,7 @@ interface CoverSource {
 class CoverExtractorImpl @Inject constructor(private val coverSources: CoverSources) :
     CoverExtractor {
     override suspend fun extract(cover: Cover.Single): ByteArray? {
+        return null
         for (coverSource in coverSources.sources) {
             val stream = coverSource.extract(cover.uri)
             if (stream != null) {

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

@@ -27,14 +27,14 @@ import java.util.UUID
 import kotlin.math.max
 import kotlinx.parcelize.IgnoredOnParcel
 import kotlinx.parcelize.Parcelize
-import org.oxycblt.auxio.musikr.cover.Cover
 import org.oxycblt.auxio.list.Item
+import org.oxycblt.auxio.musikr.cover.Cover
+import org.oxycblt.auxio.musikr.fs.MimeType
+import org.oxycblt.auxio.musikr.fs.Path
 import org.oxycblt.auxio.musikr.tag.Date
 import org.oxycblt.auxio.musikr.tag.Disc
 import org.oxycblt.auxio.musikr.tag.Name
 import org.oxycblt.auxio.musikr.tag.ReleaseType
-import org.oxycblt.auxio.musikr.fs.MimeType
-import org.oxycblt.auxio.musikr.fs.Path
 import org.oxycblt.auxio.playback.replaygain.ReplayGainAdjustment
 import org.oxycblt.auxio.util.concatLocalized
 import org.oxycblt.auxio.util.toUuidOrNull

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

@@ -25,12 +25,12 @@ import kotlinx.coroutines.Job
 import kotlinx.coroutines.withContext
 import kotlinx.coroutines.yield
 import org.oxycblt.auxio.music.MusicRepository.IndexingWorker
-import org.oxycblt.auxio.musikr.tag.Name
-import org.oxycblt.auxio.musikr.tag.interpret.Separators
 import org.oxycblt.auxio.musikr.Indexer
 import org.oxycblt.auxio.musikr.IndexingProgress
-import org.oxycblt.auxio.musikr.tag.Interpretation
 import org.oxycblt.auxio.musikr.model.impl.MutableLibrary
+import org.oxycblt.auxio.musikr.tag.Interpretation
+import org.oxycblt.auxio.musikr.tag.Name
+import org.oxycblt.auxio.musikr.tag.interpret.Separators
 import timber.log.Timber as L
 
 /**

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

@@ -24,7 +24,7 @@ import androidx.core.content.edit
 import dagger.hilt.android.qualifiers.ApplicationContext
 import javax.inject.Inject
 import org.oxycblt.auxio.R
-import org.oxycblt.auxio.musikr.fs.DocumentPathFactory
+import org.oxycblt.auxio.musikr.fs.path.DocumentPathFactory
 import org.oxycblt.auxio.settings.Settings
 import timber.log.Timber as L
 

app/src/main/java/org/oxycblt/auxio/music/locations/MusicSourcesDialog.kt

@@ -36,7 +36,7 @@ import org.oxycblt.auxio.BuildConfig
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.DialogMusicLocationsBinding
 import org.oxycblt.auxio.music.MusicSettings
-import org.oxycblt.auxio.musikr.fs.DocumentPathFactory
+import org.oxycblt.auxio.musikr.fs.path.DocumentPathFactory
 import org.oxycblt.auxio.ui.ViewBindingMaterialDialogFragment
 import org.oxycblt.auxio.util.showToast
 import timber.log.Timber as L

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

@@ -20,17 +20,16 @@ package org.oxycblt.auxio.musikr
 
 import android.net.Uri
 import javax.inject.Inject
-import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.buffer
 import kotlinx.coroutines.flow.flow
-import kotlinx.coroutines.flow.flowOn
-import org.oxycblt.auxio.musikr.explore.Explorer
-import org.oxycblt.auxio.musikr.tag.Interpretation
-import org.oxycblt.auxio.musikr.model.Modeler
 import org.oxycblt.auxio.musikr.model.impl.MutableLibrary
+import org.oxycblt.auxio.musikr.pipeline.EvaluateStep
+import org.oxycblt.auxio.musikr.pipeline.ExploreStep
+import org.oxycblt.auxio.musikr.pipeline.ExtractStep
+import org.oxycblt.auxio.musikr.tag.Interpretation
 
 interface Indexer {
     suspend fun run(
@@ -53,22 +52,19 @@ sealed interface IndexingProgress {
 
 class IndexerImpl
 @Inject
-constructor(private val explorer: Explorer, private val modeler: Modeler) : Indexer {
+constructor(
+    private val exploreStep: ExploreStep,
+    private val extractStep: ExtractStep,
+    private val evaluateStep: EvaluateStep
+) : Indexer {
     override suspend fun run(
         uris: List<Uri>,
         interpretation: Interpretation,
         onProgress: suspend (IndexingProgress) -> Unit
     ) = coroutineScope {
-        val files = explorer.explore(uris, onProgress)
+        val explored = exploreStep.explore(uris).buffer(Channel.UNLIMITED)
-        val audioFiles =
+        val extracted = extractStep.extract(explored).buffer(Channel.UNLIMITED)
-            files.audios
+        evaluateStep.evaluate(interpretation, extracted)
-                .cap(
-                    start = { onProgress(IndexingProgress.Songs(0, 0)) },
-                    end = { onProgress(IndexingProgress.Indeterminate) })
-                .flowOn(Dispatchers.IO)
-                .buffer(Channel.UNLIMITED)
-        val playlistFiles = files.playlists.flowOn(Dispatchers.IO).buffer(Channel.UNLIMITED)
-        modeler.model(audioFiles, playlistFiles, interpretation)
     }
 
     private fun <T> Flow<T>.cap(start: suspend () -> Unit, end: suspend () -> Unit): Flow<T> =

app/src/main/java/org/oxycblt/auxio/musikr/cover/Cover.kt

@@ -24,7 +24,14 @@ import org.oxycblt.auxio.music.Song
 sealed interface Cover {
     val key: String
 
-    data class Single(override val key: String) : Cover
+    data class Single(val song: Song) : Cover {
+        override val key: String
+            get() = "${song.uid}@${song.lastModified}"
+
+        val uid = song.uid
+        val uri = song.uri
+        val lastModified = song.lastModified
+    }
 
     class Multi(val all: List<Single>) : Cover {
         override val key = "multi@${all.hashCode()}"
@@ -35,7 +42,7 @@ sealed interface Cover {
 
         fun nil() = Multi(listOf())
 
-        fun single(key: String) = Single(key)
+        fun single(song: Song) = Single(song)
 
         fun multi(songs: Collection<Song>) = order(songs).run { Multi(this) }
 

app/src/main/java/org/oxycblt/auxio/musikr/cover/CoverCache.kt

@@ -44,8 +44,7 @@ constructor(
         val id = coverIdentifier.identify(data)
         coverFiles.write(id, data)
         storedCoversDao.setStoredCover(
-            StoredCover(uid = cover.uid, lastModified = cover.lastModified, coverId = id)
+            StoredCover(uid = cover.uid, lastModified = cover.lastModified, coverId = id))
-        )
         return coverFiles.read(id)
     }
 }

app/src/main/java/org/oxycblt/auxio/musikr/explore/Explorer.kt

@@ -1,135 +0,0 @@
-/*
- * Copyright (c) 2024 Auxio Project
- * Explorer.kt is part of Auxio.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
- 
-package org.oxycblt.auxio.musikr.explore
-
-import android.net.Uri
-import javax.inject.Inject
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.channels.Channel
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.asFlow
-import kotlinx.coroutines.flow.buffer
-import kotlinx.coroutines.flow.flattenMerge
-import kotlinx.coroutines.flow.flow
-import kotlinx.coroutines.flow.flowOn
-import kotlinx.coroutines.flow.merge
-import kotlinx.coroutines.flow.onEach
-import kotlinx.coroutines.flow.receiveAsFlow
-import kotlinx.coroutines.flow.withIndex
-import org.oxycblt.auxio.musikr.IndexingProgress
-import org.oxycblt.auxio.musikr.fs.DeviceFile
-import org.oxycblt.auxio.musikr.tag.cache.CacheResult
-import org.oxycblt.auxio.musikr.tag.cache.TagCache
-import org.oxycblt.auxio.musikr.tag.extractor.TagExtractor
-import org.oxycblt.auxio.musikr.fs.DeviceFiles
-import org.oxycblt.auxio.musikr.playlist.db.StoredPlaylists
-import org.oxycblt.auxio.musikr.playlist.PlaylistFile
-import org.oxycblt.auxio.musikr.tag.AudioFile
-import timber.log.Timber
-
-interface Explorer {
-    fun explore(uris: List<Uri>, onProgress: suspend (IndexingProgress.Songs) -> Unit): Files
-}
-
-data class Files(val audios: Flow<AudioFile>, val playlists: Flow<PlaylistFile>)
-
-class ExplorerImpl
-@Inject
-constructor(
-    private val deviceFiles: DeviceFiles,
-    private val tagCache: TagCache,
-    private val tagExtractor: TagExtractor,
-    private val storedPlaylists: StoredPlaylists
-) : Explorer {
-    override fun explore(
-        uris: List<Uri>,
-        onProgress: suspend (IndexingProgress.Songs) -> Unit
-    ): Files {
-        var loaded = 0
-        var explored = 0
-        val deviceFiles =
-            deviceFiles
-                .explore(uris.asFlow())
-                .onEach {
-                    Timber.d("File explored: $it")
-                    explored++
-                    onProgress(IndexingProgress.Songs(loaded, explored))
-                }
-                .flowOn(Dispatchers.IO)
-                .buffer(Channel.UNLIMITED)
-        val cacheResults =
-            tagCache.read(deviceFiles).flowOn(Dispatchers.IO).buffer(Channel.UNLIMITED)
-        val audioFiles =
-            cacheResults
-                .handleMisses { misses ->
-                    val extracted =
-                        misses
-                            .stretch(8) { tagExtractor.extract(it).flowOn(Dispatchers.IO) }
-                            .buffer(Channel.UNLIMITED)
-                    val written =
-                        tagCache.write(extracted).flowOn(Dispatchers.IO).buffer(Channel.UNLIMITED)
-                    written
-                }
-                .onEach {
-                    loaded++
-                    onProgress(IndexingProgress.Songs(loaded, explored))
-                    Timber.d("File extracted: $it")
-                }
-        val playlistFiles = storedPlaylists.read()
-        return Files(audioFiles, playlistFiles)
-    }
-
-    /** Temporarily split a flow into 8 parallel threads and then */
-    private fun <T, R> Flow<T>.stretch(n: Int, creator: (Flow<T>) -> Flow<R>): Flow<R> {
-        val posChannels = Array(n) { Channel<T>(Channel.UNLIMITED) }
-        val divert: Flow<R> = flow {
-            withIndex().collect {
-                val index = it.index % n
-                posChannels[index].send(it.value)
-            }
-            for (channel in posChannels) {
-                channel.close()
-            }
-        }
-        val handle =
-            posChannels.map { creator(it.receiveAsFlow()).buffer(Channel.UNLIMITED) }.asFlow()
-        return merge(divert, handle.flattenMerge())
-    }
-
-    private fun Flow<CacheResult>.handleMisses(
-        uncached: (Flow<DeviceFile>) -> Flow<AudioFile>
-    ): Flow<AudioFile> {
-        val uncachedChannel = Channel<DeviceFile>()
-        val cachedChannel = Channel<AudioFile>()
-        val divert: Flow<AudioFile> = flow {
-            collect {
-                when (it) {
-                    is CacheResult.Hit -> cachedChannel.send(it.audioFile)
-                    is CacheResult.Miss -> uncachedChannel.send(it.deviceFile)
-                }
-            }
-            cachedChannel.close()
-            uncachedChannel.close()
-        }
-        val uncached = uncached(uncachedChannel.receiveAsFlow())
-        val cached = cachedChannel.receiveAsFlow()
-        return merge(divert, uncached, cached)
-    }
-}

app/src/main/java/org/oxycblt/auxio/musikr/fs/DeviceFiles.kt

@@ -31,12 +31,21 @@ import kotlinx.coroutines.flow.emitAll
 import kotlinx.coroutines.flow.flatMapMerge
 import kotlinx.coroutines.flow.flattenMerge
 import kotlinx.coroutines.flow.flow
+import org.oxycblt.auxio.musikr.fs.path.DocumentPathFactory
 import timber.log.Timber
 
 interface DeviceFiles {
     fun explore(uris: Flow<Uri>): Flow<DeviceFile>
 }
 
+data class DeviceFile(
+    val uri: Uri,
+    val mimeType: String,
+    val path: Path,
+    val size: Long,
+    val lastModified: Long
+)
+
 @OptIn(ExperimentalCoroutinesApi::class)
 class DeviceFilesImpl
 @Inject
@@ -64,8 +73,7 @@ constructor(
     ): Flow<DeviceFile> = flow {
         contentResolver.useQuery(
             DocumentsContract.buildChildDocumentsUriUsingTree(rootUri, treeDocumentId),
-            PROJECTION
+            PROJECTION) { cursor ->
-        ) { cursor ->
                 val childUriIndex =
                     cursor.getColumnIndexOrThrow(DocumentsContract.Document.COLUMN_DOCUMENT_ID)
                 val displayNameIndex =
@@ -97,8 +105,7 @@ constructor(
                                 mimeType,
                                 newPath,
                                 size,
-                                lastModified)
+                                lastModified))
-                        )
                     }
                 }
                 emitAll(recursive.asFlow().flattenMerge())

app/src/main/java/org/oxycblt/auxio/musikr/fs/FsModule.kt

@@ -27,6 +27,9 @@ import dagger.Provides
 import dagger.hilt.InstallIn
 import dagger.hilt.android.qualifiers.ApplicationContext
 import dagger.hilt.components.SingletonComponent
+import org.oxycblt.auxio.musikr.fs.path.DocumentPathFactory
+import org.oxycblt.auxio.musikr.fs.path.DocumentPathFactoryImpl
+import org.oxycblt.auxio.musikr.fs.path.MediaStorePathInterpreter
 import org.oxycblt.auxio.util.getSystemServiceCompat
 
 @Module

app/src/main/java/org/oxycblt/auxio/musikr/fs/path/DocumentPathFactory.kt

@@ -16,7 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.musikr.fs
+package org.oxycblt.auxio.musikr.fs.path
 
 import android.content.ContentUris
 import android.content.Context
@@ -25,6 +25,12 @@ import android.provider.DocumentsContract
 import dagger.hilt.android.qualifiers.ApplicationContext
 import java.io.File
 import javax.inject.Inject
+import org.oxycblt.auxio.musikr.fs.Components
+import org.oxycblt.auxio.musikr.fs.Path
+import org.oxycblt.auxio.musikr.fs.Volume
+import org.oxycblt.auxio.musikr.fs.VolumeManager
+import org.oxycblt.auxio.musikr.fs.contentResolverSafe
+import org.oxycblt.auxio.musikr.fs.useQuery
 
 /**
  * A factory for parsing the reverse-engineered format of the URIs obtained from document picker.

app/src/main/java/org/oxycblt/auxio/musikr/fs/path/MediaStorePathInterpreter.kt

@@ -16,11 +16,14 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.musikr.fs
+package org.oxycblt.auxio.musikr.fs.path
 
 import android.database.Cursor
 import android.os.Build
 import android.provider.MediaStore
+import org.oxycblt.auxio.musikr.fs.Components
+import org.oxycblt.auxio.musikr.fs.Path
+import org.oxycblt.auxio.musikr.fs.VolumeManager
 import timber.log.Timber as L
 
 /**

app/src/main/java/org/oxycblt/auxio/musikr/metadata/AudioMetadata.kt

@@ -1,12 +1,27 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * AudioMetadata.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.metadata
 
 import android.media.MediaMetadataRetriever
 import androidx.media3.common.Format
-import androidx.media3.common.Metadata
-import org.oxycblt.auxio.musikr.fs.DeviceFile
 
 data class AudioMetadata(
-    val file: DeviceFile,
+    val exoPlayerFormat: Format?,
-    val exoPlayerFormat: Format,
     val mediaMetadataRetriever: MediaMetadataRetriever
 )

app/src/main/java/org/oxycblt/auxio/musikr/metadata/AudioProperties.kt

@@ -119,7 +119,6 @@ constructor(@ApplicationContext private val context: Context) : AudioProperties.
         return AudioProperties(
             bitrate,
             sampleRate,
-            MimeType(fromExtension = song.mimeType.fromExtension, fromFormat = formatMimeType)
+            MimeType(fromExtension = song.mimeType.fromExtension, fromFormat = formatMimeType))
-        )
     }
 }

app/src/main/java/org/oxycblt/auxio/musikr/metadata/MetadataExtractor.kt

@@ -1,3 +1,21 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * MetadataExtractor.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.metadata
 
 import android.content.Context
@@ -6,48 +24,38 @@ import androidx.media3.common.MediaItem
 import androidx.media3.exoplayer.MetadataRetriever
 import androidx.media3.exoplayer.source.MediaSource
 import dagger.hilt.android.qualifiers.ApplicationContext
+import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.collect
-import kotlinx.coroutines.flow.flow
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.mapNotNull
 import kotlinx.coroutines.guava.await
 import kotlinx.coroutines.withContext
 import org.oxycblt.auxio.musikr.fs.DeviceFile
-import javax.inject.Inject
 
 interface MetadataExtractor {
-    fun extract(files: Flow<DeviceFile>): Flow<AudioMetadata>
+    suspend fun extract(file: DeviceFile): AudioMetadata
 }
 
-class MetadataExtractorImpl @Inject constructor(
+class MetadataExtractorImpl
+@Inject
+constructor(
     @ApplicationContext private val context: Context,
     private val mediaSourceFactory: MediaSource.Factory
 ) : MetadataExtractor {
-    override fun extract(files: Flow<DeviceFile>) = files.mapNotNull {
+    override suspend fun extract(file: DeviceFile): AudioMetadata {
-        val exoPlayerMetadataFuture = MetadataRetriever.retrieveMetadata(
+        val exoPlayerMetadataFuture =
-            mediaSourceFactory,
+            MetadataRetriever.retrieveMetadata(mediaSourceFactory, MediaItem.fromUri(file.uri))
-            MediaItem.fromUri(it.uri)
+        val mediaMetadataRetriever =
-        )
+            MediaMetadataRetriever().apply {
-        val mediaMetadataRetriever = MediaMetadataRetriever().apply {
+                withContext(Dispatchers.IO) { setDataSource(context, file.uri) }
-            withContext(Dispatchers.IO) {
-                setDataSource(context, it.uri)
-            }
             }
         val trackGroupArray = exoPlayerMetadataFuture.await()
         if (trackGroupArray.isEmpty) {
-            return@mapNotNull null
+            return AudioMetadata(null, mediaMetadataRetriever)
         }
         val trackGroup = trackGroupArray.get(0)
         if (trackGroup.length == 0) {
-            return@mapNotNull null
+            return AudioMetadata(null, mediaMetadataRetriever)
         }
         val format = trackGroup.getFormat(0)
-        AudioMetadata(
+        return AudioMetadata(format, mediaMetadataRetriever)
-            it,
-            format,
-            mediaMetadataRetriever
-        )
     }
 }

app/src/main/java/org/oxycblt/auxio/musikr/metadata/MetadataModule.kt

@@ -29,6 +29,5 @@ interface MetadataModule {
     @Binds
     fun audioPropertiesFactory(interpreter: AudioPropertiesFactoryImpl): AudioProperties.Factory
 
-    @Binds
+    @Binds fun metadataExtractor(extractor: MetadataExtractorImpl): MetadataExtractor
-    fun metadataExtractor(extractor: MetadataExtractorImpl): MetadataExtractor
 }

app/src/main/java/org/oxycblt/auxio/musikr/metadata/ReusableMetadataRetriever.kt

@@ -1,6 +1,23 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * ReusableMetadataRetriever.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.metadata
 
-import android.net.Uri
 import android.os.Handler
 import android.os.HandlerThread
 import android.os.Message
@@ -16,11 +33,10 @@ import androidx.media3.exoplayer.source.MediaSource
 import androidx.media3.exoplayer.source.TrackGroupArray
 import androidx.media3.exoplayer.upstream.Allocator
 import androidx.media3.exoplayer.upstream.DefaultAllocator
-import com.google.common.util.concurrent.ListenableFuture
 import com.google.common.util.concurrent.SettableFuture
-import timber.log.Timber
 import java.util.concurrent.Future
 import javax.inject.Inject
+import timber.log.Timber
 
 private const val MESSAGE_PREPARE = 0
 private const val MESSAGE_CONTINUE_LOADING = 1
@@ -32,6 +48,7 @@ private const val CHECK_INTERVAL_MS = 100
 
 interface MetadataRetrieverExt {
     fun retrieveMetadata(mediaItem: MediaItem): Future<TrackGroupArray>
+
     fun retrieve()
 
     interface Factory {
@@ -39,13 +56,18 @@ interface MetadataRetrieverExt {
     }
 }
 
-class ReusableMetadataRetrieverImpl @Inject constructor(private val mediaSourceFactory: MediaSource.Factory) :
+class ReusableMetadataRetrieverImpl
+@Inject
+constructor(private val mediaSourceFactory: MediaSource.Factory) :
     MetadataRetrieverExt, Handler.Callback {
     private val mediaSourceThread = HandlerThread("Auxio:ChunkedMetadataRetriever:${hashCode()}")
     private val mediaSourceHandler: HandlerWrapper
     private var job: MetadataJob? = null
 
-    private data class JobParams(val mediaItem: MediaItem, val future: SettableFuture<TrackGroupArray>)
+    private data class JobParams(
+        val mediaItem: MediaItem,
+        val future: SettableFuture<TrackGroupArray>
+    )
 
     private class JobData(
         val params: JobParams,
@@ -64,7 +86,9 @@ class ReusableMetadataRetrieverImpl @Inject constructor(private val mediaSourceF
         val job = job
         check(job == null || job.data.params.future.isDone) { "Already working on something: $job" }
         val future = SettableFuture.create<TrackGroupArray>()
-        mediaSourceHandler.obtainMessage(MESSAGE_PREPARE, JobParams(mediaItem, future)).sendToTarget()
+        mediaSourceHandler
+            .obtainMessage(MESSAGE_PREPARE, JobParams(mediaItem, future))
+            .sendToTarget()
         return future
     }
 
@@ -78,8 +102,7 @@ class ReusableMetadataRetrieverImpl @Inject constructor(private val mediaSourceF
             MESSAGE_PREPARE -> {
                 val params = msg.obj as JobParams
 
-                val mediaSource =
+                val mediaSource = mediaSourceFactory.createMediaSource(params.mediaItem)
-                    mediaSourceFactory.createMediaSource(params.mediaItem)
                 val data = JobData(params, mediaSource, null)
                 val mediaSourceCaller = MediaSourceCaller(data)
                 mediaSource.prepareSource(
@@ -87,8 +110,7 @@ class ReusableMetadataRetrieverImpl @Inject constructor(private val mediaSourceF
                 job = MetadataJob(data, mediaSourceCaller)
 
                 mediaSourceHandler.sendEmptyMessageDelayed(
-                    MESSAGE_CHECK_FAILURE, /* delayMs= */ CHECK_INTERVAL_MS
+                    MESSAGE_CHECK_FAILURE, /* delayMs= */ CHECK_INTERVAL_MS)
-                )
 
                 return true
             }

app/src/main/java/org/oxycblt/auxio/musikr/model/graph/PlaylistLinker.kt

@@ -20,8 +20,8 @@ package org.oxycblt.auxio.musikr.model.graph
 
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.emptyFlow
-import org.oxycblt.auxio.musikr.playlist.PlaylistFile
 import org.oxycblt.auxio.musikr.model.impl.PlaylistImpl
+import org.oxycblt.auxio.musikr.playlist.PlaylistFile
 
 class PlaylistLinker {
     fun register(

app/src/main/java/org/oxycblt/auxio/musikr/model/impl/DeviceMusicImpl.kt

@@ -19,7 +19,6 @@
 package org.oxycblt.auxio.musikr.model.impl
 
 import kotlin.math.min
-import org.oxycblt.auxio.musikr.cover.Cover
 import org.oxycblt.auxio.list.sort.Sort
 import org.oxycblt.auxio.music.Album
 import org.oxycblt.auxio.music.Artist
@@ -27,6 +26,7 @@ import org.oxycblt.auxio.music.Genre
 import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.MusicType
 import org.oxycblt.auxio.music.Song
+import org.oxycblt.auxio.musikr.cover.Cover
 import org.oxycblt.auxio.musikr.model.graph.LinkedAlbum
 import org.oxycblt.auxio.musikr.model.graph.LinkedSong
 import org.oxycblt.auxio.musikr.tag.Date
@@ -43,7 +43,7 @@ import org.oxycblt.auxio.util.update
 class SongImpl(linkedSong: LinkedSong) : Song {
     private val preSong = linkedSong.preSong
 
-    override val uid = preSong.uid
+    override val uid = preSong.computeUid()
     override val name = preSong.name
     override val track = preSong.track
     override val disc = preSong.disc

app/src/main/java/org/oxycblt/auxio/musikr/model/impl/PlaylistImpl.kt

@@ -18,8 +18,8 @@
  
 package org.oxycblt.auxio.musikr.model.impl
 
-import org.oxycblt.auxio.musikr.cover.Cover
 import org.oxycblt.auxio.music.Playlist
+import org.oxycblt.auxio.musikr.cover.Cover
 import org.oxycblt.auxio.musikr.model.graph.LinkedPlaylist
 import org.oxycblt.auxio.musikr.tag.Name
 

app/src/main/java/org/oxycblt/auxio/musikr/pipeline/EvaluateStep.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2024 Auxio Project
- * Modeler.kt is part of Auxio.
+ * EvaluateStep.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,7 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.musikr.model
+package org.oxycblt.auxio.musikr.pipeline
 
 import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
@@ -24,12 +24,11 @@ import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.asFlow
 import kotlinx.coroutines.flow.buffer
+import kotlinx.coroutines.flow.filterIsInstance
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.toList
 import org.oxycblt.auxio.music.Music
-import org.oxycblt.auxio.musikr.tag.AudioFile
-import org.oxycblt.auxio.musikr.playlist.PlaylistFile
 import org.oxycblt.auxio.musikr.model.graph.AlbumLinker
 import org.oxycblt.auxio.musikr.model.graph.ArtistLinker
 import org.oxycblt.auxio.musikr.model.graph.GenreLinker
@@ -44,25 +43,28 @@ import org.oxycblt.auxio.musikr.model.impl.SongImpl
 import org.oxycblt.auxio.musikr.tag.Interpretation
 import org.oxycblt.auxio.musikr.tag.interpret.PreSong
 import org.oxycblt.auxio.musikr.tag.interpret.TagInterpreter
-import timber.log.Timber as L
+import timber.log.Timber
 
-interface Modeler {
+interface EvaluateStep {
-    suspend fun model(
+    suspend fun evaluate(
-        audioFiles: Flow<AudioFile>,
+        interpretation: Interpretation,
-        playlistFiles: Flow<PlaylistFile>,
+        extractedMusic: Flow<ExtractedMusic>
-        interpretation: Interpretation
     ): MutableLibrary
 }
 
-class ModelerImpl @Inject constructor(private val tagInterpreter: TagInterpreter) : Modeler {
+class EvaluateStepImpl
-    override suspend fun model(
+@Inject
-        audioFiles: Flow<AudioFile>,
+constructor(
-        playlistFiles: Flow<PlaylistFile>,
+    private val tagInterpreter: TagInterpreter,
-        interpretation: Interpretation
+) : EvaluateStep {
+    override suspend fun evaluate(
+        interpretation: Interpretation,
+        extractedMusic: Flow<ExtractedMusic>
     ): MutableLibrary {
         val preSongs =
-            tagInterpreter
+            extractedMusic
-                .interpret(audioFiles, interpretation)
+                .filterIsInstance<ExtractedMusic.Song>()
+                .map { tagInterpreter.interpret(it.file, it.tags, interpretation) }
                 .flowOn(Dispatchers.Main)
                 .buffer(Channel.UNLIMITED)
 
@@ -91,12 +93,12 @@ class ModelerImpl @Inject constructor(private val tagInterpreter: TagInterpreter
         val uidMap = mutableMapOf<Music.UID, SongImpl>()
         val songs =
             albumLinkedSongs.mapNotNull {
-                val uid = it.preSong.uid
+                val uid = it.preSong.computeUid()
                 val other = uidMap[uid]
                 if (other == null) {
                     SongImpl(it)
                 } else {
-                    L.d("Song @ $uid already exists at ${other.path}, ignoring")
+                    Timber.d("Song @ $uid already exists at ${other.path}, ignoring")
                     null
                 }
             }

app/src/main/java/org/oxycblt/auxio/musikr/pipeline/ExploreStep.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * ExploreStep.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.musikr.pipeline
+
+import android.net.Uri
+import javax.inject.Inject
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.asFlow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.mapNotNull
+import org.oxycblt.auxio.musikr.fs.DeviceFile
+import org.oxycblt.auxio.musikr.fs.DeviceFiles
+import org.oxycblt.auxio.musikr.playlist.m3u.M3U
+
+interface ExploreStep {
+    fun explore(uris: List<Uri>): Flow<ExploreNode>
+}
+
+class ExploreStepImpl @Inject constructor(private val deviceFiles: DeviceFiles) : ExploreStep {
+    override fun explore(uris: List<Uri>) =
+        deviceFiles
+            .explore(uris.asFlow())
+            .mapNotNull {
+                when {
+                    it.mimeType == M3U.MIME_TYPE -> null
+                    it.mimeType.startsWith("audio/") -> ExploreNode.Audio(it)
+                    else -> null
+                }
+            }
+            .flowOn(Dispatchers.IO)
+}
+
+sealed interface ExploreNode {
+    data class Audio(val file: DeviceFile) : ExploreNode
+}

app/src/main/java/org/oxycblt/auxio/musikr/pipeline/ExtractStep.kt

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * ExtractStep.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.musikr.pipeline
+
+import javax.inject.Inject
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.buffer
+import kotlinx.coroutines.flow.filterIsInstance
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.merge
+import org.oxycblt.auxio.musikr.fs.DeviceFile
+import org.oxycblt.auxio.musikr.metadata.MetadataExtractor
+import org.oxycblt.auxio.musikr.tag.cache.TagCache
+import org.oxycblt.auxio.musikr.tag.parse.ParsedTags
+import org.oxycblt.auxio.musikr.tag.parse.TagParser
+
+interface ExtractStep {
+    fun extract(nodes: Flow<ExploreNode>): Flow<ExtractedMusic>
+}
+
+class ExtractStepImpl
+@Inject
+constructor(
+    private val tagCache: TagCache,
+    private val metadataExtractor: MetadataExtractor,
+    private val tagParser: TagParser
+) : ExtractStep {
+    override fun extract(nodes: Flow<ExploreNode>): Flow<ExtractedMusic> {
+        val cacheResults =
+            nodes
+                .filterIsInstance<ExploreNode.Audio>()
+                .map {
+                    val tags = tagCache.read(it.file)
+                    MaybeCachedSong(it.file, tags)
+                }
+                .flowOn(Dispatchers.IO)
+                .buffer(Channel.UNLIMITED)
+        val (cachedSongs, uncachedSongs) =
+            cacheResults.mapPartition {
+                it.tags?.let { tags -> ExtractedMusic.Song(it.file, tags) }
+            }
+        val split = uncachedSongs.distribute(8)
+        val extractedSongs =
+            Array(split.hot.size) { i ->
+                split.hot[i]
+                    .map {
+                        val metadata = metadataExtractor.extract(it.file)
+                        val tags = tagParser.parse(it.file, metadata)
+                        ExtractedMusic.Song(it.file, tags)
+                    }
+                    .flowOn(Dispatchers.IO)
+                    .buffer(Channel.UNLIMITED)
+            }
+        return merge<ExtractedMusic>(
+            cachedSongs,
+            split.cold,
+            *extractedSongs,
+        )
+    }
+
+    data class MaybeCachedSong(val file: DeviceFile, val tags: ParsedTags?)
+}
+
+sealed interface ExtractedMusic {
+    data class Song(val file: DeviceFile, val tags: ParsedTags) : ExtractedMusic
+}

app/src/main/java/org/oxycblt/auxio/musikr/pipeline/FlowUtil.kt

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * FlowUtil.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.musikr.pipeline
+
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.consumeAsFlow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.withIndex
+
+data class HotCold<H, C>(val hot: H, val cold: Flow<C>)
+
+inline fun <T, R> Flow<T>.mapPartition(crossinline predicate: (T) -> R?): HotCold<Flow<R>, T> {
+    val passChannel = Channel<R>(Channel.UNLIMITED)
+    val passFlow = passChannel.consumeAsFlow()
+    val failFlow = flow {
+        collect {
+            val result = predicate(it)
+            if (result != null) {
+                passChannel.send(result)
+            } else {
+                emit(it)
+            }
+        }
+    }
+    return HotCold(passFlow, failFlow)
+}
+
+/**
+ * Equally "distributes" the values of some flow across n new flows.
+ *
+ * Note that this function requires the "manager" flow to be consumed alongside the split flows in
+ * order to function. Without this, all of the newly split flows will simply block.
+ */
+fun <T> Flow<T>.distribute(n: Int): HotCold<Array<Flow<T>>, Nothing> {
+    val posChannels = Array(n) { Channel<T>(Channel.UNLIMITED) }
+    val managerFlow =
+        flow<Nothing> {
+            withIndex().collect {
+                val index = it.index % n
+                posChannels[index].send(it.value)
+            }
+            for (channel in posChannels) {
+                channel.close()
+            }
+        }
+    val hotFlows = posChannels.map { it.receiveAsFlow() }.toTypedArray()
+    return HotCold(hotFlows, managerFlow)
+}

app/src/main/java/org/oxycblt/auxio/musikr/pipeline/PipelineModule.kt

@@ -1,6 +1,6 @@
 /*
- * Copyright (c) 2023 Auxio Project
+ * Copyright (c) 2024 Auxio Project
- * ModelModule.kt is part of Auxio.
+ * PipelineModule.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,7 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.musikr.model
+package org.oxycblt.auxio.musikr.pipeline
 
 import dagger.Binds
 import dagger.Module
@@ -26,5 +26,9 @@ import dagger.hilt.components.SingletonComponent
 @Module
 @InstallIn(SingletonComponent::class)
 interface InterpretModule {
-    @Binds fun interpreter(interpreter: ModelerImpl): Modeler
+    @Binds fun exploreStep(step: ExploreStepImpl): ExploreStep
+
+    @Binds fun extractStep(step: ExtractStepImpl): ExtractStep
+
+    @Binds fun evaluateStep(step: EvaluateStepImpl): EvaluateStep
 }

app/src/main/java/org/oxycblt/auxio/musikr/playlist/ExternalPlaylistManager.kt

@@ -23,11 +23,11 @@ import android.net.Uri
 import dagger.hilt.android.qualifiers.ApplicationContext
 import javax.inject.Inject
 import org.oxycblt.auxio.music.Playlist
-import org.oxycblt.auxio.musikr.playlist.m3u.M3U
 import org.oxycblt.auxio.musikr.fs.Components
-import org.oxycblt.auxio.musikr.fs.DocumentPathFactory
 import org.oxycblt.auxio.musikr.fs.Path
 import org.oxycblt.auxio.musikr.fs.contentResolverSafe
+import org.oxycblt.auxio.musikr.fs.path.DocumentPathFactory
+import org.oxycblt.auxio.musikr.playlist.m3u.M3U
 import timber.log.Timber as L
 
 /**
@@ -39,8 +39,7 @@ import timber.log.Timber as L
  */
 interface ExternalPlaylistManager {
     /**
-     * Import the playli                L.d("Unable to extract bit rate field")
+     * Import the playli L.d("Unable to extract bit rate field") st file at the given [uri].
-st file at the given [uri].
      *
      * @param uri The [Uri] of the playlist file to import.
      * @return An [ImportedPlaylist] containing the paths to the files listed in the playlist file,

app/src/main/java/org/oxycblt/auxio/musikr/playlist/PlaylistFile.kt

@@ -1,3 +1,21 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * PlaylistFile.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.playlist
 
 import org.oxycblt.auxio.music.Music

app/src/main/java/org/oxycblt/auxio/musikr/playlist/PlaylistModule.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2023 Auxio Project
- * ExternalModule.kt is part of Auxio.
+ * PlaylistModule.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -22,8 +22,6 @@ import dagger.Binds
 import dagger.Module
 import dagger.hilt.InstallIn
 import dagger.hilt.components.SingletonComponent
-import org.oxycblt.auxio.musikr.playlist.m3u.M3U
-import org.oxycblt.auxio.musikr.playlist.m3u.M3UImpl
 
 @Module
 @InstallIn(SingletonComponent::class)

app/src/main/java/org/oxycblt/auxio/musikr/playlist/m3u/M3U.kt

@@ -28,7 +28,6 @@ import java.io.OutputStream
 import javax.inject.Inject
 import org.oxycblt.auxio.music.Playlist
 import org.oxycblt.auxio.music.resolveNames
-import org.oxycblt.auxio.musikr.tag.util.correctWhitespace
 import org.oxycblt.auxio.musikr.fs.Components
 import org.oxycblt.auxio.musikr.fs.Path
 import org.oxycblt.auxio.musikr.fs.Volume
@@ -36,6 +35,7 @@ import org.oxycblt.auxio.musikr.fs.VolumeManager
 import org.oxycblt.auxio.musikr.playlist.ExportConfig
 import org.oxycblt.auxio.musikr.playlist.ImportedPlaylist
 import org.oxycblt.auxio.musikr.playlist.PossiblePaths
+import org.oxycblt.auxio.musikr.tag.util.correctWhitespace
 import org.oxycblt.auxio.util.unlikelyToBeNull
 import timber.log.Timber as L
 
@@ -154,8 +154,7 @@ constructor(
             else ->
                 listOf(
                     InterpretedPath(Components.parseUnix(path), false),
-                    InterpretedPath(Components.parseWindows(path), true)
+                    InterpretedPath(Components.parseWindows(path), true))
-                )
         }
 
     private fun expandInterpretation(

app/src/main/java/org/oxycblt/auxio/musikr/playlist/m3u/M3UModule.kt

@@ -1,13 +1,27 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * M3UModule.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.playlist.m3u
 
 import dagger.Binds
 import dagger.Module
 import dagger.hilt.InstallIn
 import dagger.hilt.components.SingletonComponent
-import org.oxycblt.auxio.musikr.playlist.ExternalPlaylistManager
-import org.oxycblt.auxio.musikr.playlist.ExternalPlaylistManagerImpl
-import org.oxycblt.auxio.musikr.playlist.m3u.M3U
-import org.oxycblt.auxio.musikr.playlist.m3u.M3UImpl
 
 @Module
 @InstallIn(SingletonComponent::class)

app/src/main/java/org/oxycblt/auxio/musikr/tag/AudioFile.kt

@@ -1,28 +0,0 @@
-package org.oxycblt.auxio.musikr.tag
-
-import org.oxycblt.auxio.musikr.fs.DeviceFile
-
-data class AudioFile(
-    val deviceFile: DeviceFile,
-    val durationMs: Long,
-    val replayGainTrackAdjustment: Float? = null,
-    val replayGainAlbumAdjustment: Float? = null,
-    val musicBrainzId: String? = null,
-    val name: String,
-    val sortName: String? = null,
-    val track: Int? = null,
-    val disc: Int? = null,
-    val subtitle: String? = null,
-    val date: Date? = null,
-    val albumMusicBrainzId: String? = null,
-    val albumName: String? = null,
-    val albumSortName: String? = null,
-    val releaseTypes: List<String> = listOf(),
-    val artistMusicBrainzIds: List<String> = listOf(),
-    val artistNames: List<String> = listOf(),
-    val artistSortNames: List<String> = listOf(),
-    val albumArtistMusicBrainzIds: List<String> = listOf(),
-    val albumArtistNames: List<String> = listOf(),
-    val albumArtistSortNames: List<String> = listOf(),
-    val genreNames: List<String> = listOf()
-)

app/src/main/java/org/oxycblt/auxio/musikr/tag/Interpretation.kt

@@ -1,3 +1,21 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * Interpretation.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.tag
 
 import org.oxycblt.auxio.musikr.tag.interpret.Separators

app/src/main/java/org/oxycblt/auxio/musikr/tag/cache/TagCache.kt

@@ -19,35 +19,19 @@
 package org.oxycblt.auxio.musikr.tag.cache
 
 import javax.inject.Inject
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.onEach
-import org.oxycblt.auxio.musikr.tag.AudioFile
 import org.oxycblt.auxio.musikr.fs.DeviceFile
-
+import org.oxycblt.auxio.musikr.tag.parse.ParsedTags
-sealed interface CacheResult {
-    data class Hit(val audioFile: AudioFile) : CacheResult
-
-    data class Miss(val deviceFile: DeviceFile) : CacheResult
-}
 
 interface TagCache {
-    fun read(files: Flow<DeviceFile>): Flow<CacheResult>
+    suspend fun read(file: DeviceFile): ParsedTags?
 
-    fun write(rawSongs: Flow<AudioFile>): Flow<AudioFile>
+    suspend fun write(file: DeviceFile, tags: ParsedTags)
 }
 
 class TagCacheImpl @Inject constructor(private val tagDao: TagDao) : TagCache {
-    override fun read(files: Flow<DeviceFile>) =
+    override suspend fun read(file: DeviceFile) =
-        files.map { file ->
+        tagDao.selectTags(file.uri.toString(), file.lastModified)?.intoParsedTags()
-            val tags = tagDao.selectTags(file.uri.toString(), file.lastModified)
-            if (tags != null) {
-                CacheResult.Hit(tags.toAudioFile(file))
-            } else {
-                CacheResult.Miss(file)
-            }
-        }
 
-    override fun write(rawSongs: Flow<AudioFile>) =
+    override suspend fun write(file: DeviceFile, tags: ParsedTags) =
-        rawSongs.onEach { file -> tagDao.updateTags(CachedTags.fromAudioFile(file)) }
+        tagDao.updateTags(CachedTags.fromParsedTags(file, tags))
 }

app/src/main/java/org/oxycblt/auxio/musikr/tag/cache/TagDatabase.kt

@@ -28,9 +28,9 @@ import androidx.room.Query
 import androidx.room.RoomDatabase
 import androidx.room.TypeConverter
 import androidx.room.TypeConverters
-import org.oxycblt.auxio.musikr.tag.Date
-import org.oxycblt.auxio.musikr.tag.AudioFile
 import org.oxycblt.auxio.musikr.fs.DeviceFile
+import org.oxycblt.auxio.musikr.tag.Date
+import org.oxycblt.auxio.musikr.tag.parse.ParsedTags
 import org.oxycblt.auxio.musikr.tag.util.correctWhitespace
 import org.oxycblt.auxio.musikr.tag.util.splitEscaped
 
@@ -100,9 +100,8 @@ data class CachedTags(
     /** @see AudioFile.genreNames */
     val genreNames: List<String> = listOf()
 ) {
-    fun toAudioFile(deviceFile: DeviceFile) =
+    fun intoParsedTags() =
-        AudioFile(
+        ParsedTags(
-            deviceFile = deviceFile,
             musicBrainzId = musicBrainzId,
             name = name,
             sortName = sortName,
@@ -139,30 +138,30 @@ data class CachedTags(
     }
 
     companion object {
-        fun fromAudioFile(audioFile: AudioFile) =
+        fun fromParsedTags(deviceFile: DeviceFile, parsedTags: ParsedTags) =
             CachedTags(
-                uri = audioFile.deviceFile.uri.toString(),
+                uri = deviceFile.uri.toString(),
-                dateModified = audioFile.deviceFile.lastModified,
+                dateModified = deviceFile.lastModified,
-                musicBrainzId = audioFile.musicBrainzId,
+                musicBrainzId = parsedTags.musicBrainzId,
-                name = audioFile.name,
+                name = parsedTags.name,
-                sortName = audioFile.sortName,
+                sortName = parsedTags.sortName,
-                durationMs = audioFile.durationMs,
+                durationMs = parsedTags.durationMs,
-                replayGainTrackAdjustment = audioFile.replayGainTrackAdjustment,
+                replayGainTrackAdjustment = parsedTags.replayGainTrackAdjustment,
-                replayGainAlbumAdjustment = audioFile.replayGainAlbumAdjustment,
+                replayGainAlbumAdjustment = parsedTags.replayGainAlbumAdjustment,
-                track = audioFile.track,
+                track = parsedTags.track,
-                disc = audioFile.disc,
+                disc = parsedTags.disc,
-                subtitle = audioFile.subtitle,
+                subtitle = parsedTags.subtitle,
-                date = audioFile.date,
+                date = parsedTags.date,
-                albumMusicBrainzId = audioFile.albumMusicBrainzId,
+                albumMusicBrainzId = parsedTags.albumMusicBrainzId,
-                albumName = audioFile.albumName,
+                albumName = parsedTags.albumName,
-                albumSortName = audioFile.albumSortName,
+                albumSortName = parsedTags.albumSortName,
-                releaseTypes = audioFile.releaseTypes,
+                releaseTypes = parsedTags.releaseTypes,
-                artistMusicBrainzIds = audioFile.artistMusicBrainzIds,
+                artistMusicBrainzIds = parsedTags.artistMusicBrainzIds,
-                artistNames = audioFile.artistNames,
+                artistNames = parsedTags.artistNames,
-                artistSortNames = audioFile.artistSortNames,
+                artistSortNames = parsedTags.artistSortNames,
-                albumArtistMusicBrainzIds = audioFile.albumArtistMusicBrainzIds,
+                albumArtistMusicBrainzIds = parsedTags.albumArtistMusicBrainzIds,
-                albumArtistNames = audioFile.albumArtistNames,
+                albumArtistNames = parsedTags.albumArtistNames,
-                albumArtistSortNames = audioFile.albumArtistSortNames,
+                albumArtistSortNames = parsedTags.albumArtistSortNames,
-                genreNames = audioFile.genreNames)
+                genreNames = parsedTags.genreNames)
     }
 }

app/src/main/java/org/oxycblt/auxio/musikr/tag/interpret/InterpretModule.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2024 Auxio Project
- * ModelModule.kt is part of Auxio.
+ * InterpretModule.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

app/src/main/java/org/oxycblt/auxio/musikr/tag/interpret/PreMusic.kt

@@ -22,13 +22,13 @@ import android.net.Uri
 import java.util.UUID
 import org.oxycblt.auxio.music.Music
 import org.oxycblt.auxio.music.MusicType
+import org.oxycblt.auxio.musikr.fs.MimeType
+import org.oxycblt.auxio.musikr.fs.Path
+import org.oxycblt.auxio.musikr.playlist.PlaylistHandle
 import org.oxycblt.auxio.musikr.tag.Date
 import org.oxycblt.auxio.musikr.tag.Disc
 import org.oxycblt.auxio.musikr.tag.Name
 import org.oxycblt.auxio.musikr.tag.ReleaseType
-import org.oxycblt.auxio.musikr.playlist.PlaylistHandle
-import org.oxycblt.auxio.musikr.fs.MimeType
-import org.oxycblt.auxio.musikr.fs.Path
 import org.oxycblt.auxio.playback.replaygain.ReplayGainAdjustment
 import org.oxycblt.auxio.util.update
 
@@ -51,7 +51,7 @@ data class PreSong(
     val preArtists: List<PreArtist>,
     val preGenres: List<PreGenre>
 ) {
-    val uid =
+    fun computeUid() =
         musicBrainzId?.let { Music.UID.musicBrainz(MusicType.SONGS, it) }
             ?: Music.UID.auxio(MusicType.SONGS) {
                 // Song UIDs are based on the raw data without parsing so that they remain
@@ -77,11 +77,7 @@ data class PreAlbum(
     val preArtists: List<PreArtist>
 )
 
-data class PreArtist(
+data class PreArtist(val musicBrainzId: UUID?, val name: Name, val rawName: String?)
-    val musicBrainzId: UUID?,
-    val name: Name,
-    val rawName: String?,
-)
 
 data class PreGenre(
     val name: Name,

app/src/main/java/org/oxycblt/auxio/musikr/tag/interpret/TagInterpreter.kt

@@ -19,91 +19,88 @@
 package org.oxycblt.auxio.musikr.tag.interpret
 
 import javax.inject.Inject
-import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
 import org.oxycblt.auxio.R
+import org.oxycblt.auxio.musikr.fs.DeviceFile
+import org.oxycblt.auxio.musikr.fs.MimeType
 import org.oxycblt.auxio.musikr.tag.Disc
+import org.oxycblt.auxio.musikr.tag.Interpretation
 import org.oxycblt.auxio.musikr.tag.Name
 import org.oxycblt.auxio.musikr.tag.ReleaseType
-import org.oxycblt.auxio.musikr.tag.AudioFile
+import org.oxycblt.auxio.musikr.tag.parse.ParsedTags
-import org.oxycblt.auxio.musikr.fs.MimeType
-import org.oxycblt.auxio.musikr.tag.Interpretation
 import org.oxycblt.auxio.musikr.tag.util.parseId3GenreNames
 import org.oxycblt.auxio.playback.replaygain.ReplayGainAdjustment
 import org.oxycblt.auxio.util.toUuidOrNull
 
 interface TagInterpreter {
-    fun interpret(audioFiles: Flow<AudioFile>, interpretation: Interpretation): Flow<PreSong>
+    fun interpret(file: DeviceFile, parsedTags: ParsedTags, interpretation: Interpretation): PreSong
 }
 
 class TagInterpreterImpl @Inject constructor() : TagInterpreter {
-    override fun interpret(audioFiles: Flow<AudioFile>, interpretation: Interpretation) =
+    override fun interpret(
-        audioFiles.map { audioFile ->
+        file: DeviceFile,
+        parsedTags: ParsedTags,
+        interpretation: Interpretation
+    ): PreSong {
         val individualPreArtists =
             makePreArtists(
-                    audioFile.artistMusicBrainzIds,
+                parsedTags.artistMusicBrainzIds,
-                    audioFile.artistNames,
+                parsedTags.artistNames,
-                    audioFile.artistSortNames,
+                parsedTags.artistSortNames,
                 interpretation)
         val albumPreArtists =
             makePreArtists(
-                    audioFile.albumArtistMusicBrainzIds,
+                parsedTags.albumArtistMusicBrainzIds,
-                    audioFile.albumArtistNames,
+                parsedTags.albumArtistNames,
-                    audioFile.albumArtistSortNames,
+                parsedTags.albumArtistSortNames,
                 interpretation)
         val preAlbum =
-                makePreAlbum(audioFile, individualPreArtists, albumPreArtists, interpretation)
+            makePreAlbum(file, parsedTags, individualPreArtists, albumPreArtists, interpretation)
         val rawArtists =
-                individualPreArtists
+            individualPreArtists.ifEmpty { albumPreArtists }.ifEmpty { listOf(unknownPreArtist()) }
-                    .ifEmpty { albumPreArtists }
-                    .ifEmpty { listOf(unknownPreArtist()) }
         val rawGenres =
-                makePreGenres(audioFile, interpretation).ifEmpty { listOf(unknownPreGenre()) }
+            makePreGenres(parsedTags, interpretation).ifEmpty { listOf(unknownPreGenre()) }
-            val uri = audioFile.deviceFile.uri
+        val uri = file.uri
-            PreSong(
+        return PreSong(
-                musicBrainzId = audioFile.musicBrainzId?.toUuidOrNull(),
+            musicBrainzId = parsedTags.musicBrainzId?.toUuidOrNull(),
-                name =
+            name = interpretation.nameFactory.parse(parsedTags.name, parsedTags.sortName),
-                    interpretation.nameFactory.parse(
+            rawName = parsedTags.name,
-                        need(audioFile, "name", audioFile.name), audioFile.sortName),
+            track = parsedTags.track,
-                rawName = audioFile.name,
+            disc = parsedTags.disc?.let { Disc(it, parsedTags.subtitle) },
-                track = audioFile.track,
+            date = parsedTags.date,
-                disc = audioFile.disc?.let { Disc(it, audioFile.subtitle) },
-                date = audioFile.date,
             uri = uri,
-                path = need(audioFile, "path", audioFile.deviceFile.path),
+            path = file.path,
-                mimeType =
+            mimeType = MimeType(file.mimeType, null),
-                    MimeType(need(audioFile, "mime type", audioFile.deviceFile.mimeType), null),
+            size = file.size,
-                size = audioFile.deviceFile.size,
+            durationMs = parsedTags.durationMs,
-                durationMs = need(audioFile, "duration", audioFile.durationMs),
             replayGainAdjustment =
                 ReplayGainAdjustment(
-                        audioFile.replayGainTrackAdjustment,
+                    parsedTags.replayGainTrackAdjustment,
-                        audioFile.replayGainAlbumAdjustment,
+                    parsedTags.replayGainAlbumAdjustment,
                 ),
-                lastModified = audioFile.deviceFile.lastModified,
+            lastModified = file.lastModified,
             // TODO: Figure out what to do with date added
-                dateAdded = audioFile.deviceFile.lastModified,
+            dateAdded = file.lastModified,
             preAlbum = preAlbum,
             preArtists = rawArtists,
             preGenres = rawGenres)
     }
 
-    private fun <T> need(audioFile: AudioFile, what: String, value: T?) =
-        requireNotNull(value) { "Invalid $what for song ${audioFile.deviceFile.path}: No $what" }
-
     private fun makePreAlbum(
-        audioFile: AudioFile,
+        file: DeviceFile,
+        parsedTags: ParsedTags,
         individualPreArtists: List<PreArtist>,
         albumPreArtists: List<PreArtist>,
         interpretation: Interpretation
     ): PreAlbum {
-        val rawAlbumName = need(audioFile, "album name", audioFile.albumName)
+        // TODO: Make fallbacks for this!
+        val rawAlbumName = requireNotNull(parsedTags.albumName)
         return PreAlbum(
-            musicBrainzId = audioFile.albumMusicBrainzId?.toUuidOrNull(),
+            musicBrainzId = parsedTags.albumMusicBrainzId?.toUuidOrNull(),
-            name = interpretation.nameFactory.parse(rawAlbumName, audioFile.albumSortName),
+            name = interpretation.nameFactory.parse(rawAlbumName, parsedTags.albumSortName),
             rawName = rawAlbumName,
             releaseType =
-                ReleaseType.parse(interpretation.separators.split(audioFile.releaseTypes))
+                ReleaseType.parse(interpretation.separators.split(parsedTags.releaseTypes))
                     ?: ReleaseType.Album(null),
             preArtists =
                 albumPreArtists
@@ -141,12 +138,12 @@ class TagInterpreterImpl @Inject constructor() : TagInterpreter {
     private fun unknownPreArtist() = PreArtist(null, Name.Unknown(R.string.def_artist), null)
 
     private fun makePreGenres(
-        audioFile: AudioFile,
+        parsedTags: ParsedTags,
         interpretation: Interpretation
     ): List<PreGenre> {
         val genreNames =
-            audioFile.genreNames.parseId3GenreNames()
+            parsedTags.genreNames.parseId3GenreNames()
-                ?: interpretation.separators.split(audioFile.genreNames)
+                ?: interpretation.separators.split(parsedTags.genreNames)
         return genreNames.map { makePreGenre(it, interpretation) }
     }
 

app/src/main/java/org/oxycblt/auxio/musikr/tag/parse/ExoPlayerTagFields.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2024 Auxio Project
- * TagFields.kt is part of Auxio.
+ * ExoPlayerTagFields.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -25,32 +25,32 @@ import org.oxycblt.auxio.musikr.tag.util.parseVorbisPositionField
 import org.oxycblt.auxio.util.nonZeroOrNull
 
 // Song
-fun TextTags.musicBrainzId() =
+fun ExoPlayerTags.musicBrainzId() =
     (vorbis["musicbrainz_releasetrackid"]
             ?: vorbis["musicbrainz release track id"]
             ?: id3v2["TXXX:musicbrainz release track id"]
             ?: id3v2["TXXX:musicbrainz_releasetrackid"])
         ?.first()
 
-fun TextTags.name() = (vorbis["title"] ?: id3v2["TIT2"])?.first()
+fun ExoPlayerTags.name() = (vorbis["title"] ?: id3v2["TIT2"])?.first()
 
-fun TextTags.sortName() = (vorbis["titlesort"] ?: id3v2["TSOT"])?.first()
+fun ExoPlayerTags.sortName() = (vorbis["titlesort"] ?: id3v2["TSOT"])?.first()
 
 // Track.
-fun TextTags.track() =
+fun ExoPlayerTags.track() =
     (parseVorbisPositionField(
         vorbis["tracknumber"]?.first(),
         (vorbis["totaltracks"] ?: vorbis["tracktotal"] ?: vorbis["trackc"])?.first())
         ?: id3v2["TRCK"]?.run { first().parseId3v2PositionField() })
 
 // Disc and it's subtitle name.
-fun TextTags.disc() =
+fun ExoPlayerTags.disc() =
     (parseVorbisPositionField(
         vorbis["discnumber"]?.first(),
         (vorbis["totaldiscs"] ?: vorbis["disctotal"] ?: vorbis["discc"])?.run { first() })
         ?: id3v2["TPOS"]?.run { first().parseId3v2PositionField() })
 
-fun TextTags.subtitle() = (vorbis["discsubtitle"] ?: id3v2["TSST"])?.first()
+fun ExoPlayerTags.subtitle() = (vorbis["discsubtitle"] ?: id3v2["TSST"])?.first()
 
 // Dates are somewhat complicated, as not only did their semantics change from a flat year
 // value in ID3v2.3 to a full ISO-8601 date in ID3v2.4, but there are also a variety of
@@ -64,7 +64,7 @@ fun TextTags.subtitle() = (vorbis["discsubtitle"] ?: id3v2["TSST"])?.first()
 // TODO: Show original and normal dates side-by-side
 // TODO: Handle dates that are in "January" because the actual specific release date
 //  isn't known?
-fun TextTags.date() =
+fun ExoPlayerTags.date() =
     (vorbis["originaldate"]?.run { Date.from(first()) }
         ?: vorbis["date"]?.run { Date.from(first()) }
         ?: vorbis["year"]?.run { Date.from(first()) }
@@ -82,18 +82,18 @@ fun TextTags.date() =
         ?: parseId3v23Date())
 
 // Album
-fun TextTags.albumMusicBrainzId() =
+fun ExoPlayerTags.albumMusicBrainzId() =
     (vorbis["musicbrainz_albumid"]
             ?: vorbis["musicbrainz album id"]
             ?: id3v2["TXXX:musicbrainz album id"]
             ?: id3v2["TXXX:musicbrainz_albumid"])
         ?.first()
 
-fun TextTags.albumName() = (vorbis["album"] ?: id3v2["TALB"])?.first()
+fun ExoPlayerTags.albumName() = (vorbis["album"] ?: id3v2["TALB"])?.first()
 
-fun TextTags.albumSortName() = (vorbis["albumsort"] ?: id3v2["TSOA"])?.first()
+fun ExoPlayerTags.albumSortName() = (vorbis["albumsort"] ?: id3v2["TSOA"])?.first()
 
-fun TextTags.releaseTypes() =
+fun ExoPlayerTags.releaseTypes() =
     (vorbis["releasetype"]
         ?: vorbis["musicbrainz album type"]
         ?: id3v2["TXXX:musicbrainz album type"]
@@ -103,20 +103,20 @@ fun TextTags.releaseTypes() =
         id3v2["GRP1"])
 
 // Artist
-fun TextTags.artistMusicBrainzIds() =
+fun ExoPlayerTags.artistMusicBrainzIds() =
     (vorbis["musicbrainz_artistid"]
         ?: vorbis["musicbrainz artist id"]
         ?: id3v2["TXXX:musicbrainz artist id"]
         ?: id3v2["TXXX:musicbrainz_artistid"])
 
-fun TextTags.artistNames() =
+fun ExoPlayerTags.artistNames() =
     (vorbis["artists"]
         ?: vorbis["artist"]
         ?: id3v2["TXXX:artists"]
         ?: id3v2["TPE1"]
         ?: id3v2["TXXX:artist"])
 
-fun TextTags.artistSortNames() =
+fun ExoPlayerTags.artistSortNames() =
     (vorbis["artistssort"]
         ?: vorbis["artists_sort"]
         ?: vorbis["artists sort"]
@@ -129,13 +129,13 @@ fun TextTags.artistSortNames() =
         ?: id3v2["artistsort"]
         ?: id3v2["TXXX:artist sort"])
 
-fun TextTags.albumArtistMusicBrainzIds() =
+fun ExoPlayerTags.albumArtistMusicBrainzIds() =
     (vorbis["musicbrainz_albumartistid"]
         ?: vorbis["musicbrainz album artist id"]
         ?: id3v2["TXXX:musicbrainz album artist id"]
         ?: id3v2["TXXX:musicbrainz_albumartistid"])
 
-fun TextTags.albumArtistNames() =
+fun ExoPlayerTags.albumArtistNames() =
     (vorbis["albumartists"]
         ?: vorbis["album_artists"]
         ?: vorbis["album artists"]
@@ -148,7 +148,7 @@ fun TextTags.albumArtistNames() =
         ?: id3v2["TXXX:albumartist"]
         ?: id3v2["TXXX:album artist"])
 
-fun TextTags.albumArtistSortNames() =
+fun ExoPlayerTags.albumArtistSortNames() =
     (vorbis["albumartistssort"]
         ?: vorbis["albumartists_sort"]
         ?: vorbis["albumartists sort"]
@@ -163,10 +163,10 @@ fun TextTags.albumArtistSortNames() =
         ?: id3v2["TXXX:album artist sort"])
 
 // Genre
-fun TextTags.genreNames() = vorbis["genre"] ?: id3v2["TCON"]
+fun ExoPlayerTags.genreNames() = vorbis["genre"] ?: id3v2["TCON"]
 
 // Compilation Flag
-fun TextTags.isCompilation() =
+fun ExoPlayerTags.isCompilation() =
     (vorbis["compilation"]
             ?: vorbis["itunescompilation"]
             ?: id3v2["TCMP"] // This is a non-standard itunes extension
@@ -178,17 +178,17 @@ fun TextTags.isCompilation() =
         }
 
 // ReplayGain information
-fun TextTags.replayGainTrackAdjustment() =
+fun ExoPlayerTags.replayGainTrackAdjustment() =
     (vorbis["r128_track_gain"]?.parseR128Adjustment()
         ?: vorbis["replaygain_track_gain"]?.parseReplayGainAdjustment()
         ?: id3v2["TXXX:replaygain_track_gain"]?.parseReplayGainAdjustment())
 
-fun TextTags.replayGainAlbumAdjustment() =
+fun ExoPlayerTags.replayGainAlbumAdjustment() =
     (vorbis["r128_album_gain"]?.parseR128Adjustment()
         ?: vorbis["replaygain_album_gain"]?.parseReplayGainAdjustment()
         ?: id3v2["TXXX:replaygain_album_gain"]?.parseReplayGainAdjustment())
 
-private fun TextTags.parseId3v23Date(): Date? {
+private fun ExoPlayerTags.parseId3v23Date(): Date? {
     // Assume that TDAT/TIME can refer to TYER or TORY depending on if TORY
     // is present.
     val year =

app/src/main/java/org/oxycblt/auxio/musikr/tag/parse/ExoPlayerTags.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2023 Auxio Project
- * TextTags.kt is part of Auxio.
+ * ExoPlayerTags.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -30,7 +30,7 @@ import org.oxycblt.auxio.musikr.tag.util.correctWhitespace
  * @param metadata The [Metadata] to wrap.
  * @author Alexander Capehart (OxygenCobalt)
  */
-class TextTags(metadata: Metadata) {
+class ExoPlayerTags(metadata: Metadata) {
     private val _id3v2 = mutableMapOf<String, MutableList<String>>()
     /** The ID3v2 text identification frames found in the file. Can have more than one value. */
     val id3v2: Map<String, List<String>>

app/src/main/java/org/oxycblt/auxio/musikr/tag/parse/MediaMetadataTagFields.kt

@@ -1,6 +1,6 @@
 /*
- * Copyright (c) 2023 Auxio Project
+ * Copyright (c) 2024 Auxio Project
- * DeviceFile.kt is part of Auxio.
+ * MediaMetadataTagFields.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,15 +16,9 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.musikr.fs
+package org.oxycblt.auxio.musikr.tag.parse
 
-import android.net.Uri
+import android.media.MediaMetadataRetriever
-
-data class DeviceFile(
-    val uri: Uri,
-    val mimeType: String,
-    val path: Path,
-    val size: Long,
-    val lastModified: Long
-)
 
+fun MediaMetadataRetriever.durationMs() =
+    extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION)?.toLong()

app/src/main/java/org/oxycblt/auxio/musikr/tag/parse/ParseModule.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2024 Auxio Project
- * ExploreModule.kt is part of Auxio.
+ * ParseModule.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,7 +16,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
  
-package org.oxycblt.auxio.musikr.explore
+package org.oxycblt.auxio.musikr.tag.parse
 
 import dagger.Binds
 import dagger.Module
@@ -25,6 +25,6 @@ import dagger.hilt.components.SingletonComponent
 
 @Module
 @InstallIn(SingletonComponent::class)
-interface ExploreModule {
+interface ParseModule {
-    @Binds fun explorer(impl: ExplorerImpl): Explorer
+    @Binds fun tagParser(factory: TagParserImpl): TagParser
 }

app/src/main/java/org/oxycblt/auxio/musikr/tag/parse/ParsedTags.kt

@@ -1,8 +1,45 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * ParsedTags.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.tag.parse
 
-import org.oxycblt.auxio.musikr.fs.DeviceFile
+import org.oxycblt.auxio.musikr.tag.Date
 
 data class ParsedTags(
-    val deviceFile: DeviceFile,
+    val durationMs: Long,
-
+    val replayGainTrackAdjustment: Float? = null,
+    val replayGainAlbumAdjustment: Float? = null,
+    val musicBrainzId: String? = null,
+    val name: String,
+    val sortName: String? = null,
+    val track: Int? = null,
+    val disc: Int? = null,
+    val subtitle: String? = null,
+    val date: Date? = null,
+    val albumMusicBrainzId: String? = null,
+    val albumName: String? = null,
+    val albumSortName: String? = null,
+    val releaseTypes: List<String> = listOf(),
+    val artistMusicBrainzIds: List<String> = listOf(),
+    val artistNames: List<String> = listOf(),
+    val artistSortNames: List<String> = listOf(),
+    val albumArtistMusicBrainzIds: List<String> = listOf(),
+    val albumArtistNames: List<String> = listOf(),
+    val albumArtistSortNames: List<String> = listOf(),
+    val genreNames: List<String> = listOf()
 )

app/src/main/java/org/oxycblt/auxio/musikr/tag/parse/TagParser.kt

@@ -1,4 +1,66 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * TagParser.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.tag.parse
 
+import javax.inject.Inject
+import org.oxycblt.auxio.musikr.fs.DeviceFile
+import org.oxycblt.auxio.musikr.metadata.AudioMetadata
+
 interface TagParser {
+    fun parse(file: DeviceFile, metadata: AudioMetadata): ParsedTags
+}
+
+class MissingTagError(what: String) : Error("missing tag: $what")
+
+class TagParserImpl @Inject constructor() : TagParser {
+    override fun parse(file: DeviceFile, metadata: AudioMetadata): ParsedTags {
+        val exoPlayerMetadata =
+            metadata.exoPlayerFormat?.metadata
+                ?: return ParsedTags(
+                    durationMs =
+                        metadata.mediaMetadataRetriever.durationMs()
+                            ?: throw MissingTagError("durationMs"),
+                    name = file.path.name ?: throw MissingTagError("name"),
+                )
+        val exoPlayerTags = ExoPlayerTags(exoPlayerMetadata)
+        return ParsedTags(
+            durationMs =
+                metadata.mediaMetadataRetriever.durationMs() ?: throw MissingTagError("durationMs"),
+            replayGainTrackAdjustment = exoPlayerTags.replayGainTrackAdjustment(),
+            replayGainAlbumAdjustment = exoPlayerTags.replayGainAlbumAdjustment(),
+            musicBrainzId = exoPlayerTags.musicBrainzId(),
+            name = exoPlayerTags.name() ?: file.path.name ?: throw MissingTagError("name"),
+            sortName = exoPlayerTags.sortName(),
+            track = exoPlayerTags.track(),
+            disc = exoPlayerTags.disc(),
+            subtitle = exoPlayerTags.subtitle(),
+            date = exoPlayerTags.date(),
+            albumMusicBrainzId = exoPlayerTags.albumMusicBrainzId(),
+            albumName = exoPlayerTags.albumName(),
+            albumSortName = exoPlayerTags.albumSortName(),
+            releaseTypes = exoPlayerTags.releaseTypes() ?: listOf(),
+            artistMusicBrainzIds = exoPlayerTags.artistMusicBrainzIds() ?: listOf(),
+            artistNames = exoPlayerTags.artistNames() ?: listOf(),
+            artistSortNames = exoPlayerTags.artistSortNames() ?: listOf(),
+            albumArtistMusicBrainzIds = exoPlayerTags.albumArtistMusicBrainzIds() ?: listOf(),
+            albumArtistNames = exoPlayerTags.albumArtistNames() ?: listOf(),
+            albumArtistSortNames = exoPlayerTags.albumArtistSortNames() ?: listOf(),
+            genreNames = exoPlayerTags.genreNames() ?: listOf())
+    }
 }

app/src/main/java/org/oxycblt/auxio/musikr/tag/util/Vorbis.kt

@@ -1,8 +1,25 @@
+/*
+ * Copyright (c) 2024 Auxio Project
+ * Vorbis.kt is part of Auxio.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
 package org.oxycblt.auxio.musikr.tag.util
 
 import org.oxycblt.auxio.util.positiveOrNull
 
-
 /**
  * Parse an ID3v2-style position + total [String] field. These fields consist of a number and an
  * (optional) total value delimited by a /.

app/src/main/java/org/oxycblt/auxio/playback/service/MediaSessionInterface.kt

@@ -38,9 +38,9 @@ import org.oxycblt.auxio.music.MusicParent
 import org.oxycblt.auxio.music.MusicRepository
 import org.oxycblt.auxio.music.Playlist
 import org.oxycblt.auxio.music.Song
-import org.oxycblt.auxio.musikr.tag.Name
 import org.oxycblt.auxio.music.service.MediaSessionUID
 import org.oxycblt.auxio.music.service.MusicBrowser
+import org.oxycblt.auxio.musikr.tag.Name
 import org.oxycblt.auxio.playback.state.PlaybackCommand
 import org.oxycblt.auxio.playback.state.PlaybackStateManager
 import org.oxycblt.auxio.playback.state.RepeatMode

app/src/test/java/org/oxycblt/auxio/music/metadata/TagUtilTest.kt

@@ -21,10 +21,10 @@ package org.oxycblt.auxio.music.metadata
 import org.junit.Assert.assertEquals
 import org.junit.Test
 import org.oxycblt.auxio.musikr.tag.util.correctWhitespace
+import org.oxycblt.auxio.musikr.tag.util.parseId3GenreNames
 import org.oxycblt.auxio.musikr.tag.util.parseId3v2PositionField
 import org.oxycblt.auxio.musikr.tag.util.parseVorbisPositionField
 import org.oxycblt.auxio.musikr.tag.util.splitEscaped
-import org.oxycblt.auxio.musikr.tag.util.parseId3GenreNames
 
 class TagUtilTest {
     @Test

app/src/test/java/org/oxycblt/auxio/music/metadata/TextCachedTagsTest.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2023 Auxio Project
- * TextTagsTest.kt is part of Auxio.
+ * TextCachedTagsTest.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -27,66 +27,67 @@ import androidx.media3.extractor.metadata.vorbis.VorbisComment
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertTrue
 import org.junit.Test
-import org.oxycblt.auxio.musikr.tag.parse.TextTags
+import org.oxycblt.auxio.musikr.tag.parse.ExoPlayerTags
 
 class TextCachedTagsTest {
     @Test
     fun textTags_vorbis() {
-        val textTags = TextTags(VORBIS_METADATA)
+        val exoPlayerTags = ExoPlayerTags(VORBIS_METADATA)
-        assertTrue(textTags.id3v2.isEmpty())
+        assertTrue(exoPlayerTags.id3v2.isEmpty())
-        assertEquals(listOf("Wheel"), textTags.vorbis["title"])
+        assertEquals(listOf("Wheel"), exoPlayerTags.vorbis["title"])
-        assertEquals(listOf("Paraglow"), textTags.vorbis["album"])
+        assertEquals(listOf("Paraglow"), exoPlayerTags.vorbis["album"])
-        assertEquals(listOf("Parannoul", "Asian Glow"), textTags.vorbis["artist"])
+        assertEquals(listOf("Parannoul", "Asian Glow"), exoPlayerTags.vorbis["artist"])
-        assertEquals(listOf("2022"), textTags.vorbis["date"])
+        assertEquals(listOf("2022"), exoPlayerTags.vorbis["date"])
-        assertEquals(listOf("ep"), textTags.vorbis["releasetype"])
+        assertEquals(listOf("ep"), exoPlayerTags.vorbis["releasetype"])
-        assertEquals(listOf("+2 dB"), textTags.vorbis["replaygain_track_gain"])
+        assertEquals(listOf("+2 dB"), exoPlayerTags.vorbis["replaygain_track_gain"])
-        assertEquals(null, textTags.id3v2["APIC"])
+        assertEquals(null, exoPlayerTags.id3v2["APIC"])
     }
 
     @Test
     fun textTags_id3v2() {
-        val textTags = TextTags(ID3V2_METADATA)
+        val exoPlayerTags = ExoPlayerTags(ID3V2_METADATA)
-        assertTrue(textTags.vorbis.isEmpty())
+        assertTrue(exoPlayerTags.vorbis.isEmpty())
-        assertEquals(listOf("Wheel"), textTags.id3v2["TIT2"])
+        assertEquals(listOf("Wheel"), exoPlayerTags.id3v2["TIT2"])
-        assertEquals(listOf("Paraglow"), textTags.id3v2["TALB"])
+        assertEquals(listOf("Paraglow"), exoPlayerTags.id3v2["TALB"])
-        assertEquals(listOf("Parannoul", "Asian Glow"), textTags.id3v2["TPE1"])
+        assertEquals(listOf("Parannoul", "Asian Glow"), exoPlayerTags.id3v2["TPE1"])
-        assertEquals(listOf("2022"), textTags.id3v2["TDRC"])
+        assertEquals(listOf("2022"), exoPlayerTags.id3v2["TDRC"])
-        assertEquals(listOf("ep"), textTags.id3v2["TXXX:musicbrainz album type"])
+        assertEquals(listOf("ep"), exoPlayerTags.id3v2["TXXX:musicbrainz album type"])
-        assertEquals(listOf("+2 dB"), textTags.id3v2["TXXX:replaygain_track_gain"])
+        assertEquals(listOf("+2 dB"), exoPlayerTags.id3v2["TXXX:replaygain_track_gain"])
-        assertEquals(null, textTags.id3v2["metadata_block_picture"])
+        assertEquals(null, exoPlayerTags.id3v2["metadata_block_picture"])
     }
 
     @Test
     fun textTags_mp4() {
-        val textTags = TextTags(MP4_METADATA)
+        val exoPlayerTags = ExoPlayerTags(MP4_METADATA)
-        assertTrue(textTags.vorbis.isEmpty())
+        assertTrue(exoPlayerTags.vorbis.isEmpty())
-        assertEquals(listOf("Wheel"), textTags.id3v2["TIT2"])
+        assertEquals(listOf("Wheel"), exoPlayerTags.id3v2["TIT2"])
-        assertEquals(listOf("Paraglow"), textTags.id3v2["TALB"])
+        assertEquals(listOf("Paraglow"), exoPlayerTags.id3v2["TALB"])
-        assertEquals(listOf("Parannoul", "Asian Glow"), textTags.id3v2["TPE1"])
+        assertEquals(listOf("Parannoul", "Asian Glow"), exoPlayerTags.id3v2["TPE1"])
-        assertEquals(listOf("2022"), textTags.id3v2["TDRC"])
+        assertEquals(listOf("2022"), exoPlayerTags.id3v2["TDRC"])
-        assertEquals(listOf("ep"), textTags.id3v2["TXXX:musicbrainz album type"])
+        assertEquals(listOf("ep"), exoPlayerTags.id3v2["TXXX:musicbrainz album type"])
-        assertEquals(listOf("+2 dB"), textTags.id3v2["TXXX:replaygain_track_gain"])
+        assertEquals(listOf("+2 dB"), exoPlayerTags.id3v2["TXXX:replaygain_track_gain"])
-        assertEquals(null, textTags.id3v2["metadata_block_picture"])
+        assertEquals(null, exoPlayerTags.id3v2["metadata_block_picture"])
     }
 
     @Test
     fun textTags_id3v2_vorbis_combined() {
-        val textTags = TextTags(VORBIS_METADATA.copyWithAppendedEntriesFrom(ID3V2_METADATA))
+        val exoPlayerTags =
-        assertEquals(listOf("Wheel"), textTags.vorbis["title"])
+            ExoPlayerTags(VORBIS_METADATA.copyWithAppendedEntriesFrom(ID3V2_METADATA))
-        assertEquals(listOf("Paraglow"), textTags.vorbis["album"])
+        assertEquals(listOf("Wheel"), exoPlayerTags.vorbis["title"])
-        assertEquals(listOf("Parannoul", "Asian Glow"), textTags.vorbis["artist"])
+        assertEquals(listOf("Paraglow"), exoPlayerTags.vorbis["album"])
-        assertEquals(listOf("2022"), textTags.vorbis["date"])
+        assertEquals(listOf("Parannoul", "Asian Glow"), exoPlayerTags.vorbis["artist"])
-        assertEquals(listOf("ep"), textTags.vorbis["releasetype"])
+        assertEquals(listOf("2022"), exoPlayerTags.vorbis["date"])
-        assertEquals(listOf("+2 dB"), textTags.vorbis["replaygain_track_gain"])
+        assertEquals(listOf("ep"), exoPlayerTags.vorbis["releasetype"])
-        assertEquals(null, textTags.id3v2["metadata_block_picture"])
+        assertEquals(listOf("+2 dB"), exoPlayerTags.vorbis["replaygain_track_gain"])
+        assertEquals(null, exoPlayerTags.id3v2["metadata_block_picture"])
 
-        assertEquals(listOf("Wheel"), textTags.id3v2["TIT2"])
+        assertEquals(listOf("Wheel"), exoPlayerTags.id3v2["TIT2"])
-        assertEquals(listOf("Paraglow"), textTags.id3v2["TALB"])
+        assertEquals(listOf("Paraglow"), exoPlayerTags.id3v2["TALB"])
-        assertEquals(listOf("Parannoul", "Asian Glow"), textTags.id3v2["TPE1"])
+        assertEquals(listOf("Parannoul", "Asian Glow"), exoPlayerTags.id3v2["TPE1"])
-        assertEquals(listOf("2022"), textTags.id3v2["TDRC"])
+        assertEquals(listOf("2022"), exoPlayerTags.id3v2["TDRC"])
-        assertEquals(null, textTags.id3v2["APIC"])
+        assertEquals(null, exoPlayerTags.id3v2["APIC"])
-        assertEquals(listOf("ep"), textTags.id3v2["TXXX:musicbrainz album type"])
+        assertEquals(listOf("ep"), exoPlayerTags.id3v2["TXXX:musicbrainz album type"])
-        assertEquals(listOf("+2 dB"), textTags.id3v2["TXXX:replaygain_track_gain"])
+        assertEquals(listOf("+2 dB"), exoPlayerTags.id3v2["TXXX:replaygain_track_gain"])
     }
 
     companion object {