musikr: introduce null covers

Will be used once covers are made configurable.

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

@@ -40,6 +40,7 @@ import org.oxycblt.musikr.Playlist
 import org.oxycblt.musikr.Song
 import org.oxycblt.musikr.Storage
 import org.oxycblt.musikr.cache.StoredCache
+import org.oxycblt.musikr.cover.CoverIdentifier
 import org.oxycblt.musikr.cover.CoverParams
 import org.oxycblt.musikr.playlist.db.StoredPlaylists
 import org.oxycblt.musikr.tag.interpret.Naming
@@ -244,11 +245,15 @@ constructor(
 ) : MusicRepository {
     private val updateListeners = mutableListOf<MusicRepository.UpdateListener>()
     private val indexingListeners = mutableListOf<MusicRepository.IndexingListener>()
-    @Volatile private var indexingWorker: MusicRepository.IndexingWorker? = null
+    @Volatile
+    private var indexingWorker: MusicRepository.IndexingWorker? = null
 
-    @Volatile override var library: MutableLibrary? = null
+    @Volatile
-    @Volatile private var previousCompletedState: IndexingState.Completed? = null
+    override var library: MutableLibrary? = null
-    @Volatile private var currentIndexingState: IndexingState? = null
+    @Volatile
+    private var previousCompletedState: IndexingState.Completed? = null
+    @Volatile
+    private var currentIndexingState: IndexingState? = null
     override val indexingState: IndexingState?
         get() = currentIndexingState ?: previousCompletedState
 
@@ -388,7 +393,11 @@ constructor(
         val currentRevision = musicSettings.revision
         val newRevision = currentRevision?.takeIf { withCache } ?: UUID.randomUUID()
         val cache = if (withCache) storedCache.visible() else storedCache.invisible()
-        val covers = SiloedCovers.at(context, CoverSilo(newRevision, CoverParams.of(750, 80)))
+        val covers = SiloedCovers.from(
+            context,
+            CoverSilo(newRevision, CoverParams.of(750, 80)),
+            CoverIdentifier.md5()
+        )
         val storage = Storage(cache, covers, storedPlaylists)
         val interpretation = Interpretation(nameFactory, separators)
 

app/src/main/java/org/oxycblt/auxio/music/covers/CoverUtil.kt

@@ -0,0 +1,9 @@
+package org.oxycblt.auxio.music.covers
+
+import android.content.Context
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+suspend fun Context.coversDir() = withContext(Dispatchers.IO) {
+    filesDir.resolve("covers").apply { mkdirs() }
+}

app/src/main/java/org/oxycblt/auxio/music/covers/NullCovers.kt

@@ -0,0 +1,24 @@
+package org.oxycblt.auxio.music.covers
+
+import android.content.Context
+import org.oxycblt.musikr.cover.Cover
+import org.oxycblt.musikr.cover.CoverIdentifier
+import org.oxycblt.musikr.cover.Covers
+import org.oxycblt.musikr.cover.MutableCovers
+import org.oxycblt.musikr.cover.ObtainResult
+import java.io.InputStream
+
+class NullCovers(private val context: Context, private val identifier: CoverIdentifier) : MutableCovers {
+    override suspend fun obtain(id: String) = ObtainResult.Hit(NullCover(id))
+
+    override suspend fun write(data: ByteArray): Cover =
+        NullCover(identifier.identify(data))
+
+    override suspend fun cleanup(excluding: Collection<Cover>) {
+        context.coversDir().listFiles()?.forEach { it.deleteRecursively() }
+    }
+}
+
+private class NullCover(override val id: String) : Cover {
+    override suspend fun open() = null
+}

app/src/main/java/org/oxycblt/auxio/music/covers/SiloedCovers.kt

@@ -25,6 +25,7 @@ import kotlinx.coroutines.withContext
 import org.oxycblt.musikr.cover.Cover
 import org.oxycblt.musikr.cover.CoverFiles
 import org.oxycblt.musikr.cover.CoverFormat
+import org.oxycblt.musikr.cover.CoverIdentifier
 import org.oxycblt.musikr.cover.Covers
 import org.oxycblt.musikr.cover.MutableCovers
 import org.oxycblt.musikr.cover.ObtainResult
@@ -56,16 +57,16 @@ class SiloedCovers(
     }
 
     companion object {
-        suspend fun at(context: Context, silo: CoverSilo): SiloedCovers {
+        suspend fun from(context: Context, silo: CoverSilo, identifier: CoverIdentifier): SiloedCovers {
             val rootDir: File
             val revisionDir: File
             withContext(Dispatchers.IO) {
-                rootDir = context.filesDir.resolve("covers").apply { mkdirs() }
+                rootDir = context.coversDir()
                 revisionDir = rootDir.resolve(silo.toString()).apply { mkdirs() }
             }
             val files = CoverFiles.at(revisionDir)
             val format = CoverFormat.jpeg(silo.params)
-            return SiloedCovers(rootDir, silo, Covers.from(files, format))
+            return SiloedCovers(rootDir, silo, Covers.from(files, format, identifier))
         }
     }
 }