musikr: separate immutable/mutable subclasses

This makes it easier for me to centralize certain DI.

app/src/main/java/org/oxycblt/auxio/image/CoverProvider.kt

@@ -25,14 +25,10 @@ import android.database.Cursor
 import android.net.Uri
 import android.os.ParcelFileDescriptor
 import kotlinx.coroutines.runBlocking
-import org.oxycblt.auxio.image.covers.MutableSiloedCovers
 import org.oxycblt.auxio.image.covers.SiloedCoverId
-import org.oxycblt.musikr.cover.CoverIdentifier
+import org.oxycblt.auxio.image.covers.SiloedCovers
 import org.oxycblt.musikr.cover.ObtainResult
 
-// AndroidManifest.xml addition
-
-// ImageProvider.java
 class CoverProvider : ContentProvider() {
     override fun onCreate(): Boolean = true
 
@@ -42,8 +38,7 @@ class CoverProvider : ContentProvider() {
         val id = requireNotNull(uri.lastPathSegment) { "No ID in URI: $uri" }
         val coverId = requireNotNull(SiloedCoverId.parse(id)) { "Invalid ID: $id" }
         return runBlocking {
-            val siloedCovers =
-                MutableSiloedCovers.from(requireContext(), coverId.silo, CoverIdentifier.md5())
+            val siloedCovers = SiloedCovers.from(requireContext(), coverId.silo)
             when (val res = siloedCovers.obtain(coverId.id)) {
                 is ObtainResult.Hit -> res.cover.fd()
                 is ObtainResult.Miss -> null

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

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2024 Auxio Project
- * MutableSiloedCovers.kt is part of Auxio.
+ * SiloedCovers.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
@@ -25,31 +25,42 @@ import kotlinx.coroutines.withContext
 import org.oxycblt.musikr.cover.Cover
 import org.oxycblt.musikr.cover.CoverFormat
 import org.oxycblt.musikr.cover.CoverIdentifier
+import org.oxycblt.musikr.cover.Covers
 import org.oxycblt.musikr.cover.FileCover
 import org.oxycblt.musikr.cover.FileCovers
 import org.oxycblt.musikr.cover.MutableCovers
+import org.oxycblt.musikr.cover.MutableFileCovers
 import org.oxycblt.musikr.cover.ObtainResult
 import org.oxycblt.musikr.fs.app.AppFiles
 
-class MutableSiloedCovers
-private constructor(
-    private val rootDir: File,
-    private val silo: CoverSilo,
-    private val inner: FileCovers
-) : MutableCovers {
+open class SiloedCovers(private val silo: CoverSilo, private val fileCovers: FileCovers) : Covers {
     override suspend fun obtain(id: String): ObtainResult<SiloedCover> {
         val coverId = SiloedCoverId.parse(id) ?: return ObtainResult.Miss()
         if (coverId.silo != silo) return ObtainResult.Miss()
-        return when (val result = inner.obtain(coverId.id)) {
+        return when (val result = fileCovers.obtain(coverId.id)) {
             is ObtainResult.Hit -> ObtainResult.Hit(SiloedCover(silo, result.cover))
             is ObtainResult.Miss -> ObtainResult.Miss()
         }
     }
 
-    override suspend fun write(data: ByteArray) = SiloedCover(silo, inner.write(data))
+    companion object {
+        suspend fun from(context: Context, silo: CoverSilo): SiloedCovers {
+            val core = SiloCore.from(context, silo)
+            return SiloedCovers(silo, FileCovers(core.files, core.format))
+        }
+    }
+}
+
+class MutableSiloedCovers
+private constructor(
+    private val rootDir: File,
+    private val silo: CoverSilo,
+    private val fileCovers: MutableFileCovers
+) : SiloedCovers(silo, fileCovers), MutableCovers {
+    override suspend fun write(data: ByteArray) = SiloedCover(silo, fileCovers.write(data))
 
     override suspend fun cleanup(excluding: Collection<Cover>) {
-        inner.cleanup(excluding.filterIsInstance<SiloedCover>().map { it.innerCover })
+        fileCovers.cleanup(excluding.filterIsInstance<SiloedCover>().map { it.innerCover })
 
         // Destroy old revisions no longer being used.
         withContext(Dispatchers.IO) {
@@ -62,17 +73,11 @@ private constructor(
         suspend fun from(
             context: Context,
             silo: CoverSilo,
-            identifier: CoverIdentifier
+            coverIdentifier: CoverIdentifier
         ): MutableSiloedCovers {
-            val rootDir: File
-            val revisionDir: File
-            withContext(Dispatchers.IO) {
-                rootDir = context.coversDir()
-                revisionDir = rootDir.resolve(silo.toString()).apply { mkdirs() }
-            }
-            val files = AppFiles.at(revisionDir)
-            val format = CoverFormat.jpeg(silo.params)
-            return MutableSiloedCovers(rootDir, silo, FileCovers(files, format, identifier))
+            val core = SiloCore.from(context, silo)
+            return MutableSiloedCovers(
+                core.rootDir, silo, MutableFileCovers(core.files, core.format, coverIdentifier))
         }
     }
 }
@@ -94,3 +99,19 @@ data class SiloedCoverId(val silo: CoverSilo, val id: String) {
         }
     }
 }
+
+private data class SiloCore(val rootDir: File, val files: AppFiles, val format: CoverFormat) {
+    companion object {
+        suspend fun from(context: Context, silo: CoverSilo): SiloCore {
+            val rootDir: File
+            val revisionDir: File
+            withContext(Dispatchers.IO) {
+                rootDir = context.coversDir()
+                revisionDir = rootDir.resolve(silo.toString()).apply { mkdirs() }
+            }
+            val files = AppFiles.at(revisionDir)
+            val format = CoverFormat.jpeg(silo.params)
+            return SiloCore(rootDir, files, format)
+        }
+    }
+}

musikr/src/main/java/org/oxycblt/musikr/cover/FileCovers.kt

@@ -22,11 +22,8 @@ import android.os.ParcelFileDescriptor
 import org.oxycblt.musikr.fs.app.AppFile
 import org.oxycblt.musikr.fs.app.AppFiles
 
-class FileCovers(
-    private val appFiles: AppFiles,
-    private val coverFormat: CoverFormat,
-    private val coverIdentifier: CoverIdentifier,
-) : Covers, MutableCovers {
+open class FileCovers(private val appFiles: AppFiles, private val coverFormat: CoverFormat) :
+    Covers {
     override suspend fun obtain(id: String): ObtainResult<FileCover> {
         val file = appFiles.find(getFileName(id))
         return if (file != null) {
@@ -36,6 +33,14 @@ class FileCovers(
         }
     }
 
+    protected fun getFileName(id: String) = "$id.${coverFormat.extension}"
+}
+
+class MutableFileCovers(
+    private val appFiles: AppFiles,
+    private val coverFormat: CoverFormat,
+    private val coverIdentifier: CoverIdentifier
+) : FileCovers(appFiles, coverFormat), MutableCovers {
     override suspend fun write(data: ByteArray): FileCover {
         val id = coverIdentifier.identify(data)
         val file = appFiles.write(getFileName(id)) { coverFormat.transcodeInto(data, it) }
@@ -46,8 +51,6 @@ class FileCovers(
         val used = excluding.mapTo(mutableSetOf()) { getFileName(it.id) }
         appFiles.deleteWhere { it !in used }
     }
-
-    private fun getFileName(id: String) = "$id.${coverFormat.extension}"
 }
 
 interface FileCover : Cover {