diff --git a/app/src/main/java/org/koitharu/kotatsu/local/data/MangaIndex.kt b/app/src/main/java/org/koitharu/kotatsu/local/data/MangaIndex.kt
index abcac17fe..9ace45a82 100644
--- a/app/src/main/java/org/koitharu/kotatsu/local/data/MangaIndex.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/local/data/MangaIndex.kt
@@ -132,6 +132,20 @@ class MangaIndex(source: String?) {
 		json.put("chapters", newJo)
 	}
 
+	fun clear() {
+		val keys = json.keys()
+		while (keys.hasNext()) {
+			json.remove(keys.next())
+		}
+	}
+
+	fun setFrom(other: MangaIndex) {
+		clear()
+		other.json.keys().forEach { key ->
+			json.putOpt(key, other.json.opt(key))
+		}
+	}
+
 	private fun getChapters(json: JSONObject, source: MangaSource): List<MangaChapter> {
 		val chapters = ArrayList<MangaChapter>(json.length())
 		for (k in json.keys()) {
diff --git a/app/src/main/java/org/koitharu/kotatsu/local/data/input/LocalMangaInput.kt b/app/src/main/java/org/koitharu/kotatsu/local/data/input/LocalMangaInput.kt
index 7fc903a13..64f076741 100644
--- a/app/src/main/java/org/koitharu/kotatsu/local/data/input/LocalMangaInput.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/local/data/input/LocalMangaInput.kt
@@ -9,7 +9,7 @@ import org.koitharu.kotatsu.parsers.model.MangaPage
 import org.koitharu.kotatsu.parsers.model.MangaSource
 import java.io.File
 
-abstract class LocalMangaInput(
+sealed class LocalMangaInput(
 	protected val root: File,
 ) {
 
diff --git a/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaDirOutput.kt b/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaDirOutput.kt
index 29343fe3b..a96b9979f 100644
--- a/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaDirOutput.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaDirOutput.kt
@@ -92,6 +92,10 @@ class LocalMangaDirOutput(
 		index.removeChapter(chapterId)
 	}
 
+	fun setIndex(newIndex: MangaIndex) {
+		index.setFrom(newIndex)
+	}
+
 	private suspend fun ZipOutput.flushAndFinish() = runInterruptible(Dispatchers.IO) {
 		finish()
 		close()
diff --git a/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaOutput.kt b/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaOutput.kt
index 55ceb940a..a486c46f0 100644
--- a/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaOutput.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaOutput.kt
@@ -6,7 +6,7 @@ import org.koitharu.kotatsu.parsers.model.MangaChapter
 import org.koitharu.kotatsu.parsers.util.toFileNameSafe
 import java.io.File
 
-abstract class LocalMangaOutput(
+sealed class LocalMangaOutput(
 	val rootFile: File,
 ) : Closeable {
 
diff --git a/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaUtil.kt b/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaUtil.kt
new file mode 100644
index 000000000..ae6f8a834
--- /dev/null
+++ b/app/src/main/java/org/koitharu/kotatsu/local/data/output/LocalMangaUtil.kt
@@ -0,0 +1,58 @@
+package org.koitharu.kotatsu.local.data.output
+
+import androidx.core.net.toFile
+import androidx.core.net.toUri
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.runInterruptible
+import org.koitharu.kotatsu.local.data.MangaIndex
+import org.koitharu.kotatsu.parsers.model.Manga
+import org.koitharu.kotatsu.parsers.model.MangaSource
+
+class LocalMangaUtil(
+	private val manga: Manga,
+) {
+
+	init {
+		require(manga.source == MangaSource.LOCAL) {
+			"Expected LOCAL source but ${manga.source} found"
+		}
+	}
+
+	suspend fun deleteChapters(ids: Set<Long>) {
+		newOutput().use { output ->
+			when (output) {
+				is LocalMangaZipOutput -> runInterruptible(Dispatchers.IO) {
+					LocalMangaZipOutput.filterChapters(output, ids)
+				}
+
+				is LocalMangaDirOutput -> {
+					for (id in ids) {
+						output.deleteChapter(id)
+					}
+					output.finish()
+				}
+			}
+		}
+	}
+
+	suspend fun writeIndex(index: MangaIndex) {
+		newOutput().use { output ->
+			when (output) {
+				is LocalMangaDirOutput -> {
+					TODO()
+				}
+
+				is LocalMangaZipOutput -> TODO()
+			}
+		}
+	}
+
+	private suspend fun newOutput(): LocalMangaOutput = runInterruptible(Dispatchers.IO) {
+		val file = manga.url.toUri().toFile()
+		if (file.isDirectory) {
+			LocalMangaDirOutput(file, manga)
+		} else {
+			LocalMangaZipOutput(file, manga)
+		}
+	}
+}
diff --git a/app/src/main/java/org/koitharu/kotatsu/local/domain/LocalMangaRepository.kt b/app/src/main/java/org/koitharu/kotatsu/local/domain/LocalMangaRepository.kt
index 3c19e9d86..c2383b572 100644
--- a/app/src/main/java/org/koitharu/kotatsu/local/domain/LocalMangaRepository.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/local/domain/LocalMangaRepository.kt
@@ -14,8 +14,7 @@ import org.koitharu.kotatsu.local.data.LocalManga
 import org.koitharu.kotatsu.local.data.LocalStorageManager
 import org.koitharu.kotatsu.local.data.TempFileFilter
 import org.koitharu.kotatsu.local.data.input.LocalMangaInput
-import org.koitharu.kotatsu.local.data.output.LocalMangaDirOutput
-import org.koitharu.kotatsu.local.data.output.LocalMangaZipOutput
+import org.koitharu.kotatsu.local.data.output.LocalMangaUtil
 import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.parsers.model.MangaChapter
 import org.koitharu.kotatsu.parsers.model.MangaPage
@@ -90,21 +89,7 @@ class LocalMangaRepository @Inject constructor(private val storageManager: Local
 	suspend fun deleteChapters(manga: Manga, ids: Set<Long>) {
 		lockManga(manga.id)
 		try {
-			val uri = Uri.parse(manga.url)
-			val file = uri.toFile()
-			if (file.isDirectory) {
-				LocalMangaDirOutput(file, manga).use { output ->
-					for (id in ids) {
-						output.deleteChapter(id)
-					}
-					output.finish()
-				}
-			} else {
-				runInterruptible(Dispatchers.IO) {
-					val cbz = LocalMangaZipOutput(file, manga)
-					LocalMangaZipOutput.filterChapters(cbz, ids)
-				}
-			}
+			LocalMangaUtil(manga).deleteChapters(ids)
 		} finally {
 			unlockManga(manga.id)
 		}