Merge branch 'feature/direct-download' into devel

app/src/main/AndroidManifest.xml

@@ -102,6 +102,7 @@
 		<service
 			android:name="org.koitharu.kotatsu.download.ui.service.DownloadService"
 			android:foregroundServiceType="dataSync" />
+		<service android:name="org.koitharu.kotatsu.local.ui.LocalChaptersRemoveService" />
 		<service
 			android:name="org.koitharu.kotatsu.widget.shelf.ShelfWidgetService"
 			android:permission="android.permission.BIND_REMOTEVIEWS" />

app/src/main/java/org/koitharu/kotatsu/base/ui/BaseViewModel.kt

@@ -1,18 +1,18 @@
 package org.koitharu.kotatsu.base.ui
 
-import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import kotlin.coroutines.CoroutineContext
 import kotlin.coroutines.EmptyCoroutineContext
 import kotlinx.coroutines.*
 import org.koitharu.kotatsu.BuildConfig
+import org.koitharu.kotatsu.base.ui.util.CountedBooleanLiveData
 import org.koitharu.kotatsu.utils.SingleLiveEvent
 
 abstract class BaseViewModel : ViewModel() {
 
 	val onError = SingleLiveEvent<Throwable>()
-	val isLoading = MutableLiveData(false)
+	val isLoading = CountedBooleanLiveData()
 
 	protected fun launchJob(
 		context: CoroutineContext = EmptyCoroutineContext,

app/src/main/java/org/koitharu/kotatsu/base/ui/CoroutineIntentService.kt

@@ -0,0 +1,37 @@
+package org.koitharu.kotatsu.base.ui
+
+import android.app.Service
+import android.content.Intent
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+
+abstract class CoroutineIntentService : BaseService() {
+
+	private val mutex = Mutex()
+	protected open val dispatcher: CoroutineDispatcher = Dispatchers.Default
+
+	override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+		super.onStartCommand(intent, flags, startId)
+		launchCoroutine(intent, startId)
+		return Service.START_REDELIVER_INTENT
+	}
+
+	private fun launchCoroutine(intent: Intent?, startId: Int) = lifecycleScope.launch {
+		mutex.withLock {
+			try {
+				withContext(dispatcher) {
+					processIntent(intent)
+				}
+			} finally {
+				stopSelf(startId)
+			}
+		}
+	}
+
+	protected abstract suspend fun processIntent(intent: Intent?)
+}

app/src/main/java/org/koitharu/kotatsu/base/ui/util/CountedBooleanLiveData.kt

@@ -0,0 +1,20 @@
+package org.koitharu.kotatsu.base.ui.util
+
+import androidx.lifecycle.MutableLiveData
+
+class CountedBooleanLiveData : MutableLiveData<Boolean>(false) {
+
+	private var counter = 0
+
+	override fun setValue(value: Boolean) {
+		if (value) {
+			counter++
+		} else {
+			counter--
+		}
+		val newValue = counter > 0
+		if (newValue != this.value) {
+			super.setValue(newValue)
+		}
+	}
+}

app/src/main/java/org/koitharu/kotatsu/core/backup/BackupArchive.kt

@@ -1,51 +0,0 @@
-package org.koitharu.kotatsu.core.backup
-
-import android.content.Context
-import java.io.File
-import java.util.*
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.runInterruptible
-import kotlinx.coroutines.withContext
-import org.json.JSONArray
-import org.koitharu.kotatsu.R
-import org.koitharu.kotatsu.utils.MutableZipFile
-import org.koitharu.kotatsu.utils.ext.format
-
-class BackupArchive(file: File) : MutableZipFile(file) {
-
-	init {
-		if (!dir.exists()) {
-			dir.mkdirs()
-		}
-	}
-
-	suspend fun put(entry: BackupEntry) {
-		put(entry.name, entry.data.toString(2))
-	}
-
-	suspend fun getEntry(name: String): BackupEntry {
-		val json = withContext(Dispatchers.Default) {
-			JSONArray(getContent(name))
-		}
-		return BackupEntry(name, json)
-	}
-
-	companion object {
-
-		private const val DIR_BACKUPS = "backups"
-
-		suspend fun createNew(context: Context): BackupArchive = runInterruptible(Dispatchers.IO) {
-			val dir = context.run {
-				getExternalFilesDir(DIR_BACKUPS) ?: File(filesDir, DIR_BACKUPS)
-			}
-			dir.mkdirs()
-			val filename = buildString {
-				append(context.getString(R.string.app_name).lowercase(Locale.ROOT))
-				append('_')
-				append(Date().format("ddMMyyyy"))
-				append(".bak")
-			}
-			BackupArchive(File(dir, filename))
-		}
-	}
-}

app/src/main/java/org/koitharu/kotatsu/core/backup/BackupZipInput.kt

@@ -0,0 +1,25 @@
+package org.koitharu.kotatsu.core.backup
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.runInterruptible
+import okio.Closeable
+import org.json.JSONArray
+import java.io.File
+import java.util.zip.ZipFile
+
+class BackupZipInput(val file: File) : Closeable {
+
+	private val zipFile = ZipFile(file)
+
+	suspend fun getEntry(name: String): BackupEntry = runInterruptible(Dispatchers.IO) {
+		val entry = zipFile.getEntry(name)
+		val json = zipFile.getInputStream(entry).use {
+			JSONArray(it.bufferedReader().readText())
+		}
+		BackupEntry(name, json)
+	}
+
+	override fun close() {
+		zipFile.close()
+	}
+}

app/src/main/java/org/koitharu/kotatsu/core/backup/BackupZipOutput.kt

@@ -0,0 +1,45 @@
+package org.koitharu.kotatsu.core.backup
+
+import android.content.Context
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.runInterruptible
+import okio.Closeable
+import org.koitharu.kotatsu.R
+import org.koitharu.kotatsu.core.zip.ZipOutput
+import org.koitharu.kotatsu.utils.ext.format
+import java.io.File
+import java.util.*
+import java.util.zip.Deflater
+
+class BackupZipOutput(val file: File) : Closeable {
+
+	private val output = ZipOutput(file, Deflater.BEST_COMPRESSION)
+
+	suspend fun put(entry: BackupEntry) {
+		output.put(entry.name, entry.data.toString(2))
+	}
+
+	suspend fun finish() {
+		output.finish()
+	}
+
+	override fun close() {
+		output.close()
+	}
+}
+
+private const val DIR_BACKUPS = "backups"
+
+suspend fun BackupZipOutput(context: Context): BackupZipOutput = runInterruptible(Dispatchers.IO) {
+	val dir = context.run {
+		getExternalFilesDir(DIR_BACKUPS) ?: File(filesDir, DIR_BACKUPS)
+	}
+	dir.mkdirs()
+	val filename = buildString {
+		append(context.getString(R.string.app_name).replace(' ', '_').lowercase(Locale.ROOT))
+		append('_')
+		append(Date().format("ddMMyyyy"))
+		append(".bk.zip")
+	}
+	BackupZipOutput(File(dir, filename))
+}

app/src/main/java/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -151,6 +151,12 @@ class AppSettings(context: Context) {
 			}
 		}
 
+	val isDownloadsSlowdownEnabled: Boolean
+		get() = prefs.getBoolean(KEY_DOWNLOADS_SLOWDOWN, false)
+
+	val downloadsParallelism: Int
+		get() = prefs.getInt(KEY_DOWNLOADS_PARALLELISM, 2)
+
 	val isSuggestionsEnabled: Boolean
 		get() = prefs.getBoolean(KEY_SUGGESTIONS, false)
 
@@ -270,6 +276,8 @@ class AppSettings(context: Context) {
 		const val KEY_SUGGESTIONS_EXCLUDE_NSFW = "suggestions_exclude_nsfw"
 		const val KEY_SUGGESTIONS_EXCLUDE_TAGS = "suggestions_exclude_tags"
 		const val KEY_SEARCH_SINGLE_SOURCE = "search_single_source"
+		const val KEY_DOWNLOADS_PARALLELISM = "downloads_parallelism"
+		const val KEY_DOWNLOADS_SLOWDOWN = "downloads_slowdown"
 
 		// About
 		const val KEY_APP_UPDATE = "app_update"

app/src/main/java/org/koitharu/kotatsu/core/zip/ZipOutput.kt

@@ -0,0 +1,118 @@
+package org.koitharu.kotatsu.core.zip
+
+import androidx.annotation.WorkerThread
+import androidx.collection.ArraySet
+import okio.Closeable
+import java.io.File
+import java.io.FileInputStream
+import java.util.zip.Deflater
+import java.util.zip.ZipEntry
+import java.util.zip.ZipFile
+import java.util.zip.ZipOutputStream
+
+class ZipOutput(
+	val file: File,
+	compressionLevel: Int = Deflater.DEFAULT_COMPRESSION,
+) : Closeable {
+
+	private val entryNames = ArraySet<String>()
+	private var isClosed = false
+	private val output = ZipOutputStream(file.outputStream()).apply {
+		setLevel(compressionLevel)
+	}
+
+	@WorkerThread
+	fun put(name: String, file: File): Boolean {
+		return output.appendFile(file, name)
+	}
+
+	@WorkerThread
+	fun put(name: String, content: String): Boolean {
+		return output.appendText(content, name)
+	}
+
+	@WorkerThread
+	fun addDirectory(name: String): Boolean {
+		val entry = if (name.endsWith("/")) {
+			ZipEntry(name)
+		} else {
+			ZipEntry("$name/")
+		}
+		return if (entryNames.add(entry.name)) {
+			output.putNextEntry(entry)
+			output.closeEntry()
+			true
+		} else {
+			false
+		}
+	}
+
+	@WorkerThread
+	fun copyEntryFrom(other: ZipFile, entry: ZipEntry): Boolean {
+		return if (entryNames.add(entry.name)) {
+			val zipEntry = ZipEntry(entry.name)
+			output.putNextEntry(zipEntry)
+			other.getInputStream(entry).use { input ->
+				input.copyTo(output)
+			}
+			output.closeEntry()
+			true
+		} else {
+			false
+		}
+	}
+
+	fun finish() {
+		output.finish()
+		output.flush()
+	}
+
+	override fun close() {
+		if (!isClosed) {
+			output.close()
+			isClosed = true
+		}
+	}
+
+	@WorkerThread
+	private fun ZipOutputStream.appendFile(fileToZip: File, name: String): Boolean {
+		if (fileToZip.isDirectory) {
+			val entry = if (name.endsWith("/")) {
+				ZipEntry(name)
+			} else {
+				ZipEntry("$name/")
+			}
+			if (!entryNames.add(entry.name)) {
+				return false
+			}
+			putNextEntry(entry)
+			closeEntry()
+			fileToZip.listFiles()?.forEach { childFile ->
+				appendFile(childFile, "$name/${childFile.name}")
+			}
+		} else {
+			FileInputStream(fileToZip).use { fis ->
+				if (!entryNames.add(name)) {
+					return false
+				}
+				val zipEntry = ZipEntry(name)
+				putNextEntry(zipEntry)
+				fis.copyTo(this)
+				closeEntry()
+			}
+		}
+		return true
+	}
+
+	@WorkerThread
+	private fun ZipOutputStream.appendText(content: String, name: String): Boolean {
+		if (!entryNames.add(name)) {
+			return false
+		}
+		val zipEntry = ZipEntry(name)
+		putNextEntry(zipEntry)
+		content.byteInputStream().copyTo(this)
+		closeEntry()
+		return true
+	}
+}

app/src/main/java/org/koitharu/kotatsu/details/ui/ChaptersFragment.kt

@@ -9,9 +9,9 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.view.ActionMode
 import androidx.appcompat.widget.SearchView
 import androidx.core.graphics.Insets
-import androidx.core.view.isGone
 import androidx.core.view.isVisible
 import androidx.core.view.updatePadding
+import com.google.android.material.snackbar.Snackbar
 import org.koin.androidx.viewmodel.ext.android.sharedViewModel
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.base.ui.BaseFragment
@@ -22,6 +22,7 @@ import org.koitharu.kotatsu.details.ui.adapter.ChaptersAdapter
 import org.koitharu.kotatsu.details.ui.adapter.ChaptersSelectionDecoration
 import org.koitharu.kotatsu.details.ui.model.ChapterListItem
 import org.koitharu.kotatsu.download.ui.service.DownloadService
+import org.koitharu.kotatsu.local.ui.LocalChaptersRemoveService
 import org.koitharu.kotatsu.parsers.model.MangaSource
 import org.koitharu.kotatsu.reader.ui.ReaderActivity
 import org.koitharu.kotatsu.reader.ui.ReaderState
@@ -67,8 +68,8 @@ class ChaptersFragment :
 		viewModel.isChaptersReversed.observe(viewLifecycleOwner) {
 			activity?.invalidateOptionsMenu()
 		}
-		viewModel.hasChapters.observe(viewLifecycleOwner) {
+		viewModel.isChaptersEmpty.observe(viewLifecycleOwner) {
-			binding.textViewHolder.isGone = it
+			binding.textViewHolder.isVisible = it
 			activity?.invalidateOptionsMenu()
 		}
 	}
@@ -94,7 +95,7 @@ class ChaptersFragment :
 	override fun onPrepareOptionsMenu(menu: Menu) {
 		super.onPrepareOptionsMenu(menu)
 		menu.findItem(R.id.action_reversed).isChecked = viewModel.isChaptersReversed.value == true
-		menu.findItem(R.id.action_search).isVisible = viewModel.hasChapters.value == true
+		menu.findItem(R.id.action_search).isVisible = viewModel.isChaptersEmpty.value == false
 	}
 
 	override fun onOptionsItemSelected(item: MenuItem) = when (item.itemId) {
@@ -154,11 +155,29 @@ class ChaptersFragment :
 				DownloadService.start(
 					context ?: return false,
 					viewModel.getRemoteManga() ?: viewModel.manga.value ?: return false,
-					selectionDecoration?.checkedItemsIds
+					selectionDecoration?.checkedItemsIds?.toSet()
 				)
 				mode.finish()
 				true
 			}
+			R.id.action_delete -> {
+				val ids = selectionDecoration?.checkedItemsIds
+				val manga = viewModel.manga.value
+				when {
+					ids.isNullOrEmpty() || manga == null -> Unit
+					ids.size == manga.chapters?.size -> viewModel.deleteLocal()
+					else -> {
+						LocalChaptersRemoveService.start(requireContext(), manga, ids)
+						Snackbar.make(
+							binding.recyclerViewChapters,
+							R.string.chapters_will_removed_background,
+							Snackbar.LENGTH_LONG
+						).show()
+					}
+				}
+				mode.finish()
+				true
+			}
 			R.id.action_select_all -> {
 				val ids = chaptersAdapter?.items?.map { it.chapter.id } ?: return false
 				selectionDecoration?.checkAll(ids)
@@ -188,6 +207,9 @@ class ChaptersFragment :
 		menu.findItem(R.id.action_save).isVisible = items.none { x ->
 			x.chapter.source == MangaSource.LOCAL
 		}
+		menu.findItem(R.id.action_delete).isVisible = items.all { x ->
+			x.chapter.source == MangaSource.LOCAL
+		}
 		mode.title = items.size.toString()
 		return true
 	}

app/src/main/java/org/koitharu/kotatsu/details/ui/DetailsActivity.kt

@@ -41,13 +41,16 @@ import org.koitharu.kotatsu.details.ui.adapter.BranchesAdapter
 import org.koitharu.kotatsu.download.ui.service.DownloadService
 import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.parsers.model.MangaSource
+import org.koitharu.kotatsu.parsers.util.mapNotNullToSet
 import org.koitharu.kotatsu.reader.ui.ReaderActivity
 import org.koitharu.kotatsu.reader.ui.ReaderState
 import org.koitharu.kotatsu.search.ui.global.GlobalSearchActivity
 import org.koitharu.kotatsu.utils.ShareHelper
 import org.koitharu.kotatsu.utils.ext.getDisplayMessage
 
-class DetailsActivity : BaseActivity<ActivityDetailsBinding>(), TabLayoutMediator.TabConfigurationStrategy,
+class DetailsActivity :
+	BaseActivity<ActivityDetailsBinding>(),
+	TabLayoutMediator.TabConfigurationStrategy,
 	AdapterView.OnItemSelectedListener {
 
 	private val viewModel by viewModel<DetailsViewModel> {
@@ -171,38 +174,23 @@ class DetailsActivity : BaseActivity<ActivityDetailsBinding>(), TabLayoutMediato
 			true
 		}
 		R.id.action_delete -> {
-			viewModel.manga.value?.let { m ->
+			val title = viewModel.manga.value?.title.orEmpty()
-				MaterialAlertDialogBuilder(this)
+			MaterialAlertDialogBuilder(this)
-					.setTitle(R.string.delete_manga)
+				.setTitle(R.string.delete_manga)
-					.setMessage(getString(R.string.text_delete_local_manga, m.title))
+				.setMessage(getString(R.string.text_delete_local_manga, title))
-					.setPositiveButton(R.string.delete) { _, _ ->
+				.setPositiveButton(R.string.delete) { _, _ ->
-						viewModel.deleteLocal(m)
+					viewModel.deleteLocal()
-					}
+				}
-					.setNegativeButton(android.R.string.cancel, null)
+				.setNegativeButton(android.R.string.cancel, null)
-					.show()
+				.show()
-			}
 			true
 		}
 		R.id.action_save -> {
 			viewModel.manga.value?.let {
 				val chaptersCount = it.chapters?.size ?: 0
-				if (chaptersCount > 5) {
+				val branches = viewModel.branches.value.orEmpty()
-					MaterialAlertDialogBuilder(this)
+				if (chaptersCount > 5 || branches.size > 1) {
-						.setTitle(R.string.save_manga)
+					showSaveConfirmation(it, chaptersCount, branches)
-						.setMessage(
-							getString(
-								R.string.large_manga_save_confirm,
-								resources.getQuantityString(
-									R.plurals.chapters,
-									chaptersCount,
-									chaptersCount
-								)
-							)
-						)
-						.setNegativeButton(android.R.string.cancel, null)
-						.setPositiveButton(R.string.save) { _, _ ->
-							DownloadService.start(this, it)
-						}.show()
 				} else {
 					DownloadService.start(this, it)
 				}
@@ -262,7 +250,7 @@ class DetailsActivity : BaseActivity<ActivityDetailsBinding>(), TabLayoutMediato
 	fun showChapterMissingDialog(chapterId: Long) {
 		val remoteManga = viewModel.getRemoteManga()
 		if (remoteManga == null) {
-			binding.snackbar.show(getString( R.string.chapter_is_missing))
+			binding.snackbar.show(getString(R.string.chapter_is_missing))
 			return
 		}
 		MaterialAlertDialogBuilder(this).apply {
@@ -328,6 +316,36 @@ class DetailsActivity : BaseActivity<ActivityDetailsBinding>(), TabLayoutMediato
 		}
 	}
 
+	private fun showSaveConfirmation(manga: Manga, chaptersCount: Int, branches: List<String?>) {
+		val dialogBuilder = MaterialAlertDialogBuilder(this)
+			.setTitle(R.string.save_manga)
+			.setNegativeButton(android.R.string.cancel, null)
+		if (branches.size > 1) {
+			val items = Array(branches.size) { i -> branches[i].orEmpty() }
+			val currentBranch = viewModel.selectedBranchIndex.value ?: -1
+			val checkedIndices = BooleanArray(branches.size) { i -> i == currentBranch }
+			dialogBuilder.setMultiChoiceItems(items, checkedIndices) { _, i, checked ->
+				checkedIndices[i] = checked
+			}.setPositiveButton(R.string.save) { _, _ ->
+				val selectedBranches = branches.filterIndexedTo(HashSet()) { i, _ -> checkedIndices[i] }
+				val chaptersIds = manga.chapters?.mapNotNullToSet { c ->
+					if (c.branch in selectedBranches) c.id else null
+				}
+				DownloadService.start(this, manga, chaptersIds)
+			}
+		} else {
+			dialogBuilder.setMessage(
+				getString(
+					R.string.large_manga_save_confirm,
+					resources.getQuantityString(R.plurals.chapters, chaptersCount, chaptersCount)
+				)
+			).setPositiveButton(R.string.save) { _, _ ->
+				DownloadService.start(this, manga)
+			}
+		}
+		dialogBuilder.show()
+	}
+
 	companion object {
 
 		fun newIntent(context: Context, manga: Manga): Intent {
@@ -340,4 +358,4 @@ class DetailsActivity : BaseActivity<ActivityDetailsBinding>(), TabLayoutMediato
 				.putExtra(MangaIntent.KEY_ID, mangaId)
 		}
 	}
-}
+}

app/src/main/java/org/koitharu/kotatsu/details/ui/DetailsViewModel.kt

@@ -28,6 +28,7 @@ import org.koitharu.kotatsu.parsers.util.mapToSet
 import org.koitharu.kotatsu.parsers.util.toTitleCase
 import org.koitharu.kotatsu.tracker.domain.TrackingRepository
 import org.koitharu.kotatsu.utils.SingleLiveEvent
+import org.koitharu.kotatsu.utils.ext.asLiveDataDistinct
 import org.koitharu.kotatsu.utils.ext.iterator
 import java.io.IOException
 
@@ -88,18 +89,18 @@ class DetailsViewModel(
 
 	val branches = mangaData.map {
 		it?.chapters?.mapToSet { x -> x.branch }?.sortedBy { x -> x }.orEmpty()
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.asLiveDataDistinct(viewModelScope.coroutineContext + Dispatchers.Default)
 
 	val selectedBranchIndex = combine(
 		branches.asFlow(),
 		selectedBranch
 	) { branches, selected ->
 		branches.indexOf(selected)
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.asLiveDataDistinct(viewModelScope.coroutineContext + Dispatchers.Default)
 
-	val hasChapters = mangaData.map {
+	val isChaptersEmpty = mangaData.mapNotNull { m ->
-		!(it?.chapters.isNullOrEmpty())
+		m?.run { chapters.isNullOrEmpty() }
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.asLiveDataDistinct(viewModelScope.coroutineContext + Dispatchers.Default, false)
 
 	val chapters = combine(
 		combine(
@@ -134,8 +135,11 @@ class DetailsViewModel(
 		loadingJob = doLoad()
 	}
 
-	fun deleteLocal(manga: Manga) {
+	fun deleteLocal() {
+		val m = mangaData.value ?: return
 		launchLoadingJob(Dispatchers.Default) {
+			val manga = if (m.source == MangaSource.LOCAL) m else localMangaRepository.findSavedManga(m)
+			checkNotNull(manga) { "Cannot find saved manga for ${m.title}" }
 			val original = localMangaRepository.getRemoteManga(manga)
 			localMangaRepository.delete(manga) || throw IOException("Unable to delete file")
 			runCatching {
@@ -252,10 +256,10 @@ class DetailsViewModel(
 		val dateFormat = settings.getDateFormat()
 		for (i in sourceChapters.indices) {
 			val chapter = sourceChapters[i]
+			val localChapter = chaptersMap.remove(chapter.id)
 			if (chapter.branch != branch) {
 				continue
 			}
-			val localChapter = chaptersMap.remove(chapter.id)
 			result += localChapter?.toListItem(
 				isCurrent = i == currentIndex,
 				isUnread = i > currentIndex,
@@ -274,15 +278,19 @@ class DetailsViewModel(
 		}
 		if (chaptersMap.isNotEmpty()) { // some chapters on device but not online source
 			result.ensureCapacity(result.size + chaptersMap.size)
-			chaptersMap.values.mapTo(result) {
+			chaptersMap.values.mapNotNullTo(result) {
-				it.toListItem(
+				if (it.branch == branch) {
-					isCurrent = false,
+					it.toListItem(
-					isUnread = true,
+						isCurrent = false,
-					isNew = false,
+						isUnread = true,
-					isMissing = false,
+						isNew = false,
-					isDownloaded = false,
+						isMissing = false,
-					dateFormat = dateFormat,
+						isDownloaded = false,
-				)
+						dateFormat = dateFormat,
+					)
+				} else {
+					null
+				}
 			}
 			result.sortBy { it.chapter.number }
 		}

app/src/main/java/org/koitharu/kotatsu/details/ui/model/ChapterListItem.kt

@@ -40,11 +40,10 @@ class ChapterListItem(
 	override fun hashCode(): Int {
 		var result = chapter.hashCode()
 		result = 31 * result + flags
-		result = 31 * result + uploadDate.hashCode()
+		result = 31 * result + (uploadDate?.hashCode() ?: 0)
 		return result
 	}
 
-
 	companion object {
 
 		const val FLAG_UNREAD = 2

app/src/main/java/org/koitharu/kotatsu/download/domain/DownloadManager.kt

@@ -7,7 +7,6 @@ import android.webkit.MimeTypeMap
 import coil.ImageLoader
 import coil.request.ImageRequest
 import coil.size.Scale
-import java.io.File
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.sync.Semaphore
@@ -18,8 +17,9 @@ import org.koitharu.kotatsu.BuildConfig
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.network.CommonHeaders
 import org.koitharu.kotatsu.core.parser.MangaRepository
-import org.koitharu.kotatsu.local.data.MangaZip
+import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.local.data.PagesCache
+import org.koitharu.kotatsu.local.domain.CbzMangaOutput
 import org.koitharu.kotatsu.local.domain.LocalMangaRepository
 import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.parsers.model.MangaSource
@@ -28,11 +28,11 @@ import org.koitharu.kotatsu.utils.ext.deleteAwait
 import org.koitharu.kotatsu.utils.ext.referer
 import org.koitharu.kotatsu.utils.ext.waitForNetwork
 import org.koitharu.kotatsu.utils.progress.ProgressJob
+import java.io.File
 
 private const val MAX_DOWNLOAD_ATTEMPTS = 3
-private const val MAX_PARALLEL_DOWNLOADS = 2
 private const val DOWNLOAD_ERROR_DELAY = 500L
-private const val TEMP_PAGE_FILE = "page.tmp"
+private const val SLOWDOWN_DELAY = 200L
 
 class DownloadManager(
 	private val coroutineScope: CoroutineScope,
@@ -41,9 +41,10 @@ class DownloadManager(
 	private val okHttp: OkHttpClient,
 	private val cache: PagesCache,
 	private val localMangaRepository: LocalMangaRepository,
+	private val settings: AppSettings,
 ) {
 
-	private val connectivityManager = context.applicationContext.getSystemService(
+	private val connectivityManager = context.getSystemService(
 		Context.CONNECTIVITY_SERVICE
 	) as ConnectivityManager
 	private val coverWidth = context.resources.getDimensionPixelSize(
@@ -52,7 +53,7 @@ class DownloadManager(
 	private val coverHeight = context.resources.getDimensionPixelSize(
 		androidx.core.R.dimen.compat_notification_large_icon_max_height
 	)
-	private val semaphore = Semaphore(MAX_PARALLEL_DOWNLOADS)
+	private val semaphore = Semaphore(settings.downloadsParallelism)
 
 	fun downloadManga(
 		manga: Manga,
@@ -80,7 +81,8 @@ class DownloadManager(
 		var cover: Drawable? = null
 		val destination = localMangaRepository.getOutputDir()
 		checkNotNull(destination) { context.getString(R.string.cannot_find_available_storage) }
-		var output: MangaZip? = null
+		val tempFileName = "${manga.id}_$startId.tmp"
+		var output: CbzMangaOutput? = null
 		try {
 			if (manga.source == MangaSource.LOCAL) {
 				manga = localMangaRepository.getRemoteManga(manga) ?: error("Cannot obtain remote manga instance")
@@ -98,10 +100,9 @@ class DownloadManager(
 			}.getOrNull()
 			outState.value = DownloadState.Preparing(startId, manga, cover)
 			val data = if (manga.chapters.isNullOrEmpty()) repo.getDetails(manga) else manga
-			output = MangaZip.findInDir(destination, data)
+			output = CbzMangaOutput.get(destination, data)
-			output.prepare(data)
 			val coverUrl = data.largeCoverUrl ?: data.coverUrl
-			downloadFile(coverUrl, data.publicUrl, destination).let { file ->
+			downloadFile(coverUrl, data.publicUrl, destination, tempFileName).let { file ->
 				output.addCover(file, MimeTypeMap.getFileExtensionFromUrl(coverUrl))
 			}
 			val chapters = checkNotNull(
@@ -118,22 +119,29 @@ class DownloadManager(
 			for ((chapterIndex, chapter) in chapters.withIndex()) {
 				val pages = repo.getPages(chapter)
 				for ((pageIndex, page) in pages.withIndex()) {
-					failsafe@ do {
+					var retryCounter = 0
+					failsafe@ while (true) {
 						try {
 							val url = repo.getPageUrl(page)
-							val file = cache[url] ?: downloadFile(url, page.referer, destination)
+							val file = cache[url] ?: downloadFile(url, page.referer, destination, tempFileName)
 							output.addPage(
 								chapter = chapter,
 								file = file,
 								pageNumber = pageIndex,
 								ext = MimeTypeMap.getFileExtensionFromUrl(url),
 							)
+							break@failsafe
 						} catch (e: IOException) {
-							outState.value = DownloadState.WaitingForNetwork(startId, data, cover)
+							if (retryCounter < MAX_DOWNLOAD_ATTEMPTS) {
-							connectivityManager.waitForNetwork()
+								outState.value = DownloadState.WaitingForNetwork(startId, data, cover)
-							continue@failsafe
+								delay(DOWNLOAD_ERROR_DELAY)
+								connectivityManager.waitForNetwork()
+								retryCounter++
+							} else {
+								throw e
+							}
 						}
-					} while (false)
+					}
 
 					outState.value = DownloadState.Progress(
 						startId, data, cover,
@@ -142,12 +150,15 @@ class DownloadManager(
 						totalPages = pages.size,
 						currentPage = pageIndex,
 					)
+
+					if (settings.isDownloadsSlowdownEnabled) {
+						delay(SLOWDOWN_DELAY)
+					}
 				}
 			}
 			outState.value = DownloadState.PostProcessing(startId, data, cover)
-			if (!output.compress()) {
+			output.mergeWithExisting()
-				throw RuntimeException("Cannot create target file")
+			output.finalize()
-			}
 			val localManga = localMangaRepository.getFromFile(output.file)
 			outState.value = DownloadState.Done(startId, data, cover, localManga)
 		} catch (e: CancellationException) {
@@ -161,14 +172,14 @@ class DownloadManager(
 		} finally {
 			withContext(NonCancellable) {
 				output?.cleanup()
-				File(destination, TEMP_PAGE_FILE).deleteAwait()
+				File(destination, tempFileName).deleteAwait()
 			}
 			coroutineContext[WakeLockNode]?.release()
 			semaphore.release()
 		}
 	}
 
-	private suspend fun downloadFile(url: String, referer: String, destination: File): File {
+	private suspend fun downloadFile(url: String, referer: String, destination: File, tempFileName: String): File {
 		val request = Request.Builder()
 			.url(url)
 			.header(CommonHeaders.REFERER, referer)
@@ -176,26 +187,14 @@ class DownloadManager(
 			.get()
 			.build()
 		val call = okHttp.newCall(request)
-		var attempts = MAX_DOWNLOAD_ATTEMPTS
+		val file = File(destination, tempFileName)
-		val file = File(destination, TEMP_PAGE_FILE)
+		val response = call.clone().await()
-		while (true) {
+		runInterruptible(Dispatchers.IO) {
-			try {
+			file.outputStream().use { out ->
-				val response = call.clone().await()
+				checkNotNull(response.body).byteStream().copyTo(out)
-				runInterruptible(Dispatchers.IO) {
-					file.outputStream().use { out ->
-						checkNotNull(response.body).byteStream().copyTo(out)
-					}
-				}
-				return file
-			} catch (e: IOException) {
-				attempts--
-				if (attempts <= 0) {
-					throw e
-				} else {
-					delay(DOWNLOAD_ERROR_DELAY)
-				}
 			}
 		}
+		return file
 	}
 
 	private fun errorStateHandler(outState: MutableStateFlow<DownloadState>) =
@@ -208,4 +207,24 @@ class DownloadManager(
 				error = throwable,
 			)
 		}
+
+	class Factory(
+		private val context: Context,
+		private val imageLoader: ImageLoader,
+		private val okHttp: OkHttpClient,
+		private val cache: PagesCache,
+		private val localMangaRepository: LocalMangaRepository,
+		private val settings: AppSettings,
+	) {
+
+		fun create(coroutineScope: CoroutineScope) = DownloadManager(
+			coroutineScope = coroutineScope,
+			context = context,
+			imageLoader = imageLoader,
+			okHttp = okHttp,
+			cache = cache,
+			localMangaRepository = localMangaRepository,
+			settings = settings,
+		)
+	}
 }

app/src/main/java/org/koitharu/kotatsu/download/ui/service/DownloadNotification.kt

@@ -6,6 +6,7 @@ import android.app.NotificationManager
 import android.app.PendingIntent
 import android.content.Context
 import android.os.Build
+import android.text.format.DateUtils
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
 import androidx.core.content.ContextCompat
@@ -49,7 +50,7 @@ class DownloadNotification(private val context: Context, startId: Int) {
 		builder.setSilent(true)
 	}
 
-	fun create(state: DownloadState): Notification {
+	fun create(state: DownloadState, timeLeft: Long): Notification {
 		builder.setContentTitle(state.manga.title)
 		builder.setContentText(context.getString(R.string.manga_downloading_))
 		builder.setProgress(1, 0, true)
@@ -117,7 +118,13 @@ class DownloadNotification(private val context: Context, startId: Int) {
 			}
 			is DownloadState.Progress -> {
 				builder.setProgress(state.max, state.progress, false)
-				builder.setContentText((state.percent * 100).format() + "%")
+				if (timeLeft > 0L) {
+					val eta = DateUtils.getRelativeTimeSpanString(timeLeft, 0L, DateUtils.SECOND_IN_MILLIS)
+					builder.setContentText(eta)
+				} else {
+					val percent = (state.percent * 100).format()
+					builder.setContentText(context.getString(R.string.percent_string_pattern, percent))
+				}
 				builder.setCategory(NotificationCompat.CATEGORY_PROGRESS)
 				builder.setStyle(null)
 				builder.setOngoing(true)

app/src/main/java/org/koitharu/kotatsu/download/ui/service/DownloadService.kt

@@ -11,10 +11,7 @@ import android.widget.Toast
 import androidx.core.content.ContextCompat
 import androidx.lifecycle.lifecycleScope
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
-import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.*
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.mapLatest
-import kotlinx.coroutines.flow.transformWhile
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.plus
 import org.koin.android.ext.android.get
@@ -32,6 +29,7 @@ import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.utils.ext.connectivityManager
 import org.koitharu.kotatsu.utils.ext.throttle
 import org.koitharu.kotatsu.utils.progress.ProgressJob
+import org.koitharu.kotatsu.utils.progress.TimeLeftEstimator
 import java.util.concurrent.TimeUnit
 
 class DownloadService : BaseService() {
@@ -46,16 +44,12 @@ class DownloadService : BaseService() {
 
 	override fun onCreate() {
 		super.onCreate()
+		isRunning = true
 		notificationSwitcher = ForegroundNotificationSwitcher(this)
 		val wakeLock = (getSystemService(Context.POWER_SERVICE) as PowerManager)
 			.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "kotatsu:downloading")
-		downloadManager = DownloadManager(
+		downloadManager = get<DownloadManager.Factory>().create(
 			coroutineScope = lifecycleScope + WakeLockNode(wakeLock, TimeUnit.HOURS.toMillis(1)),
-			context = this,
-			imageLoader = get(),
-			okHttp = get(),
-			cache = get(),
-			localMangaRepository = get(),
 		)
 		DownloadNotification.createChannel(this)
 		registerReceiver(controlReceiver, IntentFilter(ACTION_DOWNLOAD_CANCEL))
@@ -88,6 +82,7 @@ class DownloadService : BaseService() {
 	override fun onDestroy() {
 		unregisterReceiver(controlReceiver)
 		binder = null
+		isRunning = false
 		super.onDestroy()
 	}
 
@@ -104,13 +99,22 @@ class DownloadService : BaseService() {
 	private fun listenJob(job: ProgressJob<DownloadState>) {
 		lifecycleScope.launch {
 			val startId = job.progressValue.startId
+			val timeLeftEstimator = TimeLeftEstimator()
 			val notification = DownloadNotification(this@DownloadService, startId)
-			notificationSwitcher.notify(startId, notification.create(job.progressValue))
+			notificationSwitcher.notify(startId, notification.create(job.progressValue, -1L))
 			job.progressAsFlow()
+				.onEach { state ->
+					if (state is DownloadState.Progress) {
+						timeLeftEstimator.tick(value = state.progress, total = state.max)
+					} else {
+						timeLeftEstimator.emptyTick()
+					}
+				}
 				.throttle { state -> if (state is DownloadState.Progress) 400L else 0L }
 				.whileActive()
 				.collect { state ->
-					notificationSwitcher.notify(startId, notification.create(state))
+					val timeLeft = timeLeftEstimator.getEstimatedTimeLeft()
+					notificationSwitcher.notify(startId, notification.create(state, timeLeft))
 				}
 			job.join()
 			(job.progressValue as? DownloadState.Done)?.let {
@@ -124,7 +128,7 @@ class DownloadService : BaseService() {
 				if (job.isCancelled) {
 					null
 				} else {
-					notification.create(job.progressValue)
+					notification.create(job.progressValue, -1L)
 				}
 			)
 			stopSelf(startId)
@@ -160,11 +164,12 @@ class DownloadService : BaseService() {
 
 	companion object {
 
-		const val ACTION_DOWNLOAD_COMPLETE =
+		var isRunning: Boolean = false
-			"${BuildConfig.APPLICATION_ID}.action.ACTION_DOWNLOAD_COMPLETE"
+			private set
 
-		private const val ACTION_DOWNLOAD_CANCEL =
+		const val ACTION_DOWNLOAD_COMPLETE = "${BuildConfig.APPLICATION_ID}.action.ACTION_DOWNLOAD_COMPLETE"
-			"${BuildConfig.APPLICATION_ID}.action.ACTION_DOWNLOAD_CANCEL"
+
+		private const val ACTION_DOWNLOAD_CANCEL = "${BuildConfig.APPLICATION_ID}.action.ACTION_DOWNLOAD_CANCEL"
 
 		private const val EXTRA_MANGA = "manga"
 		private const val EXTRA_CHAPTERS_IDS = "chapters_ids"

app/src/main/java/org/koitharu/kotatsu/local/LocalModule.kt

@@ -3,6 +3,7 @@ package org.koitharu.kotatsu.local
 import org.koin.android.ext.koin.androidContext
 import org.koin.androidx.viewmodel.dsl.viewModel
 import org.koin.dsl.module
+import org.koitharu.kotatsu.download.domain.DownloadManager
 import org.koitharu.kotatsu.local.data.LocalStorageManager
 import org.koitharu.kotatsu.local.domain.LocalMangaRepository
 import org.koitharu.kotatsu.local.ui.LocalListViewModel
@@ -16,5 +17,7 @@ val localModule
 
 		factory { ExternalStorageHelper(androidContext()) }
 
+		factory { DownloadManager.Factory(androidContext(), get(), get(), get(), get(), get()) }
+
 		viewModel { LocalListViewModel(get(), get(), get(), get()) }
 	}

app/src/main/java/org/koitharu/kotatsu/local/data/CbzFetcher.kt

@@ -9,11 +9,11 @@ import coil.fetch.FetchResult
 import coil.fetch.Fetcher
 import coil.fetch.SourceResult
 import coil.size.Size
+import java.util.zip.ZipFile
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.runInterruptible
 import okio.buffer
 import okio.source
-import java.util.zip.ZipFile
 
 class CbzFetcher : Fetcher<Uri> {
 

app/src/main/java/org/koitharu/kotatsu/local/data/CbzFilter.kt

@@ -7,6 +7,10 @@ import java.util.*
 class CbzFilter : FilenameFilter {
 
 	override fun accept(dir: File, name: String): Boolean {
+		return isFileSupported(name)
+	}
+
+	fun isFileSupported(name: String): Boolean {
 		val ext = name.substringAfterLast('.', "").lowercase(Locale.ROOT)
 		return ext == "cbz" || ext == "zip"
 	}

app/src/main/java/org/koitharu/kotatsu/local/data/MangaIndex.kt

@@ -28,14 +28,17 @@ class MangaIndex(source: String?) {
 		json.put("state", manga.state?.name)
 		json.put("source", manga.source.name)
 		json.put("cover_large", manga.largeCoverUrl)
-		json.put("tags", JSONArray().also { a ->
+		json.put(
-			for (tag in manga.tags) {
+			"tags",
-				val jo = JSONObject()
+			JSONArray().also { a ->
-				jo.put("key", tag.key)
+				for (tag in manga.tags) {
-				jo.put("title", tag.title)
+					val jo = JSONObject()
-				a.put(jo)
+					jo.put("key", tag.key)
+					jo.put("title", tag.title)
+					a.put(jo)
+				}
 			}
-		})
+		)
 		if (!append || !json.has("chapters")) {
 			json.put("chapters", JSONObject())
 		}
@@ -84,11 +87,15 @@ class MangaIndex(source: String?) {
 			jo.put("uploadDate", chapter.uploadDate)
 			jo.put("scanlator", chapter.scanlator)
 			jo.put("branch", chapter.branch)
-			jo.put("entries", "%03d\\d{3}".format(chapter.number))
+			jo.put("entries", "%08d_%03d\\d{3}".format(chapter.branch.hashCode(), chapter.number))
 			chapters.put(chapter.id.toString(), jo)
 		}
 	}
 
+	fun removeChapter(id: Long): Boolean {
+		return json.getJSONObject("chapters").remove(id.toString()) != null
+	}
+
 	fun setCoverEntry(name: String) {
 		json.put("cover_entry", name)
 	}

app/src/main/java/org/koitharu/kotatsu/local/data/MangaZip.kt

@@ -1,70 +0,0 @@
-package org.koitharu.kotatsu.local.data
-
-import androidx.annotation.CheckResult
-import androidx.annotation.WorkerThread
-import org.koitharu.kotatsu.parsers.model.Manga
-import org.koitharu.kotatsu.parsers.model.MangaChapter
-import org.koitharu.kotatsu.parsers.util.toFileNameSafe
-import org.koitharu.kotatsu.utils.ext.takeIfReadable
-import java.io.File
-
-@WorkerThread
-class MangaZip(val file: File) {
-
-	private val writableCbz = WritableCbzFile(file)
-
-	private var index = MangaIndex(null)
-
-	suspend fun prepare(manga: Manga) {
-		writableCbz.prepare(overwrite = true)
-		index = MangaIndex(writableCbz[INDEX_ENTRY].takeIfReadable()?.readText())
-		index.setMangaInfo(manga, append = true)
-	}
-
-	suspend fun cleanup() {
-		writableCbz.cleanup()
-	}
-
-	@CheckResult
-	suspend fun compress(): Boolean {
-		writableCbz[INDEX_ENTRY].writeText(index.toString())
-		return writableCbz.flush()
-	}
-
-	suspend fun addCover(file: File, ext: String) {
-		val name = buildString {
-			append(FILENAME_PATTERN.format(0, 0))
-			if (ext.isNotEmpty() && ext.length <= 4) {
-				append('.')
-				append(ext)
-			}
-		}
-		writableCbz.put(name, file)
-		index.setCoverEntry(name)
-	}
-
-	suspend fun addPage(chapter: MangaChapter, file: File, pageNumber: Int, ext: String) {
-		val name = buildString {
-			append(FILENAME_PATTERN.format(chapter.number, pageNumber))
-			if (ext.isNotEmpty() && ext.length <= 4) {
-				append('.')
-				append(ext)
-			}
-		}
-		writableCbz.put(name, file)
-		index.addChapter(chapter)
-	}
-
-	companion object {
-
-		private const val FILENAME_PATTERN = "%03d%03d"
-
-		const val INDEX_ENTRY = "index.json"
-
-		fun findInDir(root: File, manga: Manga): MangaZip {
-			val name = manga.title.toFileNameSafe() + ".cbz"
-			val file = File(root, name)
-			return MangaZip(file)
-		}
-	}
-}

app/src/main/java/org/koitharu/kotatsu/local/data/TempFileFilter.kt

@@ -0,0 +1,11 @@
+package org.koitharu.kotatsu.local.data
+
+import java.io.File
+import java.io.FilenameFilter
+
+class TempFileFilter : FilenameFilter {
+
+	override fun accept(dir: File, name: String): Boolean {
+		return name.endsWith(".tmp", ignoreCase = true)
+	}
+}

app/src/main/java/org/koitharu/kotatsu/local/data/WritableCbzFile.kt

@@ -1,99 +0,0 @@
-package org.koitharu.kotatsu.local.data
-
-import androidx.annotation.CheckResult
-import kotlinx.coroutines.*
-import org.koitharu.kotatsu.utils.ext.deleteAwait
-import java.io.File
-import java.io.FileInputStream
-import java.io.FileOutputStream
-import java.util.zip.ZipEntry
-import java.util.zip.ZipInputStream
-import java.util.zip.ZipOutputStream
-
-class WritableCbzFile(private val file: File) {
-
-	private val dir = File(file.parentFile, file.nameWithoutExtension)
-
-	suspend fun prepare(overwrite: Boolean) = withContext(Dispatchers.IO) {
-		if (!dir.list().isNullOrEmpty()) {
-			if (overwrite) {
-				dir.deleteRecursively()
-			} else {
-				throw IllegalStateException("Dir ${dir.name} is not empty")
-			}
-		}
-		if (!dir.exists()) {
-			dir.mkdir()
-		}
-		if (!file.exists()) {
-			return@withContext
-		}
-		ZipInputStream(FileInputStream(file)).use { zip ->
-			var entry = zip.nextEntry
-			while (entry != null && currentCoroutineContext().isActive) {
-				val target = File(dir.path + File.separator + entry.name)
-				runInterruptible {
-					target.parentFile?.mkdirs()
-					target.outputStream().use { out ->
-						zip.copyTo(out)
-					}
-				}
-				zip.closeEntry()
-				entry = zip.nextEntry
-			}
-		}
-	}
-
-	suspend fun cleanup() = withContext(Dispatchers.IO) {
-		dir.deleteRecursively()
-	}
-
-	@CheckResult
-	suspend fun flush() = withContext(Dispatchers.IO) {
-		val tempFile = File(file.path + ".tmp")
-		if (tempFile.exists()) {
-			tempFile.deleteAwait()
-		}
-		try {
-			runInterruptible {
-				ZipOutputStream(FileOutputStream(tempFile)).use { zip ->
-					dir.listFiles()?.forEach {
-						zipFile(it, it.name, zip)
-					}
-					zip.flush()
-				}
-			}
-			tempFile.renameTo(file)
-		} finally {
-			if (tempFile.exists()) {
-				tempFile.deleteAwait()
-			}
-		}
-	}
-
-	operator fun get(name: String) = File(dir, name)
-
-	suspend fun put(name: String, file: File) = runInterruptible(Dispatchers.IO) {
-		file.copyTo(this[name], overwrite = true)
-	}
-
-	private fun zipFile(fileToZip: File, fileName: String, zipOut: ZipOutputStream) {
-		if (fileToZip.isDirectory) {
-			if (fileName.endsWith("/")) {
-				zipOut.putNextEntry(ZipEntry(fileName))
-			} else {
-				zipOut.putNextEntry(ZipEntry("$fileName/"))
-			}
-			zipOut.closeEntry()
-			fileToZip.listFiles()?.forEach { childFile ->
-				zipFile(childFile, "$fileName/${childFile.name}", zipOut)
-			}
-		} else {
-			FileInputStream(fileToZip).use { fis ->
-				val zipEntry = ZipEntry(fileName)
-				zipOut.putNextEntry(zipEntry)
-				fis.copyTo(zipOut)
-			}
-		}
-	}
-}

app/src/main/java/org/koitharu/kotatsu/local/domain/CbzMangaOutput.kt

@@ -0,0 +1,153 @@
+package org.koitharu.kotatsu.local.domain
+
+import androidx.annotation.WorkerThread
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.runInterruptible
+import okio.Closeable
+import org.koitharu.kotatsu.core.zip.ZipOutput
+import org.koitharu.kotatsu.local.data.MangaIndex
+import org.koitharu.kotatsu.parsers.model.Manga
+import org.koitharu.kotatsu.parsers.model.MangaChapter
+import org.koitharu.kotatsu.parsers.util.toFileNameSafe
+import org.koitharu.kotatsu.utils.ext.deleteAwait
+import org.koitharu.kotatsu.utils.ext.readText
+import java.io.File
+import java.util.zip.ZipFile
+
+class CbzMangaOutput(
+	val file: File,
+	manga: Manga,
+) : Closeable {
+
+	private val output = ZipOutput(File(file.path + ".tmp"))
+	private val index = MangaIndex(null)
+
+	init {
+		index.setMangaInfo(manga, false)
+	}
+
+	suspend fun mergeWithExisting() {
+		if (file.exists()) {
+			runInterruptible(Dispatchers.IO) {
+				mergeWith(file)
+			}
+		}
+	}
+
+	suspend fun addCover(file: File, ext: String) {
+		val name = buildString {
+			append(FILENAME_PATTERN.format(0, 0, 0))
+			if (ext.isNotEmpty() && ext.length <= 4) {
+				append('.')
+				append(ext)
+			}
+		}
+		runInterruptible(Dispatchers.IO) {
+			output.put(name, file)
+		}
+		index.setCoverEntry(name)
+	}
+
+	suspend fun addPage(chapter: MangaChapter, file: File, pageNumber: Int, ext: String) {
+		val name = buildString {
+			append(FILENAME_PATTERN.format(chapter.branch.hashCode(), chapter.number, pageNumber))
+			if (ext.isNotEmpty() && ext.length <= 4) {
+				append('.')
+				append(ext)
+			}
+		}
+		runInterruptible(Dispatchers.IO) {
+			output.put(name, file)
+		}
+		index.addChapter(chapter)
+	}
+
+	suspend fun finalize() {
+		runInterruptible(Dispatchers.IO) {
+			output.put(ENTRY_NAME_INDEX, index.toString())
+			output.finish()
+			output.close()
+		}
+		file.deleteAwait()
+		output.file.renameTo(file)
+	}
+
+	suspend fun cleanup() {
+		output.file.deleteAwait()
+	}
+
+	override fun close() {
+		output.close()
+	}
+
+	@WorkerThread
+	private fun mergeWith(other: File) {
+		var otherIndex: MangaIndex? = null
+		ZipFile(other).use { zip ->
+			for (entry in zip.entries()) {
+				if (entry.name == ENTRY_NAME_INDEX) {
+					otherIndex = MangaIndex(
+						zip.getInputStream(entry).use {
+							it.reader().readText()
+						}
+					)
+				} else {
+					output.copyEntryFrom(zip, entry)
+				}
+			}
+		}
+		otherIndex?.getMangaInfo()?.chapters?.let { chapters ->
+			for (chapter in chapters) {
+				index.addChapter(chapter)
+			}
+		}
+	}
+
+	companion object {
+
+		private const val FILENAME_PATTERN = "%08d_%03d%03d"
+
+		const val ENTRY_NAME_INDEX = "index.json"
+
+		fun get(root: File, manga: Manga): CbzMangaOutput {
+			val name = manga.title.toFileNameSafe() + ".cbz"
+			val file = File(root, name)
+			return CbzMangaOutput(file, manga)
+		}
+
+		@WorkerThread
+		fun filterChapters(subject: CbzMangaOutput, idsToRemove: Set<Long>) {
+			ZipFile(subject.file).use { zip ->
+				val index = MangaIndex(zip.readText(zip.getEntry(ENTRY_NAME_INDEX)))
+				idsToRemove.forEach { id -> index.removeChapter(id) }
+				val patterns = requireNotNull(index.getMangaInfo()?.chapters).map {
+					index.getChapterNamesPattern(it)
+				}
+				val coverEntryName = index.getCoverEntry()
+				for (entry in zip.entries()) {
+					when {
+						entry.name == ENTRY_NAME_INDEX -> {
+							subject.output.put(ENTRY_NAME_INDEX, index.toString())
+						}
+						entry.isDirectory -> {
+							subject.output.addDirectory(entry.name)
+						}
+						entry.name == coverEntryName -> {
+							subject.output.copyEntryFrom(zip, entry)
+						}
+						else -> {
+							val name = entry.name.substringBefore('.')
+							if (patterns.any { it.matches(name) }) {
+								subject.output.copyEntryFrom(zip, entry)
+							}
+						}
+					}
+				}
+				subject.output.finish()
+				subject.output.close()
+				subject.file.delete()
+				subject.output.file.renameTo(subject.file)
+			}
+		}
+	}
+}

app/src/main/java/org/koitharu/kotatsu/local/domain/LocalMangaRepository.kt

@@ -3,18 +3,17 @@ package org.koitharu.kotatsu.local.domain
 import android.annotation.SuppressLint
 import android.net.Uri
 import android.webkit.MimeTypeMap
+import androidx.annotation.WorkerThread
 import androidx.collection.ArraySet
 import androidx.core.net.toFile
 import androidx.core.net.toUri
-import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.*
-import kotlinx.coroutines.runInterruptible
-import kotlinx.coroutines.withContext
 import org.koitharu.kotatsu.core.exceptions.UnsupportedFileException
 import org.koitharu.kotatsu.core.parser.MangaRepository
 import org.koitharu.kotatsu.local.data.CbzFilter
 import org.koitharu.kotatsu.local.data.LocalStorageManager
 import org.koitharu.kotatsu.local.data.MangaIndex
-import org.koitharu.kotatsu.local.data.MangaZip
+import org.koitharu.kotatsu.local.data.TempFileFilter
 import org.koitharu.kotatsu.parsers.model.*
 import org.koitharu.kotatsu.parsers.util.longHashCode
 import org.koitharu.kotatsu.parsers.util.toCamelCase
@@ -27,6 +26,9 @@ import java.io.IOException
 import java.util.*
 import java.util.zip.ZipEntry
 import java.util.zip.ZipFile
+import kotlin.coroutines.CoroutineContext
+
+private const val MAX_PARALLELISM = 4
 
 class LocalMangaRepository(private val storageManager: LocalStorageManager) : MangaRepository {
 
@@ -39,27 +41,43 @@ class LocalMangaRepository(private val storageManager: LocalStorageManager) : Ma
 		tags: Set<MangaTag>?,
 		sortOrder: SortOrder?
 	): List<Manga> {
-		require(offset == 0) {
+		if (offset > 0) {
-			"LocalMangaRepository does not support pagination"
+			return emptyList()
 		}
 		val files = getAllFiles()
-		return files.mapNotNull { x -> runCatching { getFromFile(x) }.getOrNull() }
+		val list = coroutineScope {
+			val dispatcher = Dispatchers.IO.limitedParallelism(MAX_PARALLELISM)
+			files.map { file ->
+				getFromFileAsync(file, dispatcher)
+			}.awaitAll()
+		}.filterNotNullTo(ArrayList(files.size))
+		if (!query.isNullOrEmpty()) {
+			list.retainAll { x ->
+				x.title.contains(query, ignoreCase = true) ||
+					x.altTitle?.contains(query, ignoreCase = true) == true
+			}
+		}
+		if (!tags.isNullOrEmpty()) {
+			list.retainAll { x ->
+				x.tags.containsAll(tags)
+			}
+		}
+		return list
 	}
 
 	override suspend fun getDetails(manga: Manga) = when {
 		manga.source != MangaSource.LOCAL -> requireNotNull(findSavedManga(manga)) {
 			"Manga is not local or saved"
 		}
-		manga.chapters == null -> getFromFile(Uri.parse(manga.url).toFile())
+		else -> getFromFile(Uri.parse(manga.url).toFile())
-		else -> manga
 	}
 
 	override suspend fun getPages(chapter: MangaChapter): List<MangaPage> {
-		return runInterruptible(Dispatchers.IO){
+		return runInterruptible(Dispatchers.IO) {
 			val uri = Uri.parse(chapter.url)
 			val file = uri.toFile()
 			val zip = ZipFile(file)
-			val index = zip.getEntry(MangaZip.INDEX_ENTRY)?.let(zip::readText)?.let(::MangaIndex)
+			val index = zip.getEntry(CbzMangaOutput.ENTRY_NAME_INDEX)?.let(zip::readText)?.let(::MangaIndex)
 			var entries = zip.entries().asSequence()
 			entries = if (index != null) {
 				val pattern = index.getChapterNamesPattern(chapter)
@@ -94,10 +112,18 @@ class LocalMangaRepository(private val storageManager: LocalStorageManager) : Ma
 		return file.deleteAwait()
 	}
 
+	suspend fun deleteChapters(manga: Manga, ids: Set<Long>) = runInterruptible(Dispatchers.IO) {
+		val uri = Uri.parse(manga.url)
+		val file = uri.toFile()
+		val cbz = CbzMangaOutput(file, manga)
+		CbzMangaOutput.filterChapters(cbz, ids)
+	}
+
+	@WorkerThread
 	@SuppressLint("DefaultLocale")
 	fun getFromFile(file: File): Manga = ZipFile(file).use { zip ->
 		val fileUri = file.toUri().toString()
-		val entry = zip.getEntry(MangaZip.INDEX_ENTRY)
+		val entry = zip.getEntry(CbzMangaOutput.ENTRY_NAME_INDEX)
 		val index = entry?.let(zip::readText)?.let(::MangaIndex)
 		val info = index?.getMangaInfo()
 		if (index != null && info != null) {
@@ -158,7 +184,7 @@ class LocalMangaRepository(private val storageManager: LocalStorageManager) : Ma
 		}.getOrNull() ?: return null
 		return runInterruptible(Dispatchers.IO) {
 			ZipFile(file).use { zip ->
-				val entry = zip.getEntry(MangaZip.INDEX_ENTRY)
+				val entry = zip.getEntry(CbzMangaOutput.ENTRY_NAME_INDEX)
 				val index = entry?.let(zip::readText)?.let(::MangaIndex)
 				index?.getMangaInfo()
 			}
@@ -170,7 +196,7 @@ class LocalMangaRepository(private val storageManager: LocalStorageManager) : Ma
 		return runInterruptible(Dispatchers.IO) {
 			for (file in files) {
 				val index = ZipFile(file).use { zip ->
-					val entry = zip.getEntry(MangaZip.INDEX_ENTRY)
+					val entry = zip.getEntry(CbzMangaOutput.ENTRY_NAME_INDEX)
 					entry?.let(zip::readText)?.let(::MangaIndex)
 				} ?: continue
 				val info = index.getMangaInfo() ?: continue
@@ -187,6 +213,15 @@ class LocalMangaRepository(private val storageManager: LocalStorageManager) : Ma
 		}
 	}
 
+	private fun CoroutineScope.getFromFileAsync(
+		file: File,
+		context: CoroutineContext,
+	): Deferred<Manga?> = async(context) {
+		runInterruptible {
+			runCatching { getFromFile(file) }.getOrNull()
+		}
+	}
+
 	private fun zipUri(file: File, entryName: String) = "cbz://${file.path}#$entryName"
 
 	private fun findFirstImageEntry(entries: Enumeration<out ZipEntry>): ZipEntry? {
@@ -211,7 +246,7 @@ class LocalMangaRepository(private val storageManager: LocalStorageManager) : Ma
 		withContext(Dispatchers.IO) {
 			val name = contentResolver.resolveName(uri)
 				?: throw IOException("Cannot fetch name from uri: $uri")
-			if (!isFileSupported(name)) {
+			if (!filenameFilter.isFileSupported(name)) {
 				throw UnsupportedFileException("Unsupported file on $uri")
 			}
 			val dest = File(
@@ -228,15 +263,21 @@ class LocalMangaRepository(private val storageManager: LocalStorageManager) : Ma
 		}
 	}
 
-	fun isFileSupported(name: String): Boolean {
-		val ext = name.substringAfterLast('.').lowercase(Locale.ROOT)
-		return ext == "cbz" || ext == "zip"
-	}
-
 	suspend fun getOutputDir(): File? {
 		return storageManager.getDefaultWriteableDir()
 	}
 
+	suspend fun cleanup() {
+		val dirs = storageManager.getWriteableDirs()
+		runInterruptible(Dispatchers.IO) {
+			dirs.flatMap { dir ->
+				dir.listFiles(TempFileFilter())?.toList().orEmpty()
+			}.forEach { file ->
+				file.delete()
+			}
+		}
+	}
+
 	private suspend fun getAllFiles() = storageManager.getReadableDirs().flatMap { dir ->
 		dir.listFiles(filenameFilter)?.toList().orEmpty()
 	}

app/src/main/java/org/koitharu/kotatsu/local/ui/LocalChaptersRemoveService.kt

@@ -0,0 +1,80 @@
+package org.koitharu.kotatsu.local.ui
+
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import androidx.core.app.NotificationCompat
+import androidx.core.app.ServiceCompat
+import androidx.core.content.ContextCompat
+import org.koin.android.ext.android.inject
+import org.koitharu.kotatsu.R
+import org.koitharu.kotatsu.base.ui.CoroutineIntentService
+import org.koitharu.kotatsu.core.model.parcelable.ParcelableManga
+import org.koitharu.kotatsu.download.ui.service.DownloadService
+import org.koitharu.kotatsu.local.domain.LocalMangaRepository
+import org.koitharu.kotatsu.parsers.model.Manga
+
+class LocalChaptersRemoveService : CoroutineIntentService() {
+
+	private val localMangaRepository by inject<LocalMangaRepository>()
+
+	override suspend fun processIntent(intent: Intent?) {
+		val manga = intent?.getParcelableExtra<ParcelableManga>(EXTRA_MANGA)?.manga ?: return
+		val chaptersIds = intent.getLongArrayExtra(EXTRA_CHAPTERS_IDS)?.toSet() ?: return
+		startForeground()
+		val mangaWithChapters = localMangaRepository.getDetails(manga)
+		localMangaRepository.deleteChapters(mangaWithChapters, chaptersIds)
+		sendBroadcast(
+			Intent(DownloadService.ACTION_DOWNLOAD_COMPLETE)
+				.putExtra(EXTRA_MANGA, ParcelableManga(manga, withChapters = false))
+		)
+		ServiceCompat.stopForeground(this, ServiceCompat.STOP_FOREGROUND_REMOVE)
+	}
+
+	private fun startForeground() {
+		val title = getString(R.string.local_manga_processing)
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+			val manager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+			val channel = NotificationChannel(CHANNEL_ID, title, NotificationManager.IMPORTANCE_LOW)
+			channel.setShowBadge(false)
+			channel.enableVibration(false)
+			channel.setSound(null, null)
+			channel.enableLights(false)
+			manager.createNotificationChannel(channel)
+		}
+
+		val notification = NotificationCompat.Builder(this, CHANNEL_ID)
+			.setContentTitle(title)
+			.setPriority(NotificationCompat.PRIORITY_MIN)
+			.setDefaults(0)
+			.setColor(ContextCompat.getColor(this, R.color.blue_primary_dark))
+			.setSilent(true)
+			.setProgress(0, 0, true)
+			.setSmallIcon(android.R.drawable.stat_notify_sync)
+			.setForegroundServiceBehavior(NotificationCompat.FOREGROUND_SERVICE_DEFERRED)
+			.setOngoing(true)
+			.build()
+		startForeground(NOTIFICATION_ID, notification)
+	}
+
+	companion object {
+
+		private const val CHANNEL_ID = "local_processing"
+		private const val NOTIFICATION_ID = 21
+
+		private const val EXTRA_MANGA = "manga"
+		private const val EXTRA_CHAPTERS_IDS = "chapters_ids"
+
+		fun start(context: Context, manga: Manga, chaptersIds: Collection<Long>) {
+			if (chaptersIds.isEmpty()) {
+				return
+			}
+			val intent = Intent(context, LocalChaptersRemoveService::class.java)
+			intent.putExtra(EXTRA_MANGA, ParcelableManga(manga, withChapters = false))
+			intent.putExtra(EXTRA_CHAPTERS_IDS, chaptersIds.toLongArray())
+			ContextCompat.startForegroundService(context, intent)
+		}
+	}
+}

app/src/main/java/org/koitharu/kotatsu/local/ui/LocalListViewModel.kt

@@ -3,16 +3,18 @@ package org.koitharu.kotatsu.local.ui
 import android.net.Uri
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.viewModelScope
-import java.io.IOException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
+import org.koitharu.kotatsu.BuildConfig
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.os.ShortcutsRepository
 import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.download.ui.service.DownloadService
 import org.koitharu.kotatsu.history.domain.HistoryRepository
 import org.koitharu.kotatsu.list.ui.MangaListViewModel
 import org.koitharu.kotatsu.list.ui.model.*
@@ -21,6 +23,7 @@ import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.utils.SingleLiveEvent
 import org.koitharu.kotatsu.utils.ext.asLiveDataDistinct
 import org.koitharu.kotatsu.utils.progress.Progress
+import java.io.IOException
 
 class LocalListViewModel(
 	private val repository: LocalMangaRepository,
@@ -64,6 +67,7 @@ class LocalListViewModel(
 
 	init {
 		onRefresh()
+		cleanup()
 	}
 
 	override fun onRefresh() {
@@ -116,4 +120,18 @@ class LocalListViewModel(
 			listError.value = e
 		}
 	}
+
+	private fun cleanup() {
+		if (!DownloadService.isRunning) {
+			viewModelScope.launch {
+				runCatching {
+					repository.cleanup()
+				}.onFailure { error ->
+					if (BuildConfig.DEBUG) {
+						error.printStackTrace()
+					}
+				}
+			}
+		}
+	}
 }

app/src/main/java/org/koitharu/kotatsu/remotelist/ui/RemoteListViewModel.kt

@@ -137,6 +137,9 @@ class RemoteListViewModel(
 					e.printStackTrace()
 				}
 				listError.value = e
+				if (!mangaList.value.isNullOrEmpty()) {
+					onError.postCall(e)
+				}
 			}
 		}
 	}

app/src/main/java/org/koitharu/kotatsu/settings/ContentSettingsFragment.kt

@@ -12,6 +12,7 @@ import org.koitharu.kotatsu.base.ui.BasePreferenceFragment
 import org.koitharu.kotatsu.base.ui.dialog.StorageSelectDialog
 import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.local.data.LocalStorageManager
+import org.koitharu.kotatsu.settings.utils.SliderPreference
 import org.koitharu.kotatsu.utils.ext.getStorageName
 import org.koitharu.kotatsu.utils.ext.viewLifecycleScope
 
@@ -28,6 +29,13 @@ class ContentSettingsFragment :
 		findPreference<Preference>(AppSettings.KEY_SUGGESTIONS)?.setSummary(
 			if (settings.isSuggestionsEnabled) R.string.enabled else R.string.disabled
 		)
+		findPreference<SliderPreference>(AppSettings.KEY_DOWNLOADS_PARALLELISM)?.run {
+			summary = value.toString()
+			setOnPreferenceChangeListener { preference, newValue ->
+				preference.summary = newValue.toString()
+				true
+			}
+		}
 		bindRemoteSourcesSummary()
 	}
 

app/src/main/java/org/koitharu/kotatsu/settings/backup/AppBackupAgent.kt

@@ -5,12 +5,8 @@ import android.app.backup.BackupDataInput
 import android.app.backup.BackupDataOutput
 import android.app.backup.FullBackupDataOutput
 import android.os.ParcelFileDescriptor
-import kotlinx.coroutines.NonCancellable
 import kotlinx.coroutines.runBlocking
-import org.koitharu.kotatsu.core.backup.BackupArchive
+import org.koitharu.kotatsu.core.backup.*
-import org.koitharu.kotatsu.core.backup.BackupEntry
-import org.koitharu.kotatsu.core.backup.BackupRepository
-import org.koitharu.kotatsu.core.backup.RestoreRepository
 import org.koitharu.kotatsu.core.db.MangaDatabase
 import java.io.*
 
@@ -46,7 +42,7 @@ class AppBackupAgent : BackupAgent() {
 		mode: Long,
 		mtime: Long
 	) {
-		if (destination?.name?.endsWith(".bak") == true) {
+		if (destination?.name?.endsWith(".bk.zip") == true) {
 			restoreBackupFile(data.fileDescriptor, size)
 			destination.delete()
 		} else {
@@ -56,14 +52,14 @@ class AppBackupAgent : BackupAgent() {
 
 	private fun createBackupFile() = runBlocking {
 		val repository = BackupRepository(MangaDatabase.create(applicationContext))
-		val backup = BackupArchive.createNew(this@AppBackupAgent)
+		BackupZipOutput(this@AppBackupAgent).use { backup ->
-		backup.put(repository.createIndex())
+			backup.put(repository.createIndex())
-		backup.put(repository.dumpHistory())
+			backup.put(repository.dumpHistory())
-		backup.put(repository.dumpCategories())
+			backup.put(repository.dumpCategories())
-		backup.put(repository.dumpFavourites())
+			backup.put(repository.dumpFavourites())
-		backup.flush()
+			backup.finish()
-		backup.cleanup()
+			backup.file
-		backup.file
+		}
 	}
 
 	private fun restoreBackupFile(fd: FileDescriptor, size: Long) {
@@ -74,18 +70,15 @@ class AppBackupAgent : BackupAgent() {
 				input.copyLimitedTo(output, size)
 			}
 		}
-		val backup = BackupArchive(tempFile)
+		val backup = BackupZipInput(tempFile)
 		try {
 			runBlocking {
-				backup.unpack()
 				repository.upsertHistory(backup.getEntry(BackupEntry.HISTORY))
 				repository.upsertCategories(backup.getEntry(BackupEntry.CATEGORIES))
 				repository.upsertFavourites(backup.getEntry(BackupEntry.FAVOURITES))
 			}
 		} finally {
-			runBlocking(NonCancellable) {
+			backup.close()
-				backup.cleanup()
-			}
 			tempFile.delete()
 		}
 	}

app/src/main/java/org/koitharu/kotatsu/settings/backup/BackupViewModel.kt

@@ -3,8 +3,8 @@ package org.koitharu.kotatsu.settings.backup
 import android.content.Context
 import androidx.lifecycle.MutableLiveData
 import org.koitharu.kotatsu.base.ui.BaseViewModel
-import org.koitharu.kotatsu.core.backup.BackupArchive
 import org.koitharu.kotatsu.core.backup.BackupRepository
+import org.koitharu.kotatsu.core.backup.BackupZipOutput
 import org.koitharu.kotatsu.utils.SingleLiveEvent
 import org.koitharu.kotatsu.utils.progress.Progress
 import java.io.File
@@ -19,23 +19,25 @@ class BackupViewModel(
 
 	init {
 		launchLoadingJob {
-			val backup = BackupArchive.createNew(context)
+			val file = BackupZipOutput(context).use { backup ->
-			backup.put(repository.createIndex())
+				backup.put(repository.createIndex())
 
-			progress.value = Progress(0, 3)
+				progress.value = Progress(0, 3)
-			backup.put(repository.dumpHistory())
+				backup.put(repository.dumpHistory())
 
-			progress.value = Progress(1, 3)
+				progress.value = Progress(1, 3)
-			backup.put(repository.dumpCategories())
+				backup.put(repository.dumpCategories())
 
-			progress.value = Progress(2, 3)
+				progress.value = Progress(2, 3)
-			backup.put(repository.dumpFavourites())
+				backup.put(repository.dumpFavourites())
 
-			progress.value = Progress(3, 3)
+				progress.value = Progress(3, 3)
-			backup.flush()
+				backup.finish()
-			progress.value = null
+				progress.value = null
-			backup.cleanup()
+				backup.close()
-			onBackupDone.call(backup.file)
+				backup.file
+			}
+			onBackupDone.call(file)
 		}
 	}
 }

app/src/main/java/org/koitharu/kotatsu/settings/backup/RestoreViewModel.kt

@@ -3,19 +3,17 @@ package org.koitharu.kotatsu.settings.backup
 import android.content.Context
 import android.net.Uri
 import androidx.lifecycle.MutableLiveData
-import java.io.File
-import java.io.FileNotFoundException
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.NonCancellable
 import kotlinx.coroutines.runInterruptible
-import kotlinx.coroutines.withContext
 import org.koitharu.kotatsu.base.ui.BaseViewModel
-import org.koitharu.kotatsu.core.backup.BackupArchive
 import org.koitharu.kotatsu.core.backup.BackupEntry
+import org.koitharu.kotatsu.core.backup.BackupZipInput
 import org.koitharu.kotatsu.core.backup.CompositeResult
 import org.koitharu.kotatsu.core.backup.RestoreRepository
 import org.koitharu.kotatsu.utils.SingleLiveEvent
 import org.koitharu.kotatsu.utils.progress.Progress
+import java.io.File
+import java.io.FileNotFoundException
 
 class RestoreViewModel(
 	uri: Uri?,
@@ -40,10 +38,9 @@ class RestoreViewModel(
 						input.copyTo(output)
 					}
 				}
-				BackupArchive(tempFile)
+				BackupZipInput(tempFile)
 			}
 			try {
-				backup.unpack()
 				val result = CompositeResult()
 
 				progress.value = Progress(0, 3)
@@ -58,10 +55,8 @@ class RestoreViewModel(
 				progress.value = Progress(3, 3)
 				onRestoreDone.call(result)
 			} finally {
-				withContext(NonCancellable) {
+				backup.close()
-					backup.cleanup()
+				backup.file.delete()
-					backup.file.delete()
-				}
 			}
 		}
 	}

app/src/main/java/org/koitharu/kotatsu/utils/MutableZipFile.kt

@@ -1,103 +0,0 @@
-package org.koitharu.kotatsu.utils
-
-import androidx.annotation.WorkerThread
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.runInterruptible
-import kotlinx.coroutines.withContext
-import java.io.File
-import java.io.FileInputStream
-import java.io.FileOutputStream
-import java.util.zip.ZipEntry
-import java.util.zip.ZipInputStream
-import java.util.zip.ZipOutputStream
-
-open class MutableZipFile(val file: File) {
-
-	protected val dir = File(file.parentFile, file.nameWithoutExtension)
-
-	suspend fun unpack(): Unit = runInterruptible(Dispatchers.IO) {
-		check(dir.list().isNullOrEmpty()) {
-			"Dir ${dir.name} is not empty"
-		}
-		if (!dir.exists()) {
-			dir.mkdir()
-		}
-		if (!file.exists()) {
-			return@runInterruptible
-		}
-		ZipInputStream(FileInputStream(file)).use { zip ->
-			var entry = zip.nextEntry
-			while (entry != null) {
-				val target = File(dir.path + File.separator + entry.name)
-				target.parentFile?.mkdirs()
-				target.outputStream().use { out ->
-					zip.copyTo(out)
-				}
-				zip.closeEntry()
-				entry = zip.nextEntry
-			}
-		}
-	}
-
-	suspend fun cleanup() = withContext(Dispatchers.IO) {
-		dir.deleteRecursively()
-	}
-
-	suspend fun flush(): Boolean = runInterruptible(Dispatchers.IO) {
-		val tempFile = File(file.path + ".tmp")
-		if (tempFile.exists()) {
-			tempFile.delete()
-		}
-		try {
-			ZipOutputStream(FileOutputStream(tempFile)).use { zip ->
-				dir.listFiles()?.forEach {
-					zipFile(it, it.name, zip)
-				}
-				zip.flush()
-			}
-			tempFile.renameTo(file)
-		} finally {
-			if (tempFile.exists()) {
-				tempFile.delete()
-			}
-		}
-	}
-
-	operator fun get(name: String) = File(dir, name)
-
-	suspend fun put(name: String, file: File): Unit = withContext(Dispatchers.IO) {
-		file.copyTo(this@MutableZipFile[name], overwrite = true)
-	}
-
-	suspend fun put(name: String, data: String): Unit = withContext(Dispatchers.IO) {
-		this@MutableZipFile[name].writeText(data)
-	}
-
-	suspend fun getContent(name: String): String = withContext(Dispatchers.IO) {
-		get(name).readText()
-	}
-
-	companion object {
-
-		@WorkerThread
-		private fun zipFile(fileToZip: File, fileName: String, zipOut: ZipOutputStream) {
-			if (fileToZip.isDirectory) {
-				if (fileName.endsWith("/")) {
-					zipOut.putNextEntry(ZipEntry(fileName))
-				} else {
-					zipOut.putNextEntry(ZipEntry("$fileName/"))
-				}
-				zipOut.closeEntry()
-				fileToZip.listFiles()?.forEach { childFile ->
-					zipFile(childFile, "$fileName/${childFile.name}", zipOut)
-				}
-			} else {
-				FileInputStream(fileToZip).use { fis ->
-					val zipEntry = ZipEntry(fileName)
-					zipOut.putNextEntry(zipEntry)
-					fis.copyTo(zipOut)
-				}
-			}
-		}
-	}
-}

app/src/main/java/org/koitharu/kotatsu/utils/PausingDispatcher.kt

@@ -0,0 +1,50 @@
+package org.koitharu.kotatsu.utils
+
+import androidx.annotation.MainThread
+import java.util.concurrent.ConcurrentLinkedQueue
+import kotlin.coroutines.CoroutineContext
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Runnable
+
+class PausingDispatcher(
+	private val dispatcher: CoroutineDispatcher,
+) : CoroutineDispatcher() {
+
+	@Volatile
+	private var isPaused = false
+	private val queue = ConcurrentLinkedQueue<Task>()
+
+	override fun isDispatchNeeded(context: CoroutineContext): Boolean {
+		return isPaused || super.isDispatchNeeded(context)
+	}
+
+	override fun dispatch(context: CoroutineContext, block: Runnable) {
+		if (isPaused) {
+			queue.add(Task(context, block))
+		} else {
+			dispatcher.dispatch(context, block)
+		}
+	}
+
+	@MainThread
+	fun pause() {
+		isPaused = true
+	}
+
+	@MainThread
+	fun resume() {
+		if (!isPaused) {
+			return
+		}
+		isPaused = false
+		while (true) {
+			val task = queue.poll() ?: break
+			dispatcher.dispatch(task.context, task.block)
+		}
+	}
+
+	private class Task(
+		val context: CoroutineContext,
+		val block: Runnable,
+	)
+}

app/src/main/java/org/koitharu/kotatsu/utils/ext/AndroidExt.kt

@@ -5,6 +5,7 @@ import android.net.ConnectivityManager
 import android.net.Network
 import android.net.NetworkRequest
 import android.net.Uri
+import android.os.Build
 import androidx.work.CoroutineWorker
 import kotlin.coroutines.resume
 import kotlinx.coroutines.suspendCancellableCoroutine
@@ -14,9 +15,14 @@ val Context.connectivityManager: ConnectivityManager
 
 suspend fun ConnectivityManager.waitForNetwork(): Network {
 	val request = NetworkRequest.Builder().build()
+	if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+		// fast path
+		activeNetwork?.let { return it }
+	}
 	return suspendCancellableCoroutine { cont ->
 		val callback = object : ConnectivityManager.NetworkCallback() {
 			override fun onAvailable(network: Network) {
+				unregisterNetworkCallback(this)
 				if (cont.isActive) {
 					cont.resume(network)
 				}

app/src/main/java/org/koitharu/kotatsu/utils/progress/Progress.kt

@@ -6,7 +6,7 @@ import kotlinx.parcelize.Parcelize
 @Parcelize
 data class Progress(
 	val value: Int,
-	val total: Int
+	val total: Int,
 ) : Parcelable, Comparable<Progress> {
 
 	override fun compareTo(other: Progress): Int {

app/src/main/java/org/koitharu/kotatsu/utils/progress/TimeLeftEstimator.kt

@@ -0,0 +1,47 @@
+package org.koitharu.kotatsu.utils.progress
+
+import android.os.SystemClock
+import kotlin.math.roundToInt
+import kotlin.math.roundToLong
+
+private const val MIN_ESTIMATE_TICKS = 4
+private const val NO_TIME = -1L
+
+class TimeLeftEstimator {
+
+	private var times = ArrayList<Int>()
+	private var lastTick: Tick? = null
+
+	fun tick(value: Int, total: Int) {
+		if (total < 0) {
+			emptyTick()
+			return
+		}
+		val tick = Tick(value, total, SystemClock.elapsedRealtime())
+		lastTick?.let {
+			val ticksCount = value - it.value
+			times.add(((tick.time - it.time) / ticksCount.toDouble()).roundToInt())
+		}
+		lastTick = tick
+	}
+
+	fun emptyTick() {
+		lastTick = null
+	}
+
+	fun getEstimatedTimeLeft(): Long {
+		val progress = lastTick ?: return NO_TIME
+		if (times.size < MIN_ESTIMATE_TICKS) {
+			return NO_TIME
+		}
+		val timePerTick = times.average()
+		val ticksLeft = progress.total - progress.value
+		return (ticksLeft * timePerTick).roundToLong()
+	}
+
+	private class Tick(
+		val value: Int,
+		val total: Int,
+		val time: Long,
+	)
+}

app/src/main/res/drawable/ic_pause.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	android:width="24dp"
+	android:height="24dp"
+	android:tint="?colorControlNormal"
+	android:viewportWidth="24"
+	android:viewportHeight="24">
+	<path
+		android:fillColor="#000"
+		android:pathData="M14,19H18V5H14M6,19H10V5H6V19Z" />
+</vector>

app/src/main/res/drawable/ic_resume.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	android:width="24dp"
+	android:height="24dp"
+	android:tint="?colorControlNormal"
+	android:viewportWidth="24"
+	android:viewportHeight="24">
+	<path
+		android:fillColor="#000"
+		android:pathData="M8,5.14V19.14L19,12.14L8,5.14Z" />
+</vector>

app/src/main/res/layout/preference_slider.xml

@@ -5,13 +5,12 @@
 	xmlns:tools="http://schemas.android.com/tools"
 	android:layout_width="match_parent"
 	android:layout_height="wrap_content"
-	android:background="?android:attr/selectableItemBackground"
 	android:baselineAligned="false"
 	android:clipChildren="false"
 	android:clipToPadding="false"
-	android:orientation="horizontal"
 	android:gravity="center_vertical"
 	android:minHeight="?android:attr/listPreferredItemHeightSmall"
+	android:orientation="horizontal"
 	android:paddingStart="?android:attr/listPreferredItemPaddingStart"
 	android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
 	tools:ignore="PrivateResource">
@@ -27,17 +26,18 @@
 		android:clipToPadding="false"
 		android:orientation="vertical">
 
-		<RelativeLayout
+		<LinearLayout
-			android:layout_width="wrap_content"
+			android:layout_width="match_parent"
-			android:layout_height="0dp"
+			android:orientation="horizontal"
-			android:layout_weight="1">
+			android:baselineAligned="true"
+			android:baselineAlignedChildIndex="0"
+			android:layout_height="wrap_content">
 
 			<TextView
 				android:id="@android:id/title"
 				android:layout_width="0dp"
+				android:layout_weight="1"
 				android:layout_height="wrap_content"
-				android:layout_alignParentStart="true"
-				android:layout_toStartOf="@android:id/summary"
 				android:ellipsize="marquee"
 				android:labelFor="@id/seekbar"
 				android:singleLine="true"
@@ -49,12 +49,11 @@
 				style="@style/PreferenceSummaryTextStyle"
 				android:layout_width="wrap_content"
 				android:layout_height="wrap_content"
-				android:layout_alignParentEnd="true"
 				android:singleLine="true"
 				android:textAlignment="viewStart"
 				android:textColor="?android:attr/textColorSecondary" />
 
-		</RelativeLayout>
+		</LinearLayout>
 
 		<com.google.android.material.slider.Slider
 			android:id="@+id/slider"

app/src/main/res/menu/mode_chapters.xml

@@ -9,6 +9,12 @@
 		android:title="@string/save"
 		app:showAsAction="ifRoom|withText" />
 
+	<item
+		android:id="@+id/action_delete"
+		android:icon="@drawable/ic_delete"
+		android:title="@string/delete"
+		app:showAsAction="ifRoom|withText" />
+
 	<item
 		android:id="@+id/action_select_all"
 		android:icon="?actionModeSelectAllDrawable"

app/src/main/res/menu/opt_downloads.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu
+	xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto">
+
+	<item
+		android:icon="@drawable/ic_pause"
+		android:id="@+id/action_pause"
+		android:title="Pause"
+		app:showAsAction="ifRoom|withText" />
+
+	<item
+		android:icon="@drawable/ic_resume"
+		android:id="@+id/action_resume"
+		android:title="Resume"
+		app:showAsAction="ifRoom|withText" />
+
+</menu>

app/src/main/res/values-ru/strings.xml

@@ -271,4 +271,9 @@
 	<string name="text_delete_local_manga_batch">Удалить выбранную мангу с накопителя?</string>
 	<string name="removal_completed">Удаление завершено</string>
 	<string name="batch_manga_save_confirm">Загрузить выбранную мангу со всеми главами? Это может привести к большому расходу трафика и места на накопителе</string>
+	<string name="parallel_downloads">Загружать параллельно</string>
+	<string name="download_slowdown">Замедление загрузки</string>
+	<string name="download_slowdown_summary">Помогает избежать блокировки IP-адреса</string>
+	<string name="local_manga_processing">Обработка сохранённой манги</string>
+	<string name="chapters_will_removed_background">Главы будут удалены в фоновом режиме. Это может занять какое-то время</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -274,4 +274,9 @@
 	<string name="text_delete_local_manga_batch">Delete selected items from device permanently?</string>
 	<string name="removal_completed">Removal completed</string>
 	<string name="batch_manga_save_confirm">Are you sure you want to download all selected manga with all its chapters? This action can consume a lot of traffic and storage</string>
+	<string name="parallel_downloads">Parallel downloads</string>
+	<string name="download_slowdown">Download slowdown</string>
+	<string name="download_slowdown_summary">Helps avoid blocking your IP address</string>
+	<string name="local_manga_processing">Saved manga processing</string>
+	<string name="chapters_will_removed_background">Chapters will be removed in the background. It can take some time</string>
 </resources>

app/src/main/res/xml/pref_content.xml

@@ -8,17 +8,32 @@
 		android:key="remote_sources"
 		android:title="@string/remote_sources" />
 
-	<Preference
-		android:key="local_storage"
-		android:persistent="false"
-		android:title="@string/manga_save_location" />
-
 	<PreferenceScreen
 		android:fragment="org.koitharu.kotatsu.settings.SuggestionsSettingsFragment"
 		android:key="suggestions"
 		android:persistent="false"
 		android:title="@string/suggestions" />
 
+	<Preference
+		android:key="local_storage"
+		android:persistent="false"
+		android:title="@string/manga_save_location"
+		app:allowDividerAbove="true" />
+
+	<SwitchPreferenceCompat
+		android:defaultValue="false"
+		android:key="downloads_slowdown"
+		android:summary="@string/download_slowdown_summary"
+		android:title="@string/download_slowdown" />
+
+	<org.koitharu.kotatsu.settings.utils.SliderPreference
+		android:key="downloads_parallelism"
+		android:stepSize="1"
+		android:title="@string/parallel_downloads"
+		android:valueFrom="1"
+		android:valueTo="5"
+		app:defaultValue="2" />
+
 	<PreferenceScreen
 		android:fragment="org.koitharu.kotatsu.settings.backup.BackupSettingsFragment"
 		android:title="@string/backup_restore"