Fix pages saving #151

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

@@ -7,7 +7,6 @@ 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
-import org.koitharu.kotatsu.utils.ExternalStorageHelper
 
 val localModule
 	get() = module {
@@ -15,8 +14,6 @@ val localModule
 		single { LocalStorageManager(androidContext(), get()) }
 		single { LocalMangaRepository(get()) }
 
-		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/reader/ReaderModule.kt

@@ -1,9 +1,11 @@
 package org.koitharu.kotatsu.reader
 
+import org.koin.android.ext.koin.androidContext
 import org.koin.androidx.viewmodel.dsl.viewModel
 import org.koin.dsl.module
 import org.koitharu.kotatsu.base.domain.MangaDataRepository
 import org.koitharu.kotatsu.local.data.PagesCache
+import org.koitharu.kotatsu.reader.ui.PageSaveHelper
 import org.koitharu.kotatsu.reader.ui.ReaderViewModel
 
 val readerModule
@@ -12,6 +14,8 @@ val readerModule
 		single { MangaDataRepository(get()) }
 		single { PagesCache(get()) }
 
+		factory { PageSaveHelper(get(), androidContext()) }
+
 		viewModel { params ->
 			ReaderViewModel(
 				intent = params[0],
@@ -21,7 +25,7 @@ val readerModule
 				historyRepository = get(),
 				shortcutsRepository = get(),
 				settings = get(),
-				externalStorageHelper = get(),
+				pageSaveHelper = get(),
 			)
 		}
 	}

app/src/main/java/org/koitharu/kotatsu/reader/domain/PageLoader.kt

@@ -113,6 +113,10 @@ class PageLoader : KoinComponent, Closeable {
 		}
 	}
 
+	suspend fun getPageUrl(page: MangaPage): String {
+		return getRepository(page.source).getPageUrl(page)
+	}
+
 	private fun onIdle() {
 		synchronized(prefetchQueue) {
 			while (prefetchQueue.isNotEmpty()) {
@@ -151,7 +155,7 @@ class PageLoader : KoinComponent, Closeable {
 	}
 
 	private suspend fun loadPageImpl(page: MangaPage, progress: MutableStateFlow<Float>): File {
-		val pageUrl = getRepository(page.source).getPageUrl(page)
+		val pageUrl = getPageUrl(page)
 		check(pageUrl.isNotBlank()) { "Cannot obtain full image url" }
 		val uri = Uri.parse(pageUrl)
 		return if (uri.scheme == "cbz") {

app/src/main/java/org/koitharu/kotatsu/reader/ui/PageSaveHelper.kt

@@ -0,0 +1,60 @@
+package org.koitharu.kotatsu.reader.ui
+
+import android.content.Context
+import android.net.Uri
+import androidx.activity.result.ActivityResultLauncher
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.runInterruptible
+import kotlinx.coroutines.suspendCancellableCoroutine
+import okhttp3.HttpUrl.Companion.toHttpUrl
+import okio.IOException
+import org.koitharu.kotatsu.local.data.PagesCache
+import org.koitharu.kotatsu.parsers.model.MangaPage
+import org.koitharu.kotatsu.reader.domain.PageLoader
+import kotlin.coroutines.Continuation
+import kotlin.coroutines.coroutineContext
+import kotlin.coroutines.resume
+
+class PageSaveHelper(
+	private val cache: PagesCache,
+	context: Context,
+) {
+
+	private var continuation: Continuation<Uri>? = null
+	private val contentResolver = context.contentResolver
+
+	suspend fun savePage(
+		pageLoader: PageLoader,
+		page: MangaPage,
+		saveLauncher: ActivityResultLauncher<String>,
+	): Uri {
+		var pageFile = cache[page.url]
+		var fileName = pageFile?.name
+		if (fileName == null) {
+			fileName = pageLoader.getPageUrl(page).toHttpUrl().pathSegments.last()
+		}
+		val cc = coroutineContext
+		val destination = suspendCancellableCoroutine<Uri> { cont ->
+			continuation = cont
+			Dispatchers.Main.dispatch(cc) {
+				saveLauncher.launch(fileName)
+			}
+		}
+		continuation = null
+		if (pageFile == null) {
+			pageFile = pageLoader.loadPage(page, force = false)
+		}
+		runInterruptible(Dispatchers.IO) {
+			contentResolver.openOutputStream(destination)?.use { output ->
+				pageFile.inputStream().use { input ->
+					input.copyTo(output)
+				}
+			} ?: throw IOException("Output stream is null")
+		}
+		return destination
+	}
+
+	fun onActivityResult(uri: Uri): Boolean = continuation?.apply {
+		resume(uri)
+	} != null
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/ReaderActivity.kt

@@ -9,7 +9,6 @@ import android.view.*
 import android.widget.Toast
 import androidx.activity.result.ActivityResultCallback
 import androidx.core.graphics.Insets
-import androidx.core.net.toUri
 import androidx.core.view.*
 import androidx.fragment.app.commit
 import androidx.lifecycle.lifecycleScope
@@ -187,10 +186,7 @@ class ReaderActivity :
 			R.id.action_save_page -> {
 				viewModel.getCurrentPage()?.also { page ->
 					viewModel.saveCurrentState(reader?.getCurrentState())
-					val name = page.url.toUri().run {
-						fragment ?: lastPathSegment ?: ""
-					}
-					savePageRequest.launch(name)
+					viewModel.saveCurrentPage(page, savePageRequest)
 				} ?: showWaitWhileLoading()
 			}
 			else -> return super.onOptionsItemSelected(item)
@@ -199,9 +195,7 @@ class ReaderActivity :
 	}
 
 	override fun onActivityResult(uri: Uri?) {
-		if (uri != null) {
-			viewModel.saveCurrentPage(uri)
-		}
+		viewModel.onActivityResult(uri)
 	}
 
 	private fun onLoadingStateChanged(isLoading: Boolean) {

app/src/main/java/org/koitharu/kotatsu/reader/ui/ReaderViewModel.kt

@@ -2,6 +2,7 @@ package org.koitharu.kotatsu.reader.ui
 
 import android.net.Uri
 import android.util.LongSparseArray
+import androidx.activity.result.ActivityResultLauncher
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.*
@@ -26,7 +27,6 @@ import org.koitharu.kotatsu.parsers.model.MangaPage
 import org.koitharu.kotatsu.reader.domain.PageLoader
 import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
 import org.koitharu.kotatsu.reader.ui.pager.ReaderUiState
-import org.koitharu.kotatsu.utils.ExternalStorageHelper
 import org.koitharu.kotatsu.utils.SingleLiveEvent
 import org.koitharu.kotatsu.utils.ext.IgnoreErrors
 import org.koitharu.kotatsu.utils.ext.asLiveDataDistinct
@@ -40,10 +40,11 @@ class ReaderViewModel(
 	private val historyRepository: HistoryRepository,
 	private val shortcutsRepository: ShortcutsRepository,
 	private val settings: AppSettings,
-	private val externalStorageHelper: ExternalStorageHelper,
+	private val pageSaveHelper: PageSaveHelper,
 ) : BaseViewModel() {
 
 	private var loadingJob: Job? = null
+	private var pageSaveJob: Job? = null
 	private val currentState = MutableStateFlow(initialState)
 	private val mangaData = MutableStateFlow(intent.manga)
 	private val chapters = LongSparseArray<MangaChapter>()
@@ -137,12 +138,16 @@ class ReaderViewModel(
 		return pages.filter { it.chapterId == chapterId }.map { it.toMangaPage() }
 	}
 
-	fun saveCurrentPage(destination: Uri) {
-		launchJob(Dispatchers.Default) {
+	fun saveCurrentPage(
+		page: MangaPage,
+		saveLauncher: ActivityResultLauncher<String>,
+	) {
+		val prevJob = pageSaveJob
+		pageSaveJob = launchLoadingJob(Dispatchers.Default) {
+			prevJob?.cancelAndJoin()
 			try {
-				val page = getCurrentPage() ?: error("Page not found")
-				externalStorageHelper.savePage(page, destination)
-				onPageSaved.postCall(destination)
+				val dest = pageSaveHelper.savePage(pageLoader, page, saveLauncher)
+				onPageSaved.postCall(dest)
 			} catch (e: CancellationException) {
 				throw e
 			} catch (e: Exception) {
@@ -154,6 +159,15 @@ class ReaderViewModel(
 		}
 	}
 
+	fun onActivityResult(uri: Uri?) {
+		if (uri != null) {
+			pageSaveHelper.onActivityResult(uri)
+		} else {
+			pageSaveJob?.cancel()
+			pageSaveJob = null
+		}
+	}
+
 	fun getCurrentPage(): MangaPage? {
 		val state = currentState.value ?: return null
 		return content.value?.pages?.find {

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

@@ -1,26 +0,0 @@
-package org.koitharu.kotatsu.utils
-
-import android.content.Context
-import android.net.Uri
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.runInterruptible
-import okio.IOException
-import org.koitharu.kotatsu.parsers.model.MangaPage
-import org.koitharu.kotatsu.reader.domain.PageLoader
-
-class ExternalStorageHelper(context: Context) {
-
-	private val contentResolver = context.contentResolver
-
-	suspend fun savePage(page: MangaPage, destination: Uri) {
-		val pageLoader = PageLoader()
-		val pageFile = pageLoader.loadPage(page, force = false)
-		runInterruptible(Dispatchers.IO) {
-			contentResolver.openOutputStream(destination)?.use { output ->
-				pageFile.inputStream().use { input ->
-					input.copyTo(output)
-				}
-			} ?: throw IOException("Output stream is null")
-		}
-	}
-}