Fix obtaining manga output

app/build.gradle

@@ -15,8 +15,8 @@ android {
 		applicationId 'org.koitharu.kotatsu'
 		minSdkVersion 21
 		targetSdkVersion 33
-		versionCode 542
-		versionName '5.1-b1'
+		versionCode 543
+		versionName '5.1-b2'
 		generatedDensities = []
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 

app/src/main/java/org/koitharu/kotatsu/download/ui/worker/PausingReceiver.kt

@@ -17,8 +17,10 @@ class PausingReceiver(
 
 	override fun onReceive(context: Context, intent: Intent?) {
 		val uuid = intent?.getStringExtra(EXTRA_UUID)?.toUUIDOrNull()
-		assert(uuid == id)
-		when (intent?.action) {
+		if (uuid != id) {
+			return
+		}
+		when (intent.action) {
 			ACTION_RESUME -> pausingHandle.resume()
 			ACTION_PAUSE -> pausingHandle.pause()
 		}

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

@@ -1,6 +1,11 @@
 package org.koitharu.kotatsu.local.data.output
 
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
 import okio.Closeable
+import org.koitharu.kotatsu.local.data.input.LocalMangaInput
 import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.parsers.model.MangaChapter
 import org.koitharu.kotatsu.parsers.util.toFileNameSafe
@@ -26,25 +31,63 @@ sealed class LocalMangaOutput(
 
 		const val ENTRY_NAME_INDEX = "index.json"
 		const val SUFFIX_TMP = ".tmp"
+		private val mutex = Mutex()
 
-		fun getOrCreate(root: File, manga: Manga): LocalMangaOutput {
-			return checkNotNull(getImpl(root, manga, onlyIfExists = false))
-		}
-
-		fun get(root: File, manga: Manga): LocalMangaOutput? {
-			return getImpl(root, manga, onlyIfExists = true)
-		}
-
-		private fun getImpl(root: File, manga: Manga, onlyIfExists: Boolean): LocalMangaOutput? {
-			val fileName = manga.title.toFileNameSafe()
-			val dir = File(root, fileName)
-			val zip = File(root, "$fileName.cbz")
-			return when {
-				dir.isDirectory -> LocalMangaDirOutput(dir, manga)
-				zip.isFile -> LocalMangaZipOutput(zip, manga)
-				!onlyIfExists -> LocalMangaDirOutput(dir, manga)
-				else -> null
+		suspend fun getOrCreate(root: File, manga: Manga): LocalMangaOutput = withContext(Dispatchers.IO) {
+			val preferSingleCbz = manga.chapters.let {
+				it != null && it.size <= 3
 			}
+			checkNotNull(getImpl(root, manga, onlyIfExists = false, preferSingleCbz))
+		}
+
+		suspend fun get(root: File, manga: Manga): LocalMangaOutput? = withContext(Dispatchers.IO) {
+			getImpl(root, manga, onlyIfExists = true, preferSingleCbz = false)
+		}
+
+		private suspend fun getImpl(
+			root: File,
+			manga: Manga,
+			onlyIfExists: Boolean,
+			preferSingleCbz: Boolean,
+		): LocalMangaOutput? {
+			mutex.withLock {
+				var i = 0
+				val baseName = manga.title.toFileNameSafe()
+				while (true) {
+					val fileName = if (i == 0) baseName else baseName + "_$i"
+					val dir = File(root, fileName)
+					val zip = File(root, "$fileName.cbz")
+					i++
+					return when {
+						dir.isDirectory -> {
+							if (canWriteTo(dir, manga)) {
+								LocalMangaDirOutput(dir, manga)
+							} else {
+								continue
+							}
+						}
+
+						zip.isFile -> if (canWriteTo(zip, manga)) {
+							LocalMangaZipOutput(zip, manga)
+						} else {
+							continue
+						}
+
+						!onlyIfExists -> if (preferSingleCbz) {
+							LocalMangaZipOutput(zip, manga)
+						} else {
+							LocalMangaDirOutput(dir, manga)
+						}
+
+						else -> null
+					}
+				}
+			}
+		}
+
+		private suspend fun canWriteTo(file: File, manga: Manga): Boolean {
+			val info = LocalMangaInput.of(file).getMangaInfo() ?: return false
+			return info.id == manga.id
 		}
 	}
 }

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

@@ -200,7 +200,7 @@ class PageLoader @Inject constructor(
 				.build()
 			okHttp.newCall(request).await().use { response ->
 				check(response.isSuccessful) {
-					"Invalid response: ${response.code} ${response.message}"
+					"Invalid response: ${response.code} ${response.message} at $pageUrl"
 				}
 				val body = checkNotNull(response.body) {
 					"Null response"