Remove usage of RxJava from LibraryUpdateService

app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateService.kt

@@ -27,15 +27,16 @@ import eu.kanade.tachiyomi.source.model.toSChapter
 import eu.kanade.tachiyomi.source.model.toSManga
 import eu.kanade.tachiyomi.util.chapter.NoChaptersException
 import eu.kanade.tachiyomi.util.chapter.syncChaptersWithSource
-import eu.kanade.tachiyomi.util.lang.runAsObservable
+import eu.kanade.tachiyomi.util.lang.launchIO
 import eu.kanade.tachiyomi.util.prepUpdateCover
 import eu.kanade.tachiyomi.util.shouldDownloadNewChapters
 import eu.kanade.tachiyomi.util.storage.getUriCompat
 import eu.kanade.tachiyomi.util.system.acquireWakeLock
 import eu.kanade.tachiyomi.util.system.isServiceRunning
-import rx.Observable
-import rx.Subscription
-import rx.schedulers.Schedulers
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.MainScope
+import kotlinx.coroutines.cancel
 import timber.log.Timber
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
@@ -59,17 +60,11 @@ class LibraryUpdateService(
     val coverCache: CoverCache = Injekt.get()
 ) : Service() {
 
-    /**
-     * Wake lock that will be held until the service is destroyed.
-     */
     private lateinit var wakeLock: PowerManager.WakeLock
-
     private lateinit var notifier: LibraryUpdateNotifier
+    private lateinit var scope: CoroutineScope
 
-    /**
-     * Subscription where the update is done.
-     */
-    private var subscription: Subscription? = null
+    private var updateJob: Job? = null
 
     /**
      * Defines what should be updated within a service execution.
@@ -144,6 +139,7 @@ class LibraryUpdateService(
     override fun onCreate() {
         super.onCreate()
 
+        scope = MainScope()
         notifier = LibraryUpdateNotifier(this)
         wakeLock = acquireWakeLock(javaClass.name)
 
@@ -155,7 +151,8 @@ class LibraryUpdateService(
      * lock.
      */
     override fun onDestroy() {
-        subscription?.unsubscribe()
+        scope?.cancel()
+        updateJob?.cancel()
         if (wakeLock.isHeld) {
             wakeLock.release()
         }
@@ -183,34 +180,27 @@ class LibraryUpdateService(
             ?: return START_NOT_STICKY
 
         // Unsubscribe from any previous subscription if needed.
-        subscription?.unsubscribe()
+        updateJob?.cancel()
 
         // Update favorite manga. Destroy service when completed or in case of an error.
-        subscription = Observable
-            .defer {
-                val selectedScheme = preferences.libraryUpdatePrioritization().get()
-                val mangaList = getMangaToUpdate(intent, target)
-                    .sortedWith(rankingScheme[selectedScheme])
+        val selectedScheme = preferences.libraryUpdatePrioritization().get()
+        val mangaList = getMangaToUpdate(intent, target)
+            .sortedWith(rankingScheme[selectedScheme])
 
-                // Update either chapter list or manga details.
+        updateJob = scope.launchIO {
+            try {
                 when (target) {
                     Target.CHAPTERS -> updateChapterList(mangaList)
                     Target.COVERS -> updateCovers(mangaList)
                     Target.TRACKING -> updateTrackings(mangaList)
                 }
+            } catch (e: Throwable) {
+                Timber.e(e)
+                stopSelf(startId)
+            } finally {
+                stopSelf(startId)
             }
-            .subscribeOn(Schedulers.io())
-            .subscribe(
-                {
-                },
-                {
-                    Timber.e(it)
-                    stopSelf(startId)
-                },
-                {
-                    stopSelf(startId)
-                }
-            )
+        }
 
         return START_REDELIVER_INTENT
     }
@@ -253,7 +243,7 @@ class LibraryUpdateService(
      * @param mangaToUpdate the list to update
      * @return an observable delivering the progress of each update.
      */
-    fun updateChapterList(mangaToUpdate: List<LibraryManga>): Observable<LibraryManga> {
+    suspend fun updateChapterList(mangaToUpdate: List<LibraryManga>) {
         // Initialize the variables holding the progress of the updates.
         val count = AtomicInteger(0)
         // List containing new updates
@@ -263,67 +253,60 @@ class LibraryUpdateService(
         // Boolean to determine if DownloadManager has downloads
         var hasDownloads = false
 
-        // Emit each manga and update it sequentially.
-        return Observable.from(mangaToUpdate)
-            // Notify manga that will update.
-            .doOnNext { notifier.showProgressNotification(it, count.andIncrement, mangaToUpdate.size) }
-            // Update the chapters of the manga
-            .concatMap { manga ->
-                updateManga(manga)
+        mangaToUpdate
+            .map { manga ->
+                // Notify manga that will update.
+                notifier.showProgressNotification(manga, count.andIncrement, mangaToUpdate.size)
+
+                // Update the chapters of the manga
+                try {
+                    val newChapters = updateManga(manga).first
+                    Pair(manga, newChapters)
+                } catch (e: Throwable) {
                     // If there's any error, return empty update and continue.
-                    .onErrorReturn {
-                        val errorMessage = if (it is NoChaptersException) {
-                            getString(R.string.no_chapters_error)
-                        } else {
-                            it.message
-                        }
-                        failedUpdates.add(Pair(manga, errorMessage))
-                        Pair(emptyList(), emptyList())
-                    }
-                    // Filter out mangas without new chapters (or failed).
-                    .filter { (first) -> first.isNotEmpty() }
-                    .doOnNext {
-                        if (manga.shouldDownloadNewChapters(db, preferences)) {
-                            downloadChapters(manga, it.first)
-                            hasDownloads = true
-                        }
-                    }
-                    // Convert to the manga that contains new chapters.
-                    .map {
-                        Pair(
-                            manga,
-                            (
-                                it.first.sortedByDescending { ch -> ch.source_order }
-                                    .toTypedArray()
-                                )
-                        )
+                    val errorMessage = if (e is NoChaptersException) {
+                        getString(R.string.no_chapters_error)
+                    } else {
+                        e.message
                     }
+                    failedUpdates.add(Pair(manga, errorMessage))
+                    Pair(manga, emptyList())
+                }
             }
-            // Add manga with new chapters to the list.
-            .doOnNext { manga ->
-                // Add to the list
-                newUpdates.add(manga)
-            }
-            // Notify result of the overall update.
-            .doOnCompleted {
-                notifier.cancelProgressNotification()
-
-                if (newUpdates.isNotEmpty()) {
-                    notifier.showUpdateNotifications(newUpdates)
-                    if (hasDownloads) {
-                        DownloadService.start(this)
-                    }
+            // Filter out mangas without new chapters (or failed).
+            .filter { (_, newChapters) -> newChapters.isNotEmpty() }
+            .forEach { (manga, newChapters) ->
+                if (manga.shouldDownloadNewChapters(db, preferences)) {
+                    downloadChapters(manga, newChapters)
+                    hasDownloads = true
                 }
 
-                if (preferences.showLibraryUpdateErrors() && failedUpdates.isNotEmpty()) {
-                    val errorFile = writeErrorFile(failedUpdates)
-                    notifier.showUpdateErrorNotification(
-                        failedUpdates.map { it.first.title },
-                        errorFile.getUriCompat(this)
+                // Convert to the manga that contains new chapters.
+                newUpdates.add(
+                    Pair(
+                        manga,
+                        newChapters.sortedByDescending { ch -> ch.source_order }.toTypedArray()
                     )
-                }
+                )
             }
-            .map { (first) -> first }
+
+        // Notify result of the overall update.
+        notifier.cancelProgressNotification()
+
+        if (newUpdates.isNotEmpty()) {
+            notifier.showUpdateNotifications(newUpdates)
+            if (hasDownloads) {
+                DownloadService.start(this)
+            }
+        }
+
+        if (preferences.showLibraryUpdateErrors() && failedUpdates.isNotEmpty()) {
+            val errorFile = writeErrorFile(failedUpdates)
+            notifier.showUpdateErrorNotification(
+                failedUpdates.map { it.first.title },
+                errorFile.getUriCompat(this)
+            )
+        }
     }
 
     private fun downloadChapters(manga: Manga, chapters: List<Chapter>) {
@@ -338,49 +321,38 @@ class LibraryUpdateService(
      * @param manga the manga to update.
      * @return a pair of the inserted and removed chapters.
      */
-    fun updateManga(manga: Manga): Observable<Pair<List<Chapter>, List<Chapter>>> {
+    suspend fun updateManga(manga: Manga): Pair<List<Chapter>, List<Chapter>> {
         val source = sourceManager.getOrStub(manga.source)
 
         // Update manga details metadata in the background
         if (preferences.autoUpdateMetadata()) {
-            runAsObservable({
-                val updatedManga = source.getMangaDetails(manga.toMangaInfo())
-                val sManga = updatedManga.toSManga()
-                // Avoid "losing" existing cover
-                if (!sManga.thumbnail_url.isNullOrEmpty()) {
-                    manga.prepUpdateCover(coverCache, sManga, false)
-                } else {
-                    sManga.thumbnail_url = manga.thumbnail_url
-                }
+            val updatedManga = source.getMangaDetails(manga.toMangaInfo())
+            val sManga = updatedManga.toSManga()
+            // Avoid "losing" existing cover
+            if (!sManga.thumbnail_url.isNullOrEmpty()) {
+                manga.prepUpdateCover(coverCache, sManga, false)
+            } else {
+                sManga.thumbnail_url = manga.thumbnail_url
+            }
 
-                manga.copyFrom(sManga)
-                db.insertManga(manga).executeAsBlocking()
-                manga
-            })
-                .onErrorResumeNext { Observable.just(manga) }
-                .subscribeOn(Schedulers.io())
-                .subscribe()
+            manga.copyFrom(sManga)
+            db.insertManga(manga).executeAsBlocking()
         }
 
-        return runAsObservable({
-            source.getChapterList(manga.toMangaInfo())
-                .map { it.toSChapter() }
-        })
-            .map { syncChaptersWithSource(db, it, manga, source) }
+        val chapters = source.getChapterList(manga.toMangaInfo())
+            .map { it.toSChapter() }
+
+        return syncChaptersWithSource(db, chapters, manga, source)
     }
 
-    private fun updateCovers(mangaToUpdate: List<LibraryManga>): Observable<LibraryManga> {
+    private suspend fun updateCovers(mangaToUpdate: List<LibraryManga>) {
         var count = 0
 
-        return Observable.from(mangaToUpdate)
-            .doOnNext {
-                notifier.showProgressNotification(it, count++, mangaToUpdate.size)
-            }
-            .flatMap { manga ->
-                val source = sourceManager.get(manga.source)
-                    ?: return@flatMap Observable.empty<LibraryManga>()
+        mangaToUpdate.forEach { manga ->
+            notifier.showProgressNotification(manga, count++, mangaToUpdate.size)
 
-                runAsObservable({
+            sourceManager.get(manga.source)?.let { source ->
+                try {
                     val networkManga = source.getMangaDetails(manga.toMangaInfo())
                     val sManga = networkManga.toSManga()
                     manga.prepUpdateCover(coverCache, sManga, true)
@@ -388,49 +360,46 @@ class LibraryUpdateService(
                         manga.thumbnail_url = it
                         db.insertManga(manga).executeAsBlocking()
                     }
-                    manga
-                })
-                    .onErrorReturn { manga }
-            }
-            .doOnCompleted {
-                notifier.cancelProgressNotification()
+                } catch (e: Throwable) {
+                    // Ignore errors and continue
+                    Timber.e(e)
+                }
             }
+        }
+
+        notifier.cancelProgressNotification()
     }
 
     /**
      * Method that updates the metadata of the connected tracking services. It's called in a
      * background thread, so it's safe to do heavy operations or network calls here.
      */
-    private fun updateTrackings(mangaToUpdate: List<LibraryManga>): Observable<LibraryManga> {
+    private suspend fun updateTrackings(mangaToUpdate: List<LibraryManga>) {
         // Initialize the variables holding the progress of the updates.
         var count = 0
 
         val loggedServices = trackManager.services.filter { it.isLogged }
 
-        // Emit each manga and update it sequentially.
-        return Observable.from(mangaToUpdate)
+        mangaToUpdate.forEach { manga ->
             // Notify manga that will update.
-            .doOnNext { notifier.showProgressNotification(it, count++, mangaToUpdate.size) }
-            // Update the tracking details.
-            .concatMap { manga ->
-                val tracks = db.getTracks(manga).executeAsBlocking()
+            notifier.showProgressNotification(manga, count++, mangaToUpdate.size)
 
-                Observable.from(tracks)
-                    .concatMap { track ->
-                        val service = trackManager.getService(track.sync_id)
-                        if (service != null && service in loggedServices) {
-                            runAsObservable({ service.refresh(track) })
-                                .doOnNext { db.insertTrack(it).executeAsBlocking() }
-                                .onErrorReturn { track }
-                        } else {
-                            Observable.empty()
-                        }
+            // Update the tracking details.
+            db.getTracks(manga).executeAsBlocking().forEach { track ->
+                val service = trackManager.getService(track.sync_id)
+                if (service != null && service in loggedServices) {
+                    try {
+                        val updatedTrack = service.refresh(track)
+                        db.insertTrack(updatedTrack).executeAsBlocking()
+                    } catch (e: Throwable) {
+                        // Ignore errors and continue
+                        Timber.e(e)
                     }
-                    .map { manga }
-            }
-            .doOnCompleted {
-                notifier.cancelProgressNotification()
+                }
             }
+        }
+
+        notifier.cancelProgressNotification()
     }
 
     /**