feat(download): auto-download chapters during library update

Add configurable library-update download modes (disabled, next X unread, all)
with settings UI and enqueue downloads after chapter sync completes.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/src/main/java/eu/kanade/domain/DomainModule.kt

@@ -27,6 +27,7 @@ import eu.kanade.domain.track.interactor.SyncChapterProgressWithTrack
 import eu.kanade.domain.track.interactor.TrackChapter
 import mihon.data.repository.ExtensionRepoRepositoryImpl
 import mihon.domain.chapter.interactor.FilterChaptersForDownload
+import mihon.domain.chapter.interactor.GetChaptersForLibraryUpdateDownload
 import mihon.domain.extensionrepo.interactor.CreateExtensionRepo
 import mihon.domain.extensionrepo.interactor.DeleteExtensionRepo
 import mihon.domain.extensionrepo.interactor.GetExtensionRepo
@@ -171,6 +172,7 @@ class DomainModule : InjektModule {
         addFactory { SyncChaptersWithSource(get(), get(), get(), get(), get(), get(), get(), get(), get()) }
         addFactory { GetAvailableScanlators(get()) }
         addFactory { FilterChaptersForDownload(get(), get(), get(), get()) }
+        addFactory { GetChaptersForLibraryUpdateDownload(get(), get()) }
 
         addSingletonFactory<HistoryRepository> { HistoryRepositoryImpl(get()) }
         addFactory { GetHistory(get()) }

app/src/main/java/eu/kanade/presentation/more/settings/screen/SettingsDownloadScreen.kt

@@ -18,6 +18,7 @@ import kotlinx.collections.immutable.toImmutableMap
 import tachiyomi.domain.category.interactor.GetCategories
 import tachiyomi.domain.category.model.Category
 import tachiyomi.domain.download.service.DownloadPreferences
+import tachiyomi.domain.download.service.LibraryUpdateDownloadMode
 import tachiyomi.i18n.MR
 import tachiyomi.i18n.kmk.KMR
 import tachiyomi.presentation.core.i18n.pluralStringResource
@@ -77,6 +78,7 @@ object SettingsDownloadScreen : SearchableSettings {
                 allCategories = allCategories,
             ),
             getDownloadAheadGroup(downloadPreferences = downloadPreferences),
+            getLibraryUpdateDownloadGroup(downloadPreferences = downloadPreferences),
             // KMK -->
             getDownloadCacheRenewInterval(downloadPreferences = downloadPreferences),
             // KMK <--
@@ -216,6 +218,39 @@ object SettingsDownloadScreen : SearchableSettings {
         )
     }
 
+    @Composable
+    private fun getLibraryUpdateDownloadGroup(
+        downloadPreferences: DownloadPreferences,
+    ): Preference.PreferenceGroup {
+        val modePref = downloadPreferences.libraryUpdateDownloadMode()
+        val amountPref = downloadPreferences.libraryUpdateDownloadAmount()
+        val mode by modePref.collectAsState()
+
+        return Preference.PreferenceGroup(
+            title = stringResource(KMR.strings.library_update_download),
+            preferenceItems = persistentListOf(
+                Preference.PreferenceItem.ListPreference(
+                    preference = modePref,
+                    entries = persistentMapOf(
+                        LibraryUpdateDownloadMode.DISABLED to stringResource(MR.strings.disabled),
+                        LibraryUpdateDownloadMode.NEXT_X to stringResource(KMR.strings.library_update_download_mode_next_x),
+                        LibraryUpdateDownloadMode.ALL to stringResource(KMR.strings.library_update_download_mode_all),
+                    ),
+                    title = stringResource(KMR.strings.library_update_download_mode),
+                ),
+                Preference.PreferenceItem.ListPreference(
+                    preference = amountPref,
+                    entries = listOf(2, 3, 5, 10)
+                        .associateWith { pluralStringResource(MR.plurals.next_unread_chapters, count = it, it) }
+                        .toImmutableMap(),
+                    title = stringResource(KMR.strings.library_update_download_amount),
+                    enabled = mode == LibraryUpdateDownloadMode.NEXT_X,
+                ),
+                Preference.PreferenceItem.InfoPreference(stringResource(KMR.strings.library_update_download_info)),
+            ),
+        )
+    }
+
     // KMK -->
     @Composable
     private fun getDownloadCacheRenewInterval(

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

@@ -58,6 +58,7 @@ import kotlinx.coroutines.sync.Semaphore
 import kotlinx.coroutines.sync.withPermit
 import logcat.LogPriority
 import mihon.domain.chapter.interactor.FilterChaptersForDownload
+import mihon.domain.chapter.interactor.GetChaptersForLibraryUpdateDownload
 import tachiyomi.core.common.i18n.stringResource
 import tachiyomi.core.common.preference.getAndSet
 import tachiyomi.core.common.util.lang.withIOContext
@@ -119,6 +120,7 @@ class LibraryUpdateJob(private val context: Context, workerParams: WorkerParamet
     private val syncChaptersWithSource: SyncChaptersWithSource = Injekt.get()
     private val fetchInterval: FetchInterval = Injekt.get()
     private val filterChaptersForDownload: FilterChaptersForDownload = Injekt.get()
+    private val getChaptersForLibraryUpdateDownload: GetChaptersForLibraryUpdateDownload = Injekt.get()
 
     // SY -->
     private val getFavorites: GetFavorites = Injekt.get()
@@ -465,6 +467,12 @@ class LibraryUpdateJob(private val context: Context, workerParams: WorkerParamet
                                             // Convert to the manga that contains new chapters
                                             newUpdates.add(manga to newChapters.toTypedArray())
                                         }
+
+                                        val libraryUpdateChapters = getChaptersForLibraryUpdateDownload.await(manga)
+                                        if (libraryUpdateChapters.isNotEmpty()) {
+                                            downloadChapters(manga, libraryUpdateChapters)
+                                            hasDownloads.store(true)
+                                        }
                                         clearErrorFromDB(mangaId = manga.id)
                                     } catch (e: Throwable) {
                                         val errorMessage = when (e) {
@@ -493,10 +501,11 @@ class LibraryUpdateJob(private val context: Context, workerParams: WorkerParamet
 
         if (newUpdates.isNotEmpty()) {
             notifier.showUpdateNotifications(newUpdates)
+        }
+
         if (hasDownloads.load()) {
             downloadManager.startDownloads()
         }
-        }
 
         if (failedUpdates.isNotEmpty()) {
             notifier.showUpdateErrorNotification(

domain/src/main/java/mihon/domain/chapter/interactor/GetChaptersForLibraryUpdateDownload.kt

@@ -0,0 +1,31 @@
+package mihon.domain.chapter.interactor
+
+import tachiyomi.domain.chapter.model.Chapter
+import tachiyomi.domain.download.service.DownloadPreferences
+import tachiyomi.domain.download.service.LibraryUpdateDownloadMode
+import tachiyomi.domain.history.interactor.GetNextChapters
+import tachiyomi.domain.manga.model.Manga
+
+class GetChaptersForLibraryUpdateDownload(
+    private val downloadPreferences: DownloadPreferences,
+    private val getNextChapters: GetNextChapters,
+) {
+
+    suspend fun await(manga: Manga): List<Chapter> {
+        if (!manga.favorite) return emptyList()
+
+        val mode = downloadPreferences.libraryUpdateDownloadMode().get()
+        if (mode == LibraryUpdateDownloadMode.DISABLED) return emptyList()
+
+        val chapters = getNextChapters.await(manga.id)
+        if (chapters.isEmpty()) return emptyList()
+
+        return when (mode) {
+            LibraryUpdateDownloadMode.NEXT_X -> {
+                chapters.take(downloadPreferences.libraryUpdateDownloadAmount().get())
+            }
+            LibraryUpdateDownloadMode.ALL -> chapters
+            else -> emptyList()
+        }
+    }
+}

domain/src/main/java/tachiyomi/domain/download/service/DownloadPreferences.kt

@@ -47,6 +47,13 @@ class DownloadPreferences(
 
     // KMK -->
     fun downloadCacheRenewInterval() = preferenceStore.getInt("download_cache_renew_interval", 1)
+
+    fun libraryUpdateDownloadMode() = preferenceStore.getInt(
+        "library_update_download_mode",
+        LibraryUpdateDownloadMode.DISABLED,
+    )
+
+    fun libraryUpdateDownloadAmount() = preferenceStore.getInt("library_update_download_amount", 10)
     // KMK <--
 
     companion object {

domain/src/main/java/tachiyomi/domain/download/service/LibraryUpdateDownloadMode.kt

@@ -0,0 +1,7 @@
+package tachiyomi.domain.download.service
+
+object LibraryUpdateDownloadMode {
+    const val DISABLED = 0
+    const val NEXT_X = 1
+    const val ALL = 2
+}

i18n-kmk/src/commonMain/moko-resources/base/strings.xml

@@ -113,6 +113,12 @@
     <string name="download_cache_renew_interval_12hour">12 hours</string>
     <string name="download_cache_renew_interval_24hour">1 day</string>
     <string name="download_cache_renew_interval_info">If set to "manual", either refresh each manga or using the "Reindex downloads" action in "Advanced"</string>
+    <string name="library_update_download">Download on library update</string>
+    <string name="library_update_download_mode">Download chapters on library update</string>
+    <string name="library_update_download_mode_next_x">Next unread chapters from current position</string>
+    <string name="library_update_download_mode_all">All unread chapters from current position</string>
+    <string name="library_update_download_amount">Number of chapters to download</string>
+    <string name="library_update_download_info">Downloads unread chapters from your current reading position when the library is updated. Already downloaded chapters are skipped.</string>
     <!-- Tracking section -->
     <string name="pref_auto_sync_progress_from_trackers">Auto sync progress from Trackers</string>
     <string name="sync_progress_from_trackers_up_to_chapter">Sync progress from Trackers up to chapter %d</string>

i18n-kmk/src/commonMain/moko-resources/de/strings.xml

@@ -12,6 +12,12 @@
     <string name="download_cache_renew_interval_12hour">12 Stunden</string>
     <string name="download_cache_renew_interval_24hour">1 Tag</string>
     <string name="download_cache_renew_interval_info">Wenn auf \"Manuell\" gesetzt, aktualisieren Sie entweder jedes Manga oder verwenden Sie die Aktion \"Downloads neu indizieren\" in \"Erweitert\"</string>
+    <string name="library_update_download">Bei Bibliotheksaktualisierung herunterladen</string>
+    <string name="library_update_download_mode">Kapitel bei Bibliotheksaktualisierung herunterladen</string>
+    <string name="library_update_download_mode_next_x">Nächste ungelesene Kapitel ab aktueller Leseposition</string>
+    <string name="library_update_download_mode_all">Alle ungelesenen Kapitel ab aktueller Leseposition</string>
+    <string name="library_update_download_amount">Anzahl der herunterzuladenden Kapitel</string>
+    <string name="library_update_download_info">Lädt ungelesene Kapitel ab deiner aktuellen Leseposition herunter, wenn die Bibliothek aktualisiert wird. Bereits heruntergeladene Kapitel werden übersprungen.</string>
     <string name="pref_clean_invalid_downloads">Ungültige Downloads bereinigen</string>
     <string name="pref_clean_invalid_downloads_summary">Finden und entfernen Sie alle Downloads, Dateien, Ordner die nicht in Ihrer Bibliothek gespeichert sind</string>
     <string name="invalid_downloads_cleaned">Ungültige Downloads bereinigt</string>