Fix Continue button in offline mode

app/build.gradle

@@ -15,8 +15,8 @@ android {
 		applicationId 'org.koitharu.kotatsu'
 		minSdkVersion 21
 		targetSdkVersion 33
-		versionCode 554
-		versionName '5.2.2'
+		versionCode 555
+		versionName '5.2.3'
 		generatedDensities = []
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 

app/src/main/kotlin/org/koitharu/kotatsu/history/data/HistoryRepository.kt

@@ -45,6 +45,13 @@ class HistoryRepository @Inject constructor(
 		return entity.manga.toManga(entity.tags.toMangaTags())
 	}
 
+	fun observeLast(): Flow<Manga?> {
+		return db.historyDao.observeAll(1).map {
+			val first = it.firstOrNull()
+			first?.manga?.toManga(first.tags.toMangaTags())
+		}
+	}
+
 	fun observeAll(): Flow<List<Manga>> {
 		return db.historyDao.observeAll().mapItems {
 			it.manga.toManga(it.tags.toMangaTags())

app/src/main/kotlin/org/koitharu/kotatsu/main/domain/ReadingResumeEnabledUseCase.kt

@@ -0,0 +1,31 @@
+package org.koitharu.kotatsu.main.domain
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flatMapLatest
+import kotlinx.coroutines.flow.flowOf
+import org.koitharu.kotatsu.core.os.NetworkState
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.core.prefs.observeAsFlow
+import org.koitharu.kotatsu.history.data.HistoryRepository
+import org.koitharu.kotatsu.parsers.model.MangaSource
+import javax.inject.Inject
+
+class ReadingResumeEnabledUseCase @Inject constructor(
+	private val networkState: NetworkState,
+	private val historyRepository: HistoryRepository,
+	private val settings: AppSettings,
+) {
+
+	operator fun invoke(): Flow<Boolean> = settings.observeAsFlow(AppSettings.KEY_INCOGNITO_MODE) {
+		isIncognitoModeEnabled
+	}.flatMapLatest { incognito ->
+		if (incognito) {
+			flowOf(false)
+		} else {
+			combine(networkState, historyRepository.observeLast()) { isOnline, last ->
+				last != null && (isOnline || last.source == MangaSource.LOCAL)
+			}
+		}
+	}
+}

app/src/main/kotlin/org/koitharu/kotatsu/main/ui/MainViewModel.kt

@@ -13,12 +13,12 @@ import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.exceptions.EmptyHistoryException
 import org.koitharu.kotatsu.core.github.AppUpdateRepository
 import org.koitharu.kotatsu.core.prefs.AppSettings
-import org.koitharu.kotatsu.core.prefs.observeAsFlow
 import org.koitharu.kotatsu.core.prefs.observeAsStateFlow
 import org.koitharu.kotatsu.core.ui.BaseViewModel
 import org.koitharu.kotatsu.core.util.ext.MutableEventFlow
 import org.koitharu.kotatsu.core.util.ext.call
 import org.koitharu.kotatsu.history.data.HistoryRepository
+import org.koitharu.kotatsu.main.domain.ReadingResumeEnabledUseCase
 import org.koitharu.kotatsu.parsers.model.Manga
 import org.koitharu.kotatsu.tracker.domain.TrackingRepository
 import javax.inject.Inject
@@ -29,16 +29,12 @@ class MainViewModel @Inject constructor(
 	private val appUpdateRepository: AppUpdateRepository,
 	trackingRepository: TrackingRepository,
 	settings: AppSettings,
+	readingResumeEnabledUseCase: ReadingResumeEnabledUseCase,
 ) : BaseViewModel() {
 
 	val onOpenReader = MutableEventFlow<Manga>()
 
-	val isResumeEnabled = combine(
-		historyRepository.observeHasItems(),
-		settings.observeAsFlow(AppSettings.KEY_INCOGNITO_MODE) { isIncognitoModeEnabled },
-	) { hasItems, incognito ->
-		hasItems && !incognito
-	}.stateIn(
+	val isResumeEnabled = readingResumeEnabledUseCase().stateIn(
 		scope = viewModelScope + Dispatchers.Default,
 		started = SharingStarted.WhileSubscribed(5000),
 		initialValue = false,