Always suggest available tags in manga list header

app/src/main/java/org/koitharu/kotatsu/list/ui/adapter/ListHeader2AD.kt

@@ -29,7 +29,7 @@ fun listHeader2AD(
 			binding.scrollView.smoothScrollTo(0, 0)
 		}
 		ignoreChecking = true
-		binding.chipsTags.setChips(item.chips)
+		binding.chipsTags.setChips(item.chips) // TODO use recyclerview
 		ignoreChecking = false
 		binding.textViewFilter.setTextAndVisible(item.sortOrder?.titleRes ?: 0)
 	}

app/src/main/java/org/koitharu/kotatsu/list/ui/filter/FilterCoordinator.kt

@@ -30,7 +30,7 @@ class FilterCoordinator(
 	private var availableTagsDeferred = loadTagsAsync()
 
 	val items: LiveData<List<FilterItem>> = getItemsFlow()
-		.asLiveDataDistinct(coroutineScope.coroutineContext + Dispatchers.Default)
+		.asLiveDataDistinct(coroutineScope.coroutineContext + Dispatchers.Default, listOf(FilterItem.Loading))
 
 	init {
 		observeState()
@@ -54,6 +54,13 @@ class FilterCoordinator(
 		}
 	}
 
+	fun observeAvailableTags(): Flow<Set<MangaTag>?> = flow {
+		if (!availableTagsDeferred.isCompleted) {
+			emit(emptySet())
+		}
+		emit(availableTagsDeferred.await())
+	}
+
 	fun observeState() = currentState.asStateFlow()
 
 	fun setTags(tags: Set<MangaTag>) {

app/src/main/java/org/koitharu/kotatsu/list/ui/model/ListHeader2.kt

@@ -3,7 +3,28 @@ package org.koitharu.kotatsu.list.ui.model
 import org.koitharu.kotatsu.base.ui.widgets.ChipsView
 import org.koitharu.kotatsu.parsers.model.SortOrder
 
-data class ListHeader2(
+class ListHeader2(
 	val chips: Collection<ChipsView.ChipModel>,
 	val sortOrder: SortOrder?,
-) : ListModel
+	val hasSelectedTags: Boolean,
+) : ListModel {
+
+	override fun equals(other: Any?): Boolean {
+		if (this === other) return true
+		if (javaClass != other?.javaClass) return false
+
+		other as ListHeader2
+
+		if (chips != other.chips) return false
+		if (sortOrder != other.sortOrder) return false
+		// Not need to check hasSelectedTags
+
+		return true
+	}
+
+	override fun hashCode(): Int {
+		var result = chips.hashCode()
+		result = 31 * result + (sortOrder?.hashCode() ?: 0)
+		return result
+	}
+}

app/src/main/java/org/koitharu/kotatsu/remotelist/ui/RemoteListViewModel.kt

@@ -45,16 +45,16 @@ class RemoteListViewModel(
 	override val content = combine(
 		mangaList,
 		createListModeFlow(),
-		filter.observeState(),
+		createHeaderFlow(),
 		listError,
 		hasNextPage,
-	) { list, mode, filterState, error, hasNext ->
+	) { list, mode, header, error, hasNext ->
 		buildList(list?.size?.plus(2) ?: 2) {
-			add(ListHeader2(createChipsList(filterState), filterState.sortOrder))
+			add(header)
 			when {
 				list.isNullOrEmpty() && error != null -> add(error.toErrorState(canRetry = true))
 				list == null -> add(LoadingState)
-				list.isEmpty() -> add(createEmptyState(filterState))
+				list.isEmpty() -> add(createEmptyState(header.hasSelectedTags))
 				else -> {
 					list.toUi(this, mode)
 					when {
@@ -64,10 +64,7 @@ class RemoteListViewModel(
 				}
 			}
 		}
-	}.asLiveDataDistinct(
-		viewModelScope.coroutineContext + Dispatchers.Default,
-		listOf(ListHeader(repository.source.title, 0, null), LoadingState),
-	)
+	}.asLiveDataDistinct(viewModelScope.coroutineContext + Dispatchers.Default, listOf(LoadingState))
 
 	init {
 		filter.observeState()
@@ -144,16 +141,33 @@ class RemoteListViewModel(
 		}
 	}
 
-	private fun createEmptyState(filterState: FilterState) = EmptyState(
+	private fun createEmptyState(canResetFilter: Boolean) = EmptyState(
 		icon = R.drawable.ic_empty_search,
 		textPrimary = R.string.nothing_found,
 		textSecondary = 0,
-		actionStringRes = if (filterState.tags.isEmpty()) 0 else R.string.reset_filter,
+		actionStringRes = if (canResetFilter) R.string.reset_filter else 0,
 	)
 
-	private suspend fun createChipsList(filterState: FilterState): List<ChipsView.ChipModel> {
+	private fun createHeaderFlow() = combine(
+		filter.observeState(),
+		filter.observeAvailableTags(),
+	) { state, available ->
+		val chips = createChipsList(state, available.orEmpty())
+		ListHeader2(chips, state.sortOrder, state.tags.isNotEmpty())
+	}
+
+	private suspend fun createChipsList(
+		filterState: FilterState,
+		availableTags: Set<MangaTag>
+	): List<ChipsView.ChipModel> {
 		val selectedTags = filterState.tags.toMutableSet()
-		val tags = searchRepository.getTagsSuggestion("", 6, repository.source)
+		var tags = searchRepository.getTagsSuggestion("", 6, repository.source)
+		if (tags.isEmpty()) {
+			tags = availableTags.take(6)
+		}
+		if (tags.isEmpty() && selectedTags.isEmpty()) {
+			return emptyList()
+		}
 		val result = LinkedList<ChipsView.ChipModel>()
 		for (tag in tags) {
 			val model = ChipsView.ChipModel(