Introduce MangaListFilterCapabilities class

src/main/kotlin/org/koitharu/kotatsu/parsers/MangaParser.kt

@@ -2,6 +2,8 @@ package org.koitharu.kotatsu.parsers
 
 import androidx.annotation.CallSuper
 import androidx.annotation.VisibleForTesting
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
 import okhttp3.Headers
 import org.koitharu.kotatsu.parsers.config.ConfigKey
 import org.koitharu.kotatsu.parsers.model.*
@@ -301,6 +303,27 @@ abstract class MangaParser @InternalParsersApi constructor(
 	 */
 	abstract suspend fun getAvailableTags(): Set<MangaTag>
 
+	open suspend fun getListFilterCapabilities(): MangaListFilterCapabilities = coroutineScope {
+		val tagsDeferred = async { getAvailableTags() }
+		val localesDeferred = async { getAvailableLocales() }
+		MangaListFilterCapabilities(
+			availableSortOrders = availableSortOrders,
+			availableTags = tagsDeferred.await(),
+			availableStates = availableStates,
+			availableContentRating = availableContentRating,
+			availableContentTypes = availableContentTypes,
+			availableDemographics = availableDemographics,
+			availableLocales = localesDeferred.await(),
+			isMultipleTagsSupported = isMultipleTagsSupported,
+			isTagsExclusionSupported = isTagsExclusionSupported,
+			isSearchSupported = isSearchSupported,
+			searchSupportedWithMultipleFilters = searchSupportedWithMultipleFilters,
+			isSearchYearSupported = isSearchYearSupported,
+			isSearchYearRangeSupported = isSearchYearRangeSupported,
+			isSearchOriginalLanguages = isSearchOriginalLanguages,
+		)
+	}
+
 	/**
 	 * Fetch available locales for multilingual sources
 	 */

src/main/kotlin/org/koitharu/kotatsu/parsers/model/MangaListFilterCapabilities.kt

@@ -0,0 +1,21 @@
+package org.koitharu.kotatsu.parsers.model
+
+import org.koitharu.kotatsu.parsers.InternalParsersApi
+import java.util.*
+
+data class MangaListFilterCapabilities @InternalParsersApi constructor(
+	val availableSortOrders: Set<SortOrder>,
+	val availableTags: Set<MangaTag>,
+	val availableStates: Set<MangaState>,
+	val availableContentRating: Set<ContentRating>,
+	val availableContentTypes: Set<ContentType>,
+	val availableDemographics: Set<Demographic>,
+	val availableLocales: Set<Locale>,
+	val isMultipleTagsSupported: Boolean,
+	val isTagsExclusionSupported: Boolean,
+	val isSearchSupported: Boolean,
+	val searchSupportedWithMultipleFilters: Boolean,
+	val isSearchYearSupported: Boolean,
+	val isSearchYearRangeSupported: Boolean,
+	val isSearchOriginalLanguages: Boolean,
+)