Add Feature Content Rating Filter

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

@@ -4,6 +4,8 @@ object ErrorMessages {
 
 	const val FILTER_MULTIPLE_STATES_NOT_SUPPORTED = "Multiple states are not supported by this source"
 	const val FILTER_MULTIPLE_GENRES_NOT_SUPPORTED = "Multiple genres are not supported by this source"
+	const val FILTER_MULTIPLE_CONTENT_RATING_NOT_SUPPORTED =
+		"Multiple Content Rating are not supported by this source"
 	const val FILTER_BOTH_LOCALE_GENRES_NOT_SUPPORTED =
 		"Filtering by both genres and locale is not supported by this source"
 	const val FILTER_BOTH_STATES_GENRES_NOT_SUPPORTED =

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

@@ -33,6 +33,10 @@ abstract class MangaParser @InternalParsersApi constructor(
 	open val availableStates: Set<MangaState>
 		get() = emptySet()
 
+
+	open val availableContentRating: Set<ContentRating>
+		get() = emptySet()
+
 	/**
 	 * Whether parser supports filtering by more than one tag
 	 */
@@ -145,6 +149,7 @@ abstract class MangaParser @InternalParsersApi constructor(
 				tagsExclude.orEmpty(),
 				null,
 				emptySet(),
+				emptySet(),
 			),
 		)
 	}

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

@@ -0,0 +1,7 @@
+package org.koitharu.kotatsu.parsers.model
+
+enum class ContentRating {
+	SAFE,
+	SUGGESTIVE,
+	ADULT
+}

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

@@ -23,8 +23,9 @@ sealed interface MangaListFilter {
 		@JvmField val tagsExclude: Set<MangaTag>,
 		@JvmField val locale: Locale?,
 		@JvmField val states: Set<MangaState>,
+		@JvmField val contentRating: Set<ContentRating>,
 	) : MangaListFilter {
 
-		override fun isEmpty(): Boolean = tags.isEmpty() && tagsExclude.isEmpty() && locale == null && states.isEmpty()
+		override fun isEmpty(): Boolean = tags.isEmpty() && tagsExclude.isEmpty() && locale == null && states.isEmpty() && contentRating.isEmpty()
 	}
 }

src/main/kotlin/org/koitharu/kotatsu/parsers/site/all/MangaDexParser.kt

@@ -21,8 +21,6 @@ private const val CHAPTERS_FIRST_PAGE_SIZE = 120
 private const val CHAPTERS_MAX_PAGE_SIZE = 500
 private const val CHAPTERS_PARALLELISM = 3
 private const val CHAPTERS_MAX_COUNT = 10_000 // strange api behavior, looks like a bug
-private const val CONTENT_RATING =
-	"contentRating[]=safe&contentRating[]=suggestive&contentRating[]=erotica&contentRating[]=pornographic"
 private const val LOCALE_FALLBACK = "en"
 
 @MangaSourceParser("MANGADEX", "MangaDex")
@@ -32,6 +30,8 @@ internal class MangaDexParser(context: MangaLoaderContext) : MangaParser(context
 
 	override val availableSortOrders: EnumSet<SortOrder> = EnumSet.allOf(SortOrder::class.java)
 
+	override val availableContentRating: Set<ContentRating> = EnumSet.allOf(ContentRating::class.java)
+
 	override val availableStates: Set<MangaState> =
 		EnumSet.of(MangaState.ONGOING, MangaState.FINISHED, MangaState.PAUSED, MangaState.ABANDONED)
 
@@ -45,22 +45,30 @@ internal class MangaDexParser(context: MangaLoaderContext) : MangaParser(context
 			append(PAGE_SIZE)
 			append("&offset=")
 			append(offset)
-			append("&includes[]=cover_art&includes[]=author&includes[]=artist&")
+			append("&includes[]=cover_art&includes[]=author&includes[]=artist")
 			when (filter) {
 				is MangaListFilter.Search -> {
-					append("title=")
+					append("&title=")
 					append(filter.query)
-					append('&')
 				}
 
 				is MangaListFilter.Advanced -> {
 					filter.tags.forEach { tag ->
-						append("includedTags[]=")
+						append("&includedTags[]=")
 						append(tag.key)
-						append('&')
 					}
 
-					append(CONTENT_RATING)
+
+					if (filter.contentRating.isNotEmpty()) {
+						filter.contentRating.forEach {
+							when (it) {
+								ContentRating.SAFE -> append("&contentRating[]=safe")
+								ContentRating.SUGGESTIVE -> append("&contentRating[]=suggestive&contentRating[]=erotica")
+								ContentRating.ADULT -> append("&contentRating[]=pornographic")
+							}
+						}
+					}
+
 					append("&order")
 					append(
 						when (filter.sortOrder) {
@@ -251,8 +259,7 @@ internal class MangaDexParser(context: MangaLoaderContext) : MangaParser(context
 			append(limitedLimit)
 			append("&includes[]=scanlation_group&order[volume]=asc&order[chapter]=asc&offset=")
 			append(offset)
-			append('&')
+			append("&contentRating[]=safe&contentRating[]=suggestive&contentRating[]=erotica&contentRating[]=pornographic")
-			append(CONTENT_RATING)
 		}
 		val json = webClient.httpGet(url).parseJson()
 		if (json.getString("result") == "ok") {

src/main/kotlin/org/koitharu/kotatsu/parsers/util/MangaParserEnv.kt

@@ -68,6 +68,15 @@ fun Set<MangaState>?.oneOrThrowIfMany(): MangaState? {
 	}
 }
 
+@InternalParsersApi
+fun Set<ContentRating>?.oneOrThrowIfMany(): ContentRating? {
+	return when {
+		isNullOrEmpty() -> null
+		size == 1 -> first()
+		else -> throw IllegalArgumentException(ErrorMessages.FILTER_MULTIPLE_CONTENT_RATING_NOT_SUPPORTED)
+	}
+}
+
 val MangaParser.domain: String
 	get() {
 		return config[configKeyDomain]

src/test/kotlin/org/koitharu/kotatsu/parsers/MangaParserTest.kt

@@ -61,7 +61,7 @@ internal class MangaParserTest {
 			offset = 0,
 			filter = MangaListFilter.Advanced(
 				sortOrder = SortOrder.POPULARITY,
-				tags = emptySet(), locale = null, states = emptySet(), tagsExclude = emptySet(),
+				tags = emptySet(), locale = null, states = emptySet(), tagsExclude = emptySet(), contentRating = emptySet()
 			),
 		).minByOrNull {
 			it.title.length
@@ -130,6 +130,7 @@ internal class MangaParserTest {
 			tagsExclude = setOf(),
 			locale = locales.random(),
 			states = setOf(),
+			contentRating = setOf(),
 		)
 		val list = parser.getList(offset = 0, filter)
 		checkMangaList(list, filter.locale.toString())