[LibSoc] Default image server config option

src/main/kotlin/org/koitharu/kotatsu/parsers/config/ConfigKey.kt

@@ -29,4 +29,9 @@ sealed class ConfigKey<T>(
 	class SplitByTranslations(
 		override val defaultValue: Boolean,
 	) : ConfigKey<Boolean>("split_translations")
+
+	class PreferredImageServer(
+		val presetValues: Map<String?, String?>,
+		override val defaultValue: String?,
+	) : ConfigKey<String?>("img_server")
 }

src/main/kotlin/org/koitharu/kotatsu/parsers/site/ru/rulib/LibSocialParser.kt

@@ -38,6 +38,16 @@ internal abstract class LibSocialParser(
 	)
 	private val imageServers = SuspendLazy(::fetchServers)
 	private val splitTranslationsKey = ConfigKey.SplitByTranslations(true)
+	private val preferredServerKey = ConfigKey.PreferredImageServer(
+		presetValues = mapOf(
+			SERVER_MAIN to "Первый",
+			SERVER_SECONDARY to "Второй",
+			SERVER_COMPRESS to "Сжатия",
+			SERVER_DOWNLOAD to "Загрузки",
+			SERVER_CROP to "Обрезки",
+		),
+		defaultValue = null,
+	)
 
 	override suspend fun getListPage(page: Int, filter: MangaListFilter?): List<Manga> {
 		val urlBuilder = urlBuilder("api")
@@ -133,10 +143,7 @@ internal abstract class LibSocialParser(
 		}
 		val servers = imageServers.get()
 		val json = pages.await()
-		val primaryServer =
-			checkNotNull(servers[SERVER_MAIN] ?: servers[SERVER_DOWNLOAD] ?: servers[SERVER_SECONDARY]) {
-				"No available images servers"
-			}
+		val primaryServer = getPrimaryImageServer(servers)
 		json.getJSONArray("pages").mapJSON { jo ->
 			val url = jo.getString("url")
 			MangaPage(
@@ -193,6 +200,16 @@ internal abstract class LibSocialParser(
 		)
 	}
 
+	private fun getPrimaryImageServer(servers: ScatterMap<String, String>): String {
+		val preferred = config[preferredServerKey]
+		if (preferred != null) {
+			servers[preferred]?.let { return it }
+		}
+		return checkNotNull(servers[SERVER_MAIN] ?: servers[SERVER_DOWNLOAD] ?: servers[SERVER_SECONDARY]) {
+			"No available images servers"
+		}
+	}
+
 	private suspend fun fetchChapters(manga: Manga): List<MangaChapter> {
 		val url = urlBuilder("api")
 			.addPathSegment("api")