Move core files into new folder

src/lib/Languages.tsx

@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import { t } from 'i18next';
+import { ISOLanguage, IsoLanguages } from '@/lib/IsoLanguages.ts';
+
+export enum DefaultLanguage {
+    ALL = 'all',
+    OTHER = 'other',
+    LOCAL_SOURCE = 'localsourcelang',
+}
+
+function getISOLanguage(code: string): ISOLanguage | null {
+    if (IsoLanguages[code]) {
+        return IsoLanguages[code];
+    }
+
+    if (IsoLanguages[code.toLocaleLowerCase()]) {
+        return IsoLanguages[code.toLocaleLowerCase()];
+    }
+
+    const whereToCut = code.indexOf('-') !== -1 ? code.indexOf('-') : code.length;
+    const processedCode = code.toLocaleLowerCase().substring(0, whereToCut);
+    if (IsoLanguages[processedCode]) {
+        return IsoLanguages[processedCode];
+    }
+
+    return null;
+}
+
+export function getLanguage(code: string): { name: string; nativeName: string } {
+    const isoLanguage = getISOLanguage(code);
+
+    if (isoLanguage) {
+        return isoLanguage;
+    }
+
+    return {
+        name: t('global.language.label.language_with_code', { code }),
+        nativeName: t('global.language.label.language_with_code', { code }),
+    };
+}
+
+export function langCodeToName(code: string): string {
+    return getLanguage(code).nativeName;
+}
+
+function defaultNativeLang() {
+    return 'en'; // TODO: infer from the browser
+}
+
+export function extensionDefaultLangs() {
+    return [defaultNativeLang(), DefaultLanguage.ALL];
+}
+
+export function sourceDefualtLangs() {
+    return [defaultNativeLang(), DefaultLanguage.LOCAL_SOURCE];
+}
+
+export function sourceForcedDefaultLangs(): string[] {
+    return [DefaultLanguage.LOCAL_SOURCE];
+}
+
+export const langSortCmp = (a: string, b: string) => {
+    // puts english first for convience
+    const aLang = langCodeToName(a);
+    const bLang = langCodeToName(b);
+
+    if (a === 'en') return -1;
+    if (b === 'en') return 1;
+
+    return aLang.localeCompare(bLang);
+};