1 files changed, 114 insertions, 0 deletions
diff --git a/resources/assets/javascripts/lib/gettext.ts b/resources/assets/javascripts/lib/gettext.ts
new file mode 100644
index 0000000..23daaaa
--- /dev/null
+++ b/resources/assets/javascripts/lib/gettext.ts
@@ -0,0 +1,114 @@
+import { translate } from 'vue-gettext';
+import * as defaultTranslations from '../../../../locale/de/LC_MESSAGES/js-resources.json';
+import eventBus from './event-bus';
+
+interface StringDict {
+    [key: string]: string;
+}
+
+interface InstalledLanguage {
+    name: string;
+    selected: boolean;
+}
+
+interface InstalledLanguages {
+    [key: string]: InstalledLanguage;
+}
+
+type TranslationDict = StringDict;
+
+interface TranslationDicts {
+    [key: string]: TranslationDict | null;
+}
+
+const DEFAULT_LANG = 'de_DE';
+const DEFAULT_LANG_NAME = 'Deutsch';
+
+const state = getInitialState();
+
+const $gettext = translate.gettext.bind(translate);
+const $ngettext = translate.ngettext.bind(translate);
+const $gettextInterpolate = translate.gettextInterpolate.bind(translate);
+
+export { $gettext, $ngettext, $gettextInterpolate, translate, getLocale, setLocale, getVueConfig };
+
+function getLocale() {
+    return state.locale;
+}
+
+async function setLocale(locale = getInitialLocale()) {
+    if (!(locale in getInstalledLanguages())) {
+        throw new Error('Invalid locale: ' + locale);
+    }
+
+    state.locale = locale;
+    if (state.translations[state.locale] === null) {
+        const translations: TranslationDict = await getTranslations(state.locale);
+        state.translations[state.locale] = translations;
+    }
+
+    translate.initTranslations(state.translations, {
+        getTextPluginMuteLanguages: [DEFAULT_LANG],
+        getTextPluginSilent: false,
+        language: state.locale,
+        silent: false,
+    });
+
+    eventBus.emit('studip:set-locale', state.locale);
+}
+
+function getVueConfig() {
+    const availableLanguages = Object.entries(getInstalledLanguages()).reduce((memo, [lang, { name }]) => {
+        memo[lang] = name;
+
+        return memo;
+    }, {} as StringDict);
+
+    return {
+        availableLanguages,
+        defaultLanguage: DEFAULT_LANG,
+        muteLanguages: [DEFAULT_LANG],
+        silent: false,
+        translations: state.translations,
+    };
+}
+
+function getInitialState() {
+    const translations: TranslationDicts = Object.entries(getInstalledLanguages()).reduce((memo, [lang]) => {
+        memo[lang] = lang === DEFAULT_LANG ? defaultTranslations : null;
+
+        return memo;
+    }, {} as TranslationDicts);
+
+    return {
+        locale: DEFAULT_LANG,
+        translations,
+    };
+}
+
+function getInitialLocale() {
+    for (const [lang, { selected }] of Object.entries(getInstalledLanguages())) {
+        if (selected) {
+            return lang;
+        }
+    }
+
+    return DEFAULT_LANG;
+}
+
+function getInstalledLanguages(): InstalledLanguages {
+    return window?.STUDIP?.INSTALLED_LANGUAGES ?? { [DEFAULT_LANG]: { name: DEFAULT_LANG_NAME, selected: true } };
+}
+
+async function getTranslations(locale: string): Promise<TranslationDict> {
+    try {
+        const language = locale.split(/[_-]/)[0];
+        const translation = await import(`../../../../locale/${language}/LC_MESSAGES/js-resources.json`);
+
+        return translation;
+    } catch (exception) {
+        console.error('Could not load locale: "' + locale + '"', exception);
+
+        return {};
+    }
+}