chore(nx/server): move source code

apps/server/src/services/i18n.ts

@@ -0,0 +1,113 @@
+import i18next from "i18next";
+import Backend from "i18next-fs-backend";
+import options from "./options.js";
+import sql_init from "./sql_init.js";
+import { join } from "path";
+import { getResourceDir } from "./utils.js";
+import hidden_subtree from "./hidden_subtree.js";
+import type { Locale } from "@triliumnext/commons";
+
+const LOCALES: Locale[] = [
+    {
+        id: "en",
+        name: "English",
+        electronLocale: "en"
+    },
+    {
+        id: "de",
+        name: "Deutsch",
+        electronLocale: "de"
+    },
+    {
+        id: "es",
+        name: "Español",
+        electronLocale: "es"
+    },
+    {
+        id: "fr",
+        name: "Français",
+        electronLocale: "fr"
+    },
+    {
+        id: "cn",
+        name: "简体中文",
+        electronLocale: "zh_CN"
+    },
+    {
+        id: "tw",
+        name: "繁體中文",
+        electronLocale: "zh_TW"
+    },
+    {
+        id: "ro",
+        name: "Română",
+        electronLocale: "ro"
+    },
+
+    /*
+     * Right to left languages
+     *
+     * Currently they are only for setting the language of text notes.
+     */
+    { // Arabic
+        id: "ar",
+        name: "اَلْعَرَبِيَّةُ",
+        rtl: true,
+        contentOnly: true
+    },
+    { // Hebrew
+        id: "he",
+        name: "עברית",
+        rtl: true,
+        contentOnly: true
+    },
+    { // Kurdish
+        id: "ku",
+        name: "کوردی",
+        rtl: true,
+        contentOnly: true
+    },
+    { // Persian
+        id: "fa",
+        name: "فارسی",
+        rtl: true,
+        contentOnly: true
+    }
+].sort((a, b) => a.name.localeCompare(b.name));
+
+export async function initializeTranslations() {
+    const resourceDir = getResourceDir();
+
+    // Initialize translations
+    await i18next.use(Backend).init({
+        lng: getCurrentLanguage(),
+        fallbackLng: "en",
+        ns: "server",
+        backend: {
+            loadPath: join(resourceDir, "translations/{{lng}}/{{ns}}.json")
+        }
+    });
+}
+
+export function getLocales(): Locale[] {
+    return LOCALES;
+}
+
+function getCurrentLanguage() {
+    let language;
+    if (sql_init.isDbInitialized()) {
+        language = options.getOptionOrNull("locale");
+    }
+
+    if (!language) {
+        console.info("Language option not found, falling back to en.");
+        language = "en";
+    }
+
+    return language;
+}
+
+export async function changeLanguage(locale: string) {
+    await i18next.changeLanguage(locale);
+    hidden_subtree.checkHiddenSubtree(true, { restoreNames: true });
+}