chore: create standalone i18n utility for platform libraries (#23386)

* chore: create i18n for platform libraries

* fixup! chore: create i18n for platform libraries

* refactor: use previous version of i18n

* Revert "refactor: use previous version of i18n"

This reverts commit 0181ae1018d99ea6d5455d6dde5f3727e70422e1.

* refactor: use previous version of i18n

---------

Co-authored-by: supalarry <laurisskraucis@gmail.com>

packages/platform/libraries/i18n.ts

@@ -0,0 +1,83 @@
+import { createInstance } from "i18next";
+
+import { WEBAPP_URL } from "@calcom/lib/constants";
+import { fetchWithTimeout } from "@calcom/lib/fetchWithTimeout";
+import logger from "@calcom/lib/logger";
+
+/* eslint-disable @typescript-eslint/no-var-requires */
+const { i18n } = require("@calcom/config/next-i18next.config");
+
+const translationCache = new Map<string, Record<string, string>>();
+const i18nInstanceCache = new Map<string, any>();
+const SUPPORTED_NAMESPACES = ["common"];
+
+/**
+ * Loads translations for a specific locale and namespace with optimized caching
+ * @param {string} _locale - The locale code (e.g., 'en', 'fr', 'zh')
+ * @param {string} ns - The namespace for the translations
+ * @returns {Promise<Record<string, string>>} Translations object or fallback translations on failure
+ */
+export async function loadTranslations(_locale: string, _ns: string) {
+  let locale = _locale === "zh" ? "zh-CN" : _locale;
+  locale = i18n.locales.includes(locale) ? locale : "en";
+  const ns = SUPPORTED_NAMESPACES.includes(_ns) ? _ns : "common";
+  const cacheKey = `${locale}-${ns}`;
+
+  if (translationCache.has(cacheKey)) {
+    return translationCache.get(cacheKey);
+  }
+
+  const url = `${WEBAPP_URL}/static/locales/${locale}/${ns}.json`;
+  try {
+    const response = await fetchWithTimeout(
+      url,
+      {
+        cache: "no-store",
+      },
+      process.env.NODE_ENV === "development" ? 30000 : 3000
+    );
+
+    if (!response.ok) {
+      logger.error(`Failed to fetch translations: ${response.status}`);
+      return {};
+    }
+
+    const translations = await response.json();
+    translationCache.set(cacheKey, translations);
+    return translations;
+  } catch (err) {
+    console.error("loadTranslations Error:", err);
+
+    return {};
+  }
+}
+
+/**
+ * Creates or retrieves a cached i18next translation function for the specified locale and namespace
+ * @param {string} locale - The locale code (e.g., 'en', 'fr')
+ * @param {string} ns - The namespace for the translations
+ * @returns {Promise<Function>} A translation function bound to the specified locale and namespace
+ */
+export const getTranslation = async (locale: string, ns: string) => {
+  const cacheKey = `${locale}-${ns}`;
+  if (i18nInstanceCache.has(cacheKey)) {
+    return i18nInstanceCache.get(cacheKey).getFixedT(locale, ns);
+  }
+
+  const resources = await loadTranslations(locale, ns);
+
+  const _i18n = createInstance();
+  _i18n.init({
+    lng: locale,
+    resources: {
+      [locale]: {
+        [ns]: resources,
+      },
+    },
+    fallbackLng: "en",
+  });
+
+  // Cache the i18n instance
+  i18nInstanceCache.set(cacheKey, _i18n);
+  return _i18n.getFixedT(locale, ns);
+};

packages/platform/libraries/tsconfig.json

@@ -8,7 +8,11 @@
     "types": ["jest"],
     "outDir": "./dist",
     "emitDecoratorMetadata": true,
-    "experimentalDecorators": true
+    "experimentalDecorators": true,
+    "baseUrl": ".",
+    "paths": {
+      "@calcom/lib/server/i18n": ["./i18n.ts"]
+    }
   },
   "include": [".", "../../types/*.d.ts"],
   "exclude": [

packages/platform/libraries/vite.config.js

@@ -187,6 +187,9 @@ export default defineConfig({
   plugins: [react(), dts()],
   resolve: {
     alias: {
+      "@calcom/lib/server/i18n": path.resolve(__dirname, "./i18n.ts"),
+      "./server/i18n": path.resolve(__dirname, "./i18n.ts"),
+      "../server/i18n": path.resolve(__dirname, "./i18n.ts"),
       "@": path.resolve(__dirname, "./src"),
       "@calcom/lib": path.resolve(__dirname, "../../lib"),
       "@calcom/trpc": resolve("../../trpc"),