fix: #398

apps/venus/src/app/common/Header.tsx

@@ -13,7 +13,7 @@ import AFFiNETextLogo from './affine-text-logo.png';
 import { HoverMenu } from './HoverMenu';
 import { MobileHeader } from './MobileHeader';
 
-import { options } from '../i18n';
+import { LOCALES } from '../i18n';
 
 export const AFFiNEHeader = () => {
     const matches = useMediaQuery('(max-width: 1024px)');
@@ -140,15 +140,15 @@ export const AFFiNEHeader = () => {
                     }}
                 />
                 <Select
-                    defaultValue="en"
+                    defaultValue={i18n.language}
                     sx={{ display: matchesIPAD ? 'none' : 'intial' }}
                     onChange={changeLanguage}
                     size="md"
                     variant="plain"
                 >
-                    {options.map(option => (
-                        <Option key={option.value} value={option.value}>
-                            {option.text}
+                    {LOCALES.map(lang => (
+                        <Option key={lang.tag} value={lang.tag}>
+                            {lang.originalName}
                         </Option>
                     ))}
                 </Select>

apps/venus/src/app/i18n/index.ts

@@ -1,25 +1,63 @@
-import i18next from 'i18next';
-import { initReactI18next } from 'react-i18next';
-import en_US from './resources/en.json';
-import zh_CN from './resources/zh.json';
+import i18next, { Resource } from 'i18next';
+import {
+    I18nextProvider,
+    initReactI18next,
+    useTranslation,
+} from 'react-i18next';
+import { LOCALES } from './resources';
+import type en_US from './resources/en.json';
 
-const resources = {
-    en: en_US,
-    zh: zh_CN,
-} as const;
+// See https://react.i18next.com/latest/typescript
+declare module 'react-i18next' {
+    interface CustomTypeOptions {
+        // custom namespace type if you changed it
+        // defaultNS: 'ns1';
+        // custom resources type
+        resources: {
+            en: typeof en_US;
+        };
+    }
+}
+
+const STORAGE_KEY = 'i18n_lng';
+
+export { i18n, useTranslation, I18nProvider, LOCALES };
+
+const resources = LOCALES.reduce<Resource>(
+    (acc, { tag, res }) => ({ ...acc, [tag]: { translation: res } }),
+    {}
+);
+
+const fallbackLng = LOCALES[0].tag;
+const standardizeLocale = (language: string) => {
+    if (LOCALES.find(locale => locale.tag === language)) return language;
+    if (
+        LOCALES.find(
+            locale => locale.tag === language.slice(0, 2).toLowerCase()
+        )
+    )
+        return language;
+    return fallbackLng;
+};
+
+const language = standardizeLocale(
+    localStorage.getItem(STORAGE_KEY) ?? navigator.language
+);
+
+const i18n = i18next.createInstance();
+i18n.use(initReactI18next).init({
+    lng: language,
+    fallbackLng,
+    debug: process.env['NODE_ENV'] === 'development',
 
-i18next.use(initReactI18next).init({
-    lng: 'en',
-    fallbackLng: 'en',
     resources,
     interpolation: {
         escapeValue: false, // not needed for react as it escapes by default
     },
 });
 
-export const options = [
-    { value: 'en', text: 'English' },
-    { value: 'zh', text: '简体中文' },
-];
+i18n.on('languageChanged', lng => {
+    localStorage.setItem(STORAGE_KEY, lng);
+});
 
-export { i18next };
+const I18nProvider = I18nextProvider;