feat: add default language configuration

web/src/App.tsx

@@ -10,38 +10,7 @@ import { Routes, Route, Navigate } from 'react-router';
 import SetupPage from './pages/SetupPage.tsx';
 import { I18nProvider } from './i18n';
 
-function AppInner() {
-  const [status, setStatus] = useState<SystemStatus | null>(null);
-  useEffect(() => {
-    async function checkInitialization() {
-      try {
-        const status = await getStatus();
-        setStatus(status);
-        document.title = status.title;
-        let favicon = document.querySelector("link[rel*='icon']") as HTMLLinkElement | null;
-        if (!favicon) {
-          favicon = document.createElement('link');
-          favicon.rel = 'icon';
-          document.head.appendChild(favicon);
-        }
-        if (favicon) {
-          favicon.href = status.favicon || status.logo;
-        }
-      } catch (error) {
-        console.error("Failed to check initialization status:", error);
-      }
-    }
-    checkInitialization();
-  }, []);
-
-  if (status === null) {
-    return (
-      <div style={{ display: 'flex', justifyContent: 'center', alignItems: 'center', height: '100vh' }}>
-        <Spin size="large" />
-      </div>
-    );
-  }
-
+function AppInner({ status }: { status: SystemStatus }) {
   return (
     <SystemContext.Provider value={status}>
       <AuthProvider>
@@ -61,9 +30,41 @@ function AppInner() {
 }
 
 export default function App() {
+  const [status, setStatus] = useState<SystemStatus | null>(null);
+
+  useEffect(() => {
+    async function checkInitialization() {
+      try {
+        const nextStatus = await getStatus();
+        setStatus(nextStatus);
+        document.title = nextStatus.title;
+        let favicon = document.querySelector("link[rel*='icon']") as HTMLLinkElement | null;
+        if (!favicon) {
+          favicon = document.createElement('link');
+          favicon.rel = 'icon';
+          document.head.appendChild(favicon);
+        }
+        if (favicon) {
+          favicon.href = nextStatus.favicon || nextStatus.logo;
+        }
+      } catch (error) {
+        console.error("Failed to check initialization status:", error);
+      }
+    }
+    checkInitialization();
+  }, []);
+
+  if (status === null) {
+    return (
+      <div style={{ display: 'flex', justifyContent: 'center', alignItems: 'center', height: '100vh' }}>
+        <Spin size="large" />
+      </div>
+    );
+  }
+
   return (
-    <I18nProvider>
-      <AppInner />
+    <I18nProvider defaultLanguage={status.default_language}>
+      <AppInner status={status} />
     </I18nProvider>
   );
 }

web/src/api/config.ts

@@ -1,4 +1,5 @@
 import request from './client';
+import type { Lang } from '../i18n/lang';
 
 export async function getConfig(key: string) {
   return request<{ key: string; value: string }>('/config/?key=' + encodeURIComponent(key));
@@ -25,6 +26,7 @@ export interface SystemStatus {
   logo: string;
   favicon: string;
   is_initialized: boolean;
+  default_language?: Lang;
   app_domain?: string;
   file_domain?: string;
 }

web/src/apps/PluginHost/index.tsx

@@ -1,6 +1,7 @@
 import React, { useEffect, useMemo, useRef } from 'react';
 import type { AppComponentProps, AppOpenComponentProps } from '../types';
 import type { PluginItem } from '../../api/plugins';
+import { useI18n } from '../../i18n';
 
 export interface PluginAppHostProps extends AppComponentProps {
   plugin: PluginItem;
@@ -34,6 +35,7 @@ export const PluginAppHost: React.FC<PluginAppHostProps> = ({
   entry,
   onRequestClose,
 }) => {
+  const { lang } = useI18n();
   const iframeRef = useRef<HTMLIFrameElement>(null);
   const onCloseRef = useRef(onRequestClose);
   onCloseRef.current = onRequestClose;
@@ -45,10 +47,11 @@ export const PluginAppHost: React.FC<PluginAppHostProps> = ({
         pluginVersion: plugin.version || '',
         pluginStyles: JSON.stringify(getPluginStylePaths(plugin)),
         mode: 'file',
+        lang,
         filePath,
         entry: JSON.stringify(entry),
       }),
-    [plugin, filePath, entry]
+    [plugin, filePath, entry, lang]
   );
 
   useEffect(() => {
@@ -86,6 +89,7 @@ export interface PluginAppOpenHostProps extends AppOpenComponentProps {
  * 注意：同源且不加 sandbox 时，不是安全沙箱（插件仍可通过 window.parent 访问宿主）。
  */
 export const PluginAppOpenHost: React.FC<PluginAppOpenHostProps> = ({ plugin, onRequestClose }) => {
+  const { lang } = useI18n();
   const iframeRef = useRef<HTMLIFrameElement>(null);
   const onCloseRef = useRef(onRequestClose);
   onCloseRef.current = onRequestClose;
@@ -97,8 +101,9 @@ export const PluginAppOpenHost: React.FC<PluginAppOpenHostProps> = ({ plugin, on
         pluginVersion: plugin.version || '',
         pluginStyles: JSON.stringify(getPluginStylePaths(plugin)),
         mode: 'app',
+        lang,
       }),
-    [plugin]
+    [plugin, lang]
   );
 
   useEffect(() => {

web/src/i18n/index.tsx

@@ -2,8 +2,8 @@ import { createContext, useCallback, useContext, useMemo, useState, useEffect }
 import type { PropsWithChildren } from 'react';
 import en from './locales/en.json';
 import zhOverrides from './locales/zh.json';
+import { normalizeLang, persistLang, readStoredLang, type Lang } from './lang';
 
-type Lang = 'zh' | 'en';
 type Dict = Record<string, string>;
 
 const dicts: Record<Lang, Dict> = {
@@ -11,9 +11,13 @@ const dicts: Record<Lang, Dict> = {
   zh: { ...en, ...zhOverrides },
 };
 
+interface SetLangOptions {
+  persist?: boolean;
+}
+
 export interface I18nContextValue {
   lang: Lang;
-  setLang: (lang: Lang) => void;
+  setLang: (lang: Lang, options?: SetLangOptions) => void;
   t: (key: string, params?: Record<string, string | number>) => string;
 }
 
@@ -24,13 +28,26 @@ function interpolate(template: string, params?: Record<string, string | number>)
   return template.replace(/\{(\w+)\}/g, (_, k) => String(params[k] ?? `{${k}}`));
 }
 
-export function I18nProvider({ children }: PropsWithChildren) {
-  const [lang, setLangState] = useState<Lang>(() => (localStorage.getItem('lang') as Lang) || 'zh');
+interface I18nProviderProps {
+  defaultLanguage?: Lang;
+}
 
-  const setLang = useCallback((l: Lang) => {
-    setLangState(l);
-    localStorage.setItem('lang', l);
-  }, []);
+export function I18nProvider({ children, defaultLanguage }: PropsWithChildren<I18nProviderProps>) {
+  const fallbackLang = normalizeLang(defaultLanguage, 'zh');
+  const [lang, setLangState] = useState<Lang>(() => readStoredLang() ?? fallbackLang);
+
+  const setLang = useCallback((nextLang: Lang, options?: SetLangOptions) => {
+    const normalized = normalizeLang(nextLang, fallbackLang);
+    setLangState(normalized);
+    if (options?.persist === false) return;
+    persistLang(normalized);
+  }, [fallbackLang]);
+
+  useEffect(() => {
+    if (!readStoredLang()) {
+      setLangState(fallbackLang);
+    }
+  }, [fallbackLang]);
 
   useEffect(() => {
     document.documentElement.lang = lang;

web/src/i18n/lang.ts

@@ -0,0 +1,42 @@
+export type Lang = 'zh' | 'en';
+
+const LANG_STORAGE_KEY = 'lang';
+
+export function parseLang(raw: unknown): Lang | null {
+  if (typeof raw !== 'string') return null;
+  const value = raw.trim().toLowerCase();
+  if (!value) return null;
+  if (value === 'en' || value.startsWith('en-')) return 'en';
+  if (value === 'zh' || value.startsWith('zh-')) return 'zh';
+  return null;
+}
+
+export function normalizeLang(raw: unknown, fallback: Lang = 'zh'): Lang {
+  return parseLang(raw) ?? fallback;
+}
+
+export function readStoredLang(): Lang | null {
+  if (typeof window === 'undefined') return null;
+  try {
+    return parseLang(window.localStorage.getItem(LANG_STORAGE_KEY));
+  } catch {
+    return null;
+  }
+}
+
+export function persistLang(lang: Lang): void {
+  if (typeof window === 'undefined') return;
+  try {
+    window.localStorage.setItem(LANG_STORAGE_KEY, lang);
+  } catch {
+    void 0;
+  }
+}
+
+export function getActiveLang(fallback: Lang = 'zh'): Lang {
+  if (typeof document !== 'undefined') {
+    const documentLang = parseLang(document.documentElement.lang);
+    if (documentLang) return documentLang;
+  }
+  return readStoredLang() ?? fallback;
+}

web/src/i18n/locales/en.json

@@ -31,6 +31,8 @@
   "Language": "Language",
   "Chinese": "中文",
   "English": "English",
+  "Default Language": "Default Language",
+  "Used when the user has not selected a language": "Used when the user has not selected a language",
   "Full Name": "Full Name",
   "Email": "Email",
   "Change Password": "Change Password",

web/src/i18n/locales/zh.json

@@ -52,6 +52,10 @@
   "Profile": "个人资料",
   "Account Settings": "账户设置",
   "Language": "语言",
+  "Chinese": "中文",
+  "English": "English",
+  "Default Language": "默认语言",
+  "Used when the user has not selected a language": "用户未手动选择语言时使用",
   "Full Name": "昵称",
   "Email": "邮箱",
   "Change Password": "修改密码",

web/src/pages/SystemSettingsPage/SystemSettingsPage.tsx

@@ -66,7 +66,7 @@ export default function SystemSettingsPage({ tabKey, onTabNavigate }: SystemSett
       });
   }, [t]);
 
-  const handleSave = async (values: Record<string, unknown>) => {
+  const handleSave = async (values: Record<string, unknown>): Promise<boolean> => {
     setLoading(true);
     try {
       for (const [key, value] of Object.entries(values)) {
@@ -81,10 +81,13 @@ export default function SystemSettingsPage({ tabKey, onTabNavigate }: SystemSett
       if (Object.keys(values).some(k => Object.values(THEME_KEYS).includes(k))) {
         await refreshTheme();
       }
+      return true;
     } catch (e: any) {
       message.error(e.message || t('Save failed'));
+      return false;
+    } finally {
+      setLoading(false);
     }
-    setLoading(false);
   };
 
   // 离开“外观设置”时，恢复后端持久化配置（取消未保存的预览）

web/src/pages/SystemSettingsPage/components/AppSettingsTab.tsx

@@ -2,6 +2,7 @@ import { Alert, Button, Divider, Form, Input, Select, Switch, message } from 'an
 import { useEffect, useMemo, useState } from 'react';
 import { rolesApi, type RoleInfo } from '../../../api/roles';
 import { useI18n } from '../../../i18n';
+import { normalizeLang, readStoredLang } from '../../../i18n/lang';
 
 interface AppConfigKey {
   key: string;
@@ -12,7 +13,7 @@ interface AppConfigKey {
 interface AppSettingsTabProps {
   config: Record<string, string>;
   loading: boolean;
-  onSave: (values: Record<string, unknown>) => Promise<void>;
+  onSave: (values: Record<string, unknown>) => Promise<boolean>;
   configKeys: AppConfigKey[];
 }
 
@@ -22,7 +23,7 @@ export default function AppSettingsTab({
   onSave,
   configKeys,
 }: AppSettingsTabProps) {
-  const { t } = useI18n();
+  const { t, setLang } = useI18n();
   const [rolesLoading, setRolesLoading] = useState(false);
   const [roles, setRoles] = useState<RoleInfo[]>([]);
 
@@ -52,6 +53,7 @@ export default function AppSettingsTab({
     const roleId = roleIdRaw ? Number(roleIdRaw) : undefined;
     return {
       ...Object.fromEntries(configKeys.map(({ key, default: def }) => [key, config[key] ?? def ?? ''])),
+      APP_DEFAULT_LANGUAGE: normalizeLang(config.APP_DEFAULT_LANGUAGE, 'zh'),
       AUTH_ALLOW_REGISTER: allowRegister,
       AUTH_DEFAULT_REGISTER_ROLE_ID: Number.isFinite(roleId) ? roleId : undefined,
     };
@@ -66,12 +68,17 @@ export default function AppSettingsTab({
         for (const { key } of configKeys) {
           payload[key] = vals[key];
         }
+        const defaultLanguage = normalizeLang(vals.APP_DEFAULT_LANGUAGE, 'zh');
+        payload.APP_DEFAULT_LANGUAGE = defaultLanguage;
         const allow = !!vals.AUTH_ALLOW_REGISTER;
         payload.AUTH_ALLOW_REGISTER = allow ? 'true' : 'false';
         if (allow) {
           payload.AUTH_DEFAULT_REGISTER_ROLE_ID = String(vals.AUTH_DEFAULT_REGISTER_ROLE_ID);
         }
-        await onSave(payload);
+        const saved = await onSave(payload);
+        if (saved && !readStoredLang()) {
+          setLang(defaultLanguage, { persist: false });
+        }
       }}
       style={{ marginTop: 24 }}
       key={JSON.stringify(config)}
@@ -82,6 +89,20 @@ export default function AppSettingsTab({
         </Form.Item>
       ))}
 
+      <Form.Item
+        name="APP_DEFAULT_LANGUAGE"
+        label={t('Default Language')}
+        extra={t('Used when the user has not selected a language')}
+      >
+        <Select
+          size="large"
+          options={[
+            { value: 'zh', label: t('Chinese') },
+            { value: 'en', label: t('English') },
+          ]}
+        />
+      </Form.Item>
+
       <Divider titlePlacement="left">{t('Registration Settings')}</Divider>
 
       <Alert

web/src/pages/SystemSettingsPage/components/AppearanceSettingsTab.tsx

@@ -13,7 +13,7 @@ interface ThemeKeyMap {
 interface AppearanceSettingsTabProps {
   config: Record<string, string>;
   loading: boolean;
-  onSave: (values: Record<string, unknown>) => Promise<void>;
+  onSave: (values: Record<string, unknown>) => Promise<boolean>;
   themeKeys: ThemeKeyMap;
 }
 

web/src/pages/SystemSettingsPage/components/EmailSettingsTab.tsx

@@ -28,7 +28,7 @@ import {
 interface EmailSettingsTabProps {
   config: Record<string, string>;
   loading: boolean;
-  onSave: (values: Record<string, unknown>) => Promise<void>;
+  onSave: (values: Record<string, unknown>) => Promise<boolean>;
 }
 
 interface EmailFormValues {

web/src/pages/SystemSettingsPage/components/ProtocolMappingsTab.tsx

@@ -5,7 +5,7 @@ import { useI18n } from '../../../i18n';
 interface ProtocolMappingsTabProps {
   config: Record<string, string>;
   loading: boolean;
-  onSave: (values: Record<string, unknown>) => Promise<void>;
+  onSave: (values: Record<string, unknown>) => Promise<boolean>;
 }
 
 const WEBDAV_KEY = 'WEBDAV_MAPPING_ENABLED';

web/src/plugin-frame.ts

@@ -7,12 +7,14 @@ import type { PluginItem } from './api/plugins';
 import { pluginsApi } from './api/plugins';
 import request from './api/client';
 import { vfsApi, type VfsEntry } from './api/vfs';
+import { parseLang } from './i18n/lang';
 
 type FrameMode = 'file' | 'app';
 
 type FrameQuery = {
   pluginKey: string;
   mode: FrameMode;
+  lang: string;
   filePath: string;
   pluginVersion: string;
   pluginStyles: string[] | null;
@@ -65,6 +67,7 @@ function getQuery(): FrameQuery {
   const params = new URLSearchParams(window.location.search);
   const pluginKey = (params.get('pluginKey') || '').trim();
   const mode = (params.get('mode') || 'file') as FrameMode;
+  const lang = (params.get('lang') || '').trim();
   const filePath = (params.get('filePath') || '').trim();
   const pluginVersion = (params.get('pluginVersion') || '').trim();
 
@@ -88,7 +91,7 @@ function getQuery(): FrameQuery {
       }
       : null;
 
-  return { pluginKey, mode, filePath, pluginVersion, pluginStyles, entry };
+  return { pluginKey, mode, lang, filePath, pluginVersion, pluginStyles, entry };
 }
 
 function postToParent(data: any) {
@@ -279,9 +282,14 @@ async function buildFileContext(filePath: string, entryOverride: VfsEntry | null
 }
 
 async function main() {
+  const query = getQuery();
+  const frameLang = parseLang(query.lang);
+  if (frameLang) {
+    document.documentElement.lang = frameLang;
+  }
   initExternals();
 
-  const { pluginKey, mode, filePath, pluginVersion, pluginStyles, entry } = getQuery();
+  const { pluginKey, mode, filePath, pluginVersion, pluginStyles, entry } = query;
   if (!pluginKey) {
     renderStatus('Missing pluginKey in query string', true);
     return;

web/src/plugins/externals.ts

@@ -21,8 +21,7 @@ import { pluginsApi } from '../api/plugins';
 // 类型定义
 import type { VfsEntry, DirListing } from '../api/client';
 import type { PluginItem } from '../api/plugins';
-
-type Lang = 'zh' | 'en';
+import { getActiveLang, normalizeLang, type Lang } from '../i18n/lang';
 type Dict = Record<string, string>;
 type Dicts = Partial<Record<Lang, Dict>>;
 
@@ -197,10 +196,8 @@ declare global {
  * 初始化并暴露外部依赖
  */
 export function initExternals(): void {
-  const normalizeLang = (raw: unknown): Lang => (raw === 'en' ? 'en' : 'zh');
-
   const i18nApi = {
-    getLang: () => normalizeLang(localStorage.getItem('lang')),
+    getLang: () => getActiveLang(),
     subscribe: (cb: (lang: Lang) => void) => {
       const handler = (e: Event) => {
         const lang = (e as CustomEvent)?.detail?.lang as Lang;