fixup: i18n for prompts

app/locales/index.ts

@@ -1,56 +1,57 @@
-import CN from './cn'
-import EN from './en'
-import TW from './tw'
+import CN from "./cn";
+import EN from "./en";
+import TW from "./tw";
 
-export type { LocaleType } from './cn'
+export type { LocaleType } from "./cn";
 
-type Lang = 'en' | 'cn' | 'tw'
+export const AllLangs = ["en", "cn", "tw"] as const;
+type Lang = typeof AllLangs[number];
 
-const LANG_KEY = 'lang'
+const LANG_KEY = "lang";
 
 function getItem(key: string) {
-    try {
-        return localStorage.getItem(key)
-    } catch {
-        return null
-    }
+  try {
+    return localStorage.getItem(key);
+  } catch {
+    return null;
+  }
 }
 
 function setItem(key: string, value: string) {
-    try {
-        localStorage.setItem(key, value)
-    } catch { }
+  try {
+    localStorage.setItem(key, value);
+  } catch {}
 }
 
 function getLanguage() {
-    try {
-        return navigator.language.toLowerCase()
-    } catch {
-        return 'cn'
-    }
+  try {
+    return navigator.language.toLowerCase();
+  } catch {
+    return "cn";
+  }
 }
 
 export function getLang(): Lang {
-    const savedLang = getItem(LANG_KEY)
+  const savedLang = getItem(LANG_KEY);
 
-    if (['en', 'cn', 'tw'].includes(savedLang ?? '')) {
-        return savedLang as Lang
-    }
+  if (AllLangs.includes((savedLang ?? "") as Lang)) {
+    return savedLang as Lang;
+  }
 
-    const lang = getLanguage()
+  const lang = getLanguage();
 
-    if (lang.includes('zh') || lang.includes('cn')) {
-        return 'cn'
-    } else if (lang.includes('tw')) {
-        return 'tw'
-    } else {
-        return 'en'
-    }
+  if (lang.includes("zh") || lang.includes("cn")) {
+    return "cn";
+  } else if (lang.includes("tw")) {
+    return "tw";
+  } else {
+    return "en";
+  }
 }
 
 export function changeLang(lang: Lang) {
-    setItem(LANG_KEY, lang)
-    location.reload()
+  setItem(LANG_KEY, lang);
+  location.reload();
 }
 
-export default { en: EN, cn: CN, tw: TW }[getLang()]
+export default { en: EN, cn: CN, tw: TW }[getLang()];