package.json

@@ -27,9 +27,11 @@
     "wrangler": "^3.78.2"
   },
   "dependencies": {
+    "@formatjs/intl-localematcher": "^0.5.4",
     "@nanostores/persistent": "^0.10.2",
     "@nanostores/solid": "^0.4.2",
     "@solid-primitives/event-listener": "^2.3.3",
+    "@solid-primitives/i18n": "^2.1.1",
     "@solid-primitives/intersection-observer": "^2.1.6",
     "@solid-primitives/resize-observer": "^2.0.26",
     "@solidjs/router": "^0.14.5",

src/App.tsx

@@ -6,6 +6,7 @@ import {
   createSignal,
   ErrorBoundary,
   lazy,
+  onCleanup,
 } from "solid-js";
 import { useRootTheme } from "./material/mui.js";
 import {
@@ -15,6 +16,7 @@ import {
 } from "./masto/clients.js";
 import { $accounts } from "./accounts/stores.js";
 import { useStore } from "@nanostores/solid";
+import { DateFnScope, useLanguage } from "./platform/i18n.jsx";
 
 const AccountSignIn = lazy(() => import("./accounts/SignIn.js"));
 const AccountMastodonOAuth2Callback = lazy(
@@ -47,6 +49,7 @@ const App: Component = () => {
   const theme = useRootTheme();
   const accts = useStore($accounts);
   const clientStore = createSignal<Session[]>([]);
+  const lang = useLanguage();
 
   createRenderEffect(() => {
     const [, setClients] = clientStore;
@@ -55,6 +58,16 @@ const App: Component = () => {
     );
   });
 
+  createRenderEffect(() => {
+    const root = document.querySelector(":root")!;
+    root.setAttribute("lang", lang());
+  });
+
+  onCleanup(() => {
+    const root = document.querySelector(":root")!;
+    root.removeAttribute("lang");
+  });
+
   const UnexpectedError = lazy(() => import("./UnexpectedError.js"));
 
   return (
@@ -65,9 +78,11 @@ const App: Component = () => {
       }}
     >
       <ThemeProvider theme={theme()}>
-        <ClientProvider value={clientStore}>
-          <Routing />
-        </ClientProvider>
+        <DateFnScope>
+          <ClientProvider value={clientStore}>
+            <Routing />
+          </ClientProvider>
+        </DateFnScope>
       </ThemeProvider>
     </ErrorBoundary>
   );

src/platform/i18n.tsx

@@ -0,0 +1,170 @@
+import {
+  ParentComponent,
+  createContext,
+  createMemo,
+  createRenderEffect,
+  createResource,
+  useContext,
+} from "solid-js";
+import { match } from "@formatjs/intl-localematcher";
+import { Accessor, createEffect, createSignal } from "solid-js";
+import { $settings } from "../settings/stores";
+import { enGB } from "date-fns/locale/en-GB";
+import { useStore } from "@nanostores/solid";
+import type { Locale } from "date-fns";
+import type { Template } from "@solid-primitives/i18n";
+
+async function synchronised(
+  name: string,
+  callback: () => Promise<void> | void,
+): Promise<void> {
+  await navigator.locks.request(name, callback);
+}
+
+export const SUPPORTED_LANGS = ["en", "zh-Hans"];
+
+export const SUPPORTED_REGIONS = ["en_US", "en_GB", "zh_CN"];
+
+const DEFAULT_LANG = "en";
+
+/**
+ * Decide the using language for the user.
+ * @returns the selected language tag
+ */
+export function autoMatchLangTag() {
+  return match(Array.from(navigator.languages), SUPPORTED_LANGS, DEFAULT_LANG);
+}
+
+const DateFnLocaleCx = createContext<Accessor<Locale>>(() => enGB);
+
+const cachedDateFnLocale: Record<string, Locale> = {
+  enGB,
+};
+
+export function autoMatchRegion() {
+  const regions = navigator.languages
+    .map((x) => {
+      const parts = x.split("_");
+      if (parts.length > 1) {
+        return parts[1];
+      }
+      return undefined;
+    })
+    .filter((x): x is string => !!x);
+  for (const r of regions) {
+    for (const available of SUPPORTED_REGIONS) {
+      if (available.toLowerCase().endsWith(r.toLowerCase())) {
+        return available;
+      }
+    }
+  }
+  return "en_GB";
+}
+
+export function useRegion() {
+  const appSettings = useStore($settings);
+
+  return createMemo(() => {
+    const settings = appSettings();
+    if (typeof settings.region !== "undefined") {
+      return settings.region;
+    } else {
+      return autoMatchRegion();
+    }
+  });
+}
+
+async function importDateFnLocale(tag: string): Promise<Locale> {
+  switch (tag.toLowerCase()) {
+    case "en_us":
+      return (await import("date-fns/locale/en-US")).enUS;
+    case "en_gb":
+      return (await import("date-fns/locale/en-GB")).enGB;
+    case "zh_cn":
+      return (await import("date-fns/locale/zh-CN")).zhCN;
+    default:
+      throw new TypeError(`unsupported tag "${tag}"`);
+  }
+}
+
+/**
+ * Provides runtime values and fetch dependencies for date-fns locale
+ */
+export const DateFnScope: ParentComponent = (props) => {
+  const [dateFnLocale, setDateFnLocale] = createSignal(enGB);
+  const region = useRegion();
+
+  createEffect(() => {
+    const dateFnLocaleName = region();
+
+    if (cachedDateFnLocale[dateFnLocaleName]) {
+      setDateFnLocale(cachedDateFnLocale[dateFnLocaleName]);
+    } else {
+      synchronised("i18n-wrapper-load-date-fns-locale", async () => {
+        if (cachedDateFnLocale[dateFnLocaleName]) {
+          setDateFnLocale(cachedDateFnLocale[dateFnLocaleName]);
+          return;
+        }
+        const target = `date-fns/locale/${dateFnLocaleName}`;
+        try {
+          const mod = await importDateFnLocale(dateFnLocaleName);
+          cachedDateFnLocale[dateFnLocaleName] = mod;
+          setDateFnLocale(mod);
+        } catch (reason) {
+          console.error(
+            {
+              act: "load-date-fns-locale",
+              stat: "failed",
+              reason,
+              target,
+            },
+            "failed to load date-fns locale",
+          );
+        }
+      });
+    }
+  });
+
+  return (
+    <DateFnLocaleCx.Provider value={dateFnLocale}>
+      {props.children}
+    </DateFnLocaleCx.Provider>
+  );
+};
+
+/**
+ * Get the {@link Locale} object for date-fns.
+ *
+ * This function must be using in {@link DateFnScope}
+ *
+ * @returns Accessor for Locale
+ */
+export function useDateFnLocale(): Accessor<Locale> {
+  const cx = useContext(DateFnLocaleCx);
+  return cx;
+}
+
+export function useLanguage() {
+  const settings = useStore($settings);
+  return () => settings().language || autoMatchLangTag();
+}
+
+export function createStringResource<
+  M extends Record<string, string | Template<any>>,
+>(importFn: (code: string) => Promise<{ default: M }>) {
+  const language = useLanguage();
+  const cache: Record<string, M | undefined> = {};
+
+  return createResource(
+    () => [language()] as const,
+    async ([nlang]) => {
+      if (cache[nlang]) {
+        return cache[nlang];
+      }
+
+      const { default: dict } = await importFn(`${nlang}`);
+
+      return dict;
+    },
+  );
+}

src/settings/Settings.tsx

@@ -7,32 +7,50 @@ import {
   List,
   ListItem,
   ListItemButton,
+  ListItemIcon,
   ListItemSecondaryAction,
   ListItemText,
   ListSubheader,
+  NativeSelect,
   Switch,
   Toolbar,
 } from "@suid/material";
 import {
   Close as CloseIcon,
+  Public as PublicIcon,
   Refresh as RefreshIcon,
+  Translate as TranslateIcon,
 } from "@suid/icons-material";
 import { useNavigate } from "@solidjs/router";
 import { Title } from "../material/typography.jsx";
 import { css } from "solid-styled";
 import { useSignedInProfiles } from "../masto/acct.js";
 import { signOut, type Account } from "../accounts/stores.js";
-import { intlFormat } from "date-fns";
+import { format, intlFormat } from "date-fns";
 import { useStore } from "@nanostores/solid";
 import { $settings } from "./stores.js";
 import { useRegisterSW } from "virtual:pwa-register/solid";
+import {
+  autoMatchLangTag,
+  autoMatchRegion,
+  createStringResource,
+  SUPPORTED_LANGS,
+  SUPPORTED_REGIONS,
+  useDateFnLocale,
+} from "../platform/i18n.jsx";
+import { resolveTemplate, translator } from "@solid-primitives/i18n";
 
 const Settings: ParentComponent = () => {
+  const [strings] = createStringResource(
+    (code) => import(`./i18n/${code}.json`),
+  );
+  const t = translator(strings, resolveTemplate);
   const navigate = useNavigate();
   const settings$ = useStore($settings);
   const {
     needRefresh: [needRefresh],
   } = useRegisterSW();
+  const dateFnLocale = useDateFnLocale();
 
   const [profiles] = useSignedInProfiles();
 
@@ -60,7 +78,7 @@ const Settings: ParentComponent = () => {
             <IconButton color="inherit" onClick={[navigate, -1]} disableRipple>
               <CloseIcon />
             </IconButton>
-            <Title>Settings</Title>
+            <Title>{t("Settings")}</Title>
           </Toolbar>
         </AppBar>
       }
@@ -68,16 +86,16 @@ const Settings: ParentComponent = () => {
       <List class="setting-list" use:solid-styled>
         <li>
           <ul>
-            <ListSubheader>Accounts</ListSubheader>
+            <ListSubheader>{t("Accounts")}</ListSubheader>
             <ListItem>
-              <ListItemText>All Notifications</ListItemText>
+              <ListItemText>{t("All Notifications")}</ListItemText>
               <ListItemSecondaryAction>
                 <Switch value={false} />
               </ListItemSecondaryAction>
             </ListItem>
             <Divider />
             <ListItem>
-              <ListItemText>Sign in...</ListItemText>
+              <ListItemText>{t("Sign in...")}</ListItemText>
             </ListItem>
             <Divider />
           </ul>
@@ -101,7 +119,7 @@ const Settings: ParentComponent = () => {
           </For>
         </li>
         <li>
-          <ListSubheader>Reading</ListSubheader>
+          <ListSubheader>{t("Reading")}</ListSubheader>
           <ListItem>
             <ListItemText secondary="Regular">Fonts</ListItemText>
           </ListItem>
@@ -114,8 +132,8 @@ const Settings: ParentComponent = () => {
               )
             }
           >
-            <ListItemText secondary="Tutu will download toots before you scroll to the position.">
-              Prefetch Toots
+            <ListItemText secondary={t("Prefetch Toots.2nd")}>
+              {t("Prefetch Toots")}
             </ListItemText>
             <ListItemSecondaryAction>
               <Switch checked={!settings$().prefetchTootsDisabled} />
@@ -124,24 +142,93 @@ const Settings: ParentComponent = () => {
           <Divider />
         </li>
         <li>
-          <ListSubheader>This Application</ListSubheader>
+          <ListSubheader>{t("This Application")}</ListSubheader>
           <ListItem>
-            <ListItemText secondary="Comformtable tooting experience.">
-              About Tutu
+            <ListItemIcon>
+              <TranslateIcon />
+            </ListItemIcon>
+            <ListItemText>{t("Language")}</ListItemText>
+            <ListItemSecondaryAction>
+              <NativeSelect
+                value={settings$().language || "xauto"}
+                onChange={(e) => {
+                  $settings.setKey(
+                    "language",
+                    e.currentTarget.value === "xauto"
+                      ? undefined
+                      : e.currentTarget.value,
+                  );
+                }}
+              >
+                <option value={"xauto"}>
+                  {t("lang.auto", {
+                    detected: t("lang." + autoMatchLangTag()),
+                  })}
+                </option>
+                <For each={SUPPORTED_LANGS}>
+                  {(code) => <option value={code}>{t("lang." + code)}</option>}
+                </For>
+              </NativeSelect>
+            </ListItemSecondaryAction>
+          </ListItem>
+          <Divider />
+          <ListItem>
+            <ListItemIcon>
+              <PublicIcon />
+            </ListItemIcon>
+            <ListItemText>{t("Region")}</ListItemText>
+            <ListItemSecondaryAction>
+              <NativeSelect
+                value={settings$().region}
+                onChange={(e) => {
+                  $settings.setKey(
+                    "region",
+                    e.currentTarget.value === "xauto"
+                      ? undefined
+                      : e.currentTarget.value,
+                  );
+                }}
+              >
+                <option value={"xauto"}>
+                  {t("region.auto", {
+                    detected: t("region." + autoMatchRegion()),
+                  })}
+                </option>
+                <For each={SUPPORTED_REGIONS}>
+                  {(code) => (
+                    <option value={code}>{t("region." + code)}</option>
+                  )}
+                </For>
+              </NativeSelect>
+            </ListItemSecondaryAction>
+          </ListItem>
+          <Divider />
+          <ListItem>
+            <ListItemText secondary={t("About Tutu.2nd")}>
+              {t("About Tutu")}
             </ListItemText>
           </ListItem>
           <Divider />
           <ListItem>
             <ListItemText
-              secondary={`Using v${import.meta.env.PACKAGE_VERSION} (built on ${intlFormat(import.meta.env.BUILT_AT)}, ${import.meta.env.MODE})`}
+              secondary={t("version", {
+                packageVersion: import.meta.env.PACKAGE_VERSION,
+                builtAt: format(
+                  import.meta.env.BUILT_AT,
+                  t("datefmt") || "yyyy/MM/dd",
+                  { locale: dateFnLocale() },
+                ),
+                buildMode: import.meta.env.MODE,
+              })}
             >
-              {needRefresh()
-                ? "An update is ready, restart the Tutu to apply"
-                : "No updates"}
+              {needRefresh() ? t("updates.ready") : t("updates.no")}
             </ListItemText>
             <Show when={needRefresh()}>
               <ListItemSecondaryAction>
-                <IconButton aria-label="Restart Now" onClick={() => window.location.reload()}>
+                <IconButton
+                  aria-label="Restart Now"
+                  onClick={() => window.location.reload()}
+                >
                   <RefreshIcon />
                 </IconButton>
               </ListItemSecondaryAction>

src/settings/i18n/en.json

@@ -0,0 +1,25 @@
+{
+  "Settings": "Settings",
+  "Accounts": "Accounts",
+  "All Notifications": "All Notifications",
+  "Sign in...": "Sign in...",
+  "Reading": "Reading",
+  "Prefetch Toots": "Prefetch Toots",
+  "Prefetch Toots.2nd": "Tutu will download the toots before you need.",
+  "This Application": "This Application",
+  "About Tutu": "About Tutu",
+  "About Tutu.2nd": "Comfortable tooting experience.",
+  "updates.ready": "An update is ready, restart the Tutu to apply",
+  "updates.no": "No updates",
+  "version": "Using v{{packageVersion}} (built on {{builtAt}}, {{buildMode}})",
+  "Language": "Language",
+  "Region": "Region",
+  "lang.auto": "Auto({{detected}})",
+  "lang.zh-Hans": "中文（简体）",
+  "lang.en": "English",
+  "region.auto": "Auto({{detected}})",
+  "region.en_GB": "Great Britan (English)",
+  "region.en_US": "United States (English)",
+  "region.zh_CN": "China Mainland (Chinese)",
+  "datefmt": "yyyy/MM/dd"
+}

src/settings/i18n/zh-Hans.json

@@ -0,0 +1,25 @@
+{
+  "Settings": "设置",
+  "Accounts": "所有账号",
+  "All Notifications": "所有通知",
+  "Sign in...": "登录新账户...",
+  "Reading": "阅读",
+  "Prefetch Toots": "提前下载嘟文",
+  "Prefetch Toots.2nd": "图图会在你可能需要的时候提前下载嘟文。",
+  "This Application": "本应用",
+  "About Tutu": "关于图图",
+  "About Tutu.2nd": "舒服地刷嘟。",
+  "updates.ready": "更新已准备好，下次开启会启动新版本",
+  "updates.no": "已是最新版本",
+  "version": "正在使用 v{{packageVersion}} ({{builtAt}}构建, {{buildMode}})",
+  "Language": "语言",
+  "Region": "区域",
+  "lang.auto": "自动（{{detected}}）",
+  "lang.zh-Hans": "中文（简体）",
+  "lang.en": "English",
+  "region.auto": "自动（{{detected}}）",
+  "region.en_GB": "英国和苏格兰（英语）",
+  "region.en_US": "美国（英语）",
+  "region.zh_CN": "中国大陆（中文）",
+  "datefmt": "yyyy年MM月dd日"
+}

src/settings/stores.ts

@@ -3,6 +3,8 @@ import { persistentMap } from "@nanostores/persistent";
 type Settings = {
   onGoingOAuth2Process?: string;
   prefetchTootsDisabled?: boolean;
+  language?: string;
+  region?: string;
 };
 
 export const $settings = persistentMap<Settings>(

src/timelines/RegularToot.tsx

@@ -36,6 +36,7 @@ import Button from "../material/Button.js";
 import MediaAttachmentGrid from "./MediaAttachmentGrid.js";
 import { FastAverageColor } from "fast-average-color";
 import Color from "colorjs.io";
+import { useDateFnLocale } from "../platform/i18n";
 
 type TootContentViewProps = {
   source?: string;
@@ -170,6 +171,7 @@ function TootActionGroup<T extends mastodon.v1.Status>(
 
 function TootAuthorGroup(props: { status: mastodon.v1.Status; now: Date }) {
   const toot = () => props.status;
+  const dateFnLocale = useDateFnLocale()
 
   return (
     <div class={tootStyle.tootAuthorGrp}>
@@ -187,7 +189,7 @@ function TootAuthorGroup(props: { status: mastodon.v1.Status; now: Date }) {
           }}
         />
         <time datetime={toot().createdAt}>
-          {formatRelative(toot().createdAt, props.now)}
+          {formatRelative(toot().createdAt, props.now, {locale: dateFnLocale()})}
         </time>
         <span>
           @{toot().account.username}@{new URL(toot().account.url).hostname}