fix: dedupe post redirect language fallback

src/pages/PostRedirect/index.tsx

@@ -1,25 +1,43 @@
-import { useEffect } from "react";
+import { useEffect, useRef } from "react";
 import { useNavigate, useParams } from "react-router-dom";
 import { getJSON } from "../../api";
-import { langQuery, useI18n } from "../../i18n";
+import { langQuery, useI18n, type Lang } from "../../i18n";
 import { useLocalizedPath } from "../../useLocalizedPath";
+import { localizePath } from "../../languageRoutes";
 import { MOCK_POSTS } from "../../mocks/mockPosts";
 import { POST_STREAM_USES_MOCK } from "../../components/messageStream/hooks/usePostStream";
 import { useToast } from "../../components/Toast";
+import { Skeleton } from "../../components/Skeleton";
 import type { Post } from "../../types/post";
 
+function postLangToUiLang(code: string | undefined): Lang | null {
+  if (!code) return null;
+  const lc = code.trim().toLowerCase();
+  if (lc === "zh" || lc === "zh-cn" || lc === "zh-hans") return "zh-CN";
+  if (lc === "en") return "en";
+  if (lc === "ja") return "ja";
+  if (lc === "ko") return "ko";
+  if (lc === "vi") return "vi";
+  if (lc === "id") return "id";
+  if (lc === "ms") return "ms";
+  return null;
+}
+
 export function PostRedirect() {
   const { id } = useParams();
   const { lang, t } = useI18n();
   const navigate = useNavigate();
   const lp = useLocalizedPath();
   const { showToast } = useToast();
+  const handledIdRef = useRef<string | null>(null);
 
   useEffect(() => {
     if (!id) {
       navigate(lp("/browse"), { replace: true });
       return;
     }
+    if (handledIdRef.current === id) return;
+    handledIdRef.current = id;
 
     if (POST_STREAM_USES_MOCK) {
       const post = MOCK_POSTS.find((p) => p.id === id);
@@ -32,25 +50,47 @@ export function PostRedirect() {
       return;
     }
 
-    const goToPost = (post: Post) => {
+    const goToPostInLang = (post: Post, targetLang: Lang) => {
-      navigate(lp(`/browse?post=${encodeURIComponent(post.id)}`), {
+      navigate(
-        replace: true,
+        localizePath(`/browse?post=${encodeURIComponent(post.id)}`, targetLang),
-      });
+        { replace: true },
+      );
     };
 
     getJSON<Post>(
       `/api/posts/${id}?lang=${encodeURIComponent(langQuery(lang))}`,
     )
-      .then(goToPost)
+      .then((post) => goToPostInLang(post, lang))
       .catch(() => {
         getJSON<Post>(`/api/posts/${id}`)
           .then((post) => {
+            const sourceLang =
+              postLangToUiLang(post.sourceLanguage) ||
+              postLangToUiLang(post.language) ||
+              lang;
             showToast(t("postShownInOriginalLanguage"));
-            goToPost(post);
+            goToPostInLang(post, sourceLang);
           })
           .catch(() => navigate(lp("/browse"), { replace: true }));
       });
   }, [id, lang, navigate, lp, showToast, t]);
 
-  return <div className="text-neutral-400">…</div>;
+  return (
+    <div
+      aria-live="polite"
+      aria-label={t("loading")}
+      className="mx-auto flex max-w-[1180px] flex-col gap-3 px-4 pt-4 md:px-0 md:pt-2"
+    >
+      {Array.from({ length: 6 }).map((_, i) => (
+        <div
+          key={i}
+          className="mx-auto w-full max-w-[358px] md:max-w-[680px] lg:max-w-[900px] xl:max-w-[1120px]"
+        >
+          <Skeleton
+            className={`rounded-2xl ${i % 3 === 0 ? "h-[220px]" : "h-[80px]"}`}
+          />
+        </div>
+      ))}
+    </div>
+  );
 }