fix: fall back to original language on post redirect

src/pages/PostRedirect/index.tsx

@@ -5,13 +5,15 @@ import { langQuery, useI18n } from "../../i18n";
 import { useLocalizedPath } from "../../useLocalizedPath";
 import { MOCK_POSTS } from "../../mocks/mockPosts";
 import { POST_STREAM_USES_MOCK } from "../../components/messageStream/hooks/usePostStream";
+import { useToast } from "../../components/Toast";
 import type { Post } from "../../types/post";
 
 export function PostRedirect() {
   const { id } = useParams();
-  const { lang } = useI18n();
+  const { lang, t } = useI18n();
   const navigate = useNavigate();
   const lp = useLocalizedPath();
+  const { showToast } = useToast();
 
   useEffect(() => {
     if (!id) {
@@ -30,16 +32,25 @@ export function PostRedirect() {
       return;
     }
 
+    const goToPost = (post: Post) => {
+      navigate(lp(`/browse?post=${encodeURIComponent(post.id)}`), {
+        replace: true,
+      });
+    };
+
     getJSON<Post>(
       `/api/posts/${id}?lang=${encodeURIComponent(langQuery(lang))}`,
     )
-      .then((post) => {
-        navigate(lp(`/browse?post=${encodeURIComponent(post.id)}`), {
-          replace: true,
-        });
-      })
-      .catch(() => navigate(lp("/browse"), { replace: true }));
-  }, [id, lang, navigate, lp]);
+      .then(goToPost)
+      .catch(() => {
+        getJSON<Post>(`/api/posts/${id}`)
+          .then((post) => {
+            showToast(t("postShownInOriginalLanguage"));
+            goToPost(post);
+          })
+          .catch(() => navigate(lp("/browse"), { replace: true }));
+      });
+  }, [id, lang, navigate, lp, showToast, t]);
 
   return <div className="text-neutral-400">…</div>;
 }