Refactor Study Desk application structure

src/app/(protected)/[classSlug]/flashcards/[deckId]/page.tsx

@@ -25,6 +25,8 @@ interface DeckData {
     currentIndex: number;
     orderJson: string;
     cardResultsJson: string | null;
+    sessionId: string;
+    revision: number;
     updatedAt: string;
   }>;
 }
@@ -42,19 +44,24 @@ export default function DeckStudyPage() {
   async function handleRestart() {
     if (!deck) return;
     
-    // Clear progress in database for both modes
-    await Promise.all([
-      fetch("/api/progress", {
-        method: "DELETE",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ contentType: "DECK", contentId: deck.id, mode: "SEQUENTIAL" })
-      }).catch(() => {}),
-      fetch("/api/progress", {
-        method: "DELETE",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ contentType: "DECK", contentId: deck.id, mode: "SHUFFLED" })
-      }).catch(() => {})
-    ]);
+    const responses = await Promise.all(
+      deck.progress.map((progress) =>
+        fetch("/api/progress", {
+          method: "DELETE",
+          headers: { "Content-Type": "application/json" },
+          body: JSON.stringify({
+            contentType: "DECK",
+            contentId: deck.id,
+            mode: progress.mode,
+            sessionId: progress.sessionId,
+          }),
+        })
+      )
+    ).catch(() => null);
+    if (!responses || responses.some((response) => !response.ok)) {
+      window.alert("The session could not be restarted. Your saved progress was kept.");
+      return;
+    }
     
     // Clear locally and force remount
     setDeck({ ...deck, progress: [] });
@@ -75,7 +82,8 @@ export default function DeckStudyPage() {
   }, [deckId, classSlug, router]);
 
   useEffect(() => {
-    fetchDeck();
+    const timer = window.setTimeout(() => void fetchDeck(), 0);
+    return () => window.clearTimeout(timer);
   }, [fetchDeck]);
 
   if (loading || !deck) {