Refactor Study Desk application structure

src/app/(protected)/[classSlug]/quizzes/[quizId]/page.tsx

@@ -27,6 +27,7 @@ interface QuizAttempt {
   score: number;
   maxScore: number;
   answersJson: string;
+  reviewSnapshotJson?: string | null;
   isPartialRetake: boolean;
   completedAt: string;
 }
@@ -42,6 +43,8 @@ interface QuizData {
     currentIndex: number;
     orderJson: string;
     answersJson: string | null;
+    sessionId: string;
+    revision: number;
   }>;
 }
 
@@ -60,13 +63,23 @@ export default function QuizStudyPage() {
   
   async function handleRestart() {
     if (!quiz) return;
-    
-    // Clear progress in database
-    await fetch("/api/progress", {
-      method: "DELETE",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ contentType: "QUIZ", contentId: quiz.id, mode: "SEQUENTIAL" })
-    }).catch(() => {});
+    const progress = quiz.progress.find((item) => item.mode === "SEQUENTIAL");
+    if (progress) {
+      const response = await fetch("/api/progress", {
+        method: "DELETE",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          contentType: "QUIZ",
+          contentId: quiz.id,
+          mode: "SEQUENTIAL",
+          sessionId: progress.sessionId,
+        }),
+      }).catch(() => null);
+      if (!response?.ok) {
+        window.alert("The quiz could not be restarted. Your saved progress was kept.");
+        return;
+      }
+    }
     
     // Clear locally and force remount
     setQuiz({ ...quiz, progress: [] });
@@ -104,7 +117,8 @@ export default function QuizStudyPage() {
   }, [quizId, classSlug, router]);
 
   useEffect(() => {
-    fetchQuizAndAttempts();
+    const timer = window.setTimeout(() => void fetchQuizAndAttempts(), 0);
+    return () => window.clearTimeout(timer);
   }, [fetchQuizAndAttempts]);
 
   const [showTopics, setShowTopics] = useState(false);
@@ -221,6 +235,7 @@ export default function QuizStudyPage() {
           key={restartKey}
           quiz={quiz} 
           retakeIds={retakeIds}
+          sessionKey={restartKey}
           onFinished={() => {
             router.push(`/${classSlug}/quizzes`);
           }}