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src/services/classroom.js

@@ -480,3 +480,25 @@ export async function getUser(userId) {
     const snap = await getDoc(userRef);
     return snap.exists() ? snap.data() : null;
 }
+
+/**
+ * Subscribes to a single user's progress for real-time updates
+ * @param {string} userId 
+ * @param {Function} callback (progressMap) => void
+ * @returns {Function} unsubscribe
+ */
+export function subscribeToUserProgress(userId, callback) {
+    const q = query(
+        collection(db, PROGRESS_COLLECTION),
+        where("userId", "==", userId)
+    );
+
+    return onSnapshot(q, (snapshot) => {
+        const progressMap = {};
+        snapshot.forEach(doc => {
+            const data = doc.data();
+            progressMap[data.challengeId] = data;
+        });
+        callback(progressMap);
+    });
+}