Teacher “class leaderboard” + group assignment mode

class_manager.js

@@ -0,0 +1,85 @@
+// class_manager.js – Handles teacher class sessions and progress aggregation
+
+const CLASS_SESSIONS_KEY = 'learnsphere_class_sessions_v1';
+
+function _loadClasses() {
+  try {
+    const raw = localStorage.getItem(CLASS_SESSIONS_KEY);
+    return raw ? JSON.parse(raw) : [];
+  } catch (e) {
+    console.warn('LearnSphere: Failed to load class sessions', e);
+    return [];
+  }
+}
+
+function _saveClasses(classes) {
+  try {
+    localStorage.setItem(CLASS_SESSIONS_KEY, JSON.stringify(classes));
+  } catch (e) {
+    console.warn('LearnSphere: Failed to save class sessions', e);
+  }
+}
+
+function generateInviteCode(length = 6) {
+  const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
+  let code = '';
+  for (let i = 0; i < length; i++) {
+    code += chars.charAt(Math.floor(Math.random() * chars.length));
+  }
+  return code;
+}
+
+function createClassSession({ name, topics = [], dueDate }) {
+  const classes = _loadClasses();
+  const id = 'cls_' + Date.now();
+  const inviteCode = generateInviteCode();
+  const newClass = {
+    id,
+    name,
+    inviteCode,
+    topics,
+    dueDate: dueDate || null,
+    attempts: [], // each { studentId, quizId, score }
+    createdAt: new Date().toISOString()
+  };
+  classes.push(newClass);
+  _saveClasses(classes);
+  return newClass;
+}
+
+function recordClassAttempt(classId, { studentId = 'anonymous', quizId, score }) {
+  if (!classId) return;
+  const classes = _loadClasses();
+  const cls = classes.find(c => c.id === classId);
+  if (!cls) return;
+  cls.attempts.push({ studentId, quizId, score, timestamp: Date.now() });
+  _saveClasses(classes);
+}
+
+function getClassStats(classId) {
+  const classes = _loadClasses();
+  const cls = classes.find(c => c.id === classId);
+  if (!cls) return null;
+  const total = cls.attempts.length;
+  const avgScore = total ? (cls.attempts.reduce((a, b) => a + b.score, 0) / total).toFixed(2) : '-';
+  const bestScore = total ? Math.max(...cls.attempts.map(a => a.score)).toFixed(2) : '-';
+  return { ...cls, totalAttempts: total, avgScore, bestScore };
+}
+
+function getAllClassStats() {
+  const classes = _loadClasses();
+  return classes.map(c => {
+    const total = c.attempts.length;
+    const avgScore = total ? (c.attempts.reduce((a, b) => a + b.score, 0) / total).toFixed(2) : '-';
+    const bestScore = total ? Math.max(...c.attempts.map(a => a.score)).toFixed(2) : '-';
+    return { id: c.id, name: c.name, inviteCode: c.inviteCode, totalAttempts: total, avgScore, bestScore };
+  });
+}
+
+// Expose globally for other modules
+window.classManager = {
+  createClassSession,
+  recordClassAttempt,
+  getClassStats,
+  getAllClassStats
+};

teachers.html

@@ -72,6 +72,8 @@ <h1>Empowering Teachers</h1>
         </div>
         <div class="hero-image">
             <img src="images/teacher.jpeg" alt="Teacher guiding students">
+            <button id="createClassBtn" style="margin-top:12px;background:var(--accent-color);color:#fff;padding:10px 16px;border:none;border-radius:8px;cursor:pointer;box-shadow:0 4px 12px rgba(0,0,0,0.2);transition:transform 0.2s;" onmouseover="this.style.transform='scale(1.05)'" onmouseout="this.style.transform='scale(1)'">Create Class</button>
+            <div id="leaderboardContainer" style="margin-top:24px;"></div>
         </div>
     </section>