LearnSpace: full-stack educational whiteboard platform

Node.js/Express backend + vanilla JS frontend. Features: real-time collaborative whiteboard (SSE), multi-page support, LaTeX formulas, shapes/connectors, coordinate systems, number lines, compass, zoom/pan, Catmull-Rom pencil smoothing, ruler/protractor with rotation & resize controls, minimap navigation overlay, auto-measurements, multi-page thumbnails sidebar, PNG export, page templates. Student/teacher workflows: classes, assignments, library, dashboard. Mobile responsive. SQLite (better-sqlite3). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-12 10:10:37 +03:00
commit be4d43105e
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+const db = require('../db/db');
+
+function teacherOverview(req, res) {
+  const user    = req.user;
+  const classId = req.query.classId ? Number(req.query.classId) : null;
+
+  const classes = user.role === 'admin'
+    ? db.prepare('SELECT id, name FROM classes ORDER BY name').all()
+    : db.prepare('SELECT id, name FROM classes WHERE teacher_id = ? ORDER BY name').all(user.id);
+
+  if (!classId) return res.json({ classes, data: null });
+
+  if (user.role !== 'admin') {
+    const cls = db.prepare('SELECT id FROM classes WHERE id = ? AND teacher_id = ?').get(classId, user.id);
+    if (!cls) return res.status(403).json({ error: 'Forbidden' });
+  }
+
+  const overview = db.prepare(`
+    SELECT
+      COUNT(DISTINCT cm.user_id) AS students,
+      COUNT(DISTINCT CASE WHEN ts.status='completed' THEN ts.id END) AS sessions,
+      ROUND(AVG(CASE WHEN ts.status='completed' AND ts.total>0
+                     THEN ts.score*100.0/ts.total END), 1) AS avgScore
+    FROM class_members cm
+    LEFT JOIN test_sessions ts ON ts.user_id = cm.user_id
+    WHERE cm.class_id = ?
+  `).get(classId);
+
+  const scoreByWeek = db.prepare(`
+    SELECT
+      strftime('%Y-W%W', ts.finished_at) AS week,
+      ROUND(AVG(ts.score*100.0/ts.total), 1) AS avg,
+      COUNT(*) AS sessions
+    FROM test_sessions ts
+    JOIN class_members cm ON cm.user_id = ts.user_id AND cm.class_id = ?
+    WHERE ts.status='completed' AND ts.total>0
+      AND ts.finished_at >= datetime('now','-56 days')
+    GROUP BY week ORDER BY week
+  `).all(classId);
+
+  const hardQuestions = db.prepare(`
+    SELECT q.id, q.text, q.difficulty,
+      COUNT(ua.id) AS attempts,
+      ROUND(SUM(CASE WHEN ua.is_correct=0 THEN 1.0 ELSE 0 END)*100/COUNT(ua.id),1) AS errorRate,
+      t.name AS topic
+    FROM user_answers ua
+    JOIN questions q       ON q.id  = ua.question_id
+    JOIN test_sessions ts  ON ts.id = ua.session_id
+    JOIN class_members cm  ON cm.user_id = ts.user_id AND cm.class_id = ?
+    LEFT JOIN topics t     ON t.id  = q.topic_id
+    WHERE ts.status='completed'
+    GROUP BY q.id HAVING attempts >= 3
+    ORDER BY errorRate DESC LIMIT 10
+  `).all(classId);
+
+  const heatmap = db.prepare(`
+    SELECT date(ts.started_at) AS day,
+      COUNT(DISTINCT ts.user_id) AS students,
+      COUNT(ts.id) AS sessions
+    FROM test_sessions ts
+    JOIN class_members cm ON cm.user_id = ts.user_id AND cm.class_id = ?
+    WHERE ts.started_at >= datetime('now','-90 days')
+    GROUP BY day ORDER BY day
+  `).all(classId);
+
+  const assignments = db.prepare(`
+    SELECT a.id, a.title, a.deadline,
+      COUNT(DISTINCT cm.user_id) AS total,
+      COUNT(DISTINCT CASE WHEN ass.session_id IS NOT NULL THEN ass.user_id END) AS done
+    FROM assignments a
+    JOIN class_members cm ON cm.class_id = a.class_id
+    LEFT JOIN assignment_sessions ass ON ass.assignment_id=a.id AND ass.user_id=cm.user_id
+    WHERE a.class_id = ?
+    GROUP BY a.id ORDER BY a.created_at DESC LIMIT 10
+  `).all(classId);
+
+  res.json({ classes, overview, scoreByWeek, hardQuestions, heatmap, assignments });
+}
+
+module.exports = { teacherOverview };