feat(geom9 ch3 wave2 + final): §12 «Герон» + Финал Главы 3

backend/src/routes/exam-prep.js

@@ -0,0 +1,86 @@
+'use strict';
+const router = require('express').Router();
+const db = require('../db/db');
+const { authMiddleware } = require('../middleware/auth');
+
+router.use(authMiddleware);
+
+/* ── Statements (prepared once) ────────────────────────────────── */
+const SQL = {
+  listTracks: db.prepare(`
+    SELECT exam_key, title, subject_slug, grade, duration_min,
+           tasks_per_variant, variants_count, intro_html, sort_order
+      FROM exam_tracks
+     WHERE enabled = 1
+     ORDER BY sort_order, exam_key
+  `),
+  getTrack: db.prepare(`
+    SELECT exam_key, title, subject_slug, grade, duration_min,
+           tasks_per_variant, variants_count, scoring_json, intro_html
+      FROM exam_tracks
+     WHERE exam_key = ? AND enabled = 1
+  `),
+  countTasks: db.prepare(`
+    SELECT
+      COUNT(*) AS total,
+      COALESCE(SUM(CASE WHEN task_type = 'mc'   THEN 1 ELSE 0 END), 0) AS mc,
+      COALESCE(SUM(CASE WHEN task_type = 'open' THEN 1 ELSE 0 END), 0) AS open,
+      COALESCE(SUM(CASE WHEN task_type = 'long' THEN 1 ELSE 0 END), 0) AS long
+      FROM exam_tasks
+     WHERE exam_key = ?
+  `),
+  /* For each (user, task) — was the most-recent attempt correct?
+     A task counts as «solved» iff at least one historical attempt is_correct = 1. */
+  userProgress: db.prepare(`
+    SELECT
+      COUNT(DISTINCT exam_task_id) AS tasks_attempted,
+      COUNT(DISTINCT CASE WHEN is_correct = 1 THEN exam_task_id END) AS tasks_solved,
+      COUNT(*) AS total_attempts,
+      COALESCE(SUM(CASE WHEN is_correct = 1 THEN 1 ELSE 0 END), 0) AS correct_attempts
+      FROM exam_attempts a
+      JOIN exam_tasks t ON t.id = a.exam_task_id
+     WHERE a.user_id = ? AND t.exam_key = ?
+  `),
+};
+
+/* ── GET /api/exam-prep/tracks ──
+   Public list of enabled exam tracks (for a future landing page). */
+router.get('/tracks', (_req, res) => {
+  const tracks = SQL.listTracks.all();
+  res.json({ tracks });
+});
+
+/* ── GET /api/exam-prep/:examKey/info ──
+   Track metadata + global counts + this user's aggregate progress. */
+router.get('/:examKey/info', (req, res) => {
+  const { examKey } = req.params;
+  const track = SQL.getTrack.get(examKey);
+  if (!track) return res.status(404).json({ error: 'Unknown exam track' });
+
+  const counts   = SQL.countTasks.get(examKey);
+  const progress = SQL.userProgress.get(req.user.id, examKey);
+
+  // Parse scoring grid (JSON in DB). Tolerant of malformed values.
+  let scoring = null;
+  if (track.scoring_json) {
+    try { scoring = JSON.parse(track.scoring_json); } catch { scoring = null; }
+  }
+
+  res.json({
+    track: {
+      exam_key: track.exam_key,
+      title:    track.title,
+      subject:  track.subject_slug,
+      grade:    track.grade,
+      duration_min:      track.duration_min,
+      tasks_per_variant: track.tasks_per_variant,
+      variants_count:    track.variants_count,
+      intro_html:        track.intro_html,
+      scoring,
+    },
+    counts,
+    progress,
+  });
+});
+
+module.exports = router;

backend/src/server.js

@@ -51,6 +51,7 @@ const collectionRoutes    = require('./routes/collection');
 const redBookRoutes       = require('./routes/red-book');
 const parentRoutes        = require('./routes/parent');
 const exam9Routes         = require('./routes/exam9');
+const examPrepRoutes      = require('./routes/exam-prep');
 const textbookRoutes      = require('./routes/textbooks');
 const teacherStudentsRoutes = require('./routes/teacherStudents');
 
@@ -171,6 +172,7 @@ app.use('/api/red-book',     requireFeature('red_book'),      redBookRoutes);
 app.use('/api/biochem',      requireFeature('biochem'),       require('./routes/biochem'));
 app.use('/api/parent',       parentRoutes);
 app.use('/api/exam9',        exam9Routes);
+app.use('/api/exam-prep',    examPrepRoutes);
 app.use('/api/textbooks',    textbookRoutes);
 app.use('/api/teacher-students', teacherStudentsRoutes);
 
@@ -340,6 +342,34 @@ app.get('/textbooks', (_req, res) => {
   res.sendFile(path.join(frontendDir, 'textbooks.html'));
 });
 
+// ── Exam preparation module: /exam-prep/:examKey/{,variants,practice,topics,mock}[/...]
+// All sub-pages share the same examKey segment; sub-view is the second segment.
+// The HTML file is chosen by the sub-view; examKey is parsed client-side from URL.
+function sendExamPrep(res, file) {
+  if (!isProd) res.setHeader('Cache-Control', 'no-store');
+  res.sendFile(path.join(frontendDir, file));
+}
+const EXAM_PREP_VIEWS = {
+  variants: 'exam-prep-variants.html',
+  practice: 'exam-prep-practice.html',
+  topics:   'exam-prep-topics.html',
+  mock:     'exam-prep-mock.html',
+};
+// /exam-prep → redirect to default track (math9 for now)
+app.get('/exam-prep', (_req, res) => res.redirect(302, '/exam-prep/math9'));
+// /exam-prep/:examKey → dashboard
+app.get('/exam-prep/:examKey', (_req, res) => sendExamPrep(res, 'exam-prep.html'));
+// /exam-prep/:examKey/:view → corresponding sub-page (sub-view + optional trailing segments)
+app.get(['/exam-prep/:examKey/:view', '/exam-prep/:examKey/:view/*'], (req, res, next) => {
+  const file = EXAM_PREP_VIEWS[req.params.view];
+  if (!file) return next();
+  sendExamPrep(res, file);
+});
+
+// NOTE: /exam9 remains live (served by static middleware as exam9.html) until F2
+// ports the variant browser into /exam-prep/:examKey/variants. The 301 redirect
+// will be added at that point.
+
 // Serve HTML files without extension  (/dashboard → dashboard.html)
 // In dev: disable cache so edits are always picked up immediately
 const htmlCacheOpts = isProd ? { extensions: ['html'] } : {