const express = require('express');
const { Pool, types } = require('pg');
const multer = require('multer');
const rateLimit = require('express-rate-limit');
const helmet = require('helmet');
const bcrypt = require('bcrypt');
const heicConvert = require('heic-convert');
const { createEntryAutoChecker, createPhotoEnhanceWorker } = require('./worker');

const https = require('https');
const path = require('path');
const fs = require('fs');
const crypto = require('crypto');

types.setTypeParser(1082, v => v);

const app = express();
const pool = new Pool({ connectionString: process.env.DATABASE_URL });

const pgClient = require('pg').Client;
const lister = new pgClient({ connectionString: process.env.DATABASE_URL });
let listerConnected = false;
function connectLister() {
  if (listerConnected) return;
  listerConnected = true;
  lister.connect()
    .then(() => lister.query('LISTEN entries_changed'))
    .catch(e => {
      listerConnected = false;
      console.error('LISTEN entries_changed failed:', e.message);
      setTimeout(connectLister, 5000);
    });
}
connectLister();
lister.on('error', (e) => {
  console.error('LISTEN connection error:', e.message);
});
lister.on('end', () => {
  listerConnected = false;
  setTimeout(connectLister, 3000);
});
lister.on('notification', (msg) => {
  let payload = null;
  try { payload = JSON.parse(msg.payload || '{}'); } catch (e) { payload = null; }
  const type = payload && payload.type ? payload.type : 'entry_created';
  if (type === 'ai_status') {
    broadcastAiStatus(payload);
  } else {
    broadcastEntryChanged();
  }
});

const cacheStore = new Map();
const SETTINGS_TTL_MS = 30 * 1000;
const PUBLIC_TTL_MS = 60 * 1000;
const SHARE_TTL_MS = 60 * 1000;
const STATS_TTL_MS = 15 * 1000;
const SYSTEM_TTL_MS = 30 * 1000;

function cacheGet(key) {
  const entry = cacheStore.get(key);
  if (!entry) return undefined;
  if (entry.exp && entry.exp <= Date.now()) {
    cacheStore.delete(key);
    return undefined;
  }
  return entry.value;
}

function cacheSet(key, value, ttlMs) {
  cacheStore.set(key, { value, exp: ttlMs ? Date.now() + ttlMs : 0 });
}

function cacheDrop(prefix) {
  for (const key of cacheStore.keys()) {
    if (key.startsWith(prefix)) cacheStore.delete(key);
  }
}

async function cacheWrap(key, ttlMs, fn) {
  const hit = cacheGet(key);
  if (hit !== undefined) return hit;
  const value = await fn();
  cacheSet(key, value, ttlMs);
  return value;
}

function scopeKey(user) {
  if (!user) return 'anon';
  const s = branchScope(user);
  if (s.admin) return 'all';
  return s.ids.length ? s.ids.slice().sort((a, b) => a - b).join('-') : 'none';
}

function invalidateSettings() { cacheDrop('setting:'); cacheDrop('share:payload:'); cacheDrop('public-settings'); }
function invalidateStudents() { cacheDrop('students:'); }
function invalidateGroups() { cacheDrop('groups:'); cacheDrop('students:'); cacheDrop('share:payload:'); }
function invalidateEntries() { cacheDrop('entries:'); cacheDrop('students:'); cacheDrop('share:payload:'); }

const sseClients = new Set();
function broadcastEntryChanged() {
  const frame = `event: entries_changed\ndata: ${JSON.stringify({ ts: Date.now() })}\n\n`;
  for (const client of sseClients) {
    try { client.write(frame); } catch (e) { sseClients.delete(client); }
  }
}

function broadcastAiStatus(payload) {
  const data = {
    id: payload.id,
    ai_status: payload.status,
    ai_error: payload.error || null,
    description: payload.description === undefined ? null : payload.description,
    description_ai: payload.description_ai === undefined ? null : payload.description_ai,
    description_original: payload.description_original === undefined ? null : payload.description_original,
    ts: Date.now()
  };
  const frame = `event: ai_status\ndata: ${JSON.stringify(data)}\n\n`;
  for (const client of sseClients) {
    try { client.write(frame); } catch (e) { sseClients.delete(client); }
  }
}

app.get('/api/events', async (req, res) => {
  try {
    const token = req.headers['x-auth-token'] || req.query.token;
    const user = await loadUserByToken(token);
    if (!user || !user.is_active) return res.status(401).end();
  } catch (e) {
    return res.status(500).end();
  }
  res.writeHead(200, {
    'Content-Type': 'text/event-stream',
    'Cache-Control': 'no-cache, no-transform',
    Connection: 'keep-alive',
    'X-Accel-Buffering': 'no'
  });
  res.write(':ok\n\n');
  sseClients.add(res);
  const ping = setInterval(() => {
    try { res.write(':ping\n\n'); } catch (e) { clearInterval(ping); sseClients.delete(res); }
  }, 25000);
  req.on('close', () => { clearInterval(ping); sseClients.delete(res); });
});
function invalidateShare() { cacheDrop('share:payload:'); }
function invalidateStats() { cacheDrop('stats:'); cacheDrop('dashboard:'); cacheDrop('system-info'); }
function invalidateAll() { cacheStore.clear(); }

const BAN_TTL_MS = 24 * 60 * 60 * 1000;
const FAIL_WINDOW_MS = 15 * 60 * 1000;
const banMemory = new Map();
const failMemory = new Map();

function ipOf(req) {
  return String(req.ip || req.socket?.remoteAddress || 'unknown').slice(0, 64);
}

async function banIP(req, reason, ms) {
  await banIpAddr(ipOf(req), reason, ms, req);
}

async function banIpAddr(ip, reason, ms, actorReq) {
  const until = new Date(Date.now() + ms);
  banMemory.set(ip, { reason, banned_until: until.toISOString() });
  await pool.query(
    'INSERT INTO banned_ips (ip, reason, banned_until) VALUES ($1, $2, $3) ON CONFLICT (ip) DO UPDATE SET reason = $2, banned_until = $3',
    [ip, reason, until.toISOString()]
  );
  await logAudit(actorReq, 'ip.ban', { ip, reason });
  console.log(`IP banned: ${ip} (${reason})`);
}

function ipGuard(req, res, next) {
  const entry = banMemory.get(ipOf(req));
  if (entry && new Date(entry.banned_until) > new Date()) {
    return res.status(403).json({ error: 'Доступ заблокирован' });
  }
  next();
}

function recordFailure(req, kind, limit, ms) {
  const ip = ipOf(req);
  const now = Date.now();
  let entry = failMemory.get(kind + ':' + ip);
  if (!entry || entry.resetAt <= now) {
    entry = { count: 0, resetAt: now + FAIL_WINDOW_MS };
    failMemory.set(kind + ':' + ip, entry);
  }
  entry.count += 1;
  if (entry.count >= limit) {
    failMemory.delete(kind + ':' + ip);
    return banIP(req, kind, ms).catch(err => console.error('Ban error:', err));
  }
  return Promise.resolve();
}

async function loadBans() {
  const { rows } = await pool.query('SELECT ip, reason, banned_until FROM banned_ips WHERE banned_until > now()');
  const active = new Set();
  for (const r of rows) {
    active.add(r.ip);
    banMemory.set(r.ip, { reason: r.reason, banned_until: r.banned_until });
  }
  for (const key of banMemory.keys()) {
    if (!active.has(key)) banMemory.delete(key);
  }
}

app.set('trust proxy', 'loopback');

const apiLimiter = rateLimit({
  windowMs: 15 * 60 * 1000,
  max: 300,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: 'Слишком много запросов. Попробуйте позже.' },
});

const entryLimiter = rateLimit({
  windowMs: 15 * 60 * 1000,
  max: 10,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: 'Слишком много запросов. Подождите немного.' },
});

const fileLimiter = rateLimit({
  windowMs: 15 * 60 * 1000,
  max: 300,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: 'Слишком много запросов. Попробуйте позже.' },
});

const ADMIN_USERNAME = (process.env.ADMIN_USERNAME || 'admin').toLowerCase().trim();
const ADMIN_PASSWORD = process.env.ADMIN_PASSWORD;
if (!ADMIN_PASSWORD) {
  console.warn('ADMIN_PASSWORD не задан. Первый админ не будет создан автоматически.');
}

app.use(helmet({
  contentSecurityPolicy: {
    directives: {
      defaultSrc: ["'self'"],
      scriptSrc: ["'self'"],
      styleSrc: ["'self'", "'unsafe-inline'"],
      imgSrc: ["'self'", "data:", "blob:"],
      mediaSrc: ["'self'", "blob:"],
      connectSrc: ["'self'"],
      objectSrc: ["'none'"],
      baseUri: ["'self'"],
      formAction: ["'self'"],
      frameAncestors: ["'none'"]
    }
  }
}));
app.use(express.json({ limit: '1mb' }));
app.use(ipGuard);
const THUMBS_DIR = path.join(__dirname, 'uploads', '.thumbs');
const ORIGINALS_DIR = path.join(__dirname, 'uploads', '.originals');
const THUMB_WIDTH = 480;
let sharp = null;
try { sharp = require('sharp'); } catch {}
if (sharp) {
  try { fs.mkdirSync(THUMBS_DIR, { recursive: true }); } catch {}
}
try { fs.mkdirSync(ORIGINALS_DIR, { recursive: true }); } catch {}

function thumbFileFor(fp) {
  const base = path.basename(fp).replace(/\.[^.]+$/, '') + '.webp';
  return path.join(THUMBS_DIR, base);
}

async function sendImageThumb(res, fp) {
  if (!sharp) {
    res.setHeader('Cache-Control', 'public, max-age=3600');
    return res.sendFile(fp);
  }
  const tp = thumbFileFor(fp);
  try {
    if (!fs.existsSync(tp)) {
      const tmp = tp + '.' + crypto.randomBytes(4).toString('hex') + '.tmp';
      await sharp(fp).rotate().resize({ width: THUMB_WIDTH, withoutEnlargement: true }).webp({ quality: 85 }).toFile(tmp);
      fs.renameSync(tmp, tp);
    }
    res.setHeader('Cache-Control', 'public, max-age=31536000, immutable');
    return res.sendFile(tp);
  } catch {
    try { if (fs.existsSync(tp)) fs.unlinkSync(tp); } catch {}
    res.setHeader('Cache-Control', 'public, max-age=3600');
    return res.sendFile(fp);
  }
}

app.get('/uploads/thumb/:name', fileLimiter, async (req, res) => {
  const name = req.params.name;
  if (!/^[A-Za-z0-9._-]+$/.test(name)) return res.status(400).end();
  const fp = path.join(__dirname, 'uploads', name);
  if (!fs.existsSync(fp) || !fs.statSync(fp).isFile()) return res.status(404).end();
  return sendImageThumb(res, fp);
});

app.get('/uploads/.originals/:name', fileLimiter, async (req, res) => {
  const name = req.params.name;
  if (!/^[A-Za-z0-9._-]+$/.test(name)) return res.status(400).end();
  const fp = path.join(ORIGINALS_DIR, name);
  if (!fs.existsSync(fp) || !fs.statSync(fp).isFile()) return res.status(404).end();
  return sendImageThumb(res, fp);
});

app.use((req, res, next) => {
  const p = req.path;
  if (!p.startsWith('/uploads') && !p.startsWith('/vendor')) {
    res.setHeader('Cache-Control', 'no-cache');
  }
  next();
});

app.use('/uploads', express.static(path.join(__dirname, 'uploads'), { maxAge: '365d', immutable: true }));
app.use('/vendor', express.static(path.join(__dirname, 'public', 'vendor'), { maxAge: '30d' }));
app.use(express.static(path.join(__dirname, 'public')));

const SESSION_TTL_MS = 30 * 24 * 60 * 60 * 1000;

function formatBytes(bytes) {
  if (bytes === 0) return '0 B';
  const k = 1024;
  const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
  const i = Math.floor(Math.log(bytes) / Math.log(k));
  return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
}

function getDiskInfo() {
  const totalDisk = fs.statfsSync ? fs.statfsSync(__dirname) : null;
  if (totalDisk) {
    const blockSize = totalDisk.bsize || 4096;
    const total = totalDisk.blocks * blockSize;
    const free = totalDisk.bfree * blockSize;
    const used = total - free;
    return {
      total: formatBytes(total),
      total_bytes: total,
      used: formatBytes(used),
      used_bytes: used,
      free: formatBytes(free),
      free_bytes: free,
      used_pct: Math.min(100, Math.max(0, Math.round((used / total) * 100))),
    };
  }
  try {
    const { execSync } = require('child_process');
    const out = execSync('df -B1 .', { encoding: 'utf8' });
    const lines = out.trim().split('\n');
    if (lines.length > 1) {
      const parts = lines[1].split(/\s+/);
      const total = parseInt(parts[1], 10);
      const used = parseInt(parts[2], 10);
      const free = parseInt(parts[3], 10);
      return {
        total: formatBytes(total),
        total_bytes: total,
        used: formatBytes(used),
        used_bytes: used,
        free: formatBytes(free),
        free_bytes: free,
        used_pct: Math.min(100, Math.max(0, Math.round((used / total) * 100))),
      };
    }
  } catch {}
  return null;
}

function safeUser(u) {
  return {
    id: u.id,
    username: u.username,
    name: u.name,
    role: u.role,
    is_active: u.is_active,
    branch_ids: u.branch_ids || [],
  };
}

async function loadUserByToken(token) {
  if (!token || typeof token !== 'string') return null;
  const { rows } = await pool.query(
    `SELECT u.id, u.username, u.name, u.role, u.is_active,
            COALESCE(array_agg(ub.branch_id) FILTER (WHERE ub.branch_id IS NOT NULL), '{}') AS branch_ids
     FROM sessions s
     JOIN users u ON u.id = s.user_id
     LEFT JOIN user_branches ub ON ub.user_id = u.id
     WHERE s.token = $1 AND s.expires_at > now()
     GROUP BY u.id`,
    [token]
  );
  if (!rows.length) return null;
  return rows[0];
}

async function requireAuth(req, res, next) {
  try {
    const token = req.headers['x-auth-token'];
    const user = await loadUserByToken(token);
    if (!user || !user.is_active) {
      return res.status(401).json({ error: 'Unauthorized' });
    }
    req.user = user;
    req.authToken = token;
    next();
  } catch (e) {
    console.error('requireAuth error:', e);
    res.status(500).json({ error: 'Internal server error' });
  }
}

function requireAdmin(req, res, next) {
  if (req.user) {
    if (req.user.role !== 'admin') return res.status(403).json({ error: 'Forbidden: требуется роль администратора' });
    return next();
  }
  requireAuth(req, res, () => {
    if (req.user?.role !== 'admin') return res.status(403).json({ error: 'Forbidden: требуется роль администратора' });
    next();
  });
}

function branchScope(user) {
  if (user.role === 'admin') return { admin: true, ids: null };
  return { admin: false, ids: user.branch_ids || [] };
}

async function optionalAuth(req, res, next) {
  try {
    const token = req.headers['x-auth-token'];
    if (token && typeof token === 'string') {
      const user = await loadUserByToken(token);
      if (user?.is_active) {
        req.user = user;
        req.authToken = token;
      }
    }
  } catch {}
  next();
}

function branchWhere(user, alias) {
  const s = branchScope(user);
  if (s.admin) return { where: '', params: [] };
  const ids = s.ids;
  if (!ids.length) return { where: ` AND 1 = 0`, params: [] };
  return { where: ` AND ${alias}.branch_id IN (${ids.map((_, i) => '$' + (i + 1)).join(',')})`, params: ids };
}

function assertAccessToGroup(user, groupId, res) {
  const s = branchScope(user);
  if (s.admin) return true;
  return s.ids.includes(Number(groupId));
}

async function groupBelongsToBranches(user, groupId) {
  const s = branchScope(user);
  if (s.admin) return true;
  if (!s.ids.length) return false;
  const { rows } = await pool.query(
    'SELECT 1 AS one FROM groups WHERE id = $1 AND branch_id = ANY($2::int[])',
    [groupId, s.ids]
  );
  return !!rows.length;
}

async function entryAccessible(user, entryId) {
  const { rows } = await pool.query(
    `SELECT e.group_id FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.id = $1`,
    [entryId]
  );
  if (!rows.length) return { found: false };
  const groupId = rows[0].group_id;
  if (user.role === 'admin') return { found: true, group_id: groupId };
  const allowed = groupId && (await groupBelongsToBranches(user, groupId));
  if (!allowed) {
    console.warn(`[ACCESS DENIED] entryAccessible: user=${user.id} (${user.username}) branch_ids=${JSON.stringify(user.branch_ids)} entry=${entryId} group_id=${groupId}`);
  }
  return { found: true, group_id: groupId, allowed };
}

function fixFilename(str) {
  try {
    return Buffer.from(str, 'latin1').toString('utf8');
  } catch {
    return str;
  }
}

const BLOCKED_EXT = /\.(?:html?|js|mjs|cjs|svg|xml|json|map|wasm|php\d?|phtml|asp|aspx|jsp|sh|bat|cmd|cgi|exe|dll|com|msi|scr|hta|vbs|py|r|rb|htaccess)$/i;
const ALLOWED_IMAGE_EXT = new Set(['.jpg', '.jpeg', '.png', '.gif', '.webp', '.bmp', '.avif', '.ico', '.heic', '.heif', '.jfif']);
const MAX_TOTAL_UPLOAD_BYTES = 30 * 1024 * 1024;

const upload = multer({
  storage: multer.diskStorage({
    destination: (_, __, cb) => {
      fs.mkdirSync('uploads', { recursive: true });
      cb(null, 'uploads');
    },
    filename: (_, file, cb) => {
      const original = fixFilename(file.originalname);
      const ext = path.extname(original) || '.jpg';
      cb(null, `${Date.now()}-${Math.random().toString(36).slice(2, 8)}${ext}`);
    },
  }),
  limits: { fileSize: 10 * 1024 * 1024 },
  fileFilter: (req, file, cb) => {
    file.originalname = fixFilename(file.originalname);
    const ext = path.extname(file.originalname).toLowerCase();
    const isImageExt = ALLOWED_IMAGE_EXT.has(ext);
    if (file.fieldname === 'photo') {
      if (!isImageExt) {
        return cb(new Error('Only images'));
      }
    }
    if (ext && BLOCKED_EXT.test(ext)) return cb(new Error('Not allowed extension'));
    cb(null, true);
  },
});

const ADMIN_ALLOWED_EXT = new Set(['.pdf', '.doc', '.docx', '.txt', '.md', '.html', '.htm', '.zip', '.rar', '.7z', '.jpg', '.jpeg', '.png', '.gif', '.webp', '.bmp', '.avif', '.heic', '.heif', '.jfif']);
const adminUpload = multer({
  storage: multer.diskStorage({
    destination: (_, __, cb) => {
      fs.mkdirSync('uploads', { recursive: true });
      cb(null, 'uploads');
    },
    filename: (_, file, cb) => {
      const original = fixFilename(file.originalname);
      const ext = path.extname(original) || '.bin';
      cb(null, `${Date.now()}-${Math.random().toString(36).slice(2, 8)}${ext}`);
    },
  }),
  limits: { fileSize: 10 * 1024 * 1024 },
  fileFilter: (req, file, cb) => {
    file.originalname = fixFilename(file.originalname);
    const ext = path.extname(file.originalname).toLowerCase();
    if (ext && BLOCKED_EXT.test(ext) && !ADMIN_ALLOWED_EXT.has(ext)) {
      return cb(new Error('Not allowed extension'));
    }
    cb(null, true);
  },
});

async function getSetting(key, def) {
  const cached = cacheGet('setting:' + key);
  if (cached !== undefined) return cached;
  const { rows } = await pool.query('SELECT value FROM settings WHERE key = $1', [key]);
  const value = rows.length ? rows[0].value : def;
  cacheSet('setting:' + key, value, SETTINGS_TTL_MS);
  return value;
}

const UPLOADS_DIR = path.join(__dirname, 'uploads');

function safeUnlink(relPath) {
  if (!relPath || typeof relPath !== 'string') return;
  const parts = String(relPath).replace(/\\/g, '/').replace(/^\/+/, '').split('/');
  if (parts[0] === 'uploads') parts.shift();
  if (!parts.length || parts.includes('..') || parts.includes('')) return;
  const fp = path.resolve(UPLOADS_DIR, ...parts);
  if (fp === UPLOADS_DIR || !fp.startsWith(UPLOADS_DIR + path.sep)) return;
  if (fs.existsSync(fp)) fs.unlinkSync(fp);
}

function removeUpload(file) {
  safeUnlink(file && file.path);
}

async function convertPhoto(file) {
  if (!file || !file.path) return;
  const ext = (path.extname(file.originalname || '') || '').toLowerCase();
  if (ext !== '.heic' && ext !== '.heif' && ext !== '.jfif') return;
  try {
    if (ext === '.jfif') {
      // JFIF is already JPEG, just rename to .jpg for consistency
      const outName = `${path.basename(file.path, path.extname(file.path))}.jpg`;
      const outPath = path.join(path.dirname(file.path), outName);
      fs.renameSync(file.path, outPath);
      file.path = outPath;
      file.filename = outName;
      file.originalname = outName;
      return;
    }
    // HEIC/HEIF conversion
    const outName = `${path.basename(file.path, path.extname(file.path))}.jpg`;
    const outPath = path.join(path.dirname(file.path), outName);
    const jpeg = await heicConvert({ buffer: fs.readFileSync(file.path), format: 'JPEG', quality: 0.92 });
    fs.writeFileSync(outPath, jpeg);
    safeUnlink(file.path);
    file.path = outPath;
    file.filename = outName;
    file.originalname = outName;
  } catch (e) {
    console.error('Photo convert failed:', e);
  }
}

async function removeEntryFiles(entryId) {
  const { rows } = await pool.query(
    `SELECT photo_path AS p FROM entries WHERE id = $1
     UNION ALL
     SELECT path AS p FROM project_files WHERE entry_id = $1
     UNION ALL
     SELECT photo_path AS p FROM entry_photos WHERE entry_id = $1`,
    [entryId]
  );
  rows.forEach(r => safeUnlink(r.p));
}

async function sweepOrphanedUploads() {
  const dir = path.join(__dirname, 'uploads');
  if (!fs.existsSync(dir)) return;
  const [{ rows: photos }, { rows: files }, { rows: gphotos }, { rows: ephotos }] = await Promise.all([
    pool.query('SELECT photo_path AS p FROM entries WHERE photo_path IS NOT NULL'),
    pool.query('SELECT path AS p FROM project_files'),
    pool.query('SELECT photo_path AS p FROM group_photos'),
    pool.query('SELECT photo_path AS p FROM entry_photos'),
  ]);
  const refs = new Set();
  [...photos, ...files, ...gphotos, ...ephotos].forEach(r => refs.add('/' + String(r.p).replace(/^\/+/, '')));
  for (const f of fs.readdirSync(dir)) {
    const fp = path.join(dir, f);
    if (!fs.statSync(fp).isFile()) continue;
    if (!refs.has('/uploads/' + f)) {
      try { fs.unlinkSync(fp); } catch {}
    }
  }
}

async function ensureAuditTable() {
  await pool.query(`CREATE TABLE IF NOT EXISTS audit_log (
    id SERIAL PRIMARY KEY,
    action VARCHAR(100) NOT NULL,
    target JSONB,
    ip VARCHAR(45),
    created_at TIMESTAMPTZ DEFAULT now()
  )`);
  await pool.query('CREATE INDEX IF NOT EXISTS idx_audit_log_created_at ON audit_log(created_at DESC)');
  await pool.query('ALTER TABLE audit_log ADD COLUMN IF NOT EXISTS user_id INT REFERENCES users(id) ON DELETE SET NULL');
}

async function ensureBranchesTable() {
  await pool.query(`CREATE TABLE IF NOT EXISTS branches (
    id SERIAL PRIMARY KEY,
    name VARCHAR(200) NOT NULL UNIQUE,
    address TEXT,
    phone VARCHAR(50),
    created_at TIMESTAMPTZ DEFAULT now()
  )`);
  await pool.query(`ALTER TABLE groups ADD COLUMN IF NOT EXISTS branch_id INTEGER REFERENCES branches(id) ON DELETE SET NULL`);
}

async function ensureBannedIpsTable() {
  await pool.query(`CREATE TABLE IF NOT EXISTS banned_ips (
    ip VARCHAR(64) PRIMARY KEY,
    reason VARCHAR(100) NOT NULL,
    banned_until TIMESTAMPTZ NOT NULL,
    created_at TIMESTAMPTZ DEFAULT now()
  )`);
}

async function ensureEntryPhotosTable() {
  await pool.query(`CREATE TABLE IF NOT EXISTS entry_photos (
    id SERIAL PRIMARY KEY,
    entry_id INT NOT NULL REFERENCES entries(id) ON DELETE CASCADE,
    photo_path VARCHAR(255) NOT NULL,
    caption TEXT,
    sort_order INT DEFAULT 0,
    created_at TIMESTAMPTZ DEFAULT now()
  )`);
  await pool.query('CREATE INDEX IF NOT EXISTS idx_entry_photos_entry_id ON entry_photos(entry_id)');
}

async function ensurePhotoOriginalColumn() {
  await pool.query(`ALTER TABLE entries ADD COLUMN IF NOT EXISTS photo_original_path VARCHAR(255)`);
}

async function ensureEntryAiColumns() {
  await pool.query(`ALTER TABLE entries ADD COLUMN IF NOT EXISTS description_original TEXT`);
  await pool.query(`ALTER TABLE entries ADD COLUMN IF NOT EXISTS description_ai TEXT`);
  await pool.query(`ALTER TABLE entries ADD COLUMN IF NOT EXISTS ai_status VARCHAR(20) NOT NULL DEFAULT 'pending'`);
  await pool.query(`ALTER TABLE entries ADD COLUMN IF NOT EXISTS ai_checked_at TIMESTAMPTZ`);
  await pool.query(`ALTER TABLE entries ADD COLUMN IF NOT EXISTS ai_error TEXT`);
  await pool.query(`CREATE INDEX IF NOT EXISTS idx_entries_ai_pending ON entries(id) WHERE ai_status = 'pending' AND deleted_at IS NULL`);
  await pool.query(`
    CREATE OR REPLACE FUNCTION notify_entries_changed() RETURNS trigger AS $$
    BEGIN
      IF (TG_OP = 'INSERT') THEN
        PERFORM pg_notify('entries_changed', json_build_object('type', 'entry_created', 'id', NEW.id)::text);
      ELSIF (TG_OP = 'UPDATE' AND OLD.ai_status IS DISTINCT FROM NEW.ai_status) THEN
        PERFORM pg_notify('entries_changed', json_build_object('type', 'ai_status', 'id', NEW.id, 'status', NEW.ai_status, 'error', NEW.ai_error, 'description', NEW.description, 'description_ai', NEW.description_ai, 'description_original', NEW.description_original)::text);
      END IF;
      RETURN NULL;
    END;
    $$ LANGUAGE plpgsql
  `);
  await pool.query(`DROP TRIGGER IF EXISTS trg_entries_notify ON entries`);
  await pool.query(`CREATE TRIGGER trg_entries_notify AFTER INSERT OR UPDATE OF ai_status ON entries FOR EACH ROW EXECUTE FUNCTION notify_entries_changed()`);
  await pool.query(`INSERT INTO settings (key, value) VALUES ('ai_autocheck_enabled', 'true') ON CONFLICT (key) DO NOTHING`);
  const marker = await getSetting('ai_autocheck_migrated', '');
  if (marker !== '1') {
    await pool.query(`UPDATE entries SET description_original = description WHERE description_original IS NULL`);
    await pool.query(`UPDATE entries SET ai_status = 'skipped' WHERE ai_status = 'pending'`);
    await pool.query(`INSERT INTO settings (key, value) VALUES ('ai_autocheck_migrated', '1') ON CONFLICT (key) DO UPDATE SET value = '1'`);
  }
}

async function ensurePhotoJobsTable() {
  await pool.query(`CREATE TABLE IF NOT EXISTS photo_jobs (
    id SERIAL PRIMARY KEY,
    entry_id INT NOT NULL REFERENCES entries(id) ON DELETE CASCADE,
    action VARCHAR(20) NOT NULL DEFAULT 'ai',
    params JSONB,
    before_path VARCHAR(255),
    after_path VARCHAR(255),
    status VARCHAR(20) NOT NULL DEFAULT 'pending',
    attempts INT NOT NULL DEFAULT 0,
    error TEXT,
    created_at TIMESTAMPTZ DEFAULT now(),
    finished_at TIMESTAMPTZ
  )`);
  await pool.query(`CREATE INDEX IF NOT EXISTS idx_photo_jobs_pending ON photo_jobs(id) WHERE status = 'pending'`);
  await pool.query(`CREATE INDEX IF NOT EXISTS idx_photo_jobs_entry_id ON photo_jobs(entry_id)`);
  await pool.query(`INSERT INTO settings (key, value) VALUES ('photo_worker_enabled', 'true') ON CONFLICT (key) DO NOTHING`);
}

async function ensureUserTables() {
  await pool.query(`CREATE TABLE IF NOT EXISTS users (
    id SERIAL PRIMARY KEY,
    username VARCHAR(100) NOT NULL UNIQUE,
    password_hash VARCHAR(255) NOT NULL,
    name VARCHAR(150),
    role VARCHAR(20) NOT NULL DEFAULT 'tutor' CHECK (role IN ('admin','tutor')),
    is_active BOOLEAN DEFAULT true,
    created_at TIMESTAMPTZ DEFAULT now()
  )`);
  await pool.query(`CREATE TABLE IF NOT EXISTS user_branches (
    user_id INT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    branch_id INT NOT NULL REFERENCES branches(id) ON DELETE CASCADE,
    PRIMARY KEY (user_id, branch_id)
  )`);
  await pool.query(`CREATE TABLE IF NOT EXISTS sessions (
    id SERIAL PRIMARY KEY,
    user_id INT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    token VARCHAR(64) NOT NULL UNIQUE,
    created_at TIMESTAMPTZ DEFAULT now(),
    expires_at TIMESTAMPTZ NOT NULL
  )`);
  await pool.query(`CREATE INDEX IF NOT EXISTS idx_sessions_token ON sessions(token)`);
  await pool.query(`CREATE INDEX IF NOT EXISTS idx_sessions_expires_at ON sessions(expires_at)`);
  await pool.query('ALTER TABLE audit_log ADD COLUMN IF NOT EXISTS user_id INT REFERENCES users(id) ON DELETE SET NULL');
}

async function ensureFirstAdmin() {
  if (!ADMIN_PASSWORD) return;
  const { rows } = await pool.query('SELECT id FROM users WHERE role = \'admin\' LIMIT 1');
  if (rows.length) return;
  const exists = await pool.query('SELECT id FROM users WHERE username = $1', [ADMIN_USERNAME]);
  const username = exists.rows.length ? (ADMIN_USERNAME + '-' + Date.now()) : ADMIN_USERNAME;
  const hash = await bcrypt.hash(ADMIN_PASSWORD, 10);
  await pool.query(
    'INSERT INTO users (username, password_hash, name, role) VALUES ($1, $2, $3, $4)',
    [username, hash, 'Администратор', 'admin']
  );
  console.log(`Создан первый администратор: ${username}`);
}

async function ensureUsersAndFirstAdmin() {
  await ensureUserTables();
  await ensureFirstAdmin();
}

async function logAudit(req, action, target) {
  try {
    await pool.query(
      'INSERT INTO audit_log (user_id, action, target, ip) VALUES ($1, $2, $3, $4)',
      [req?.user?.id || null, action, target ?? null, req?.ip?.slice(0, 45) || null]
    );
  } catch (e) {
    console.error('audit log failed:', e);
  }
}

// --- Auth ---
app.post('/api/auth/login', apiLimiter, async (req, res) => {
  const rawUsername = typeof req.body?.username === 'string' ? req.body.username.trim().toLowerCase() : '';
  const password = String(req.body?.password || '');
  if (typeof req.body?.website === 'string' && req.body.website) {
    await recordFailure(req, 'honeypot', 1, BAN_TTL_MS);
    return res.status(401).json({ error: 'Неверный логин или пароль' });
  }
  if (!rawUsername || rawUsername.length > 100 || !password) {
    return res.status(401).json({ error: 'Неверный логин или пароль' });
  }
  const username = rawUsername;
  const { rows } = await pool.query('SELECT * FROM users WHERE username = $1', [username]);
  const user = rows[0];
  if (!user || !user.is_active) {
    await recordFailure(req, 'login-bruteforce', 10, BAN_TTL_MS);
    return res.status(401).json({ error: 'Неверный логин или пароль' });
  }
  const valid = await bcrypt.compare(password, user.password_hash || '');
  if (!valid) {
    await recordFailure(req, 'login-bruteforce', 10, BAN_TTL_MS);
    return res.status(401).json({ error: 'Неверный логин или пароль' });
  }
  const token = crypto.randomBytes(32).toString('hex');
  const expiresAt = new Date(Date.now() + SESSION_TTL_MS);
  await pool.query('INSERT INTO sessions (user_id, token, expires_at) VALUES ($1, $2, $3)', [user.id, token, expiresAt.toISOString()]);
  await logAudit(req, 'auth.login', { username: user.username });
  res.json({ token, expires_at: expiresAt.toISOString() });
});

app.post('/api/auth/logout', requireAuth, async (req, res) => {
  await pool.query('DELETE FROM sessions WHERE token = $1', [req.authToken]);
  res.json({ ok: true });
});

app.get('/api/auth/me', requireAuth, async (req, res) => {
  res.json(safeUser(req.user));
});

app.get('/api/bans', requireAuth, requireAdmin, async (_, res) => {
  const { rows } = await pool.query(
    'SELECT ip, reason, banned_until, created_at FROM banned_ips WHERE banned_until > now() ORDER BY banned_until DESC'
  );
  res.json(rows);
});

app.post('/api/bans', requireAuth, requireAdmin, async (req, res) => {
  const ip = String(req.body?.ip || '').trim();
  if (!ip || ip.length > 64 || !/^[0-9a-fA-F:.]+$/.test(ip)) {
    return res.status(400).json({ error: 'Некорректный IP' });
  }
  const reason = (typeof req.body?.reason === 'string' && req.body.reason.trim())
    ? req.body.reason.trim().slice(0, 100)
    : 'manual';
  const hours = Math.min(Math.max(parseInt(req.body?.hours, 10) || 24, 1), 24 * 30);
  await banIpAddr(ip, reason, hours * 60 * 60 * 1000, req);
  res.json({ ok: true, ip, reason, banned_until: banMemory.get(ip).banned_until });
});

app.delete('/api/bans/:ip', requireAuth, requireAdmin, async (req, res) => {
  const ip = String(req.params.ip || '').trim();
  if (!ip || ip.length > 64 || !/^[0-9a-fA-F:.]+$/.test(ip)) {
    return res.status(400).json({ error: 'Некорректный IP' });
  }
  await pool.query('DELETE FROM banned_ips WHERE ip = $1', [ip]);
  banMemory.delete(ip);
  failMemory.forEach((_, key) => { if (key.endsWith(':' + ip)) failMemory.delete(key); });
  await logAudit(req, 'ip.unban', { ip });
  res.json({ ok: true });
});

// --- Users (admin only) ---
app.get('/api/users', requireAuth, requireAdmin, async (_, res) => {
  const { rows } = await pool.query(
    `SELECT u.id, u.username, u.name, u.role, u.is_active, u.created_at,
            COALESCE(array_agg(ub.branch_id) FILTER (WHERE ub.branch_id IS NOT NULL), '{}') AS branch_ids
     FROM users u
     LEFT JOIN user_branches ub ON ub.user_id = u.id
     GROUP BY u.id
     ORDER BY u.id`
  );
  res.json(rows.map(r => ({ ...r, branch_ids: r.branch_ids || [] })));
});

app.get('/api/users/branches', requireAuth, async (req, res) => {
  const s = branchScope(req.user);
  const params = [];
  let where = '';
  if (!s.admin) {
    if (!s.ids.length) return res.json([]);
    where = `WHERE id = ANY($1::int[])`;
    params.push(s.ids);
  }
  const { rows } = await pool.query(`SELECT * FROM branches ${where} ORDER BY id`, params);
  res.json(rows);
});

app.post('/api/users', requireAuth, requireAdmin, async (req, res) => {
  const username = reqStr(req.body?.username, 100).toLowerCase();
  const password = String(req.body?.password || '');
  const name = optStr(req.body?.name, 150);
  const role = req.body?.role === 'admin' ? 'admin' : 'tutor';
  const isActive = req.body?.is_active !== false;
  let branchIds = Array.isArray(req.body?.branch_ids) ?
    [...new Set(req.body.branch_ids.map(Number).filter(Boolean))] : [];
  if (role === 'admin') branchIds = [];
  if (password.length < 6) return res.status(400).json({ error: 'Пароль должен быть не короче 6 символов' });
  const hash = await bcrypt.hash(password, 10);
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    const { rows } = await client.query(
      'INSERT INTO users (username, password_hash, name, role, is_active) VALUES ($1, $2, $3, $4, $5) RETURNING *',
      [username, hash, name, role, isActive]
    );
    const user = rows[0];
    for (const b of branchIds) {
      await client.query('INSERT INTO user_branches (user_id, branch_id) VALUES ($1, $2)', [user.id, b]);
    }
    await client.query('COMMIT');
    await logAudit(req, 'user.create', { id: user.id, username: user.username, role });
    res.status(201).json(safeUser({ ...user, branch_ids: branchIds }));
  } catch (e) {
    await client.query('ROLLBACK').catch(() => {});
    if (e.code === '23505') return res.status(409).json({ error: 'Логин уже занят' });
    throw e;
  } finally {
    client.release();
  }
});

app.put('/api/users/:id', requireAuth, requireAdmin, async (req, res) => {
  const id = req.params.id;
  const current = await pool.query('SELECT * FROM users WHERE id = $1', [id]);
  if (!current.rows.length) return res.status(404).json({ error: 'Пользователь не найден' });
  const target = current.rows[0];
  if (target.id === req.user.id && req.body?.is_active === false) {
    return res.status(400).json({ error: 'Нельзя деактивировать самого себя' });
  }
  if (target.id === req.user.id && req.body?.role && req.body.role !== 'admin') {
    return res.status(400).json({ error: 'Нельзя снять роль администратора с самого себя' });
  }
  const name = req.body?.name !== undefined ? optStr(req.body.name, 150) : target.name;
  const newRole = req.body?.role ? (req.body.role === 'admin' ? 'admin' : 'tutor') : target.role;
  const isActive = req.body?.is_active !== undefined ? req.body.is_active !== false : target.is_active;
  let branchIds = null;
  if (Array.isArray(req.body?.branch_ids)) {
    branchIds = [...new Set(req.body.branch_ids.map(Number).filter(Boolean))];
  }
  let hash = null;
  if (req.body?.password) {
    if (String(req.body.password).length < 6) return res.status(400).json({ error: 'Пароль должен быть не короче 6 символов' });
    hash = await bcrypt.hash(String(req.body.password), 10);
  }
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    if (hash) {
      await client.query('UPDATE users SET password_hash = $1 WHERE id = $2', [hash, id]);
    }
    await client.query(
      'UPDATE users SET name = $1, role = $2, is_active = $3 WHERE id = $4',
      [name, newRole, isActive, id]
    );
    if (branchIds !== null) {
      await client.query('DELETE FROM user_branches WHERE user_id = $1', [id]);
      if (newRole === 'tutor') {
        for (const b of branchIds) {
          await client.query('INSERT INTO user_branches (user_id, branch_id) VALUES ($1, $2)', [id, b]);
        }
      }
    }
    if (!isActive) {
      await client.query('DELETE FROM sessions WHERE user_id = $1', [id]);
    }
    await client.query('COMMIT');
    await logAudit(req, 'user.update', { id, role: newRole, is_active: isActive });
    const fresh = await pool.query(
      `SELECT u.id, u.username, u.name, u.role, u.is_active, u.created_at,
              COALESCE(array_agg(ub.branch_id) FILTER (WHERE ub.branch_id IS NOT NULL), '{}') AS branch_ids
       FROM users u LEFT JOIN user_branches ub ON ub.user_id = u.id WHERE u.id = $1 GROUP BY u.id`,
      [id]
    );
    res.json(safeUser({ ...fresh.rows[0], branch_ids: fresh.rows[0].branch_ids || [] }));
  } catch (e) {
    await client.query('ROLLBACK').catch(() => {});
    if (e.code === '23505') return res.status(409).json({ error: 'Логин уже занят' });
    throw e;
  } finally {
    client.release();
  }
});

app.delete('/api/users/:id', requireAuth, requireAdmin, async (req, res) => {
  if (req.params.id === String(req.user.id)) {
    return res.status(400).json({ error: 'Нельзя удалить самого себя' });
  }
  await pool.query('DELETE FROM users WHERE id = $1', [req.params.id]);
  await logAudit(req, 'user.delete', { id: req.params.id });
  res.json({ ok: true });
});

// --- Settings ---
app.get('/api/settings', requireAdmin, async (_, res) => {
  const { rows } = await pool.query('SELECT key, value FROM settings ORDER BY key');
  const out = {};
  rows.forEach(r => { out[r.key] = r.value; });
  res.json(out);
});

app.get('/api/public-settings', apiLimiter, async (_, res) => {
  const out = await cacheWrap('public-settings', PUBLIC_TTL_MS, async () => {
    const keys = ['footer_left', 'footer_right', 'share_show_student_message', 'share_show_entry_date', 'share_show_student_names', 'share_show_group_photos', 'cookie_notice_text', 'spam_interval_min', 'photo_capture_resolution', 'photo_capture_quality', 'photo_enhance_engine'];
    const defaults = { spam_interval_min: '30', photo_capture_resolution: '640x480', photo_capture_quality: '0.92', photo_enhance_engine: 'auto' };
    const result = {};
    for (const k of keys) result[k] = await getSetting(k, defaults[k] || '');
    const rm = /^(\d{2,5})x(\d{2,5})$/.exec(result.photo_capture_resolution);
    if (rm) {
      result.photo_capture_width = rm[1];
      result.photo_capture_height = rm[2];
    } else {
      result.photo_capture_width = '640';
      result.photo_capture_height = '480';
    }
    const q = parseFloat(result.photo_capture_quality);
    result.photo_capture_quality = Number.isFinite(q) && q >= 0.5 && q <= 1 ? String(q) : '0.92';
    result.photo_ai_enabled = PHOTO_AI_URL ? 'true' : 'false';
    return result;
  });
  res.json(out);
});

app.put('/api/settings', requireAdmin, async (req, res) => {
  const { settings } = req.body;
  if (!settings || typeof settings !== 'object') return res.status(400).json({ error: 'settings required' });
  for (const [key, value] of Object.entries(settings)) {
    if (key === 'spam_interval_min') {
      const n = parseInt(String(value), 10);
      if (!Number.isFinite(n) || n < 1 || n > 10080) {
        return res.status(400).json({ error: 'spam_interval_min должен быть целым числом от 1 до 10080 (7 дней)' });
      }
    }
    if (key === 'photo_capture_resolution') {
      if (!/^\d{2,5}x\d{2,5}$/.test(String(value))) {
        return res.status(400).json({ error: 'photo_capture_resolution должен быть в формате ШИРИНАxВЫСОТА, например 640x480' });
      }
    }
    if (key === 'photo_capture_quality') {
      const q = parseFloat(String(value));
      if (!Number.isFinite(q) || q < 0.5 || q > 1) {
        return res.status(400).json({ error: 'photo_capture_quality должен быть числом от 0.5 до 1' });
      }
    }
    if (key === 'photo_enhance_engine' && !['auto', 'server', 'client'].includes(String(value))) {
      return res.status(400).json({ error: 'photo_enhance_engine должен быть auto, server или client' });
    }
  }
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    for (const [key, value] of Object.entries(settings)) {
      await client.query(
        `INSERT INTO settings (key, value) VALUES ($1, $2)
         ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
        [key, String(value ?? '')]
      );
    }
    await client.query('COMMIT');
    await logAudit(req, 'settings.update', { settings });
    invalidateSettings();
    const { rows } = await pool.query('SELECT key, value FROM settings ORDER BY key');
    const out = {};
    rows.forEach(r => { out[r.key] = r.value; });
    res.json(out);
  } catch (e) {
    await client.query('ROLLBACK');
    throw e;
  } finally {
    client.release();
  }
});

app.get('/api/audit', requireAdmin, async (req, res) => {
  const limit = Math.min(parseInt(req.query.limit, 10) || 100, 1000);
  const offset = Math.max(parseInt(req.query.offset, 10) || 0, 0);
  let where = '';
  const params = [];
  const action = typeof req.query.action === 'string' && req.query.action.trim() ? req.query.action.trim() : null;
  if (action) {
    where = 'WHERE a.action = $1';
    params.push(action);
  }
  params.push(limit, offset);
  const { rows } = await pool.query(
    `SELECT a.id, a.action, a.target, a.ip, a.created_at, a.user_id, u.username AS user_name
     FROM audit_log a LEFT JOIN users u ON u.id = a.user_id
     ${where} ORDER BY a.id DESC LIMIT $${params.length - 1} OFFSET $${params.length}`,
    params
  );
  res.json(rows);
});

// --- Backup / Restore ---
const gunzipAsync = require('util').promisify(require('zlib').gunzip);
const zlib = require('zlib');
const tar = require('tar');
const os = require('os');
const AI_URL = process.env.AI_URL || 'http://text-corrector:8080';
const PHOTO_AI_URL = process.env.PHOTO_AI_URL || '';
const AI_MODEL = process.env.AI_MODEL || 'qwen2.5-1.5b-instruct-q4_k_m.gguf';
const AI_DEFAULT_PROMPT = process.env.AI_PROMPT || 'Ты — редактор текстов. Исправь ТОЛЬКО грамматические, орфографические и пунктуационные ошибки в тексте. Приведи к правильному регистру буквы. НЕ меняй слова, структуру предложений, стиль или смысл текста. Верни ТОЛЬКО исправленный текст без пояснений.';
let entryAutoChecker = null;
let photoWorker = null;

async function getAiPrompt() {
  const prompt = await getSetting('ai_prompt', AI_DEFAULT_PROMPT);
  return prompt;
}

async function getAiProfiles() {
  try {
    const raw = await getSetting('ai_profiles', '[]');
    const list = JSON.parse(raw || '[]');
    return Array.isArray(list) ? list.filter(p => p && p.id && p.base_url && p.model) : [];
  } catch (e) {
    return [];
  }
}

async function getActiveAiProfile() {
  const active = await getSetting('ai_active_profile', 'native');
  if (!active || active === 'native') return null;
  const profiles = await getAiProfiles();
  return profiles.find(p => p.id === active) || null;
}

function normalizeOpenAiBase(base) {
  let b = String(base || '').trim().replace(/\/+$/, '');
  if (!/^https?:\/\//i.test(b)) return null;
  if (!/\/v1$/i.test(b)) b += '/v1';
  return b;
}

async function aiCorrectText(text) {
  const profile = await getActiveAiProfile();
  let url = `${AI_URL.replace(/\/+$/, '')}/v1/chat/completions`;
  let model = AI_MODEL;
  const headers = { 'Content-Type': 'application/json' };
  let maxTokens = Math.min(256, Math.max(128, text.length + 64));
  if (profile) {
    const base = normalizeOpenAiBase(profile.base_url);
    if (!base) throw new Error('Некорректный base_url профиля ИИ');
    url = `${base}/chat/completions`;
    model = profile.model;
    if (profile.api_key) headers.Authorization = `Bearer ${profile.api_key}`;
    maxTokens = parseInt(profile.max_tokens, 10) || Math.min(4096, Math.max(1024, text.length * 2 + 512));
  }
  try {
    const systemPrompt = await getAiPrompt();
    const res = await fetch(url, {
      method: 'POST',
      headers,
      body: JSON.stringify({
        model,
        messages: [
          { role: 'system', content: systemPrompt },
          { role: 'user', content: text }
        ],
        temperature: 0.1,
        max_tokens: maxTokens
      })
    });
    if (!res.ok) throw new Error(`AI service error: ${res.status}`);
    const data = await res.json();
    return data.choices?.[0]?.message?.content?.trim() || text;
  } catch (e) {
    console.error('AI correct error:', e);
    throw e;
  }
}

const BACKUP_UPLOAD_LIMIT_MB = parseInt(process.env.BACKUP_UPLOAD_LIMIT_MB || '500', 10);

const uploadBackup = multer({
  storage: multer.diskStorage({
    destination: (_, __, cb) => {
      const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'wido-up-'));
      cb(null, dir);
    },
    filename: (_, file, cb) => {
      const ext = path.extname(file.originalname) || '.bin';
      cb(null, `backup-${Date.now()}${ext}`);
    },
  }),
  limits: { fileSize: BACKUP_UPLOAD_LIMIT_MB * 1024 * 1024 },
});

const SAFE_NAME = /^[\w,.()-]+$/;

function isSafeUploadPath(p) {
  if (typeof p !== 'string' || !p.startsWith('/uploads/')) return false;
  const name = p.slice('/uploads/'.length);
  return name !== '' && !name.includes('/') && !name.includes('..') && SAFE_NAME.test(name);
}

function reqInt(v) {
  const n = Number(v);
  if (!Number.isInteger(n)) throw new Error('Invalid integer');
  return n;
}

function optInt(v, lo = -Infinity, hi = Infinity) {
  if (v === null || v === undefined || v === '') return null;
  const n = Number(v);
  if (!Number.isInteger(n) || n < lo || n > hi) throw new Error('Invalid integer');
  return n;
}

function reqStr(v, max) {
  if (typeof v !== 'string') throw new Error('Invalid string');
  const s = v.trim();
  if (!s || s.length > max) throw new Error('Invalid string length');
  return s;
}

function optStr(v, max) {
  if (v === null || v === undefined) return null;
  return reqStr(v, max);
}

function optTs(v) {
  if (v === null || v === undefined) return null;
  if (typeof v !== 'string' || !/^\d{4}-\d{2}-\d{2}[T ]\d{2}:\d{2}/.test(v)) throw new Error('Invalid timestamp');
  return v;
}

function optTime(v) {
  if (v === null || v === undefined) return null;
  if (typeof v !== 'string' || !/^\d{2}:\d{2}(:\d{2})?$/.test(v)) throw new Error('Invalid time');
  return v;
}

function optDate(v) {
  if (v === null || v === undefined) return null;
  if (typeof v !== 'string' || !/^\d{4}-\d{2}-\d{2}$/.test(v)) throw new Error('Invalid date');
  return v;
}

function optBool(v) {
  if (v === null || v === undefined) return null;
  return !!v;
}

function reqToken(v) {
  if (typeof v !== 'string' || !/^[0-9a-f]{16,64}$/.test(v)) throw new Error('Invalid token');
  return v;
}

function reqUploadPath(v, max) {
  if (typeof v !== 'string' || v.length > max) throw new Error('Invalid path');
  if (!isSafeUploadPath(v)) throw new Error('Invalid upload path');
  return v;
}

function optUploadPath(v, max) {
  if (v === null || v === undefined) return null;
  return reqUploadPath(v, max);
}

const AI_STATUSES = new Set(['pending', 'processing', 'done', 'skipped', 'error', 'reverted']);

function optAiText(v, max) {
  if (v === null || v === undefined) return null;
  return reqStr(v, max);
}

function reqAiStatus(v, fallback) {
  if (v === null || v === undefined) return fallback;
  const s = String(v);
  if (s === 'processing') return 'pending';
  return AI_STATUSES.has(s) ? s : fallback;
}

function normalizeRestoreData(data) {
  const groups = (data.groups || []).map(x => ({
    id: reqInt(x.id),
    name: reqStr(x.name, 100),
    created_at: optTs(x.created_at),
    day_of_week: optInt(x.day_of_week, 0, 6),
    time_start: optTime(x.time_start),
    time_end: optTime(x.time_end),
    branch_id: optInt(x.branch_id, 0, 2147483647),
  }));
  const students = (data.students || []).map(x => ({
    id: reqInt(x.id),
    name: reqStr(x.name, 150),
    created_at: optTs(x.created_at),
    group_id: optInt(x.group_id, 0, 2147483647),
  }));
  const entries = (data.entries || []).map(x => ({
    id: reqInt(x.id),
    student_name: reqStr(x.student_name, 150),
    group_id: reqInt(x.group_id),
    description: reqStr(x.description, 100000),
    description_original: optAiText(x.description_original, 100000) ?? reqStr(x.description, 100000),
    description_ai: optAiText(x.description_ai, 100000),
    ai_status: reqAiStatus(x.ai_status, 'skipped'),
    ai_checked_at: optTs(x.ai_checked_at),
    ai_error: optAiText(x.ai_error, 500),
    photo_path: optUploadPath(x.photo_path, 255),
    deleted_at: optTs(x.deleted_at),
    created_at: optTs(x.created_at),
  }));
  const project_files = (data.project_files || []).map(x => ({
    id: reqInt(x.id),
    entry_id: optInt(x.entry_id, 0, 2147483647),
    token: reqToken(x.token),
    path: reqUploadPath(x.path, 255),
    name: reqStr(x.name, 255),
    created_at: optTs(x.created_at),
  }));
  const branches = (data.branches || []).map(x => ({
    id: reqInt(x.id),
    name: reqStr(x.name, 200),
    address: optStr(x.address, 1000),
    phone: optStr(x.phone, 50),
    created_at: optTs(x.created_at),
  }));
  const users = (data.users || []).map(x => ({
    id: reqInt(x.id),
    username: reqStr(x.username, 100),
    password_hash: reqStr(x.password_hash, 255),
    name: optStr(x.name, 150),
    role: (x.role === 'admin' || x.role === 'tutor') ? x.role : 'tutor',
    is_active: !!x.is_active,
    created_at: optTs(x.created_at),
  }));
  const user_branches = (data.user_branches || []).map(x => ({
    user_id: reqInt(x.user_id),
    branch_id: reqInt(x.branch_id),
  }));
  const entry_photos = (data.entry_photos || []).map(x => ({
    id: reqInt(x.id),
    entry_id: reqInt(x.entry_id),
    photo_path: reqUploadPath(x.photo_path, 255),
    caption: optStr(x.caption, 10000),
    sort_order: optInt(x.sort_order, -2147483648, 2147483647),
    created_at: optTs(x.created_at),
  }));
  const group_photos = (data.group_photos || []).map(x => ({
    id: reqInt(x.id),
    group_id: reqInt(x.group_id),
    photo_path: reqUploadPath(x.photo_path, 255),
    caption: optStr(x.caption, 10000),
    taken_at: optDate(x.taken_at),
    sort_order: optInt(x.sort_order, -2147483648, 2147483647),
    created_at: optTs(x.created_at),
  }));
  const share_links = (data.share_links || []).map(x => ({
    id: reqInt(x.id),
    token: optStr(x.token, 40),
    name: reqStr(x.name, 200),
    group_id: optInt(x.group_id, 0, 2147483647),
    student_name: optStr(x.student_name, 150),
    date_from: optDate(x.date_from),
    date_to: optDate(x.date_to),
    show_student_names: optBool(x.show_student_names),
    expires_at: optTs(x.expires_at),
    access_password_hash: optStr(x.access_password_hash, 255),
    message: optStr(x.message, 2000),
    link_url: optStr(x.link_url, 500),
    show_student_message: optBool(x.show_student_message),
    show_entry_date: optBool(x.show_entry_date),
    show_group_photos: optBool(x.show_group_photos),
    created_at: optTs(x.created_at),
  }));
  const settings = {};
  for (const [k, v] of Object.entries(data.settings || {})) {
    settings[reqStr(k, 100)] = reqStr(String(v), 10000);
  }
  return { groups, students, entries, project_files, settings, branches, users, user_branches, entry_photos, group_photos, share_links };
}

app.get('/api/backup', requireAdmin, async (req, res) => {
  const staging = fs.mkdtempSync(path.join(os.tmpdir(), 'wido-bk-'));
  try {
    const [g, s, e, st, pf, br, us, ub, gp, ep] = await Promise.all([
      pool.query('SELECT * FROM groups ORDER BY id'),
      pool.query('SELECT * FROM students ORDER BY id'),
      pool.query('SELECT * FROM entries ORDER BY id'),
      pool.query('SELECT key, value FROM settings'),
      pool.query('SELECT * FROM project_files ORDER BY id'),
      pool.query('SELECT * FROM branches ORDER BY id'),
      pool.query('SELECT * FROM users ORDER BY id'),
      pool.query('SELECT * FROM user_branches ORDER BY user_id, branch_id'),
      pool.query('SELECT * FROM group_photos ORDER BY id'),
      pool.query('SELECT * FROM entry_photos ORDER BY id'),
    ]);
    const settings = {};
    st.rows.forEach(r => { settings[r.key] = r.value; });
    const payload = { version: 1, created_at: new Date().toISOString(), groups: g.rows, students: s.rows, entries: e.rows, settings, project_files: pf.rows, branches: br.rows, users: us.rows, user_branches: ub.rows, group_photos: gp.rows, entry_photos: ep.rows };
    fs.writeFileSync(path.join(staging, 'data.json'), JSON.stringify(payload));
    fs.mkdirSync(path.join(staging, 'uploads'), { recursive: true });
    const dir = path.join(__dirname, 'uploads');
    if (fs.existsSync(dir)) {
      for (const f of fs.readdirSync(dir)) {
        const fp = path.join(dir, f);
        if (fs.statSync(fp).isFile() && SAFE_NAME.test(f)) fs.copyFileSync(fp, path.join(staging, 'uploads', f));
      }
    }
    const stamp = new Date().toISOString().slice(0, 16).replace(/[:T]/g, '-');
    const outPath = path.join(os.tmpdir(), `whatido-backup-${stamp}.tar.gz`);
    await tar.c({ gzip: true, file: outPath, cwd: staging }, ['data.json', 'uploads']);
    const buf = fs.readFileSync(outPath);
    fs.unlinkSync(outPath);
    res.setHeader('Content-Type', 'application/gzip');
    res.setHeader('Content-Disposition', `attachment; filename="whatido-backup-${stamp}.tar.gz"`);
    await logAudit(req, 'backup.download', {});
    res.send(buf);
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: err.message });
  } finally {
    fs.rmSync(staging, { recursive: true, force: true });
  }
});

function cleanupUpload(req) {
  try {
    if (req?.file?.destination) fs.rmSync(req.file.destination, { recursive: true, force: true });
  } catch {}
}

function peekGunzip(filePath, n) {
  return new Promise((resolve) => {
    const gunz = zlib.createGunzip();
    const bufs = [];
    let total = 0;
    let done = false;
    gunz.on('data', (c) => {
      if (done) return;
      const need = n - total;
      bufs.push(c.length > need ? c.subarray(0, need) : c);
      total += Math.min(c.length, need);
      if (total >= n) {
        done = true;
        gunz.destroy();
      }
    });
    gunz.on('error', () => resolve(null));
    gunz.on('close', () => resolve(Buffer.concat(bufs)));
    fs.createReadStream(filePath).pipe(gunz);
  });
}

app.post('/api/restore', requireAdmin, uploadBackup.single('backup'), async (req, res) => {
  if (!req.file) return res.status(400).json({ error: 'backup file required' });
  let data;
  let legacyPhotos = [];
  const staging = fs.mkdtempSync(path.join(os.tmpdir(), 'wido-rst-'));
  try {
    const head = await peekGunzip(req.file.path, 8);
    if (head && head[0] === 0x7b) {
      const buf = await fs.promises.readFile(req.file.path);
      const gunz = await gunzipAsync(buf);
      data = JSON.parse(gunz.toString('utf8'));
      legacyPhotos = data.photos || [];
    } else {
      await tar.x({ file: req.file.path, cwd: staging });
      data = JSON.parse(fs.readFileSync(path.join(staging, 'data.json'), 'utf8'));
    }
  } catch {
    fs.rmSync(staging, { recursive: true, force: true });
    cleanupUpload(req);
    return res.status(400).json({ error: 'Неверный файл бэкапа' });
  }
  if (!data || data.version !== 1 || !Array.isArray(data.groups)) {
    fs.rmSync(staging, { recursive: true, force: true });
    cleanupUpload(req);
    return res.status(400).json({ error: 'Неверный формат бэкапа' });
  }
  let ndata;
  try {
    ndata = normalizeRestoreData(data);
  } catch (e) {
    fs.rmSync(staging, { recursive: true, force: true });
    cleanupUpload(req);
    return res.status(400).json({ error: 'Неверный формат бэкапа: ' + e.message });
  }
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    await client.query('DELETE FROM project_files');
    await client.query('DELETE FROM entries');
    await client.query('DELETE FROM students');
    await client.query('DELETE FROM groups');
    await client.query('DELETE FROM user_branches');
    await client.query('DELETE FROM sessions');
    await client.query('DELETE FROM users');
    await client.query('DELETE FROM branches');
    for (const x of ndata.branches) {
      await client.query(
        'INSERT INTO branches (id, name, address, phone, created_at) VALUES ($1,$2,$3,$4,$5)',
        [x.id, x.name, x.address, x.phone, x.created_at]
      );
    }
    for (const x of ndata.groups) {
      await client.query(
        'INSERT INTO groups (id, name, created_at, day_of_week, time_start, time_end, branch_id) VALUES ($1,$2,$3,$4,$5,$6,$7)',
        [x.id, x.name, x.created_at, x.day_of_week, x.time_start, x.time_end, x.branch_id]
      );
    }
    for (const x of ndata.students) {
      await client.query(
        'INSERT INTO students (id, name, created_at, group_id) VALUES ($1,$2,$3,$4)',
        [x.id, x.name, x.created_at, x.group_id]
      );
    }
    for (const x of ndata.entries) {
      await client.query(
        'INSERT INTO entries (id, student_name, group_id, description, description_original, description_ai, ai_status, ai_checked_at, ai_error, photo_path, deleted_at, created_at) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12)',
        [x.id, x.student_name, x.group_id, x.description, x.description_original, x.description_ai, x.ai_status, x.ai_checked_at, x.ai_error, x.photo_path, x.deleted_at, x.created_at]
      );
    }
    for (const x of ndata.project_files) {
      await client.query(
        'INSERT INTO project_files (id, entry_id, token, path, name, created_at) VALUES ($1,$2,$3,$4,$5,$6)',
        [x.id, x.entry_id, x.token, x.path, x.name, x.created_at]
      );
    }
    for (const x of ndata.group_photos) {
      await client.query(
        'INSERT INTO group_photos (id, group_id, photo_path, caption, taken_at, sort_order, created_at) VALUES ($1,$2,$3,$4,$5,$6,$7)',
        [x.id, x.group_id, x.photo_path, x.caption, x.taken_at, x.sort_order, x.created_at]
      );
    }
    for (const x of ndata.entry_photos) {
      await client.query(
        'INSERT INTO entry_photos (id, entry_id, photo_path, caption, sort_order, created_at) VALUES ($1,$2,$3,$4,$5,$6)',
        [x.id, x.entry_id, x.photo_path, x.caption, x.sort_order, x.created_at]
      );
    }
    for (const x of ndata.users) {
      await client.query(
        'INSERT INTO users (id, username, password_hash, name, role, is_active, created_at) VALUES ($1,$2,$3,$4,$5,$6,$7)',
        [x.id, x.username, x.password_hash, x.name, x.role, x.is_active, x.created_at]
      );
    }
    for (const x of ndata.user_branches) {
      await client.query(
        'INSERT INTO user_branches (user_id, branch_id) VALUES ($1,$2)',
        [x.user_id, x.branch_id]
      );
    }
    for (const [k, v] of Object.entries(ndata.settings)) {
      await client.query(
        'INSERT INTO settings (key, value) VALUES ($1,$2) ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value',
        [k, String(v ?? '')]
      );
    }
    for (const tbl of ['groups', 'students', 'entries', 'project_files', 'branches', 'users', 'group_photos', 'entry_photos']) {
      const r = await client.query('SELECT COALESCE(MAX(id), 1) AS m FROM ' + tbl);
      await client.query('SELECT setval(pg_get_serial_sequence($1, $2), $3)', [tbl, 'id', r.rows[0].m]);
    }
    await client.query('COMMIT');
  } catch (e) {
    await client.query('ROLLBACK');
    fs.rmSync(staging, { recursive: true, force: true });
    cleanupUpload(req);
    throw e;
  } finally {
    client.release();
  }
  const dir = path.join(__dirname, 'uploads');
  fs.mkdirSync(dir, { recursive: true });
  if (legacyPhotos.length) {
    for (const p of legacyPhotos) {
      if (!p.path || !SAFE_NAME.test(p.path)) continue;
      fs.writeFileSync(path.join(dir, p.path), Buffer.from(p.data, 'base64'));
    }
  } else {
    const src = path.join(staging, 'uploads');
    if (fs.existsSync(src)) {
      for (const f of fs.readdirSync(src)) {
        if (!SAFE_NAME.test(f)) continue;
        const fp = path.join(src, f);
        if (fs.statSync(fp).isFile()) fs.copyFileSync(fp, path.join(dir, f));
      }
    }
  }
  fs.rmSync(staging, { recursive: true, force: true });
  cleanupUpload(req);
  await sweepOrphanedUploads().catch(err => console.error('Upload sweep:', err));
  await ensureFirstAdmin().catch(err => console.error('First admin:', err));
  await logAudit(req, 'backup.restore', {});
  invalidateAll();
  res.json({ ok: true });
});

// --- Share links ---
function normDates(o) {
  if (o && o.date_from) o.date_from = o.date_from instanceof Date ? o.date_from.toISOString().slice(0, 10) : String(o.date_from).slice(0, 10);
  if (o && o.date_to) o.date_to = o.date_to instanceof Date ? o.date_to.toISOString().slice(0, 10) : String(o.date_to).slice(0, 10);
  return o;
}

function parseShareMessage(v) {
  const s = typeof v === 'string' ? v.trim() : '';
  if (s.length > 2000) throw new Error('Сообщение слишком длинное (макс. 2000 символов)');
  return s || null;
}

function parseShareLinkUrl(v) {
  const s = typeof v === 'string' ? v.trim() : '';
  if (!s) return null;
  if (s.length > 500) throw new Error('Ссылка слишком длинная (макс. 500 символов)');
  let u;
  try { u = new URL(s); } catch { throw new Error('Некорректная ссылка'); }
  if (u.protocol !== 'http:' && u.protocol !== 'https:') throw new Error('Ссылка должна начинаться с http:// или https://');
  return s;
}

app.get('/api/links', requireAuth, async (req, res) => {
  const s = branchScope(req.user);
  let where = '';
  const params = [];
  if (!s.admin) {
    if (s.ids.length) {
      const ph = s.ids.map(id => `$${params.push(id)}`).join(',');
      where = `WHERE l.group_id IN (${ph})`;
    } else {
      where = `WHERE l.group_id IS NULL AND 1 = 0`;
    }
  }
  const limit = optInt(req.query.limit, 1, 200);
  const offset = optInt(req.query.offset, 0, Infinity) || 0;
  if (limit != null) {
    params.push(limit);
    params.push(offset);
    const { rows: totalRows } = await pool.query(
      `SELECT COUNT(*)::int AS total FROM share_links l
       LEFT JOIN groups g ON g.id = l.group_id ${where}`,
      params.slice(0, params.length - 2)
    );
    const { rows } = await pool.query(
      `SELECT l.*, g.name AS group_name FROM share_links l
       LEFT JOIN groups g ON g.id = l.group_id ${where} ORDER BY l.created_at DESC LIMIT $${params.length - 1} OFFSET $${params.length}`,
      params
    );
    rows.forEach(normDates);
    return res.json({ items: rows, total: totalRows[0].total });
  }
  const { rows } = await pool.query(
    `SELECT l.*, g.name AS group_name FROM share_links l
     LEFT JOIN groups g ON g.id = l.group_id ${where} ORDER BY l.created_at DESC`,
    params
  );
  rows.forEach(normDates);
  res.json(rows);
});

app.post('/api/links', requireAuth, async (req, res) => {
  const { name, group_id, student_name, date_from, date_to, expires_at, access_password } = req.body;
  if (!name?.trim()) return res.status(400).json({ error: 'Название обязательно' });
  let message, linkUrl;
  try {
    message = parseShareMessage(req.body.message);
    linkUrl = parseShareLinkUrl(req.body.link_url);
  } catch (e) {
    return res.status(400).json({ error: e.message });
  }
  if (req.user.role !== 'admin' && group_id && !(await groupBelongsToBranches(req.user, group_id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const token = crypto.randomBytes(20).toString('hex');
  let passwordHash = null;
  if (access_password && access_password.trim()) {
    passwordHash = await bcrypt.hash(access_password.trim(), 10);
  }
  let expiresAt = null;
  if (expires_at) {
    const parsed = new Date(expires_at);
    if (isNaN(parsed.getTime())) {
      return res.status(400).json({ error: 'Неверный формат даты истечения' });
    }
    expiresAt = parsed.toISOString();
  } else {
    // Default 7 days from now
    const defaultExp = new Date(Date.now() + 7 * 24 * 60 * 60 * 1000);
    expiresAt = defaultExp.toISOString();
  }
  const { rows } = await pool.query(
    `INSERT INTO share_links (token, name, group_id, student_name, date_from, date_to, show_student_names, expires_at, access_password_hash, message, link_url, show_student_message, show_entry_date, show_group_photos)
     VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14) RETURNING *`,
    [token, name.trim(), group_id || null, student_name || null, date_from || null, date_to || null, req.body.show_student_names == null ? null : !!req.body.show_student_names, expiresAt, passwordHash, message, linkUrl, req.body.show_student_message == null ? null : !!req.body.show_student_message, req.body.show_entry_date == null ? null : !!req.body.show_entry_date, req.body.show_group_photos == null ? null : !!req.body.show_group_photos]
  );
  await logAudit(req, 'link.create', { id: rows[0].id, name: name.trim() });
  invalidateShare();
  res.status(201).json(normDates(rows[0]));
});

app.put('/api/links/:id', requireAuth, async (req, res) => {
  const { name, group_id, student_name, date_from, date_to, expires_at, access_password } = req.body;
  if (!name?.trim()) return res.status(400).json({ error: 'Название обязательно' });
  let message, linkUrl;
  try {
    message = parseShareMessage(req.body.message);
    linkUrl = parseShareLinkUrl(req.body.link_url);
  } catch (e) {
    return res.status(400).json({ error: e.message });
  }
  if (req.user.role !== 'admin') {
    const { rows: lr } = await pool.query('SELECT group_id FROM share_links WHERE id = $1', [req.params.id]);
    if (!lr.length) return res.status(404).json({ error: 'Не найдено' });
    const curGid = lr[0].group_id;
    if (curGid && !(await groupBelongsToBranches(req.user, curGid))) {
      return res.status(403).json({ error: 'Нет доступа к этой ссылке' });
    }
    if (group_id && !(await groupBelongsToBranches(req.user, group_id))) {
      return res.status(403).json({ error: 'Нет доступа к этой группе' });
    }
  }
  let passwordHash = undefined;
  if (access_password !== undefined) {
    if (access_password && access_password.trim()) {
      passwordHash = await bcrypt.hash(access_password.trim(), 10);
    } else {
      passwordHash = null; // Clear password if empty string sent
    }
  }
  let expiresAt = undefined;
  if (expires_at !== undefined) {
    if (expires_at) {
      const parsed = new Date(expires_at);
      if (isNaN(parsed.getTime())) {
        return res.status(400).json({ error: 'Неверный формат даты истечения' });
      }
      expiresAt = parsed.toISOString();
    } else {
      expiresAt = null; // Clear expiry if null sent
    }
  }
  const fields = ['name = $1', 'group_id = $2', 'student_name = $3', 'date_from = $4', 'date_to = $5', 'show_student_names = $6', 'message = $7', 'link_url = $8', 'show_student_message = $9', 'show_entry_date = $10', 'show_group_photos = $11'];
  const values = [name.trim(), group_id || null, student_name || null, date_from || null, date_to || null, req.body.show_student_names == null ? null : !!req.body.show_student_names, message, linkUrl, req.body.show_student_message == null ? null : !!req.body.show_student_message, req.body.show_entry_date == null ? null : !!req.body.show_entry_date, req.body.show_group_photos == null ? null : !!req.body.show_group_photos];
  let paramIdx = 12;
  if (passwordHash !== undefined) {
    fields.push(`access_password_hash = $${paramIdx++}`);
    values.push(passwordHash);
  }
  if (expiresAt !== undefined) {
    fields.push(`expires_at = $${paramIdx++}`);
    values.push(expiresAt);
  }
  values.push(req.params.id);
  const { rows } = await pool.query(
    `UPDATE share_links SET ${fields.join(', ')} WHERE id = $${paramIdx} RETURNING *`,
    values
  );
  if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
  await logAudit(req, 'link.update', { id: req.params.id, name: name.trim() });
  invalidateShare();
  res.json(normDates(rows[0]));
});

app.delete('/api/links/:id', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const { rows: lr } = await pool.query('SELECT group_id FROM share_links WHERE id = $1', [req.params.id]);
    if (!lr.length) return res.status(404).json({ error: 'Не найдено' });
    if (lr[0].group_id && !(await groupBelongsToBranches(req.user, lr[0].group_id))) {
      return res.status(403).json({ error: 'Нет доступа к этой ссылке' });
    }
  }
  await pool.query('DELETE FROM share_links WHERE id = $1', [req.params.id]);
  await logAudit(req, 'link.delete', { id: req.params.id });
  invalidateShare();
  res.json({ ok: true });
});

app.get('/api/share/:token', fileLimiter, async (req, res) => {
  const { rows } = await pool.query(
    `SELECT l.*, g.name AS group_name FROM share_links l
     LEFT JOIN groups g ON g.id = l.group_id WHERE l.token = $1`,
    [req.params.token]
  );
  if (!rows.length) return res.status(404).json({ error: 'Ссылка не найдена' });
  normDates(rows[0]);
  const l = rows[0];

  // Check expiry
  if (l.expires_at && new Date(l.expires_at) < new Date()) {
    return res.status(410).json({ error: 'Срок действия ссылки истёк' });
  }

  // Check password
  if (l.access_password_hash) {
    const providedPassword = req.headers['x-share-password'] || req.query.password;
    if (!providedPassword) {
      return res.status(401).json({ error: 'Требуется пароль', passwordRequired: true });
    }
    const valid = await bcrypt.compare(providedPassword, l.access_password_hash);
    if (!valid) {
      await recordFailure(req, 'share-password-bruteforce', 10, BAN_TTL_MS);
      return res.status(401).json({ error: 'Неверный пароль' });
    }
  }

  const payload = await cacheWrap('share:payload:' + req.params.token, SHARE_TTL_MS, async () => {
    const conditions = [];
    const params = [];
    if (l.group_id) { params.push(l.group_id); conditions.push(`e.group_id = $${params.length}`); }
    if (l.student_name) { params.push(l.student_name); conditions.push(`e.student_name = $${params.length}`); }
    if (l.date_from) { params.push(l.date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
    if (l.date_to) { params.push(l.date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
    conditions.push('e.deleted_at IS NULL');
    const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
    const { rows: entries } = await pool.query(
      `SELECT e.*, g.name AS group_name FROM entries e
       JOIN groups g ON g.id = e.group_id${where} ORDER BY e.created_at DESC`,
      params
    );
    let files = {};
    if (entries.length) {
      const fRes = await pool.query(
        'SELECT entry_id, token, name FROM project_files WHERE entry_id = ANY($1) ORDER BY id',
        [entries.map(r => r.id)]
      );
      fRes.rows.forEach(f => { (files[f.entry_id] = files[f.entry_id] || []).push({ token: f.token, name: f.name }); });
    }
    entries.forEach(r => { r.files = files[r.id] || []; });

    const showStudentNames = l.show_student_names != null ? l.show_student_names : (await getSetting('share_show_student_names', 'true')) !== 'false';

    if (!showStudentNames) {
      const nameMap = new Map();
      let counter = 1;
      entries.forEach(e => {
        if (!nameMap.has(e.student_name)) {
          nameMap.set(e.student_name, `Ученик ${counter++}`);
        }
        e.student_name = nameMap.get(e.student_name);
      });
    }

    let photos = [];
    if (l.group_id) {
      const pRes = await pool.query(
        `SELECT id, photo_path, caption, taken_at, created_at FROM group_photos
         WHERE group_id = $1 ORDER BY sort_order ASC, taken_at DESC NULLS LAST, created_at DESC LIMIT 12`,
        [l.group_id]
      );
      photos = pRes.rows.map(r => ({ id: r.id, photo_path: r.photo_path, caption: r.caption, taken_at: r.taken_at, created_at: r.created_at }));
    }
    return {
      name: l.name,
      group_name: l.group_name,
      student_name: l.student_name,
      group_id: l.group_id,
      date_from: l.date_from,
      date_to: l.date_to,
      message: l.message,
      link_url: l.link_url,
      created_at: l.created_at,
      expires_at: l.expires_at,
      show_student_names: showStudentNames,
      show_student_message: l.show_student_message != null ? l.show_student_message : (await getSetting('share_show_student_message', 'false')) === 'true',
      show_entry_date: l.show_entry_date != null ? l.show_entry_date : (await getSetting('share_show_entry_date', 'false')) === 'true',
      show_group_photos: l.show_group_photos != null ? l.show_group_photos : (await getSetting('share_show_group_photos', 'true')) !== 'false',
      entries,
      photos: (l.show_group_photos != null ? l.show_group_photos : (await getSetting('share_show_group_photos', 'true')) !== 'false') ? photos : [],
    };
  });
  res.json(payload);
});

app.get('/api/share/:shareToken/files/:fileToken', fileLimiter, async (req, res) => {
  const { shareToken, fileToken } = req.params;
  const { rows: shareRows } = await pool.query(
    `SELECT l.* FROM share_links l WHERE l.token = $1`, [shareToken]
  );
  if (!shareRows.length) return res.status(404).json({ error: 'Ссылка не найдена' });
  const l = shareRows[0];
  if (l.expires_at && new Date(l.expires_at) < new Date()) {
    return res.status(410).json({ error: 'Срок действия ссылки истёк' });
  }
  if (l.access_password_hash) {
    const providedPassword = req.headers['x-share-password'] || req.query.password;
    if (!providedPassword) return res.status(401).json({ error: 'Требуется пароль' });
    const valid = await bcrypt.compare(providedPassword, l.access_password_hash);
    if (!valid) {
      await recordFailure(req, 'share-password-bruteforce', 10, BAN_TTL_MS);
      return res.status(401).json({ error: 'Неверный пароль' });
    }
  }
  const conditions = ['e.deleted_at IS NULL'];
  const params = [];
  if (l.group_id) { params.push(l.group_id); conditions.push(`e.group_id = $${params.length}`); }
  if (l.student_name) { params.push(l.student_name); conditions.push(`e.student_name = $${params.length}`); }
  if (l.date_from) { params.push(l.date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
  if (l.date_to) { params.push(l.date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
  params.push(fileToken);
  const { rows } = await pool.query(
    `SELECT pf.path, pf.name FROM project_files pf
     JOIN entries e ON e.id = pf.entry_id
     WHERE pf.token = $${params.length} AND ${conditions.join(' AND ')}`,
    params
  );
  if (!rows.length) return res.status(404).json({ error: 'Not found' });
  const r = rows[0];
  const fp = path.join(__dirname, r.path);
  if (!fs.existsSync(fp)) return res.status(404).json({ error: 'File missing' });
  if (isImageName(r.name)) {
    if (req.query.thumb) return sendImageThumb(res, fp);
    res.setHeader('Cache-Control', 'public, max-age=31536000, immutable');
    return res.sendFile(fp);
  }
  return res.download(fp, r.name);
});

app.get('/s/:token', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'share.html'));
});

// --- Groups CRUD ---
app.get('/api/groups', apiLimiter, optionalAuth, async (req, res) => {
  const rows = await cacheWrap('groups:list:' + scopeKey(req.user), PUBLIC_TTL_MS, async () => {
    const bw = req.user ? branchWhere(req.user, 'g') : { where: '', params: [] };
    const { rows } = await pool.query(
      `SELECT g.*,
         COALESCE(g.cover_path,
           (SELECT photo_path FROM group_photos
            WHERE group_id = g.id
            ORDER BY sort_order ASC, taken_at DESC NULLS LAST, created_at DESC
            LIMIT 1)) AS cover_path,
         b.name AS branch_name
       FROM groups g
       LEFT JOIN branches b ON b.id = g.branch_id
       WHERE 1=1${bw.where}
       ORDER BY g.id`,
      bw.params
    );
    return rows;
  });
  res.json(rows);
});

app.get('/api/groups/active', apiLimiter, async (_, res) => {
  const rows = await cacheWrap('groups:active', PUBLIC_TTL_MS, async () => {
    const { rows } = await pool.query(`
      SELECT * FROM groups
      WHERE day_of_week IS NOT NULL
        AND time_start IS NOT NULL
        AND time_end IS NOT NULL
        AND day_of_week = EXTRACT(DOW FROM (now() AT TIME ZONE 'Europe/Moscow'))::int
        AND (now() AT TIME ZONE 'Europe/Moscow')::time BETWEEN time_start AND time_end
      ORDER BY id
    `);
    return rows;
  });
  res.json(rows);
});

app.put('/api/groups/:id', requireAuth, async (req, res) => {
  const { name, day_of_week, time_start, time_end, branch_id } = req.body;
  if (!(await groupBelongsToBranches(req.user, req.params.id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const isAdmin = req.user.role === 'admin';
  if (!isAdmin && branch_id !== undefined) {
    return res.status(403).json({ error: 'Назначение филиала — только для администратора' });
  }
  try {
    const { rows } = await pool.query(
      `UPDATE groups SET
        name = COALESCE($1, name),
        day_of_week = $2,
        time_start = $3,
        time_end = $4,
        branch_id = $5
       WHERE id = $6 RETURNING *`,
      [name,
       day_of_week === undefined || day_of_week === null || day_of_week === '' ? null : day_of_week,
       time_start || null, time_end || null,
       branch_id === undefined || branch_id === null || branch_id === '' ? null : branch_id,
       req.params.id]
    );
    await logAudit(req, 'group.update', { id: req.params.id, ...req.body });
    invalidateGroups();
    invalidateStats();
    res.json(rows[0]);
  } catch (e) {
    if (e.code === '23505') return res.status(409).json({ error: 'Duplicate name' });
    throw e;
  }
});

app.post('/api/groups', requireAuth, async (req, res) => {
  const { name, branch_id } = req.body;
  if (!name?.trim()) return res.status(400).json({ error: 'Name required' });
  const isAdmin = req.user.role === 'admin';
  const effectiveBranch = branch_id === undefined || branch_id === null || branch_id === '' ? null : Number(branch_id);
  if (!isAdmin && branch_id !== undefined && branch_id !== null && branch_id !== '') {
    return res.status(403).json({ error: 'Назначение филиала — только для администратора' });
  }
  try {
    const { rows } = await pool.query(
      'INSERT INTO groups (name, branch_id) VALUES ($1, $2) RETURNING *',
      [name.trim(), isAdmin ? effectiveBranch : null]
    );
    await logAudit(req, 'group.create', { id: rows[0].id, name: name.trim(), branch_id });
    invalidateGroups();
    invalidateStats();
    res.status(201).json(rows[0]);
  } catch (e) {
    if (e.code === '23505') return res.status(409).json({ error: 'Duplicate' });
    throw e;
  }
});

app.delete('/api/groups/:id', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin' && !(await groupBelongsToBranches(req.user, req.params.id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const { rows } = await pool.query(
    'SELECT photo_path FROM group_photos WHERE group_id = $1',
    [req.params.id]
  );
  rows.forEach(r => safeUnlink(r.photo_path));
  await pool.query('DELETE FROM groups WHERE id = $1', [req.params.id]);
  await logAudit(req, 'group.delete', { id: req.params.id });
  invalidateGroups();
  invalidateStats();
  res.json({ ok: true });
});

// --- Branches CRUD ---
app.get('/api/branches', requireAuth, async (req, res) => {
  const bw = branchScope(req.user);
  let where = '';
  const params = [];
  if (!bw.admin) {
    if (bw.ids.length) {
      where = ` WHERE b.id IN (${bw.ids.map(id => `$${params.push(id)}`).join(',')})`;
    } else {
      where = ' WHERE 1 = 0';
    }
  }
  const { rows } = await pool.query(
    `SELECT b.*, count(g.id)::int AS groups_count
     FROM branches b
     LEFT JOIN groups g ON g.branch_id = b.id
     ${where}
     GROUP BY b.id
     ORDER BY b.id`,
    params
  );
  res.json(rows);
});

app.post('/api/branches', requireAdmin, async (req, res) => {
  const { name, address, phone } = req.body;
  if (!name?.trim()) return res.status(400).json({ error: 'Название обязательно' });
  try {
    const { rows } = await pool.query(
      'INSERT INTO branches (name, address, phone) VALUES ($1, $2, $3) RETURNING *',
      [name.trim(), address?.trim() || null, phone?.trim() || null]
    );
    await logAudit(req, 'branch.create', { id: rows[0].id, name: name.trim() });
    invalidateGroups();
    res.status(201).json(rows[0]);
  } catch (e) {
    if (e.code === '23505') return res.status(409).json({ error: 'Филиал с таким названием уже существует' });
    throw e;
  }
});

app.put('/api/branches/:id', requireAdmin, async (req, res) => {
  const { name, address, phone } = req.body;
  if (!name?.trim()) return res.status(400).json({ error: 'Название обязательно' });
  try {
    const { rows } = await pool.query(
      `UPDATE branches SET
        name = $1,
        address = $2,
        phone = $3
       WHERE id = $4 RETURNING *`,
      [name.trim(), address?.trim() || null, phone?.trim() || null, req.params.id]
    );
    if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
    await logAudit(req, 'branch.update', { id: req.params.id, ...req.body });
    invalidateGroups();
    res.json(rows[0]);
  } catch (e) {
    if (e.code === '23505') return res.status(409).json({ error: 'Филиал с таким названием уже существует' });
    throw e;
  }
});

app.delete('/api/branches/:id', requireAdmin, async (req, res) => {
  const { rows } = await pool.query('SELECT id FROM groups WHERE branch_id = $1', [req.params.id]);
  if (rows.length) return res.status(400).json({ error: 'Нельзя удалить филиал: есть привязанные группы' });
  await pool.query('DELETE FROM branches WHERE id = $1', [req.params.id]);
  await logAudit(req, 'branch.delete', { id: req.params.id });
  invalidateGroups();
  res.json({ ok: true });
});

app.get('/api/groups/:id/photos', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin' && !(await groupBelongsToBranches(req.user, req.params.id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const { limit, offset } = req.query;
  const { rows: crows } = await pool.query(
    'SELECT count(*)::int AS n FROM group_photos WHERE group_id = $1',
    [req.params.id]
  );
  const total = crows[0].n;
  let q = `SELECT * FROM group_photos WHERE group_id = $1
           ORDER BY sort_order ASC, taken_at DESC NULLS LAST, created_at DESC`;
  const qparams = [req.params.id];
  const lim = parseInt(limit, 10);
  if (lim > 0) { qparams.push(lim); q += ` LIMIT $${qparams.length}`; }
  const off = parseInt(offset, 10);
  if (off > 0) { qparams.push(off); q += ` OFFSET $${qparams.length}`; }
  const { rows } = await pool.query(q, qparams);
  res.json({ photos: rows, total });
});

const groupPhotoUpload = upload.single('photo');
app.post('/api/groups/:id/photos', requireAuth, (req, res, next) => {
  groupPhotoUpload(req, res, async (err) => {
    if (err) {
      if (err.code === 'LIMIT_FILE_SIZE') return res.status(400).json({ error: 'Файл слишком большой (макс. 10 МБ)' });
      if (err.message === 'Only images') return res.status(400).json({ error: 'Фото: допустимы только изображения (jpg, png, gif, webp, bmp, avif, ico, heic, heif, jfif)' });
      if (err.message === 'Not allowed extension') return res.status(400).json({ error: 'Недопустимый тип файла (*.html, *.js, *.svg и т.п. запрещены)' });
      return res.status(400).json({ error: 'Недопустимый файл' });
    }
    try {
      if (req.user.role !== 'admin' && !(await groupBelongsToBranches(req.user, req.params.id))) {
        removeUpload(req.file);
        return res.status(403).json({ error: 'Нет доступа к этой группе' });
      }
      next();
    } catch (e) {
      removeUpload(req.file);
      res.status(500).json({ error: e.message });
    }
  });
}, async (req, res) => {
  const { caption, taken_at } = req.body;
  if (!req.file) return res.status(400).json({ error: 'Файл обязателен' });
  try {
    await convertPhoto(req.file);
    const { rows } = await pool.query(
      `INSERT INTO group_photos (group_id, photo_path, caption, taken_at, sort_order)
       VALUES ($1, $2, $3, $4,
         COALESCE((SELECT MIN(sort_order) - 1 FROM group_photos WHERE group_id = $1), 0))
       RETURNING *`,
      [req.params.id, `/uploads/${req.file.filename}`, caption?.trim() || null, taken_at || null]
    );
    await logAudit(req, 'group.photo.create', { group_id: req.params.id, photo_path: rows[0].photo_path });
    invalidateShare();
    invalidateGroups();
    invalidateStats();
    res.status(201).json(rows[0]);
  } catch (e) {
    safeUnlink(`uploads/${req.file.filename}`);
    console.error('POST /api/groups/:id/photos:', e);
    res.status(500).json({ error: e.message });
  }
});

app.put('/api/groups/:id/photos/reorder', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin' && !(await groupBelongsToBranches(req.user, req.params.id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const { order } = req.body;
  if (!Array.isArray(order) || order.some(id => !Number.isInteger(Number(id)))) {
    return res.status(400).json({ error: 'Некорректный порядок фото' });
  }
  const ids = order.map(id => Number(id));
  if (new Set(ids).size !== ids.length) {
    return res.status(400).json({ error: 'Порядок фото содержит дубликаты' });
  }
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    const { rows: owned } = await client.query(
      'SELECT id FROM group_photos WHERE group_id = $1 ORDER BY sort_order ASC, taken_at DESC NULLS LAST, created_at DESC',
      [req.params.id]
    );
    const ownedIds = owned.map(r => r.id);
    if (ids.some(id => !ownedIds.includes(id))) {
      throw { http: 404, message: 'Фото не найдено' };
    }
    const rest = ownedIds.filter(id => !ids.includes(id));
    const allIds = [...ids, ...rest];
    for (let i = 0; i < allIds.length; i++) {
      await client.query(
        'UPDATE group_photos SET sort_order = $1 WHERE id = $2',
        [i + 1, allIds[i]]
      );
    }
    await client.query('COMMIT');
    await logAudit(req, 'group.photo.reorder', { group_id: req.params.id, order: ids });
    invalidateShare();
    invalidateGroups();
    res.json({ ok: true });
  } catch (e) {
    await client.query('ROLLBACK');
    if (e.http) return res.status(e.http).json({ error: e.message });
    throw e;
  } finally {
    client.release();
  }
});

app.put('/api/groups/:id/photos/:photoId', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin' && !(await groupBelongsToBranches(req.user, req.params.id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const { caption, taken_at } = req.body;
  const { rows } = await pool.query(
    `UPDATE group_photos SET
       caption = $1,
       taken_at = $2
     WHERE id = $3 AND group_id = $4 RETURNING *`,
    [caption?.trim() || null, taken_at || null, req.params.photoId, req.params.id]
  );
  if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
  await logAudit(req, 'group.photo.update', { group_id: req.params.id, photo_id: req.params.photoId });
  invalidateShare();
  res.json(rows[0]);
});

app.delete('/api/groups/:id/photos/:photoId', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin' && !(await groupBelongsToBranches(req.user, req.params.id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const { rows } = await pool.query(
    'SELECT photo_path FROM group_photos WHERE id = $1 AND group_id = $2',
    [req.params.photoId, req.params.id]
  );
  if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
  safeUnlink(rows[0].photo_path);
  await pool.query('UPDATE groups SET cover_path = NULL WHERE id = $1 AND cover_path = $2', [req.params.id, rows[0].photo_path]);
  await pool.query('DELETE FROM group_photos WHERE id = $1', [req.params.photoId]);
  await logAudit(req, 'group.photo.delete', { group_id: req.params.id, photo_id: req.params.photoId });
  invalidateShare();
  invalidateGroups();
  invalidateStats();
  res.json({ ok: true });
});

app.put('/api/groups/:id/photos/:photoId/cover', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin' && !(await groupBelongsToBranches(req.user, req.params.id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const { rows } = await pool.query(
    'SELECT photo_path FROM group_photos WHERE id = $1 AND group_id = $2',
    [req.params.photoId, req.params.id]
  );
  if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
  await pool.query('UPDATE groups SET cover_path = $1 WHERE id = $2', [rows[0].photo_path, req.params.id]);
  await logAudit(req, 'group.photo.set_cover', { group_id: req.params.id, photo_id: req.params.photoId });
  invalidateShare();
  invalidateGroups();
  const { rows: gRows } = await pool.query('SELECT * FROM groups WHERE id = $1', [req.params.id]);
  res.json(gRows[0]);
});

// --- Students CRUD ---
app.get('/api/students', apiLimiter, optionalAuth, async (req, res) => {
  const rows = await cacheWrap('students:list:' + scopeKey(req.user), PUBLIC_TTL_MS, async () => {
    const bw = req.user ? branchWhere(req.user, 'g') : { where: '', params: [] };
    const { rows } = await pool.query(
      `SELECT s.*, g.name AS group_name FROM students s
       LEFT JOIN groups g ON g.id = s.group_id
       WHERE 1=1${bw.where} ORDER BY s.name`,
      bw.params
    );
    return rows;
  });
  res.json(rows);
});

app.get('/api/students/names', requireAuth, async (req, res) => {
  const bw = branchWhere(req.user, 'g');
  const { rows } = await pool.query(
    `SELECT DISTINCT e.student_name AS name FROM entries e
     JOIN groups g ON g.id = e.group_id
     WHERE e.student_name IS NOT NULL AND e.student_name <> ''${bw.where}
     ORDER BY name`,
    bw.params
  );
  res.json(rows.map(r => r.name));
});

app.post('/api/students', requireAuth, async (req, res) => {
  const { name, group_id } = req.body;
  if (!name?.trim()) return res.status(400).json({ error: 'Name required' });
  const gid = group_id ? Number(group_id) : null;
  if (req.user.role !== 'admin' && gid && !(await groupBelongsToBranches(req.user, gid))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  try {
    const { rows } = await pool.query(
      'INSERT INTO students (name, group_id) VALUES ($1, $2) RETURNING *',
      [name.trim(), gid]
    );
    await logAudit(req, 'student.create', { id: rows[0].id, name: name.trim() });
    invalidateStudents();
    invalidateStats();
    res.status(201).json(rows[0]);
  } catch (e) {
    if (e.code === '23505') return res.status(409).json({ error: 'Duplicate' });
    throw e;
  }
});

app.put('/api/students/:id', requireAuth, async (req, res) => {
  const { name, group_id } = req.body;
  if (!name?.trim()) return res.status(400).json({ error: 'Name required' });
  const newGid = group_id === undefined || group_id === null || group_id === '' ? null : Number(group_id);
  if (req.user.role !== 'admin') {
    const { rows: cur } = await pool.query(
      `SELECT s.group_id FROM students s LEFT JOIN groups g ON g.id = s.group_id WHERE s.id = $1`,
      [req.params.id]
    );
    if (!cur.length) return res.status(404).json({ error: 'Not found' });
    const curGid = cur[0].group_id;
    if (curGid && !(await groupBelongsToBranches(req.user, curGid))) {
      return res.status(403).json({ error: 'Нет доступа к этому ученику' });
    }
    if (newGid && !(await groupBelongsToBranches(req.user, newGid))) {
      return res.status(403).json({ error: 'Нет доступа к этой группе' });
    }
  }
  try {
    const { rows } = await pool.query(
      `UPDATE students SET
        name = $1,
        group_id = $2
       WHERE id = $3 RETURNING *`,
      [name.trim(), newGid, req.params.id]
    );
    if (!rows.length) return res.status(404).json({ error: 'Not found' });
    await logAudit(req, 'student.update', { id: req.params.id, name: name.trim() });
    invalidateStudents();
    res.json(rows[0]);
  } catch (e) {
    if (e.code === '23505') return res.status(409).json({ error: 'Duplicate' });
    throw e;
  }
});

app.post('/api/students/batch-group', requireAuth, async (req, res) => {
  const { group_id, student_ids } = req.body;
  if (!group_id || !Array.isArray(student_ids) || !student_ids.length) {
    return res.status(400).json({ error: 'group_id and student_ids required' });
  }
  if (req.user.role !== 'admin' && !(await groupBelongsToBranches(req.user, group_id))) {
    return res.status(403).json({ error: 'Нет доступа к этой группе' });
  }
  const ids = [...new Set(student_ids.map(Number).filter(Boolean))];
  if (!ids.length) return res.status(400).json({ error: 'No valid students' });
  const params = [group_id, ...ids];
  const placeholders = ids.map((_, i) => `$${i + 2}`).join(',');
  const { rows } = await pool.query(
    `UPDATE students SET group_id = $1 WHERE id IN (${placeholders}) RETURNING id`,
    params
  );
  await logAudit(req, 'student.batch-group', { group_id, count: rows.length });
  invalidateStudents();
  res.json({ ok: true, updated: rows.length });
});

app.delete('/api/students/:id', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const { rows: cur } = await pool.query(
      'SELECT s.group_id FROM students s WHERE s.id = $1', [req.params.id]
    );
    if (!cur.length) return res.status(404).json({ error: 'Not found' });
    const gid = cur[0].group_id;
    if (gid && !(await groupBelongsToBranches(req.user, gid))) {
      return res.status(403).json({ error: 'Нет доступа к этому ученику' });
    }
  }
  await pool.query('DELETE FROM students WHERE id = $1', [req.params.id]);
  await logAudit(req, 'student.delete', { id: req.params.id });
  invalidateStudents();
  invalidateStats();
  res.json({ ok: true });
});

// --- Student portfolio export (ZIP: HTML report + photos + files) ---
const CRC_TABLE = (() => {
  const table = new Int32Array(256);
  for (let n = 0; n < 256; n++) {
    let c = n;
    for (let k = 0; k < 8; k++) c = (c & 1) ? (0xedb88320 ^ (c >>> 1)) : (c >>> 1);
    table[n] = c;
  }
  return table;
})();

function crc32(buf) {
  let crc = 0xffffffff;
  for (let i = 0; i < buf.length; i++) crc = CRC_TABLE[(crc ^ buf[i]) & 0xff] ^ (crc >>> 8);
  return (crc ^ 0xffffffff) >>> 0;
}

function dosDateTime(d = new Date()) {
  return {
    time: (d.getHours() << 11) | (d.getMinutes() << 5) | Math.floor(d.getSeconds() / 2),
    date: ((Math.max(1980, d.getFullYear()) - 1980) << 9) | ((d.getMonth() + 1) << 5) | d.getDate(),
  };
}

function createZipWriter() {
  const parts = [];
  const central = [];
  let count = 0;
  let offset = 0;
  function buildEntry(nameBuf, method, crc, compressed, plain, dt) {
    const local = Buffer.alloc(30);
    local.writeUInt32LE(0x04034b50, 0);
    local.writeUInt16LE(20, 4);
    local.writeUInt16LE(0x0800, 6);
    local.writeUInt16LE(method, 8);
    local.writeUInt16LE(dt.time, 10);
    local.writeUInt16LE(dt.date, 12);
    local.writeUInt32LE(crc, 14);
    local.writeUInt32LE(compressed, 18);
    local.writeUInt32LE(plain, 22);
    local.writeUInt16LE(nameBuf.length, 26);
    local.writeUInt16LE(0, 28);
    const cen = Buffer.alloc(46);
    cen.writeUInt32LE(0x02014b50, 0);
    cen.writeUInt16LE(20, 4);
    cen.writeUInt16LE(20, 6);
    cen.writeUInt16LE(0x0800, 8);
    cen.writeUInt16LE(method, 10);
    cen.writeUInt16LE(dt.time, 12);
    cen.writeUInt16LE(dt.date, 14);
    cen.writeUInt32LE(crc, 16);
    cen.writeUInt32LE(compressed, 20);
    cen.writeUInt32LE(plain, 24);
    cen.writeUInt16LE(nameBuf.length, 28);
    cen.writeUInt16LE(0, 30);
    cen.writeUInt16LE(0, 32);
    cen.writeUInt16LE(0, 34);
    cen.writeUInt16LE(0, 36);
    cen.writeUInt32LE(0, 38);
    cen.writeUInt32LE(offset, 42);
    return { local, cen, nameBuf };
  }
  return {
    addFile(name, data, d) {
      const nameBuf = Buffer.from(name, 'utf8');
      const dt = dosDateTime(d);
      const crc = crc32(data);
      const compressed = zlib.deflateRawSync(data, { level: 9 });
      const e = buildEntry(nameBuf, 8, crc, compressed.length, data.length, dt);
      const chunk = Buffer.concat([e.local, e.nameBuf, compressed]);
      parts.push(chunk);
      central.push(Buffer.concat([e.cen, e.nameBuf]));
      offset += chunk.length;
      count++;
    },
    addDir(name) {
      const nameBuf = Buffer.from(String(name).replace(/\/?$/, '/'), 'utf8');
      const dt = dosDateTime();
      const e = buildEntry(nameBuf, 0, 0, 0, 0, dt);
      const chunk = Buffer.concat([e.local, e.nameBuf]);
      parts.push(chunk);
      central.push(Buffer.concat([e.cen, e.nameBuf]));
      offset += chunk.length;
      count++;
    },
    toBuffer() {
      const centralStart = offset;
      const centralBuf = Buffer.concat(central);
      const eocd = Buffer.alloc(22);
      eocd.writeUInt32LE(0x06054b50, 0);
      eocd.writeUInt16LE(0, 4);
      eocd.writeUInt16LE(0, 6);
      eocd.writeUInt16LE(count, 8);
      eocd.writeUInt16LE(count, 10);
      eocd.writeUInt32LE(centralBuf.length, 12);
      eocd.writeUInt32LE(centralStart, 16);
      eocd.writeUInt16LE(0, 20);
      return Buffer.concat([...parts, centralBuf, eocd]);
    },
  };
}

function fmtLongDate(iso) {
  if (!iso) return '';
  return new Date(iso).toLocaleDateString('ru-RU', { day: 'numeric', month: 'long', year: 'numeric' });
}

function fmtBytes(n) {
  if (!Number.isFinite(n)) return '';
  if (n < 1024) return n + ' Б';
  if (n < 1024 * 1024) return (n / 1024).toFixed(1).replace(/\.0$/, '') + ' КБ';
  return (n / (1024 * 1024)).toFixed(1).replace(/\.0$/, '') + ' МБ';
}

function truncate(str, max) {
  const s = String(str || '');
  return s.length > max ? s.slice(0, max - 1) + '…' : s;
}

function renderStudentReport(data, opts) {
  const o = opts || {};
  const showEntries = o.includeEntries !== false;
  const showPhotos = o.includePhotos !== false;
  const showFiles = o.includeFiles !== false;
  const showCaptions = o.includeCaptions !== false;
  const showDates = o.showDates !== false;
  const { name, groups, entries, photos, files, generatedAt, period } = data;
  const IMG_EXT = new Set(['JPG','JPEG','PNG','GIF','WEBP','BMP','AVIF','SVG','ICO','JFIF']);
  const VID_EXT = new Set(['MP4','WEBM','MOV','M4V','OGV','MKV','MPEG','MPG','3GP','AVI']);
  const gallery = [];
  const galIdx = new Map();
  for (const p of photos) { gallery.push({ type: 'image', src: 'photos/' + p.stored }); galIdx.set('photos/' + p.stored, gallery.length - 1); }
  for (const f of files) {
    const fn = String(f.original || f.saved || '');
    const ext = fn.indexOf('.') >= 0 ? fn.split('.').pop().toUpperCase() : '';
    if (VID_EXT.has(ext)) { gallery.push({ type: 'video', src: 'files/' + f.saved }); galIdx.set('files/' + f.saved, gallery.length - 1); }
    else if (IMG_EXT.has(ext)) { gallery.push({ type: 'image', src: 'files/' + f.saved }); galIdx.set('files/' + f.saved, gallery.length - 1); }
  }
  const avatar = showPhotos && photos.length ? photos[0].stored : null;
  const statsChips = [];
  if (showEntries) statsChips.push(`<div class="chip"><b>${entries.length}</b><span>занятий</span></div>`);
  if (showPhotos) statsChips.push(`<div class="chip"><b>${photos.length}</b><span>фотографий</span></div>`);
  if (showFiles) statsChips.push(`<div class="chip"><b>${files.length}</b><span>файлов</span></div>`);
  const photoCards = showPhotos ? photos.map(p => {
    let caption = '';
    if (showCaptions && p.caption) caption = truncate(p.caption, 120);
    if (!caption && showDates && !p.caption) caption = fmtLongDate(p.createdAt);
    const pg = galIdx.get('photos/' + p.stored);
    return `
      <figure class="ph" data-g="${pg}">
        <img src="photos/${escapeHtml(p.stored)}" alt="${escapeHtml(name)} — фото" loading="lazy">
        ${caption ? `<figcaption>${escapeHtml(caption)}</figcaption>` : ''}
      </figure>`;
  }).join('') : '';
  const fileRows = showFiles ? files.map(f => {
    const ext = f.original.indexOf('.') >= 0 ? f.original.split('.').pop().toUpperCase().slice(0, 8) : 'FILE';
    const meta = showDates ? `${fmtLongDate(f.createdAt)} · ${fmtBytes(f.size)}` : fmtBytes(f.size);
    const fg = galIdx.get('files/' + f.saved);
    const gattr = fg !== undefined ? ` class="gfile" data-g="${fg}"` : ' target="_blank" rel="noopener"';
    return `
      <li>
        <a href="files/${escapeHtml(f.saved)}"${gattr}>
          <span class="badge">${escapeHtml(ext)}</span>
          <span class="fname">${escapeHtml(f.original)}</span>
          <span class="fmeta">${escapeHtml(meta)}</span>
        </a>
      </li>`;
  }).join('') : '';
  const photosByEntry = new Map();
  for (const p of photos) {
    if (!photosByEntry.has(p.entryId)) photosByEntry.set(p.entryId, []);
    photosByEntry.get(p.entryId).push(p.stored);
  }
  const lessonRows = showEntries ? entries.map(e => {
    const thumbs = showPhotos ? (photosByEntry.get(e.id) || []).slice(0, 4).map(t => `
      <img class="tph" src="photos/${escapeHtml(t)}" alt="фото" data-g="${galIdx.get('photos/' + t)}" loading="lazy">`).join('') : '';
    const entryFiles = showFiles ? files.filter(f => f.entryId === e.id) : [];
    const fls = entryFiles.length ? `<div class="lfiles">${entryFiles.map(f => `<a href="files/${escapeHtml(f.saved)}" target="_blank" rel="noopener">${escapeHtml(f.original)}</a>`).join('')}</div>` : '';
    const desc = e.description ? `<p class="ldesc">${escapeHtml(e.description)}</p>` : '';
    const gr = e.group_name ? `<span class="lgroup">${escapeHtml(e.group_name)}</span>` : '';
    const dt = showDates && e.created_at ? `<span class="ldate">${escapeHtml(fmtLongDate(e.created_at))}</span>` : '';
    const head = dt + gr;
    return `
      <article class="lesson">
        ${head ? `<div class="lhead">${head}</div>` : ''}
        ${desc}
        ${thumbs ? `<div class="lthumbs">${thumbs}</div>` : ''}
        ${fls}
      </article>`;
  }).join('') : '';
  const groupLine = groups.length ? escapeHtml(groups.join(' · ')) : '';
  const genLabel = escapeHtml(fmtLongDate(generatedAt));
  const metaBits = [];
  if (groupLine) metaBits.push(groupLine);
  if (period) metaBits.push(escapeHtml(period));
  metaBits.push(`Сформировано ${genLabel}`);
  const heroAvatar = avatar ? `<div class="avatar"><img src="photos/${escapeHtml(avatar)}" alt="${escapeHtml(name)}"></div>` : '';
  const navItems = [];
  if (showPhotos) navItems.push('<a class="navlink" href="#photos">Фотографии</a>');
  if (showFiles) navItems.push('<a class="navlink" href="#files">Работы</a>');
  if (showEntries) navItems.push('<a class="navlink" href="#lessons">Занятия</a>');
  const nav = navItems.length >= 2 ? '<nav class="nav" id="topNav">' + navItems.join('') + '</nav>' : '';
  return `<!DOCTYPE html>
<html lang="ru">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>${escapeHtml(name)} — портфолио</title>
<style>
:root{--cream:#FFF7EC;--ink:#2B2B33;--muted:#98919B;--yellow:#F7C90E;--teal:#14B8A6;--violet:#8B5CF6;--coral:#FF6B6B;--sky:#38BDF8;--line:#FFEAD2}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:"Segoe UI",system-ui,-apple-system,Roboto,"Helvetica Neue",Arial,sans-serif;background:var(--cream);color:var(--ink);line-height:1.55}
body::before{content:"";position:fixed;inset:0;z-index:-1;background:radial-gradient(520px 400px at 8% -2%,rgba(247,201,14,.18),transparent 62%),radial-gradient(620px 430px at 100% 3%,rgba(20,184,166,.15),transparent 58%)}
.wrap{max-width:960px;margin:0 auto;padding:28px 18px 58px}

.nav{position:sticky;top:12px;z-index:40;display:flex;justify-content:center;gap:8px;flex-wrap:wrap;background:rgba(255,255,255,.92);border:1px solid #F1E2C6;border-radius:999px;padding:8px 14px;box-shadow:0 12px 26px -16px rgba(20,30,50,.35);margin-top:26px}
.nav .navlink{text-decoration:none;color:var(--ink);background:#fff;border:1px solid #F1E2C6;border-radius:999px;padding:8px 18px;font-size:.9rem;font-weight:600;transition:all .15s}
.nav .navlink:hover{transform:translateY(-1px)}
.nav .navlink.on{background:var(--yellow);color:#231f12;border-color:transparent;box-shadow:0 4px 12px -4px rgba(247,201,14,.5)}

.hero{overflow:hidden;border-radius:34px;padding:36px 34px;background:linear-gradient(135deg,#FFF6DB,#FFEDBF 52%,#FFE19A);box-shadow:0 24px 50px -24px rgba(247,201,14,.5);position:relative}
.hero .deco{position:absolute;border-radius:50%;background:rgba(255,255,255,.55);pointer-events:none}
.hero .deco.d1{width:150px;height:150px;right:-40px;top:-46px}
.hero .deco.d2{width:80px;height:80px;left:40%;bottom:-30px;background:rgba(20,184,166,.14)}
.hero .deco.d3{width:44px;height:44px;left:-14px;top:30%}
.avatar-col{position:relative;display:flex;gap:24px;align-items:center}
.avatar{flex:0 0 auto;width:104px;height:104px;border-radius:50%;overflow:hidden;border:5px solid #fff;background:#fff;box-shadow:0 10px 24px -6px rgba(0,0,0,.26);transform:rotate(-4deg)}
.avatar img{width:100%;height:100%;object-fit:cover;display:block;border-radius:50%}
.avatar.aemp{display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#F7C90E,#FFB34A);font-size:2.4rem;transform:rotate(-4deg)}
.kicker{font-size:.82rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:#B07A00;margin-bottom:6px}
h1{font-size:clamp(1.65rem,4.4vw,2.35rem);font-weight:800;letter-spacing:-.02em;line-height:1.12;margin-bottom:6px}
.meta{font-size:.95rem;color:#7A6A33;display:flex;flex-wrap:wrap;gap:6px;margin-bottom:18px}
.stats{display:flex;gap:12px;flex-wrap:wrap}
.chip{background:#fff;border:1px solid #F3DFC0;border-radius:18px;padding:10px 16px;display:flex;flex-direction:column;min-width:92px;box-shadow:0 8px 18px -12px rgba(20,30,50,.35)}
.chip b{font-size:1.5rem;line-height:1.05}
.chip span{font-size:.78rem;color:var(--muted)}
.stats .chip:nth-child(1) b{color:var(--coral)}
.stats .chip:nth-child(2) b{color:var(--teal)}
.stats .chip:nth-child(3) b{color:var(--violet)}
section{background:#fff;border:1px solid var(--line);border-radius:30px;padding:26px 26px 28px;margin-top:26px;box-shadow:0 16px 34px -22px rgba(20,30,50,.4)}
.p-sec{border-top:6px solid var(--teal)}
.f-sec{border-top:6px solid var(--violet)}
.l-sec{border-top:6px solid var(--coral)}
h2{font-size:1.25rem;font-weight:800;display:flex;align-items:center;gap:10px;margin-bottom:18px}
h2 .sico{width:38px;height:38px;border-radius:12px;display:inline-flex;align-items:center;justify-content:center;font-size:1.25rem;flex:0 0 auto}
.p-sec h2 .sico{background:#E3FAF7}
.f-sec h2 .sico{background:#EFE9FF}
.l-sec h2 .sico{background:#FFE9EE}
.empty{color:var(--muted);border:2px dashed #F0DDBE;border-radius:20px;padding:24px 18px;text-align:center;font-size:.95rem}

.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:16px}
.ph{background:#fff;border-radius:20px;overflow:hidden;cursor:zoom-in;border:3px solid #fff;box-shadow:0 10px 22px -14px rgba(20,30,50,.4);transition:transform .16s ease,box-shadow .16s ease}
.ph:hover{transform:translateY(-4px) rotate(-1deg);box-shadow:0 18px 30px -16px rgba(20,30,50,.45)}
.ph img{width:100%;aspect-ratio:4/3;object-fit:cover;display:block}
.ph figcaption{background:rgba(255,247,236,.92);padding:9px 12px;font-size:.82rem;color:#6A6155;line-height:1.35}

.filelist{list-style:none;display:flex;flex-direction:column;gap:9px}
.filelist li a{display:flex;align-items:center;gap:14px;background:#FDFAF4;border:1px solid #F1E2C6;border-radius:18px;padding:12px 16px;text-decoration:none;color:var(--ink);transition:transform .15s,box-shadow .15s}
.filelist li a:hover{transform:translateX(4px);box-shadow:0 10px 20px -12px rgba(20,30,50,.35)}
.badge{flex:0 0 auto;min-width:52px;text-align:center;font-size:.68rem;font-weight:800;letter-spacing:.04em;padding:6px 9px;border-radius:10px;background:linear-gradient(135deg,#F7C90E,#FFB34A);color:#231f12}
.fname{flex:1;min-width:0;font-weight:700;word-break:break-word}
.fmeta{flex:0 0 auto;color:var(--muted);font-size:.8rem;white-space:nowrap}
.gfile{cursor:pointer}

.lessons{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:14px;align-items:stretch}
.lesson{background:#FFFCF6;border:1px solid #F3E4CA;border-left:6px solid var(--coral);border-radius:20px;padding:16px 20px}
.lhead{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-bottom:8px}
.ldate{background:var(--coral);color:#fff;border-radius:999px;padding:3px 12px;font-size:.74rem;font-weight:700}
.lgroup{background:rgba(20,184,166,.14);color:#0C9488;font-weight:700;border-radius:999px;padding:3px 12px;font-size:.74rem}
.ldesc{white-space:pre-wrap;color:#3A3733;font-size:.95rem}
.lthumbs{display:flex;gap:8px;margin-top:12px;flex-wrap:wrap}
.tph{width:80px;height:80px;object-fit:cover;border-radius:14px;cursor:zoom-in;border:2px solid #fff;box-shadow:0 6px 12px -8px rgba(20,30,50,.35)}
.lfiles{margin-top:10px;display:flex;flex-wrap:wrap;gap:8px}
.lfiles a{font-size:.8rem;color:#0C9488;background:rgba(20,184,166,.1);border-radius:999px;padding:5px 12px;text-decoration:none;word-break:break-word}
.lfiles a:hover{background:rgba(20,184,166,.18)}

footer{margin-top:44px;color:#B9B4BE;font-size:.82rem;text-align:center}
.lightbox{position:fixed;inset:0;background:rgba(22,20,40,.9);display:none;flex-direction:column;z-index:60;padding:16px 92px 48px;cursor:zoom-out;overflow:hidden}
.lightbox.open{display:flex}
.lightbox .lb-media{display:flex;align-items:center;justify-content:center;flex:1;min-height:0}
.lightbox .lb-media img,.lightbox .lb-media video{display:block;max-width:100%;max-height:100%;object-fit:contain;border-radius:14px}
.lightbox .lb-media video{background:#000;max-height:calc(100% - 16px)}
.lightbox .lb-btn{position:absolute;top:50%;transform:translateY(-50%);z-index:5;width:52px;height:52px;border-radius:50%;border:none;background:rgba(247,201,14,.94);color:#231f12;font-size:1.7rem;line-height:1;cursor:pointer;display:flex;align-items:center;justify-content:center;box-shadow:0 10px 22px -8px rgba(0,0,0,.5)}
.lightbox .lb-btn:hover{background:#F7C90E}
.lightbox .lb-prev{left:20px}
.lightbox .lb-next{right:20px}
.lightbox .lb-count{position:absolute;bottom:16px;left:50%;transform:translateX(-50%);background:rgba(22,20,40,.72);color:#fff;border-radius:999px;padding:6px 16px;font-size:.85rem;letter-spacing:.03em}
.lightbox .lb-close{position:absolute;top:16px;right:20px;z-index:6;width:44px;height:44px;border-radius:50%;border:none;background:rgba(22,20,40,.6);color:#fff;font-size:1.35rem;line-height:1;cursor:pointer;display:flex;align-items:center;justify-content:center;box-shadow:0 8px 18px -8px rgba(0,0,0,.5)}
.lightbox .lb-close:hover{background:rgba(247,201,14,.92);color:#231f12}

@media print{body::before{display:none}.nav{display:none}.wrap{max-width:none;padding:0;-webkit-print-color-adjust:exact}body{background:#fff}.hero,section{box-shadow:none}section,.lesson,.ph{break-inside:avoid}}
@media (max-width:560px){.avatar-col{flex-direction:column;align-items:flex-start;gap:16px}.hero{padding:26px 22px}.grid{grid-template-columns:repeat(auto-fill,minmax(140px,1fr))}.stats{gap:8px}.fmeta{display:none}.chip{min-width:74px;padding:8px 12px}.lessons{grid-template-columns:1fr}.lightbox{padding:8px 6px 44px}.lb-prev{left:6px}.lb-next{right:6px}.lb-btn{width:44px;height:44px;font-size:1.4rem}.lb-close{width:38px;height:38px;top:10px;right:10px;font-size:1.15rem}}
</style>
</head>
<body>
<div class="wrap">
  <header class="hero">
    <span class="deco d1"></span>
    <span class="deco d2"></span>
    <span class="deco d3"></span>
    <div class="avatar-col">
      ${heroAvatar || '<div class="avatar aemp"><span>🎨</span></div>'}
      <div>
        <p class="kicker">✦ Портфолио ученика</p>
        <h1>${escapeHtml(name)}</h1>
        <p class="meta">${metaBits.join(' · ')}</p>
        <div class="stats">
          ${statsChips.join('')}
        </div>
      </div>
    </div>
  </header>

  ${nav}

  ${showPhotos ? `<section id="photos" class="p-sec">
    <h2><span class="sico">🏞️</span>Фотографии</h2>
    ${photoCards ? `<div class="grid">${photoCards}</div>` : '<p class="empty">🎈 Фотографий пока нет</p>'}
  </section>` : ''}

  ${showFiles ? `<section id="files" class="f-sec">
    <h2><span class="sico">📁</span>Работы и файлы</h2>
    ${fileRows ? `<ul class="filelist">${fileRows}</ul>` : '<p class="empty">🎈 Файлов пока нет</p>'}
  </section>` : ''}

  ${showEntries ? `<section id="lessons" class="l-sec">
    <h2><span class="sico">🎒</span>Журнал занятий</h2>
    ${lessonRows ? `<div class="lessons">${lessonRows}</div>` : '<p class="empty">🎈 Записей о занятиях пока нет</p>'}
  </section>` : ''}

  <footer>Сформировано ${genLabel} · WhatIDo</footer>
</div>
<div class="lightbox" id="lightbox">
  <button type="button" class="lb-btn lb-prev" id="lbPrev" aria-label="Назад">&#10094;</button>
  <div class="lb-media" id="lbMedia"></div>
  <button type="button" class="lb-btn lb-next" id="lbNext" aria-label="Вперёд">&#10095;</button>
  <button type="button" class="lb-close" id="lbClose" aria-label="Закрыть">&#10005;</button>
  <div class="lb-count" id="lbCount"></div>
</div>
<script>
(function () {
  var GAL = ${JSON.stringify(gallery)};
  var box = document.getElementById('lightbox');
  var media = document.getElementById('lbMedia');
  var count = document.getElementById('lbCount');
  var current = 0;
  function isVid(m) { return m && m.type === 'video'; }
  function render(i) {
    if (!GAL.length) return;
    var m = GAL[i];
    current = i;
    count.textContent = (i + 1) + ' / ' + GAL.length;
    media.innerHTML = '';
    if (isVid(m)) {
      var v = document.createElement('video');
      v.src = m.src;
      v.controls = true;
      v.autoplay = true;
      media.appendChild(v);
    } else {
      var im = document.createElement('img');
      im.src = m.src;
      im.alt = '';
      media.appendChild(im);
    }
  }
  function open(i) { if (!GAL.length) return; render(i); box.classList.add('open'); }
  function close() { box.classList.remove('open'); media.innerHTML = ''; }
  function step(d) { if (!GAL.length) return; render((current + d + GAL.length) % GAL.length); }
  document.addEventListener('click', function (e) {
    var t = e.target.closest('[data-g]');
    if (t) { e.preventDefault(); var gi = parseInt(t.getAttribute('data-g'), 10); if (!isNaN(gi) && gi >= 0 && GAL[gi]) open(gi); return; }
    if (e.target === box) close();
  });
  document.getElementById('lbPrev').addEventListener('click', function (e) { e.preventDefault(); e.stopPropagation(); step(-1); });
  document.getElementById('lbNext').addEventListener('click', function (e) { e.preventDefault(); e.stopPropagation(); step(1); });
  document.getElementById('lbClose').addEventListener('click', function (e) { e.preventDefault(); e.stopPropagation(); close(); });
  document.addEventListener('keydown', function (e) {
    if (!box.classList.contains('open')) return;
    if (e.key === 'Escape') close();
    else if (e.key === 'ArrowRight') step(1);
    else if (e.key === 'ArrowLeft') step(-1);
  });
  var links = Array.prototype.slice.call(document.querySelectorAll('.navlink'));
  function spy() {
    if (!links.length) return;
    var hit = null;
    for (var i = 0; i < links.length; i++) {
      var el = document.getElementById(links[i].getAttribute('href').slice(1));
      if (el && el.getBoundingClientRect().top <= 140) hit = links[i];
    }
    for (var j = 0; j < links.length; j++) {
      if (links[j] === hit) links[j].classList.add('on');
      else links[j].classList.remove('on');
    }
  }
  if (links.length) window.addEventListener('scroll', spy, { passive: true });
  spy();
})();
</script>
</body>
</html>`;
}

app.get('/api/export/student', requireAuth, async (req, res) => {
  let name;
  try {
    name = reqStr(req.query.name, 150);
  } catch {
    return res.status(400).json({ error: 'Укажите имя ученика' });
  }
  const opts = {
    includeEntries: req.query.include_entries !== '0',
    includePhotos: req.query.include_photos !== '0',
    includeFiles: req.query.include_files !== '0',
    includeCaptions: req.query.include_captions !== '0',
    showDates: req.query.show_dates !== '0',
  };
  if (!opts.includeEntries && !opts.includePhotos && !opts.includeFiles) {
    return res.status(400).json({ error: 'Выберите, что включать в отчёт' });
  }
  let dateFrom = null;
  let dateTo = null;
  try {
    if (req.query.date_from) dateFrom = optDate(req.query.date_from);
    if (req.query.date_to) dateTo = optDate(req.query.date_to);
  } catch {
    return res.status(400).json({ error: 'Неверный период' });
  }
  if (dateFrom && dateTo && dateFrom > dateTo) {
    return res.status(400).json({ error: 'Дата «С» позже даты «По»' });
  }
  const hasPeriod = !!(dateFrom || dateTo);
  try {
    const conds = ['e.student_name = $1', 'e.deleted_at IS NULL'];
    const params = [name];
    const bw = branchWhere(req.user, 'g');
    if (dateFrom) {
      params.push(dateFrom);
      conds.push(`e.created_at >= $${params.length}::date`);
    }
    if (dateTo) {
      params.push(dateTo);
      conds.push(`e.created_at < ($${params.length}::date + interval '1 day')`);
    }
    if (bw.params.length) {
      const start = params.length + 1;
      conds.push(`g.branch_id IN (${bw.params.map((_, i) => '$' + (start + i)).join(',')})`);
      params.push(...bw.params);
    }
    const condStr = conds.join(' AND ');
    const whereStr = ' WHERE ' + condStr;
    const [studRes, entriesRes, photosRes, mainsRes, filesRes] = await Promise.all([
      pool.query(`SELECT s.name, g.name AS group_name FROM students s LEFT JOIN groups g ON g.id = s.group_id WHERE s.name = $1`, [name]),
      pool.query(`SELECT e.id, e.description, e.created_at, g.name AS group_name
                  FROM entries e JOIN groups g ON g.id = e.group_id${whereStr}
                  ORDER BY e.created_at DESC`, params),
      pool.query(`SELECT ep.photo_path, ep.caption, ep.entry_id, e.description, e.created_at
                  FROM entry_photos ep
                  JOIN entries e ON e.id = ep.entry_id
                  JOIN groups g ON g.id = e.group_id${whereStr}
                  ORDER BY e.created_at DESC, ep.sort_order ASC, ep.id ASC`, params),
      pool.query(`SELECT e.photo_path, e.description, e.created_at, e.id AS entry_id
                  FROM entries e JOIN groups g ON g.id = e.group_id
                  WHERE e.photo_path IS NOT NULL AND ${condStr}
                  ORDER BY e.created_at DESC`, params),
      pool.query(`SELECT pf.path, pf.name, pf.entry_id, e.created_at
                  FROM project_files pf
                  JOIN entries e ON e.id = pf.entry_id
                  JOIN groups g ON g.id = e.group_id
                  WHERE ${condStr} AND pf.detached_at IS NULL
                  ORDER BY e.created_at DESC, pf.id DESC`, params),
    ]);
    const entryRows = entriesRes.rows;
    if (!entryRows.length && !photosRes.rows.length && !filesRes.rows.length) {
      return res.status(404).json({ error: hasPeriod ? 'Нет данных за выбранный период' : 'У ученика нет данных для отчёта' });
    }
    const zip = createZipWriter();
    if (opts.includePhotos) zip.addDir('photos');
    if (opts.includeFiles) zip.addDir('files');

    const seenPhotos = new Set();
    const photosBuilt = [];
    function addPhoto(p) {
      if (!isSafeUploadPath(p.photo_path)) return;
      const stored = p.photo_path.slice('/uploads/'.length);
      if (seenPhotos.has(stored)) return;
      seenPhotos.add(stored);
      const src = path.join(UPLOADS_DIR, stored);
      if (!fs.existsSync(src)) return;
      const data = fs.readFileSync(src);
      zip.addFile('photos/' + stored, data, new Date(p.created_at));
      photosBuilt.push({ stored, caption: p.caption, createdAt: p.created_at, desc: p.description, entryId: p.entry_id });
    }
    if (opts.includePhotos) {
      for (const p of photosRes.rows) addPhoto(p);
      for (const m of mainsRes.rows) addPhoto(m);
      photosBuilt.sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt));
    }

    const seenFiles = new Map();
    const filesBuilt = [];
    if (opts.includeFiles) {
      for (const f of filesRes.rows) {
        if (!isSafeUploadPath(f.path)) continue;
        const stored = f.path.slice('/uploads/'.length);
        const src = path.join(UPLOADS_DIR, stored);
        if (!fs.existsSync(src)) continue;
        const data = fs.readFileSync(src);
        let base = String(f.name || 'file').replace(/[\\/:*?"<>|]/g, '_').replace(/^[.\s]+/, '').slice(0, 120) || 'file';
        const ext = path.extname(base);
        const stem = ext ? base.slice(0, -ext.length) : base;
        let saved = base;
        let n = 1;
        while (seenFiles.has(saved)) {
          n++;
          saved = `${stem}(${n})${ext}`;
        }
        seenFiles.set(saved, true);
        zip.addFile('files/' + saved, data, new Date(f.created_at));
        filesBuilt.push({ saved, original: f.name, size: data.length, createdAt: f.created_at, entryId: f.entry_id });
      }
    }

    const groupSet = new Set();
    if (studRes.rows[0]?.group_name) groupSet.add(studRes.rows[0].group_name);
    for (const e of entryRows) if (e.group_name) groupSet.add(e.group_name);
    const groups = [...groupSet];

    let period = null;
    if (hasPeriod) {
      period = `Период: ${dateFrom ? fmtLongDate(dateFrom + 'T00:00:00') : 'начало'} — ${dateTo ? fmtLongDate(dateTo + 'T00:00:00') : 'сегодня'}`;
    }

    const html = renderStudentReport({
      name,
      groups,
      entries: entryRows,
      photos: photosBuilt,
      files: filesBuilt,
      generatedAt: new Date(),
      period,
    }, opts);
    zip.addFile('index.html', Buffer.from(html, 'utf8'));

    const buf = zip.toBuffer();
    await logAudit(req, 'export.student', {
      student: name,
      entries: entryRows.length,
      photos: photosBuilt.length,
      files: filesBuilt.length,
      opts,
      date_from: dateFrom,
      date_to: dateTo,
    });
    const safeName = name.replace(/[^a-zA-Z0-9._-]+/g, '_').slice(0, 80) || 'student';
    const zipDate = new Date().toISOString().slice(0, 10);
    const zipFname = `student_${safeName}_${zipDate}.zip`;
    res.setHeader('Content-Type', 'application/zip');
    res.setHeader('Content-Disposition', `attachment; filename="${zipFname}"; filename*=UTF-8''${encodeURIComponent(`student_${name}_${zipDate}.zip`)}`);
    res.send(buf);
  } catch (err) {
    console.error('export student:', err);
    res.status(500).json({ error: err.message });
  }
});

// --- Entries ---
app.get('/api/entries', requireAuth, async (req, res) => {
  const { group_id, date_from, date_to, student_name, search, limit, offset, deleted } = req.query;
  const conditions = [];
  const params = [];
  if (deleted === '1') conditions.push('e.deleted_at IS NOT NULL');
  else conditions.push('e.deleted_at IS NULL');
  if (group_id) { params.push(group_id); conditions.push(`e.group_id = $${params.length}`); }
  if (date_from) { params.push(date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
  if (date_to) { params.push(date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
  if (student_name) { params.push(student_name); conditions.push(`e.student_name = $${params.length}`); }
  if (search) { params.push(`%${search}%`); conditions.push(`(e.student_name ILIKE $${params.length} OR e.description ILIKE $${params.length})`); }
  if (req.user.role !== 'admin') {
    if (group_id && !(await groupBelongsToBranches(req.user, group_id))) {
      return res.status(403).json({ error: 'Нет доступа к этой группе' });
    }
    const s = branchScope(req.user);
    if (!s.ids.length) {
      conditions.push('1 = 0');
    } else {
      const ph = s.ids.map(id => `$${params.push(id)}`).join(',');
      conditions.push(`g.branch_id IN (${ph})`);
    }
  }
  const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
  const { rows: crows } = await pool.query(
    `SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id${where}`,
    params
  );
  const total = crows[0].n;
  let q = `SELECT e.*, g.name AS group_name FROM entries e
           JOIN groups g ON g.id = e.group_id${where} ORDER BY e.created_at DESC`;
  const qparams = params.slice();
  const lim = parseInt(limit, 10);
  if (lim > 0) { qparams.push(lim); q += ` LIMIT $${qparams.length}`; }
  const off = parseInt(offset, 10);
  if (off > 0) { qparams.push(off); q += ` OFFSET $${qparams.length}`; }
  const { rows } = await pool.query(q, qparams);
  let files;
  if (rows.length) {
    const ids = rows.map(r => r.id);
    const fRes = await pool.query(
      'SELECT id, entry_id, token, name FROM project_files WHERE entry_id = ANY($1) ORDER BY id',
      [ids]
    );
    files = {};
    fRes.rows.forEach(f => { (files[f.entry_id] = files[f.entry_id] || []).push(f); });
  } else {
    files = {};
  }
  rows.forEach(r => { r.files = files[r.id] || []; });

  if (rows.length) {
    const ids = rows.map(r => r.id);
    const pRes = await pool.query(
      'SELECT id, entry_id, photo_path, caption, sort_order FROM entry_photos WHERE entry_id = ANY($1) ORDER BY sort_order, id',
      [ids]
    );
    const photos = {};
    pRes.rows.forEach(p => { (photos[p.entry_id] = photos[p.entry_id] || []).push(p); });
    rows.forEach(r => { r.photos = photos[r.id] || []; });
  } else {
    rows.forEach(r => { r.photos = []; });
  }

  res.json({ entries: rows, total });
});

app.get('/api/entries/:id', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { rows } = await pool.query(
    'SELECT e.*, g.name AS group_name FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.id = $1',
    [req.params.id]
  );
  if (!rows.length) return res.status(404).json({ error: 'Not found' });
  const entry = rows[0];
  const fRes = await pool.query(
    'SELECT id, entry_id, token, name FROM project_files WHERE entry_id = $1 ORDER BY id',
    [entry.id]
  );
  entry.files = fRes.rows;
  const pRes = await pool.query(
    'SELECT id, entry_id, photo_path, caption, sort_order FROM entry_photos WHERE entry_id = $1 ORDER BY sort_order, id',
    [entry.id]
  );
  entry.photos = pRes.rows;
  res.json(entry);
});

app.get('/api/entries/:id/files', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const { rows } = await pool.query(`SELECT e.group_id FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.id = $1`, [req.params.id]);
    if (!rows.length) return res.status(404).json({ error: 'Запись не найдена' });
    if (rows[0].group_id && !(await groupBelongsToBranches(req.user, rows[0].group_id))) {
      return res.status(403).json({ error: 'Нет доступа к этой записи' });
    }
  }
  const { rows } = await pool.query(
    'SELECT id, token, name FROM project_files WHERE entry_id = $1 ORDER BY id',
    [req.params.id]
  );
  res.json(rows);
});

const entryFilesUpload = adminUpload.array('files', 10);
app.post('/api/entries/:id/files', requireAuth, (req, res, next) => {
  entryFilesUpload(req, res, (err) => {
    if (!err) return next();
    if (err.code === 'LIMIT_FILE_SIZE') return res.status(400).json({ error: 'Файл слишком большой (макс. 10 МБ)' });
    if (err.message === 'Not allowed extension') return res.status(400).json({ error: 'Недопустимый тип файла' });
    return res.status(400).json({ error: 'Недопустимый файл' });
  });
}, async (req, res) => {
  const entryId = req.params.id;
  const files = req.files || [];
  if (!files.length) return res.status(400).json({ error: 'Файлы не выбраны' });

  if (req.user.role !== 'admin') {
    const { rows } = await pool.query(`SELECT e.group_id FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.id = $1`, [entryId]);
    if (!rows.length) {
      files.forEach(removeUpload);
      return res.status(404).json({ error: 'Запись не найдена' });
    }
    if (rows[0].group_id && !(await groupBelongsToBranches(req.user, rows[0].group_id))) {
      files.forEach(removeUpload);
      return res.status(403).json({ error: 'Нет доступа к этой записи' });
    }
  }

  const entryCheck = await pool.query('SELECT id FROM entries WHERE id = $1', [entryId]);
  if (!entryCheck.rows.length) {
    files.forEach(removeUpload);
    return res.status(404).json({ error: 'Запись не найдена' });
  }

  const totalBytes = files.reduce((s, f) => s + (f.size || 0), 0);
  if (totalBytes > MAX_TOTAL_UPLOAD_BYTES) {
    files.forEach(removeUpload);
    return res.status(400).json({ error: 'Суммарный размер файлов слишком велик (макс. 30 МБ)' });
  }

  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    for (const f of files) {
      const token = crypto.randomBytes(16).toString('hex');
      await client.query(
        'INSERT INTO project_files (entry_id, token, path, name) VALUES ($1, $2, $3, $4)',
        [entryId, token, `/uploads/${f.filename}`, f.originalname]
      );
    }
    await client.query('COMMIT');
    invalidateShare();
    invalidateEntries();
    res.status(201).json({ ok: true, count: files.length });
  } catch (e) {
    await client.query('ROLLBACK').catch(() => {});
    files.forEach(removeUpload);
    console.error('POST /api/entries/:id/files:', e);
    res.status(500).json({ error: e.message });
  } finally {
    client.release();
  }
});

function isImageName(name) {
  return /\.(jpe?g|jfif|png|gif|webp|bmp|avif|ico)$/i.test(name || '');
}

app.get('/api/files', requireAuth, async (req, res) => {
  const { search, student_name, group_id, date_from, date_to, limit, offset } = req.query;
  const conditions = [];
  const params = [];
  conditions.push('e.deleted_at IS NULL');
  if (search) { params.push(`%${search}%`); conditions.push(`pf.name ILIKE $${params.length}`); }
  if (student_name) { params.push(student_name); conditions.push(`e.student_name = $${params.length}`); }
  if (group_id) { params.push(group_id); conditions.push(`e.group_id = $${params.length}`); }
  if (date_from) { params.push(date_from); conditions.push(`e.created_at >= $${params.length}::date`); }
  if (date_to) { params.push(date_to); conditions.push(`e.created_at < ($${params.length}::date + interval '1 day')`); }
  if (req.user.role !== 'admin') {
    if (group_id && !(await groupBelongsToBranches(req.user, group_id))) {
      return res.status(403).json({ error: 'Нет доступа к этой группе' });
    }
    const s = branchScope(req.user);
    if (!s.ids.length) {
      conditions.push('1 = 0');
    } else {
      const ph = s.ids.map(id => `$${params.push(id)}`).join(',');
      conditions.push(`g.branch_id IN (${ph})`);
    }
  }
  const where = conditions.length ? ' WHERE ' + conditions.join(' AND ') : '';
  const { rows: crows } = await pool.query(
    `SELECT count(*)::int AS n FROM project_files pf JOIN entries e ON e.id = pf.entry_id JOIN groups g ON g.id = e.group_id${where}`,
    params
  );
  const total = crows[0].n;
  let q = `SELECT pf.id, pf.token, pf.name, pf.path, e.student_name, e.created_at, g.name AS group_name
           FROM project_files pf
           JOIN entries e ON e.id = pf.entry_id
           JOIN groups g ON g.id = e.group_id${where}
           ORDER BY pf.id DESC`;
  const qparams = params.slice();
  const lim = parseInt(limit, 10);
  if (lim > 0) { qparams.push(lim); q += ` LIMIT $${qparams.length}`; }
  const off = parseInt(offset, 10);
  if (off > 0) { qparams.push(off); q += ` OFFSET $${qparams.length}`; }
  const { rows } = await pool.query(q, qparams);
  const files = rows.map(r => {
    let size = 0;
    try { size = fs.statSync(path.join(__dirname, r.path)).size; } catch {}
    return { id: r.id, token: r.token, name: r.name, student_name: r.student_name, group_name: r.group_name, created_at: r.created_at, size };
  });
  res.json({ files, total });
});

app.get('/api/files/detached', requireAdmin, async (req, res) => {
  const { search, limit, offset } = req.query;
  const conditions = [];
  const params = [];
  conditions.push('entry_id IS NULL');
  if (search) { params.push(`%${search}%`); conditions.push(`name ILIKE $${params.length}`); }
  const where = conditions.join(' AND ');
  const { rows: crows } = await pool.query(
    `SELECT count(*)::int AS n FROM project_files WHERE ${where}`,
    params
  );
  const total = crows[0].n;
  let q = `SELECT id, token, name, path, created_at FROM project_files
           WHERE ${where} ORDER BY created_at DESC`;
  const qparams = params.slice();
  const lim = parseInt(limit, 10);
  if (lim > 0) { qparams.push(lim); q += ` LIMIT $${qparams.length}`; }
  const off = parseInt(offset, 10);
  if (off > 0) { qparams.push(off); q += ` OFFSET $${qparams.length}`; }
  const { rows } = await pool.query(q, qparams);
  const files = rows.map(r => {
    let size = 0;
    try { size = fs.statSync(path.join(__dirname, r.path)).size; } catch {}
    return { id: r.id, token: r.token, name: r.name, created_at: r.created_at, size };
  });
  res.json({ files, total });
});

app.post('/api/files/:id/detach', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const { rows } = await pool.query(
      `SELECT pf.entry_id, e.group_id FROM project_files pf LEFT JOIN entries e ON e.id = pf.entry_id WHERE pf.id = $1`,
      [req.params.id]
    );
    if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
    const { entry_id, group_id } = rows[0];
    if (!entry_id || (group_id && !(await groupBelongsToBranches(req.user, group_id)))) {
      return res.status(403).json({ error: 'Нет доступа к этому файлу' });
    }
  }
  const { rows } = await pool.query(
    'UPDATE project_files SET entry_id = NULL, detached_at = now() WHERE id = $1 RETURNING *',
    [req.params.id]
  );
  if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
  invalidateShare();
  invalidateEntries();
  res.json({ ok: true });
});

app.delete('/api/files/:id', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const { rows } = await pool.query(
      `SELECT pf.entry_id, e.group_id FROM project_files pf LEFT JOIN entries e ON e.id = pf.entry_id WHERE pf.id = $1`,
      [req.params.id]
    );
    if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
    const { entry_id, group_id } = rows[0];
    if (!entry_id || (group_id && !(await groupBelongsToBranches(req.user, group_id)))) {
      return res.status(403).json({ error: 'Нет доступа к этому файлу' });
    }
  }
  const { rows } = await pool.query('SELECT path FROM project_files WHERE id = $1', [req.params.id]);
  if (!rows.length) return res.status(404).json({ error: 'Не найдено' });
  safeUnlink(rows[0].path);
  await pool.query('DELETE FROM project_files WHERE id = $1', [req.params.id]);
  invalidateShare();
  invalidateEntries();
  res.json({ ok: true });
});

app.get('/api/files/:token', fileLimiter, async (req, res) => {
  const { rows } = await pool.query('SELECT path, name FROM project_files WHERE token = $1', [req.params.token]);
  if (!rows.length) return res.status(404).json({ error: 'Not found' });
  const r = rows[0];
  const fp = path.join(__dirname, r.path);
  if (!fs.existsSync(fp)) return res.status(404).json({ error: 'File missing' });
  if (isImageName(r.name)) {
    if (req.query.thumb) return sendImageThumb(res, fp);
    res.setHeader('Cache-Control', 'public, max-age=31536000, immutable');
    return res.sendFile(fp);
  }
  return res.download(fp, r.name);
});

app.get('/api/stats', requireAuth, async (req, res) => {
  const payload = await cacheWrap('stats:' + scopeKey(req.user), STATS_TTL_MS, async () => {
    const isAdmin = req.user.role === 'admin';
    const s = branchScope(req.user);
    let groupFilter;
    if (isAdmin) {
      groupFilter = { where: '', params: [] };
    } else if (!s.ids.length) {
      groupFilter = { where: ' AND 1 = 0', params: [] };
    } else {
      const ph = s.ids.map(id => `$${s.ids.indexOf(id) + 1}`).join(',');
      groupFilter = { where: ` AND g.branch_id IN (${ph})`, params: s.ids };
    }
    const groupsParams = isAdmin ? [] : (s.ids.length ? s.ids : [0]);
    const groupsWhere = isAdmin ? '' : (s.ids.length ? ` WHERE g.branch_id IN (${groupsParams.map((_, i) => `$${i + 1}`).join(',')})` : ' WHERE 1 = 0');
    const [entries, trash, groups, students, today] = await Promise.all([
      pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${groupFilter.where}`, groupFilter.params),
      pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NOT NULL${groupFilter.where}`, groupFilter.params),
      pool.query(`SELECT count(*)::int AS n FROM groups g${groupsWhere}`, groupsParams),
      pool.query(`SELECT count(DISTINCT e.student_name)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${groupFilter.where}`, groupFilter.params),
      pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL AND e.created_at >= now()::date${groupFilter.where}`, groupFilter.params),
    ]);
    return {
      entries: entries.rows[0].n,
      trash: trash.rows[0].n,
      groups: groups.rows[0].n,
      students: students.rows[0].n,
      today: today.rows[0].n,
    };
  });
  res.json(payload);
});

app.get('/api/system-info', requireAdmin, async (_, res) => {
  try {
    const payload = await cacheWrap('system-info', SYSTEM_TTL_MS, async () => {
    const db = await pool.query(`
      SELECT 
        pg_size_pretty(pg_database_size(current_database())) AS db_size,
        pg_database_size(current_database()) AS db_size_bytes
    `);
    
    const tables = await pool.query(`
      SELECT 
        schemaname,
        relname,
        pg_size_pretty(pg_total_relation_size(schemaname || '.' || relname)) AS size,
        pg_total_relation_size(schemaname || '.' || relname) AS size_bytes
      FROM pg_stat_user_tables
      ORDER BY pg_total_relation_size(schemaname || '.' || relname) DESC
    `);

    const photoStats = await pool.query(`
      SELECT count(*)::int AS count,
             sum(pg_column_size(photo_path))::bigint AS path_size_bytes
      FROM group_photos
    `);
    
    const fileStats = await pool.query(`
      SELECT count(*)::int AS count,
             sum(pg_column_size(path))::bigint AS path_size_bytes
      FROM project_files
    `);

    const entryPhotoStats = await pool.query(`
      SELECT count(*)::int AS count
      FROM entries
      WHERE photo_path IS NOT NULL AND deleted_at IS NULL
    `);

    function sumPhotoSizes(paths) {
      let bytes = 0;
      for (const p of paths) {
        if (!p) continue;
        const fp = path.join(__dirname, p);
        try {
          const st = fs.statSync(fp);
          if (st.isFile()) bytes += st.size;
        } catch {}
      }
      return bytes;
    }

    const groupPhotoSizes = await pool.query('SELECT photo_path FROM group_photos');
    const entryPhotoSizes = await pool.query('SELECT photo_path FROM entries WHERE photo_path IS NOT NULL AND deleted_at IS NULL');
    const groupPhotoBytes = sumPhotoSizes(groupPhotoSizes.rows.map(r => r.photo_path));
    const entryPhotoBytes = sumPhotoSizes(entryPhotoSizes.rows.map(r => r.photo_path));

    const uploadsDir = path.join(__dirname, 'uploads');
    let uploadsSize = 0;
    let uploadsCount = 0;
    if (fs.existsSync(uploadsDir)) {
      for (const f of fs.readdirSync(uploadsDir)) {
        const fp = path.join(uploadsDir, f);
        if (fs.statSync(fp).isFile()) {
          uploadsCount++;
          uploadsSize += fs.statSync(fp).size;
        }
      }
    }

    const diskInfo = getDiskInfo();

    return {
      database: {
        size: db.rows[0].db_size,
        size_bytes: parseInt(db.rows[0].db_size_bytes, 10),
        tables: tables.rows.map(t => ({
          name: t.relname,
          size: t.size,
          size_bytes: parseInt(t.size_bytes, 10),
        })),
      },
      photos: {
        group_photos: { count: photoStats.rows[0].count || 0, size: formatBytes(groupPhotoBytes), size_bytes: groupPhotoBytes },
        entry_photos: { count: entryPhotoStats.rows[0].count || 0, size: formatBytes(entryPhotoBytes), size_bytes: entryPhotoBytes },
        total_count: (photoStats.rows[0].count || 0) + (entryPhotoStats.rows[0].count || 0),
        total_size: formatBytes(groupPhotoBytes + entryPhotoBytes),
        total_size_bytes: groupPhotoBytes + entryPhotoBytes,
      },
      files: {
        project_files: { count: fileStats.rows[0].count || 0 },
      },
      uploads: {
        count: uploadsCount,
        size: formatBytes(uploadsSize),
        size_bytes: uploadsSize,
      },
      disk: diskInfo,
    };
    });
    res.json(payload);
  } catch (e) {
    console.error('System info error:', e);
    res.status(500).json({ error: e.message });
  }
});

app.get('/api/dashboard', requireAuth, async (req, res) => {
  const payload = await cacheWrap('dashboard:' + scopeKey(req.user), STATS_TTL_MS, async () => {
  const DAYS = ['Вс', 'Пн', 'Вт', 'Ср', 'Чт', 'Пт', 'Сб'];
  const isAdmin = req.user.role === 'admin';
  const s = branchScope(req.user);
  const branchIds = isAdmin ? [] : s.ids;
  const whereGroup = isAdmin ? '' : (branchIds.length ? ` AND g.branch_id IN (${branchIds.map((_, i) => `$${i + 1}`).join(',')})` : ' AND 1 = 0');
  const whereGroupParams = isAdmin ? [] : branchIds;
  const whereEntry = isAdmin ? '' : (branchIds.length ? ` AND g.branch_id IN (${branchIds.map((_, i) => `$${i + 1}`).join(',')})` : ' AND 1 = 0');

  const [stats, activity, active, recent, top, photos, latestPhotos] = await Promise.all([
    (async () => {
      const ew = !!whereEntry;
      const entriesP = `SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${ew ? whereEntry : ''}`;
      const [entries, trash, groups, students, today] = await Promise.all([
        pool.query(entriesP, ew ? whereGroupParams : []),
        pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NOT NULL${ew ? whereEntry : ''}`, ew ? whereGroupParams : []),
        pool.query(`SELECT count(*)::int AS n FROM groups g${isAdmin ? '' : (branchIds.length ? ` WHERE g.branch_id IN (${branchIds.map((_, i) => `$${i + 1}`).join(',')})` : ' WHERE 1 = 0')}`, isAdmin ? [] : branchIds),
        pool.query(`SELECT count(DISTINCT e.student_name)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL${ew ? whereEntry : ''}`, ew ? whereGroupParams : []),
        pool.query(`SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id WHERE e.deleted_at IS NULL AND e.created_at >= now()::date${ew ? whereEntry : ''}`, ew ? whereGroupParams : []),
      ]);
      return { entries: entries.rows[0].n, trash: trash.rows[0].n, groups: groups.rows[0].n, students: students.rows[0].n, today: today.rows[0].n };
    })(),
    pool.query(
      `SELECT to_char(e.created_at, 'YYYY-MM-DD') AS d, count(*)::int AS n
       FROM entries e JOIN groups g ON g.id = e.group_id
       WHERE e.deleted_at IS NULL AND e.created_at >= (now() - interval '13 days')::date${whereEntry}
       GROUP BY 1 ORDER BY 1`,
      whereEntry ? whereGroupParams : []
    ),
    pool.query(
      `SELECT g.* FROM groups g
       WHERE g.day_of_week IS NOT NULL AND g.time_start IS NOT NULL AND g.time_end IS NOT NULL
         AND g.day_of_week = EXTRACT(DOW FROM (now() AT TIME ZONE 'Europe/Moscow'))::int
         AND (now() AT TIME ZONE 'Europe/Moscow')::time BETWEEN g.time_start AND g.time_end${whereGroup}
       ORDER BY g.id`,
      whereGroup ? whereGroupParams : []
    ),
    pool.query(
      `SELECT e.id, e.student_name, e.photo_path, e.created_at, g.name AS group_name
       FROM entries e JOIN groups g ON g.id = e.group_id
       WHERE e.deleted_at IS NULL${whereEntry}
       ORDER BY e.created_at DESC LIMIT 7`,
      whereEntry ? whereGroupParams : []
    ),
    pool.query(
      `SELECT e.student_name, count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id
       WHERE e.deleted_at IS NULL${whereEntry} GROUP BY e.student_name ORDER BY n DESC, e.student_name LIMIT 5`,
      whereEntry ? whereGroupParams : []
    ),
    pool.query(
      `SELECT gp.id, gp.photo_path, gp.caption, gp.taken_at, g.name AS group_name
       FROM group_photos gp JOIN groups g ON g.id = gp.group_id${whereGroup}
       ORDER BY gp.sort_order ASC, gp.taken_at DESC NULLS LAST, gp.created_at DESC LIMIT 8`,
      whereGroup ? whereGroupParams : []
    ),
    pool.query(
      `SELECT gp.photo_path, gp.taken_at FROM group_photos gp JOIN groups g ON g.id = gp.group_id${whereGroup}
       ORDER BY gp.sort_order ASC, gp.taken_at DESC NULLS LAST, gp.created_at DESC LIMIT 1`,
      whereGroup ? whereGroupParams : []
    ),
  ]);
  const activeGroups = active.rows.map(g => ({
    id: g.id,
    name: g.name,
    day_label: DAYS[g.day_of_week],
    time_start: (g.time_start || '').slice(0, 5),
    time_end: (g.time_end || '').slice(0, 5),
  }));
  return {
    stats: stats,
    activity: activity.rows,
    active_groups: activeGroups,
    recent_entries: recent.rows,
    top_students: top.rows,
    photos: photos.rows,
    latest_photo_taken: (latestPhotos.rows[0] || {}).taken_at || null,
    disk: getDiskInfo(),
  };
  });
  res.json(payload);
});

const entryFields = upload.fields([{ name: 'photo', maxCount: 10 }, { name: 'files', maxCount: 10 }]);
app.post('/api/entries', entryLimiter, (req, res, next) => {
  entryFields(req, res, (err) => {
    if (!err) return next();
    if (err.code === 'LIMIT_FILE_SIZE') return res.status(400).json({ error: 'Файл слишком большой (макс. 10 МБ)' });
    if (err.message === 'Only images') return res.status(400).json({ error: 'Фото: допустимы только изображения (jpg, png, gif, webp, bmp, avif, ico, heic, heif, jfif)' });
    if (err.message === 'Not allowed extension') return res.status(400).json({ error: 'Недопустимый тип файла (*.html, *.js, *.svg и т.п. запрещены)' });
    return res.status(400).json({ error: 'Недопустимый файл' });
  });
}, async (req, res) => {
  const { student_name, group_id, description, website } = req.body;
  const photos = req.files?.photo || [];
  const projectFiles = req.files?.files || [];
  if (website) {
    photos.forEach(removeUpload);
    projectFiles.forEach(removeUpload);
    await recordFailure(req, 'honeypot', 1, BAN_TTL_MS);
    return res.status(400).json({ error: 'Spam detected' });
  }
  if (!student_name?.trim() || !group_id || !description?.trim()) {
    photos.forEach(removeUpload);
    projectFiles.forEach(removeUpload);
    return res.status(400).json({ error: 'All fields required' });
  }
  if (!photos.length) {
    projectFiles.forEach(removeUpload);
    return res.status(400).json({ error: 'Фото обязательно' });
  }
  const totalBytes = photos.reduce((s, f) => s + (f.size || 0), 0) + projectFiles.reduce((s, f) => s + (f.size || 0), 0);
  if (totalBytes > MAX_TOTAL_UPLOAD_BYTES) {
    photos.forEach(removeUpload);
    projectFiles.forEach(removeUpload);
    return res.status(400).json({ error: 'Суммарный размер файлов слишком велик (макс. 30 МБ)' });
  }
  const gid = Number.parseInt(group_id, 10);
  if (!Number.isInteger(gid)) {
    photos.forEach(removeUpload);
    projectFiles.forEach(removeUpload);
    return res.status(400).json({ error: 'Группа не найдена' });
  }
  const grpCheck = await pool.query('SELECT id FROM groups WHERE id = $1', [gid]);
  if (!grpCheck.rows.length) {
    photos.forEach(removeUpload);
    projectFiles.forEach(removeUpload);
    return res.status(400).json({ error: 'Группа не найдена' });
  }
  const intervalMin = parseInt(await getSetting('spam_interval_min', '30'), 10) || 0;
  if (intervalMin > 0) {
    const dup = await pool.query(
      'SELECT count(*)::int AS n FROM entries WHERE student_name = $1 AND created_at >= now() - ($2 || \' minutes\')::interval',
      [student_name.trim(), intervalMin]
    );
    if (dup.rows[0].n > 0) {
      photos.forEach(removeUpload);
      projectFiles.forEach(removeUpload);
      return res.status(429).json({ error: `Уже ответили: подождите ${intervalMin} минут` });
    }
  }
  for (const p of photos) {
    await convertPhoto(p);
  }
  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    await client.query(
      'INSERT INTO students (name) VALUES ($1) ON CONFLICT (name) DO NOTHING',
      [student_name.trim()]
    );
    const mainPhotoPath = photos.length ? `/uploads/${photos[0].filename}` : null;
    const { rows } = await client.query(
      `INSERT INTO entries (student_name, group_id, description, description_original, photo_path)
       VALUES ($1, $2, $3, $3, $4) RETURNING *`,
      [student_name.trim(), gid, description.trim(), mainPhotoPath]
    );
    for (let i = 0; i < photos.length; i++) {
      const p = photos[i];
      await client.query(
        'INSERT INTO entry_photos (entry_id, photo_path, sort_order) VALUES ($1, $2, $3)',
        [rows[0].id, `/uploads/${p.filename}`, i]
      );
    }
    for (const f of projectFiles) {
      const token = crypto.randomBytes(16).toString('hex');
      await client.query(
        'INSERT INTO project_files (entry_id, token, path, name) VALUES ($1, $2, $3, $4)',
        [rows[0].id, token, `/uploads/${f.filename}`, f.originalname]
      );
    }
    await client.query('COMMIT');
    if (entryAutoChecker) entryAutoChecker.notify();
    invalidateEntries();
    invalidateStats();
    broadcastEntryChanged();
    res.status(201).json({ ...rows[0], files: projectFiles.length, photos: photos.length });
  } catch (e) {
    await client.query('ROLLBACK').catch(() => {});
    photos.forEach(removeUpload);
    projectFiles.forEach(removeUpload);
    console.error('POST /api/entries:', e);
    res.status(500).json({ error: e.message });
  } finally {
    client.release();
  }
});

app.put('/api/entries/:id', requireAuth, upload.array('photo', 10), async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { student_name, group_id, description } = req.body;
  const newPhotos = req.files || [];
  for (const p of newPhotos) {
    await convertPhoto(p);
  }

  const { rows } = await pool.query(
    `UPDATE entries SET
      student_name = COALESCE($1, student_name),
      group_id = COALESCE($2, group_id),
      description = COALESCE($3, description),
      description_original = COALESCE($3, description_original),
      description_ai = CASE WHEN $3 IS NULL THEN description_ai ELSE NULL END,
      ai_status = CASE WHEN $3 IS NULL THEN ai_status ELSE 'pending' END,
      ai_error = CASE WHEN $3 IS NULL THEN ai_error ELSE NULL END,
      ai_checked_at = CASE WHEN $3 IS NULL THEN ai_checked_at ELSE NULL END
     WHERE id = $4 RETURNING *`,
    [
      student_name ? student_name.trim() : null,
      group_id || null,
      description ? description.trim() : null,
      req.params.id,
    ]
  );
  if (!rows.length) {
    newPhotos.forEach(p => safeUnlink(p.path));
    return res.status(404).json({ error: 'Not found' });
  }
  if (description && entryAutoChecker) entryAutoChecker.notify();

  const { rows: existingPhotos } = await pool.query('SELECT id, photo_path FROM entry_photos WHERE entry_id = $1 ORDER BY sort_order, id', [req.params.id]);
  const nextSortOrder = existingPhotos.length;

  for (let i = 0; i < newPhotos.length; i++) {
    const p = newPhotos[i];
    await pool.query(
      'INSERT INTO entry_photos (entry_id, photo_path, sort_order) VALUES ($1, $2, $3)',
      [req.params.id, `/uploads/${p.filename}`, nextSortOrder + i]
    );
  }
  if (!rows[0].photo_path && newPhotos.length) {
    rows[0].photo_path = `/uploads/${newPhotos[0].filename}`;
    await pool.query('UPDATE entries SET photo_path = $1 WHERE id = $2', [rows[0].photo_path, req.params.id]);
  }

  await logAudit(req, 'entry.update', { id: req.params.id });
  invalidateEntries();
  invalidateStats();
  res.json(rows[0]);
});

app.get('/api/entries/:id/photos', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { rows } = await pool.query(
    'SELECT id, photo_path, caption, sort_order, created_at FROM entry_photos WHERE entry_id = $1 ORDER BY sort_order, id',
    [req.params.id]
  );
  res.json(rows);
});

app.delete('/api/entries/:id/photos/:photoId', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { rows } = await pool.query('SELECT photo_path, sort_order FROM entry_photos WHERE id = $1 AND entry_id = $2', [req.params.photoId, req.params.id]);
  if (!rows.length) return res.status(404).json({ error: 'Фото не найдено' });
  const { photo_path: photoPath, sort_order: photoSort } = rows[0];
  await pool.query('DELETE FROM entry_photos WHERE id = $1 AND entry_id = $2', [req.params.photoId, req.params.id]);
  safeUnlink(photoPath);
  await pool.query('UPDATE entry_photos SET sort_order = sort_order - 1 WHERE entry_id = $1 AND sort_order > $2', [req.params.id, photoSort]);
  const { rows: mainRows } = await pool.query('SELECT id FROM entries WHERE id = $1 AND photo_path = $2', [req.params.id, photoPath]);
  if (mainRows.length) {
    const { rows: nextRows } = await pool.query('SELECT photo_path FROM entry_photos WHERE entry_id = $1 ORDER BY sort_order, id LIMIT 1', [req.params.id]);
    await pool.query('UPDATE entries SET photo_path = $1 WHERE id = $2', [nextRows.length ? nextRows[0].photo_path : null, req.params.id]);
  }
  await logAudit(req, 'entry.photo.delete', { entry_id: req.params.id, photo_id: req.params.photoId });
  invalidateEntries();
  res.json({ ok: true });
});

app.put('/api/entries/:id/photos/:photoId', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { caption, sort_order } = req.body;
  const { rows } = await pool.query(
    'UPDATE entry_photos SET caption = COALESCE($1, caption), sort_order = COALESCE($2, sort_order) WHERE id = $3 AND entry_id = $4 RETURNING *',
    [caption ?? null, sort_order !== undefined ? sort_order : null, req.params.photoId, req.params.id]
  );
  if (!rows.length) return res.status(404).json({ error: 'Фото не найдено' });
  await logAudit(req, 'entry.photo.update', { entry_id: req.params.id, photo_id: req.params.photoId });
  invalidateEntries();
  res.json(rows[0]);
});

app.put('/api/entries/:id/photos/:photoId/main', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { rows } = await pool.query('SELECT photo_path FROM entry_photos WHERE id = $1 AND entry_id = $2', [req.params.photoId, req.params.id]);
  if (!rows.length) return res.status(404).json({ error: 'Фото не найдено' });
  await pool.query('UPDATE entries SET photo_path = $1 WHERE id = $2', [rows[0].photo_path, req.params.id]);
  await logAudit(req, 'entry.photo.set_main', { entry_id: req.params.id, photo_id: req.params.photoId });
  invalidateEntries();
  res.json({ ok: true, photo_path: rows[0].photo_path });
});
function clampEnhanceParam(v, min, max, def) {
  const n = parseFloat(v);
  return Number.isFinite(n) ? Math.min(max, Math.max(min, n)) : def;
}

async function swapEntryPhotoFiles(req, entryId, oldPath, newPath, { keepOriginal = true, action = 'enhance' } = {}) {
  let originalPath = null;
  const { rows: prevRows } = await pool.query('SELECT photo_original_path FROM entries WHERE id = $1', [entryId]);
  const prevOriginal = prevRows.length ? prevRows[0].photo_original_path : null;
  const oldAbs = path.join(UPLOADS_DIR, String(oldPath).replace(/^\/+/, '').replace(/^uploads\//, ''));
  if (prevOriginal) {
    originalPath = prevOriginal;
    try { if (fs.existsSync(oldAbs)) fs.unlinkSync(oldAbs); } catch {}
  } else if (keepOriginal && fs.existsSync(oldAbs)) {
    try {
      const backupName = crypto.randomBytes(12).toString('hex') + (path.extname(oldAbs) || '.jpg');
      const backupPath = path.join(ORIGINALS_DIR, backupName);
      fs.renameSync(oldAbs, backupPath);
      originalPath = `/uploads/.originals/${backupName}`;
    } catch (e) {
      console.error('photo original backup failed:', e);
    }
  } else {
    try { if (fs.existsSync(oldAbs)) fs.unlinkSync(oldAbs); } catch {}
  }
  await pool.query('UPDATE entries SET photo_path = $1, photo_original_path = $2 WHERE id = $3', [newPath, originalPath, entryId]);
  await pool.query('UPDATE entry_photos SET photo_path = $1 WHERE entry_id = $2 AND photo_path = $3', [newPath, entryId, oldPath]);
  const oldThumb = path.join('uploads', '.thumbs', path.basename(oldPath).replace(/\.[^.]+$/, '') + '.webp');
  safeUnlink(oldThumb);
  await pool.query(
    'INSERT INTO photo_jobs (entry_id, action, status, before_path, after_path, finished_at) VALUES ($1, $2, $3, $4, $5, now())',
    [entryId, action, 'done', originalPath, newPath]
  );
  await logAudit(req, 'entry.photo.enhance', { entry_id: entryId, old_path: oldPath, new_path: newPath, original_path: originalPath });
  invalidateEntries();
}

app.put('/api/entries/:id/photo/enhance', requireAuth, (req, res, next) => {
  if (req.is('json')) return next();
  upload.single('photo')(req, res, next);
}, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  try {
    const { rows: cur } = await pool.query('SELECT photo_path FROM entries WHERE id = $1', [req.params.id]);
    if (!cur.length) {
      if (req.file) safeUnlink(req.file.path);
      return res.status(404).json({ error: 'Запись не найдена' });
    }
    const oldPath = cur[0].photo_path;
    if (!oldPath) {
      if (req.file) safeUnlink(req.file.path);
      return res.status(400).json({ error: 'У записи нет фото' });
    }
    let newPath;
    let engine = 'client';
    if (req.is('json')) {
      if (!sharp) return res.status(503).json({ error: 'sharp недоступен на сервере' });
      const p = req.body.params || {};
      const brightness = clampEnhanceParam(p.brightness, 10, 300, 100);
      const contrast = clampEnhanceParam(p.contrast, 10, 300, 100);
      const saturate = clampEnhanceParam(p.saturate, 0, 300, 100);
      const sharpAmt = clampEnhanceParam(p.sharp, 0, 100, 0);
      const denoise = clampEnhanceParam(p.denoise, 0, 100, 0);
      const srcPath = path.join(__dirname, oldPath.replace(/^\/+/, ''));
      let pipeline = sharp(srcPath).rotate();
      if (denoise > 0) pipeline = pipeline.median(denoise > 70 ? 5 : 3);
      pipeline = pipeline.modulate({ brightness: brightness / 100, saturation: saturate / 100 });
      if (contrast !== 100) {
        const a = contrast / 100;
        pipeline = pipeline.linear(a, 128 * (1 - a));
      }
      if (sharpAmt > 0) {
        pipeline = pipeline.sharpen({ sigma: 0.5 + (sharpAmt / 100) * 1.5, m1: 0, m2: 1 + sharpAmt / 50 });
      }
      const newName = crypto.randomBytes(12).toString('hex') + '.jpg';
      const outPath = path.join(__dirname, 'uploads', newName);
      await pipeline.jpeg({ quality: 92, mozjpeg: true }).toFile(outPath);
      newPath = `/uploads/${newName}`;
      engine = 'sharp';
    } else {
      if (!req.file) return res.status(400).json({ error: 'Нет файла' });
      await convertPhoto(req.file);
      newPath = `/uploads/${req.file.filename}`;
    }
    await swapEntryPhotoFiles(req, req.params.id, oldPath, newPath, { action: 'enhance' });
    res.json({ ok: true, photo_path: newPath, engine });
  } catch (e) {
    if (req.file) safeUnlink(req.file.path);
    console.error('PUT /api/entries/:id/photo/enhance:', e);
    res.status(500).json({ error: 'Ошибка замены фото' });
  }
});

app.post('/api/entries/:id/photo/enhance-ai', requireAuth, async (req, res) => {
  if (!PHOTO_AI_URL) return res.status(503).json({ error: 'ИИ-обработка фото не настроена' });
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { rows: cur } = await pool.query('SELECT photo_path FROM entries WHERE id = $1', [req.params.id]);
  if (!cur.length) return res.status(404).json({ error: 'Запись не найдена' });
  if (!cur[0].photo_path) return res.status(400).json({ error: 'У записи нет фото' });
  try {
    const { rows } = await pool.query(
      `INSERT INTO photo_jobs (entry_id, action, status, params) VALUES ($1, 'ai', 'pending', NULL) RETURNING id`,
      [req.params.id]
    );
    if (photoWorker) photoWorker.notify();
    await logAudit(req, 'entry.photo.enhance-ai.queue', { entry_id: req.params.id, job_id: rows[0].id });
    res.json({ jobId: rows[0].id });
  } catch (e) {
    console.error('POST /api/entries/:id/photo/enhance-ai:', e);
    res.status(500).json({ error: 'Ошибка постановки задания в очередь' });
  }
});

app.get('/api/entries/:id/photo/enhance-ai/:jobId', requireAuth, async (req, res) => {
  const jobId = parseInt(req.params.jobId, 10);
  if (!Number.isFinite(jobId)) return res.status(404).json({ error: 'Задание не найдено' });
  const { rows } = await pool.query(
    'SELECT status, error, after_path FROM photo_jobs WHERE id = $1 AND entry_id = $2',
    [jobId, req.params.id]
  );
  if (!rows.length) return res.status(404).json({ error: 'Задание не найдено' });
  const job = rows[0];
  const out = { status: job.status };
  if (job.status === 'error') out.error = job.error;
  if (job.status === 'done') out.photo_path = job.after_path;
  res.json(out);
});

app.get('/api/entries/:id/photo/jobs', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { rows } = await pool.query(
    `SELECT id, action, status, params, before_path, after_path, error, created_at, finished_at
     FROM photo_jobs WHERE entry_id = $1 ORDER BY id DESC LIMIT 50`,
    [req.params.id]
  );
  res.json(rows);
});

app.post('/api/entries/:id/photo/jobs/:jobId/rollback', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  try {
    const jobId = parseInt(req.params.jobId, 10);
    if (!Number.isFinite(jobId)) return res.status(404).json({ error: 'Задание не найдено' });
    const { rows: jobRows } = await pool.query(
      `SELECT id, before_path FROM photo_jobs WHERE id = $1 AND entry_id = $2 AND status = 'done'`,
      [jobId, req.params.id]
    );
    if (!jobRows.length) return res.status(404).json({ error: 'Задание не найдено' });
    const job = jobRows[0];
    if (!job.before_path || !job.before_path.startsWith('/uploads/.originals/')) {
      return res.status(400).json({ error: 'Нет сохранённой версии для отката' });
    }
    const beforeName = path.basename(job.before_path);
    if (!/^[A-Za-z0-9._-]+$/.test(beforeName)) return res.status(400).json({ error: 'Некорректный путь' });
    const beforeAbs = path.join(ORIGINALS_DIR, beforeName);
    if (!fs.existsSync(beforeAbs)) return res.status(400).json({ error: 'Файл версии не найден' });
    const { rows: cur } = await pool.query('SELECT photo_path FROM entries WHERE id = $1', [req.params.id]);
    if (!cur.length) return res.status(404).json({ error: 'Запись не найдена' });
    const oldPath = cur[0].photo_path;
    if (!oldPath) return res.status(400).json({ error: 'У записи нет фото' });
    const ext = path.extname(beforeName) || '.jpg';
    const newPath = `/uploads/${crypto.randomBytes(12).toString('hex')}${ext}`;
    fs.copyFileSync(beforeAbs, path.join(UPLOADS_DIR, path.basename(newPath)));
    const oldAbs = path.join(UPLOADS_DIR, String(oldPath).replace(/^\/+/, '').replace(/^uploads\//, ''));
    let rollbackBefore = null;
    if (fs.existsSync(oldAbs)) {
      try {
        const backupName = crypto.randomBytes(12).toString('hex') + (path.extname(oldAbs) || '.jpg');
        fs.renameSync(oldAbs, path.join(ORIGINALS_DIR, backupName));
        rollbackBefore = `/uploads/.originals/${backupName}`;
      } catch (e) {
        console.error('photo rollback backup failed:', e);
      }
    }
    const oldThumb = path.join('uploads', '.thumbs', path.basename(oldPath).replace(/\.[^.]+$/, '') + '.webp');
    safeUnlink(oldThumb);
    await pool.query('UPDATE entries SET photo_path = $1 WHERE id = $2', [newPath, req.params.id]);
    await pool.query('UPDATE entry_photos SET photo_path = $1 WHERE entry_id = $2 AND photo_path = $3', [newPath, req.params.id, oldPath]);
    await pool.query(
      'INSERT INTO photo_jobs (entry_id, action, status, before_path, after_path, error, finished_at) VALUES ($1, $2, $3, $4, $5, NULL, now())',
      [req.params.id, 'rollback', 'done', rollbackBefore, newPath]
    );
    await logAudit(req, 'entry.photo.rollback', { entry_id: req.params.id, job_id: jobId, restored_path: newPath });
    invalidateEntries();
    res.json({ ok: true, photo_path: newPath });
  } catch (e) {
    console.error('POST /api/entries/:id/photo/jobs/:jobId/rollback:', e);
    res.status(500).json({ error: 'Ошибка отката фотографии' });
  }
});

app.delete('/api/entries/:id/photo/enhance-ai/preview', requireAuth, async (req, res) => {
  const { path: p } = req.body || {};
  if (!isSafeUploadPath(p)) return res.status(400).json({ error: 'Некорректный путь' });
  safeUnlink(p);
  res.json({ ok: true });
});

app.post('/api/entries/:id/photo/restore-original', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  try {
    const { rows } = await pool.query('SELECT photo_path, photo_original_path FROM entries WHERE id = $1', [req.params.id]);
    if (!rows.length) return res.status(404).json({ error: 'Запись не найдена' });
    const origPath = rows[0].photo_original_path;
    if (!origPath) return res.status(400).json({ error: 'Оригинал не сохранён' });
    const origName = path.basename(origPath);
    if (!/^[A-Za-z0-9._-]+$/.test(origName)) return res.status(400).json({ error: 'Некорректный путь оригинала' });
    const origAbs = path.join(ORIGINALS_DIR, origName);
    if (!fs.existsSync(origAbs)) return res.status(400).json({ error: 'Файл оригинала не найден' });
    const newPath = `/uploads/${crypto.randomBytes(12).toString('hex')}${path.extname(origName) || '.jpg'}`;
    fs.renameSync(origAbs, path.join(UPLOADS_DIR, path.basename(newPath)));
    const oldPath = rows[0].photo_path;
    await pool.query('UPDATE entries SET photo_path = $1, photo_original_path = NULL WHERE id = $2', [newPath, req.params.id]);
    await pool.query('UPDATE entry_photos SET photo_path = $1 WHERE entry_id = $2 AND photo_path = $3', [newPath, req.params.id, oldPath]);
    const oldAbs = path.join(UPLOADS_DIR, String(oldPath).replace(/^\/+/, '').replace(/^uploads\//, ''));
    let beforePath = null;
    if (fs.existsSync(oldAbs)) {
      try {
        const backupName = crypto.randomBytes(12).toString('hex') + (path.extname(oldAbs) || '.jpg');
        fs.renameSync(oldAbs, path.join(ORIGINALS_DIR, backupName));
        beforePath = `/uploads/.originals/${backupName}`;
      } catch (e) {
        console.error('photo original backup failed:', e);
      }
    }
    const oldThumb = path.join('uploads', '.thumbs', path.basename(oldPath).replace(/\.[^.]+$/, '') + '.webp');
    safeUnlink(oldThumb);
    await pool.query(
      'INSERT INTO photo_jobs (entry_id, action, status, before_path, after_path, error, finished_at) VALUES ($1, $2, $3, $4, $5, NULL, now())',
      [req.params.id, 'restore', 'done', beforePath, newPath]
    );
    await logAudit(req, 'entry.photo.restore_original', { entry_id: req.params.id, restored_path: newPath });
    invalidateEntries();
    res.json({ ok: true, photo_path: newPath });
  } catch (e) {
    console.error('POST /api/entries/:id/photo/restore-original:', e);
    res.status(500).json({ error: 'Ошибка восстановления оригинала' });
  }
});

app.delete('/api/entries/:id', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  await pool.query('UPDATE entries SET deleted_at = now() WHERE id = $1', [req.params.id]);
  await logAudit(req, 'entry.soft-delete', { id: req.params.id });
  invalidateEntries();
  invalidateStats();
  res.json({ ok: true });
});

app.put('/api/entries/:id/restore', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) {
      console.warn(`[RESTORE DENIED] User ${req.user.id} (${req.user.username}) role=${req.user.role} branches=${JSON.stringify(req.user.branch_ids)} tried to restore entry ${req.params.id} (group_id=${acc.group_id})`);
      return res.status(403).json({ error: 'Нет доступа к этой записи' });
    }
  }
  const result = await pool.query('UPDATE entries SET deleted_at = NULL WHERE id = $1', [req.params.id]);
  console.log(`[RESTORE] User ${req.user.id} (${req.user.username}) restored entry ${req.params.id}, rowCount=${result.rowCount}`);
  if (result.rowCount === 0) {
    return res.status(404).json({ error: 'Запись не найдена или уже восстановлена' });
  }
  await logAudit(req, 'entry.restore', { id: req.params.id });
  invalidateEntries();
  invalidateStats();
  res.json({ ok: true });
});

app.delete('/api/entries/:id/permanent', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) {
      console.warn(`[PERM DELETE DENIED] User ${req.user.id} (${req.user.username}) role=${req.user.role} branches=${JSON.stringify(req.user.branch_ids)} tried to perm delete entry ${req.params.id} (group_id=${acc.group_id})`);
      return res.status(403).json({ error: 'Нет доступа к этой записи' });
    }
  }
  await removeEntryFiles(req.params.id);
  await pool.query('DELETE FROM entries WHERE id = $1', [req.params.id]);
  await logAudit(req, 'entry.permanent-delete', { id: req.params.id });
  invalidateEntries();
  invalidateStats();
  res.json({ ok: true });
});

app.post('/api/ai/correct', requireAuth, async (req, res) => {
  const text = reqStr(req.body?.text, 5000);
  if (!text) return res.status(400).json({ error: 'Текст не указан' });
  try {
    const corrected = await aiCorrectText(text);
    res.json({ suggestion: corrected });
  } catch (e) {
    res.status(502).json({ error: 'Сервис ИИ недоступен: ' + e.message });
  }
});

// --- AI model profiles ---
function validateProfileBody(body) {
  const name = String(body?.name || '').trim();
  const base = String(body?.base_url || '').trim().replace(/\/+$/, '');
  const model = String(body?.model || '').trim();
  const apiKey = String(body?.api_key || '').trim();
  let maxTokens = null;
  if (body?.max_tokens !== null && body?.max_tokens !== undefined && String(body.max_tokens).trim() !== '') {
    maxTokens = parseInt(String(body.max_tokens), 10);
    if (!Number.isFinite(maxTokens) || maxTokens < 16 || maxTokens > 32768) {
      return { error: 'max_tokens должен быть целым числом от 16 до 32768' };
    }
  }
  if (!name || name.length > 100) return { error: 'Укажите название профиля (до 100 символов)' };
  if (!/^https?:\/\//i.test(base) || base.length > 300) return { error: 'Base URL должен быть корректным http(s)://… (до 300 символов)' };
  if (!model || model.length > 150) return { error: 'Укажите название модели (до 150 символов)' };
  if (apiKey.length > 300) return { error: 'API-ключ слишком длинный' };
  return { name, base_url: base, model, api_key: apiKey, max_tokens: maxTokens };
}

app.get('/api/ai/profiles', requireAdmin, async (_, res) => {
  const profiles = await getAiProfiles();
  const active = await getSetting('ai_active_profile', 'native');
  res.json({
    active,
    native: { id: 'native', name: 'Нативная (llama.cpp в Docker)', base_url: AI_URL, model: AI_MODEL },
    profiles,
  });
});

app.post('/api/ai/profiles', requireAdmin, async (req, res) => {
  const v = validateProfileBody(req.body);
  if (v.error) return res.status(400).json({ error: v.error });
  const profiles = await getAiProfiles();
  if (profiles.length >= 20) return res.status(400).json({ error: 'Слишком много профилей (макс. 20)' });
  const profile = { id: crypto.randomBytes(8).toString('hex'), ...v };
  profiles.push(profile);
  await pool.query(
    `INSERT INTO settings (key, value) VALUES ('ai_profiles', $1)
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
    [JSON.stringify(profiles)]
  );
  await logAudit(req, 'ai.profile.create', { id: profile.id, name: profile.name, model: profile.model });
  invalidateSettings();
  if (entryAutoChecker) entryAutoChecker.notify();
  res.status(201).json(profile);
});

app.put('/api/ai/profiles/:id', requireAdmin, async (req, res) => {
  const profiles = await getAiProfiles();
  const idx = profiles.findIndex(p => p.id === req.params.id);
  if (idx === -1) return res.status(404).json({ error: 'Профиль не найден' });
  const v = validateProfileBody(req.body);
  if (v.error) return res.status(400).json({ error: v.error });
  profiles[idx] = { id: req.params.id, ...v };
  await pool.query(
    `INSERT INTO settings (key, value) VALUES ('ai_profiles', $1)
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
    [JSON.stringify(profiles)]
  );
  await logAudit(req, 'ai.profile.update', { id: req.params.id, name: v.name, model: v.model });
  invalidateSettings();
  if (entryAutoChecker) entryAutoChecker.notify();
  res.json(profiles[idx]);
});

app.delete('/api/ai/profiles/:id', requireAdmin, async (req, res) => {
  const profiles = await getAiProfiles();
  const idx = profiles.findIndex(p => p.id === req.params.id);
  if (idx === -1) return res.status(404).json({ error: 'Профиль не найден' });
  const removed = profiles.splice(idx, 1)[0];
  await pool.query(
    `INSERT INTO settings (key, value) VALUES ('ai_profiles', $1)
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
    [JSON.stringify(profiles)]
  );
  const active = await getSetting('ai_active_profile', 'native');
  if (active === req.params.id) {
    await pool.query(
      `INSERT INTO settings (key, value) VALUES ('ai_active_profile', 'native')
       ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`
    );
  }
  await logAudit(req, 'ai.profile.delete', { id: req.params.id, name: removed.name });
  invalidateSettings();
  if (entryAutoChecker) entryAutoChecker.notify();
  res.json({ ok: true });
});

app.post('/api/ai/profiles/activate', requireAdmin, async (req, res) => {
  const id = String(req.body?.id || '').trim();
  if (id !== 'native') {
    const profiles = await getAiProfiles();
    if (!profiles.some(p => p.id === id)) return res.status(400).json({ error: 'Профиль не найден' });
  }
  await pool.query(
    `INSERT INTO settings (key, value) VALUES ('ai_active_profile', $1)
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
    [id]
  );
  await logAudit(req, 'ai.profile.activate', { id });
  invalidateSettings();
  if (entryAutoChecker) entryAutoChecker.notify();
  res.json({ ok: true, active: id });
});

app.post('/api/ai/profiles/test', requireAdmin, async (req, res) => {
  const v = validateProfileBody(req.body);
  if (v.error) return res.status(400).json({ error: v.error });
  const base = normalizeOpenAiBase(v.base_url);
  const startedAt = Date.now();
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), 15000);
  try {
    const headers = { 'Content-Type': 'application/json' };
    if (v.api_key) headers.Authorization = `Bearer ${v.api_key}`;
    const r = await fetch(`${base}/chat/completions`, {
      method: 'POST',
      headers,
      signal: controller.signal,
      body: JSON.stringify({
        model: v.model,
        messages: [{ role: 'user', content: 'Ответь одним словом: ок' }],
        max_tokens: 8,
        temperature: 0,
      }),
    });
    const latency_ms = Date.now() - startedAt;
    if (!r.ok) {
      const t = await r.text().catch(() => '');
      return res.json({ ok: false, latency_ms, error: `HTTP ${r.status}${t ? ': ' + t.slice(0, 200) : ''}` });
    }
    const d = await r.json();
    const sample = (d.choices?.[0]?.message?.content || '').trim();
    res.json({ ok: true, latency_ms, sample: sample.slice(0, 120) });
  } catch (e) {
    const latency_ms = Date.now() - startedAt;
    res.json({ ok: false, latency_ms, error: e.name === 'AbortError' ? 'Таймаут 15 с' : (e.message || 'unreachable') });
  } finally {
    clearTimeout(timer);
  }
});

app.get('/api/ai/queue', requireAdmin, async (_, res) => {
  const { rows } = await pool.query(
    `SELECT ai_status, count(*)::int AS n FROM entries WHERE deleted_at IS NULL GROUP BY ai_status`
  );
  const counts = { pending: 0, processing: 0, done: 0, skipped: 0, error: 0, reverted: 0 };
  rows.forEach(r => { counts[r.ai_status] = r.n; });
  const enabled = String(await getSetting('ai_autocheck_enabled', 'true')) !== 'false';
  const activeProfile = await getActiveAiProfile();
  res.json({
    enabled,
    counts,
    worker: entryAutoChecker ? entryAutoChecker.getStats() : null,
    model: activeProfile ? `${activeProfile.name} (${activeProfile.model})` : AI_MODEL,
  });
});

async function aiHealthCheck() {
  const startedAt = Date.now();
  const profile = await getActiveAiProfile();
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), 5000);
  try {
    const headers = {};
    let url;
    if (profile) {
      const base = normalizeOpenAiBase(profile.base_url);
      if (!base) return { reachable: false, latency_ms: 0, error: 'Некорректный base_url профиля' };
      url = `${base}/models`;
      if (profile.api_key) headers.Authorization = `Bearer ${profile.api_key}`;
    } else {
      url = `${AI_URL}/health`;
    }
    const r = await fetch(url, { headers, signal: controller.signal });
    const latency_ms = Date.now() - startedAt;
    if (!r.ok) return { reachable: false, latency_ms, error: `HTTP ${r.status}` };
    return { reachable: true, latency_ms, error: null };
  } catch (e) {
    const latency_ms = Date.now() - startedAt;
    const error = e && e.name === 'AbortError' ? 'timeout' : (e && e.message ? e.message : 'unreachable');
    return { reachable: false, latency_ms, error };
  } finally {
    clearTimeout(timer);
  }
}

app.get('/api/ai/status', requireAdmin, async (_, res) => {
  const { rows } = await pool.query(
    `SELECT ai_status, count(*)::int AS n FROM entries WHERE deleted_at IS NULL GROUP BY ai_status`
  );
  const counts = { pending: 0, processing: 0, done: 0, skipped: 0, error: 0, reverted: 0 };
  rows.forEach(r => { counts[r.ai_status] = r.n; });
  const [pending, recent, errors] = await Promise.all([
    pool.query(
      `SELECT e.id, e.student_name, e.created_at, g.name AS group_name
       FROM entries e JOIN groups g ON g.id = e.group_id
       WHERE e.ai_status IN ('pending', 'processing') AND e.deleted_at IS NULL
       ORDER BY e.id ASC LIMIT 20`
    ),
    pool.query(
      `SELECT e.id, e.student_name, e.ai_status, e.ai_checked_at, e.ai_error, g.name AS group_name,
              e.description_original, e.description_ai,
              (e.description_ai IS NOT NULL AND e.description_original IS NOT NULL AND e.description_ai <> e.description_original) AS changed
       FROM entries e JOIN groups g ON g.id = e.group_id
       WHERE e.ai_checked_at IS NOT NULL AND e.deleted_at IS NULL
       ORDER BY e.ai_checked_at DESC LIMIT 30`
    ),
    pool.query(
      `SELECT e.id, e.student_name, e.ai_error, e.ai_checked_at, g.name AS group_name
       FROM entries e JOIN groups g ON g.id = e.group_id
       WHERE e.ai_status = 'error' AND e.deleted_at IS NULL
       ORDER BY e.ai_checked_at DESC NULLS LAST, e.id DESC LIMIT 20`
    ),
  ]);
  const enabled = String(await getSetting('ai_autocheck_enabled', 'true')) !== 'false';
  const service = await aiHealthCheck();
  const activeProfile = await getActiveAiProfile();
  res.json({
    enabled,
    model: activeProfile ? `${activeProfile.name} (${activeProfile.model})` : AI_MODEL,
    ai_url: AI_URL,
    service,
    worker: entryAutoChecker ? entryAutoChecker.getInfo() : null,
    counts,
    pending: pending.rows,
    recent: recent.rows,
    errors: errors.rows,
  });
});

app.post('/api/ai/wake', requireAdmin, async (req, res) => {
  if (entryAutoChecker) entryAutoChecker.notify();
  await logAudit(req, 'ai.wake', {});
  res.json({ ok: true });
});

app.post('/api/ai/enabled', requireAdmin, async (req, res) => {
  const enabled = !!req.body?.enabled;
  await pool.query(
    `INSERT INTO settings (key, value) VALUES ('ai_autocheck_enabled', $1)
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
    [enabled ? 'true' : 'false']
  );
  if (enabled && entryAutoChecker) entryAutoChecker.notify();
  await logAudit(req, 'ai.enabled', { enabled });
  res.json({ ok: true, enabled });
});

app.post('/api/ai/requeue-failed', requireAdmin, async (req, res) => {
  const { rowCount } = await pool.query(
    `UPDATE entries SET ai_status = 'pending', ai_error = NULL, ai_checked_at = NULL
     WHERE ai_status = 'error' AND deleted_at IS NULL`
  );
  if (entryAutoChecker) entryAutoChecker.notify();
  await logAudit(req, 'ai.requeue-failed', { count: rowCount });
  invalidateEntries();
  res.json({ ok: true, count: rowCount });
});

app.post('/api/entries/:id/ai/recheck', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { rows } = await pool.query(
    `UPDATE entries SET ai_status = 'pending', ai_error = NULL, ai_checked_at = NULL WHERE id = $1 RETURNING id`,
    [req.params.id]
  );
  if (!rows.length) return res.status(404).json({ error: 'Запись не найдена' });
  if (entryAutoChecker) entryAutoChecker.notify();
  await logAudit(req, 'entry.ai.recheck', { id: req.params.id });
  invalidateEntries();
  invalidateStats();
  res.json({ ok: true });
});

app.post('/api/entries/:id/ai/revert', requireAuth, async (req, res) => {
  if (req.user.role !== 'admin') {
    const acc = await entryAccessible(req.user, req.params.id);
    if (!acc.found) return res.status(404).json({ error: 'Not found' });
    if (!acc.allowed) return res.status(403).json({ error: 'Нет доступа к этой записи' });
  }
  const { rows } = await pool.query(
    `UPDATE entries SET description = description_original, description_ai = NULL,
       ai_status = 'reverted', ai_error = NULL, ai_checked_at = now()
     WHERE id = $1 AND description_original IS NOT NULL RETURNING id`,
    [req.params.id]
  );
  if (!rows.length) return res.status(400).json({ error: 'Оригинал текста недоступен' });
  await logAudit(req, 'entry.ai.revert', { id: req.params.id });
  invalidateEntries();
  invalidateStats();
  res.json({ ok: true });
});

app.get('/api/photo-jobs/status', requireAdmin, async (_, res) => {
  const { rows } = await pool.query(
    `SELECT status, count(*)::int AS n FROM photo_jobs GROUP BY status`
  );
  const counts = { pending: 0, processing: 0, done: 0, error: 0 };
  rows.forEach(r => { counts[r.status] = r.n; });
  const [pending, recent, errors] = await Promise.all([
    pool.query(
      `SELECT j.id, j.entry_id, j.action, j.created_at, e.student_name, g.name AS group_name
       FROM photo_jobs j
       JOIN entries e ON e.id = j.entry_id
       JOIN groups g ON g.id = e.group_id
       WHERE j.status IN ('pending', 'processing')
       ORDER BY j.id ASC LIMIT 20`
    ),
    pool.query(
      `SELECT j.id, j.entry_id, j.action, j.status, j.params, j.before_path, j.after_path, j.error, j.created_at, j.finished_at,
              e.student_name, g.name AS group_name
       FROM photo_jobs j
       JOIN entries e ON e.id = j.entry_id
       JOIN groups g ON g.id = e.group_id
       WHERE j.finished_at IS NOT NULL
       ORDER BY j.finished_at DESC LIMIT 30`
    ),
    pool.query(
      `SELECT j.id, j.entry_id, j.action, j.error, j.finished_at, e.student_name, g.name AS group_name
       FROM photo_jobs j
       JOIN entries e ON e.id = j.entry_id
       JOIN groups g ON g.id = e.group_id
       WHERE j.status = 'error'
       ORDER BY j.finished_at DESC NULLS LAST, j.id DESC LIMIT 20`
    ),
  ]);
  const enabled = String(await getSetting('photo_worker_enabled', 'true')) !== 'false';
  const service = await aiHealthCheck();
  res.json({
    enabled,
    ai_configured: !!PHOTO_AI_URL,
    ai_url: PHOTO_AI_URL,
    worker: photoWorker ? photoWorker.getInfo() : null,
    counts,
    pending: pending.rows,
    recent: recent.rows,
    errors: errors.rows,
  });
});

app.post('/api/photo-jobs/wake', requireAdmin, async (req, res) => {
  if (photoWorker) photoWorker.notify();
  await logAudit(req, 'photo-jobs.wake', {});
  res.json({ ok: true });
});

app.post('/api/photo-jobs/enabled', requireAdmin, async (req, res) => {
  const enabled = !!req.body?.enabled;
  await pool.query(
    `INSERT INTO settings (key, value) VALUES ('photo_worker_enabled', $1)
     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
    [enabled ? 'true' : 'false']
  );
  if (enabled && photoWorker) photoWorker.notify();
  await logAudit(req, 'photo-jobs.enabled', { enabled });
  res.json({ ok: true, enabled });
});

app.post('/api/photo-jobs/requeue-failed', requireAdmin, async (req, res) => {
  const { rowCount } = await pool.query(
    `UPDATE photo_jobs SET status = 'pending', error = NULL, finished_at = NULL
     WHERE status = 'error'`
  );
  if (photoWorker) photoWorker.notify();
  await logAudit(req, 'photo-jobs.requeue-failed', { count: rowCount });
  invalidateEntries();
  res.json({ ok: true, count: rowCount });
});

app.get('/api/trash', requireAuth, async (req, res) => {
  const { limit, offset } = req.query;
  const bw = branchScope(req.user);
  const scoped = req.user.role !== 'admin';
  let where = ' WHERE e.deleted_at IS NOT NULL';
  const params = [];
  if (scoped) {
    if (bw.ids.length) {
      where += ` AND g.branch_id IN (${bw.ids.map(id => `$${params.push(id)}`).join(',')})`;
    } else {
      where += ' AND 1 = 0';
    }
  }
  console.log(`[TRASH] User ${req.user.id} (${req.user.username}) role=${req.user.role} branch_ids=${JSON.stringify(bw.ids)} scoped=${scoped} where=${where} params=${JSON.stringify(params)}`);
  const { rows: crows } = await pool.query(
    `SELECT count(*)::int AS n FROM entries e JOIN groups g ON g.id = e.group_id ${where}`,
    params
  );
  const total = crows[0].n;
  let q = `SELECT e.*, g.name AS group_name FROM entries e
           JOIN groups g ON g.id = e.group_id
           ${where} ORDER BY e.deleted_at DESC`;
  const qparams = params.slice();
  const lim = parseInt(limit, 10);
  if (lim > 0) { qparams.push(lim); q += ` LIMIT $${qparams.length}`; }
  const off = parseInt(offset, 10);
  if (off > 0) { qparams.push(off); q += ` OFFSET $${qparams.length}`; }
  const { rows } = await pool.query(q, qparams);
  console.log(`[TRASH] Found ${rows.length} entries for user ${req.user.id}`);
  let files = {};
  if (rows.length) {
    const fRes = await pool.query(
      'SELECT id, entry_id, token, name FROM project_files WHERE entry_id = ANY($1) ORDER BY id',
      [rows.map(r => r.id)]
    );
    fRes.rows.forEach(f => { (files[f.entry_id] = files[f.entry_id] || []).push(f); });
  }
  rows.forEach(r => { r.files = files[r.id] || []; });
  res.json({ entries: rows, total });
});

app.delete('/api/trash', requireAuth, requireAdmin, async (req, res) => {
  const { rows } = await pool.query(
    `SELECT photo_path AS p FROM entries WHERE deleted_at IS NOT NULL
     UNION ALL
     SELECT pf.path AS p FROM project_files pf
     JOIN entries e ON e.id = pf.entry_id WHERE e.deleted_at IS NOT NULL`
  );
  rows.forEach(r => safeUnlink(r.p));
  const d = await pool.query('DELETE FROM entries WHERE deleted_at IS NOT NULL');
  invalidateEntries();
  invalidateStats();
  res.json({ ok: true, deleted: d.rowCount });
});

// --- Error handlers ---
const ERROR_HTML = fs.readFileSync(path.join(__dirname, 'public', 'error.html'), 'utf8');

function isApiRoute(req) {
  return req.path.startsWith('/api/') || req.path.startsWith('/s/');
}

function escapeHtml(str) {
  return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;').replace(/'/g, '&#039;');
}

function renderErrorPage(code, title, message, details) {
  return ERROR_HTML
    .replace('id="errorCode">404', `id="errorCode">${code}`)
    .replace('id="errorTitle">Страница не найдена', `id="errorTitle">${title}`)
    .replace('id="errorMessage">Запрашиваемая страница не существует или была перемещена.', `id="errorMessage">${message}`)
    .replace('style="display:none"', details ? '' : 'style="display:none"')
    .replace('<pre id="errorStack"></pre>', details ? `<pre id="errorStack">${escapeHtml(details)}</pre>` : '<pre id="errorStack"></pre>');
}

app.use((req, res, next) => {
  if (isApiRoute(req)) {
    return res.status(404).json({ error: 'Not found' });
  }
  res.status(404).send(renderErrorPage(404, 'Страница не найдена', 'Запрашиваемая страница не существует или была перемещена.'));
});

app.use((err, req, res, next) => {
  console.error('Error:', err);
  if (isApiRoute(req)) {
    return res.status(500).json({ error: 'Internal server error' });
  }
  const msg = process.env.NODE_ENV === 'production' ? 'Произошла ошибка на сервере.' : (err?.message || 'Internal server error');
  const details = process.env.NODE_ENV === 'production' ? '' : (err?.stack || '');
  res.status(500).send(renderErrorPage(500, 'Ошибка сервера', msg, details));
});

const PORT = process.env.PORT || 3003;
const HTTPS_PORT = process.env.HTTPS_PORT || 3443;

process.on('unhandledRejection', (err) => { console.error('Unhandled rejection:', err); });
process.on('uncaughtException', (err) => { console.error('Uncaught exception:', err); });

const certPath = path.join(__dirname, 'certs', 'cert.pem');
const keyPath = path.join(__dirname, 'certs', 'key.pem');

if (fs.existsSync(certPath) && fs.existsSync(keyPath)) {
  const httpsServer = https.createServer({ key: fs.readFileSync(keyPath), cert: fs.readFileSync(certPath) }, app);
  httpsServer.listen(HTTPS_PORT, '0.0.0.0', () => console.log(`HTTPS : ${HTTPS_PORT}`));
  app.listen(PORT, '0.0.0.0', () => console.log(`HTTP  : ${PORT}`));
} else {
  app.listen(PORT, '0.0.0.0', () => console.log(`HTTP  : ${PORT} (no TLS certs)`));
}

(async () => {
  try { await ensureBranchesTable(); } catch (err) { console.error('Branches table:', err); }
  try { await ensureUsersAndFirstAdmin(); } catch (err) { console.error('Users table:', err); }
  try { await ensureAuditTable(); } catch (err) { console.error('Audit table:', err); }
  try { await ensureBannedIpsTable(); } catch (err) { console.error('Banned IPs table:', err); }
  try { await loadBans(); } catch (err) { console.error('Load bans:', err); }
  setInterval(() => { loadBans().catch(err => console.error('Load bans:', err)); }, 60 * 1000).unref();
  try { await ensureEntryPhotosTable(); } catch (err) { console.error('Entry photos table:', err); }
  try { await ensurePhotoOriginalColumn(); } catch (err) { console.error('Entry original photo column:', err); }
  try { await ensureEntryAiColumns(); } catch (err) { console.error('Entry AI columns:', err); }
  try { await ensurePhotoJobsTable(); } catch (err) { console.error('Photo jobs table:', err); }
  try { await sweepOrphanedUploads(); } catch (err) { console.error('Upload sweep:', err); }
  entryAutoChecker = createEntryAutoChecker({ pool, getSetting, logAudit, aiUrl: AI_URL, defaultPrompt: AI_DEFAULT_PROMPT });
  entryAutoChecker.start();
  console.log('AI auto-check worker started');
  photoWorker = createPhotoEnhanceWorker({
    pool,
    getSetting,
    logAudit,
    invalidateEntries,
    sharp,
    photoAiUrl: PHOTO_AI_URL,
    uploadsDir: UPLOADS_DIR,
    originalsDir: ORIGINALS_DIR,
  });
  photoWorker.start();
  console.log('Photo enhance worker started');
})();