const API = location.origin;
let token = sessionStorage.getItem('authToken');
let currentUser = null;
function hdr() { return { 'X-Auth-Token': token }; }
function hdrJson() { return { 'Content-Type': 'application/json', 'X-Auth-Token': token }; }
function esc(s) { const d = document.createElement('div'); d.textContent = s; return d.innerHTML; }
function thumbSrc(p) {
  if (!p) return p;
  if (p.startsWith('/uploads/')) return `${API}/uploads/thumb/${p.slice('/uploads/'.length)}`;
  if (p.includes('/api/files/')) return p + (p.includes('?') ? '&' : '?') + 'thumb=1';
  return p;
}

// --- Auth check ---
async function checkAuth() {
  if (!token) { location.href = 'login.html'; return false; }
  try {
    const res = await fetch(`${API}/api/auth/me`, { headers: hdr() });
    if (!res.ok) { cleanupSession(); return false; }
    currentUser = await res.json();
    return true;
  } catch { cleanupSession(); return false; }
}

function cleanupSession() {
  sessionStorage.removeItem('authToken');
  token = null;
  currentUser = null;
  location.href = 'login.html';
}

function isAdmin() { return currentUser && currentUser.role === 'admin'; }

async function requireAdminPage() {
  if (!(await checkAuth())) return false;
  if (!isAdmin()) { location.href = 'journal.html'; return false; }
  return true;
}

async function doLogout() {
  try { await fetch(`${API}/api/auth/logout`, { method: 'POST', headers: hdr() }); } catch {}
  cleanupSession();
}

// --- Sidebar ---
function buildSidebar(active) {
  const el = document.getElementById('sidebar');
  if (!el) return;
  const base = [
    { page: 'dashboard', label: 'Дашборд', icon: 'layout-dashboard' },
    { page: 'journal', label: 'Журнал', icon: 'book-open' },
    { page: 'notifications', label: 'Уведомления', icon: 'bell', badge: true },
    { page: 'students', label: 'Ученики', icon: 'graduation-cap' },
    { page: 'groups', label: 'Группы', icon: 'users' },
    { page: 'photos', label: 'Фото', icon: 'Image' },
    { page: 'files', label: 'Файлы', icon: 'folder' },
    { page: 'links', label: 'Ссылки', icon: 'link' },
    { page: 'trash', label: 'Корзина', icon: 'trash-2' },
  ];
  const adminNav = [
    { page: 'modules', label: 'Темы модулей', icon: 'layers' },
    { page: 'branches', label: 'Филиалы', icon: 'building-2' },
    { page: 'users', label: 'Пользователи', icon: 'user-cog' },
    { page: 'worker', label: 'Воркер ИИ', icon: 'bot' },
    { page: 'audit', label: 'Аудит', icon: 'scroll-text' },
    { page: 'bans', label: 'Блокировки', icon: 'shield-off' },
    { page: 'settings', label: 'Настройки', icon: 'settings' },
  ];
  const userName = currentUser?.name || currentUser?.username || '';
  const roleLabel = isAdmin() ? 'Администратор' : 'Тутор';
  const renderItem = n => {
    const isAct = n.page === active;
    const badgeHtml = n.badge ? `<span class="sidebar-badge" id="sidebarNotifyBadge" ${notifyUnread > 0 ? '' : 'hidden'}>${notifyUnread > 99 ? '99+' : notifyUnread}</span>` : '';
    return `<a href="${n.page}.html" data-nav="${n.page}" class="${isAct ? 'active' : ''}" title="${n.label}">
      <i data-lucide="${n.icon}"></i>
      <span class="nav-text">${n.label}</span>
      ${badgeHtml}
    </a>`;
  };
  el.innerHTML = `
    <div class="logo">
      <span class="logo-ic" id="sidebarLogo"></span>
      <span id="sidebarName">Админ-панель</span>
    </div>
    <div class="user-box">
      <div class="user-avatar"><i data-lucide="${isAdmin() ? 'shield-check' : 'user'}"></i></div>
      <div class="user-meta">
        <div class="user-name" title="${esc(userName)}">${esc(userName)}</div>
        <div class="user-role">${roleLabel}</div>
      </div>
    </div>
    <div class="nav-scroll-wrap">
      <nav>
        <div class="nav-group">
          <div class="nav-group-title">Основное</div>
          <div class="nav-items">
            ${base.map(renderItem).join('')}
          </div>
        </div>
        ${isAdmin() ? `
        <div class="nav-group">
          <div class="nav-group-title">Администрирование</div>
          <div class="nav-items">
            ${adminNav.map(renderItem).join('')}
          </div>
        </div>` : ''}
      </nav>
    </div>
    <div class="bottom">
      <div class="bottom-actions">
        <a href="#" class="notify-bell" id="notifyBell" title="Быстрые уведомления">
          <i data-lucide="bell"></i>
          <span>Уведомления</span>
          <span class="notify-badge" id="notifyBadge" ${notifyUnread > 0 ? '' : 'hidden'}>${notifyUnread > 99 ? '99+' : notifyUnread}</span>
        </a>
        <a href="/" data-nav="home" title="Перейти на главную страницу">
          <i data-lucide="home"></i>
          <span>На главную</span>
        </a>
      </div>
      <div class="bottom-footer">
        <a class="logout-btn" href="#" data-action="logout" title="Выйти из аккаунта">
          <i data-lucide="log-out"></i>
          <span>Выйти</span>
        </a>
        <span class="version" id="sidebarVersion"></span>
      </div>
    </div>`;
  renderIcons();
  loadVersion();
  loadBrand();
  initNotifications();
}

async function loadBrand() {
  const logoEl = document.getElementById('sidebarLogo');
  const nameEl = document.getElementById('sidebarName');
  if (!logoEl || !nameEl) return;
  try {
    const res = await fetch(`${API}/api/public-settings`);
    if (!res.ok) return;
    const s = await res.json();
    if ((s.system_name || '').trim()) nameEl.textContent = s.system_name;
    if (s.system_logo) {
      const img = document.createElement('img');
      img.src = s.system_logo;
      img.alt = '';
      logoEl.classList.add('has-logo');
      logoEl.appendChild(img);
    }
  } catch {}
}

async function loadVersion() {
  const el = document.getElementById('sidebarVersion');
  if (!el) return;
  try {
    const res = await fetch(`${API}/version.json?t=${Date.now()}`);
    if (!res.ok) { el.textContent = ''; return; }
    const v = await res.json();
    if (!v.short) { el.textContent = ''; return; }
    const d = (v.date || '').slice(0, 10);
    el.textContent = `v${v.short}${d ? ' · ' + d : ''}`;
    el.title = `${v.short} · ${v.date || ''}`;
  } catch { el.textContent = ''; }
}

// --- Notifications ---
const NOTIFY_ICONS = {
  'entry.new': 'book-open',
  'entry.ai.corrected': 'sparkles',
  'entry.ai.error': 'bot',
  'photo.job.done': 'image',
  'photo.job.error': 'image-off',
  'ip.ban': 'shield-off',
  'backup.restore': 'database',
  'backup.create': 'download',
  'system.test': 'send',
};
const NOTIFY_LEVELS = { warning: 'Предупреждение', critical: 'Важно', info: '' };

let notifyList = [];
let notifyUnread = 0;
let notifyStream = null;
let notifyReconnectTimer = null;
let desktopNotify = localStorage.getItem('notifyDesktop') === '1';

function notifyIcon(type) { return NOTIFY_ICONS[type] || 'bell'; }

function attrEsc(s) { return esc(String(s === null || s === undefined ? '' : s).replace(/"/g, '&quot;')); }

function notifyTime(ts) {
  const d = new Date(ts);
  if (Number.isNaN(d.getTime())) return '';
  const diff = Date.now() - d.getTime();
  if (diff < 60000) return 'только что';
  if (diff < 3600000) return `${Math.floor(diff / 60000)} мин назад`;
  if (diff < 86400000) return `${Math.floor(diff / 3600000)} ч назад`;
  return d.toLocaleString('ru-RU', { day: '2-digit', month: '2-digit', hour: '2-digit', minute: '2-digit' });
}

function setNotifyUnread(n) {
  notifyUnread = Number(n) || 0;
  const badge = document.getElementById('notifyBadge');
  if (badge) {
    badge.textContent = notifyUnread > 99 ? '99+' : String(notifyUnread);
    badge.hidden = notifyUnread <= 0;
  }
  const navBadge = document.getElementById('sidebarNotifyBadge');
  if (navBadge) {
    navBadge.textContent = notifyUnread > 99 ? '99+' : String(notifyUnread);
    navBadge.hidden = notifyUnread <= 0;
  }
}

function notifyItemHtml(n, expanded) {
  const level = NOTIFY_LEVELS[n.level] ? ` level-${n.level}` : '';
  return `<a href="#" class="notify-item${n.read ? '' : ' unread'}${level}" data-notify-id="${n.id}" data-notify-link="${attrEsc(n.link || '')}">
    <span class="notify-ic"><i data-lucide="${notifyIcon(n.type)}"></i></span>
    <span class="notify-body">
      <span class="notify-title">${esc(n.title)}</span>
      ${n.body ? `<span class="notify-text">${esc(n.body)}</span>` : ''}
      <span class="notify-time">${esc(notifyTime(n.created_at))}</span>
    </span>
  </a>`;
}

function notifyPanelEl() {
  let panel = document.getElementById('notifyPanel');
  if (panel) return panel;
  panel = document.createElement('div');
  panel.className = 'notify-panel';
  panel.id = 'notifyPanel';
  panel.hidden = true;
  document.body.appendChild(panel);
  return panel;
}

function renderNotifyPanel() {
  const panel = notifyPanelEl();
  if (!panel) return;
  const items = notifyList.slice(0, 12);
  panel.innerHTML = `
    <div class="notify-head">
      <b>Уведомления</b>
      <button type="button" class="notify-link" id="notifyReadAll">Прочитать все</button>
    </div>
    <div class="notify-list">
      ${items.length ? items.map(n => notifyItemHtml(n, false)).join('') : '<div class="notify-empty">Пока уведомлений нет</div>'}
    </div>
    <div class="notify-foot">
      <a href="notifications.html">Все уведомления${notifyUnread ? ` (${notifyUnread})` : ''}</a>
      <button type="button" class="notify-link" id="notifyDesktopToggle">${desktopNotify ? 'В браузере: вкл' : 'В браузере: выкл'}</button>
    </div>`;
  renderIcons();
}

async function loadNotifications() {
  try {
    const res = await fetch(`${API}/api/notifications?limit=20`, { headers: hdr() });
    if (!res.ok) return;
    const data = await res.json();
    notifyList = data.items || [];
    setNotifyUnread(data.unread);
    renderNotifyPanel();
  } catch {}
}

function toggleNotifyPanel(force) {
  const panel = notifyPanelEl();
  if (!panel) return;
  const open = force === undefined ? panel.hidden : !!force;
  panel.hidden = !open;
  if (open) { renderNotifyPanel(); loadNotifications(); }
}
async function markNotifyRead(id) {
  const item = notifyList.find(n => n.id === id);
  if (item && !item.read) {
    item.read = true;
    setNotifyUnread(Math.max(0, notifyUnread - 1));
    renderNotifyPanel();
  }
  try { await fetch(`${API}/api/notifications/${id}/read`, { method: 'POST', headers: hdr() }); } catch {}
}

async function markAllNotifyRead() {
  try {
    const res = await fetch(`${API}/api/notifications/read-all`, { method: 'POST', headers: hdr() });
    if (!res.ok) return;
    notifyList.forEach(n => { n.read = true; });
    setNotifyUnread(0);
    renderNotifyPanel();
    if (typeof onNotifyListChanged === 'function') onNotifyListChanged();
  } catch {}
}

function showDesktopNotification(n) {
  if (!desktopNotify) return;
  if (typeof Notification === 'undefined' || Notification.permission !== 'granted') return;
  try {
    const note = new Notification(n.title, { body: n.body || '', tag: 'whatido-' + n.id });
    note.onclick = () => {
      window.focus();
      if (n.link) location.href = n.link;
      note.close();
    };
  } catch {}
}

async function toggleDesktopNotifications() {
  if (desktopNotify) {
    desktopNotify = false;
    localStorage.setItem('notifyDesktop', '0');
    renderNotifyPanel();
    return;
  }
  if (typeof Notification === 'undefined') { showToast('Браузер не поддерживает уведомления'); return; }
  let perm = Notification.permission;
  if (perm === 'default') {
    try { perm = await Notification.requestPermission(); } catch {}
  }
  if (perm !== 'granted') { showToast('Разрешение на уведомления не выдано'); return; }
  desktopNotify = true;
  localStorage.setItem('notifyDesktop', '1');
  renderNotifyPanel();
  showToast('Уведомления в браузере включены');
}

function handleIncomingNotification(n) {
  notifyList.unshift(n);
  if (notifyList.length > 40) notifyList.length = 40;
  setNotifyUnread(notifyUnread + 1);
  renderNotifyPanel();
  if (n.level === 'warning' || n.level === 'critical') showToast(n.title);
  showDesktopNotification(n);
  if (typeof onNotificationArrived === 'function') onNotificationArrived(n);
}

function connectNotifyStream() {
  if (notifyStream) { notifyStream.close(); notifyStream = null; }
  const connect = () => {
    const t = sessionStorage.getItem('authToken');
    if (!t) return;
    notifyStream = new EventSource(`${API}/api/notifications/stream?token=${encodeURIComponent(t)}`);
    notifyStream.addEventListener('ready', ev => {
      try { setNotifyUnread(JSON.parse(ev.data).unread); } catch {}
    });
    notifyStream.addEventListener('notification', ev => {
      let n = null;
      try { n = JSON.parse(ev.data); } catch { return; }
      if (!n || !n.id) return;
      handleIncomingNotification(n);
    });
    notifyStream.onerror = () => {
      if (notifyStream) { notifyStream.close(); notifyStream = null; }
      clearTimeout(notifyReconnectTimer);
      notifyReconnectTimer = setTimeout(connect, 5000);
    };
  };
  connect();
  window.addEventListener('beforeunload', () => { if (notifyStream) notifyStream.close(); });
}

function initNotifications() {
  const bell = document.getElementById('notifyBell');
  const panel = notifyPanelEl();
  if (!bell || !panel) return;
  bell.addEventListener('click', e => { e.preventDefault(); toggleNotifyPanel(); });
  panel.addEventListener('click', e => {
    if (e.target.closest('#notifyReadAll')) { markAllNotifyRead(); return; }
    if (e.target.closest('#notifyDesktopToggle')) { toggleDesktopNotifications(); return; }
    const item = e.target.closest('[data-notify-id]');
    if (!item) return;
    e.preventDefault();
    const id = parseInt(item.dataset.notifyId, 10);
    const link = item.dataset.notifyLink;
    toggleNotifyPanel(false);
    markNotifyRead(id);
    if (link) location.href = link;
  });
  document.addEventListener('click', e => {
    if (panel.hidden) return;
    if (e.target.closest('#notifyPanel') || e.target.closest('#notifyBell')) return;
    toggleNotifyPanel(false);
  });
  document.addEventListener('keydown', e => { if (e.key === 'Escape' && !panel.hidden) toggleNotifyPanel(false); });
  loadNotifications();
  connectNotifyStream();
}

// --- Common UI ---
function renderIcons() {
  if (window.lucide && typeof window.lucide.createIcons === 'function') {
    window.lucide.createIcons();
  }
}

function showToast(msg) {
  const t = document.getElementById('toast');
  if (!t) return;
  t.textContent = msg;
  t.classList.add('show');
  setTimeout(() => t.classList.remove('show'), 3000);
}

function showImg(src) {
  const img = document.getElementById('imgModalSrc');
  const m = document.getElementById('imgModal');
  if (img && m) { img.src = src; m.classList.add('open'); }
}

async function fillAutocomplete() {
  const res = await fetch(`${API}/api/students`, { headers: hdr() });
  const students = await res.json();
  const names = students.map(s => s.name);
  const dlEdit = document.getElementById('studentEditList');
  if (dlEdit) {
    dlEdit.innerHTML = '';
    names.forEach(n => { const o = document.createElement('option'); o.value = n; dlEdit.appendChild(o); });
  }
  const dlAdd = document.getElementById('studentAddList');
  if (dlAdd) {
    dlAdd.innerHTML = '';
    names.forEach(n => { const o = document.createElement('option'); o.value = n; dlAdd.appendChild(o); });
  }
}

function copyStudentLink(name) {
  const url = `${location.origin}/?nameInput=${encodeURIComponent(name)}`;
  const done = () => showToast('Ссылка скопирована: ' + url);
  if (navigator.clipboard && window.isSecureContext) {
    navigator.clipboard.writeText(url).then(done).catch(() => fallbackCopy(url, done));
  } else {
    fallbackCopy(url, done);
  }
}

function fallbackCopy(text, done) {
  const ta = document.createElement('textarea');
  ta.value = text;
  ta.style.position = 'fixed';
  ta.style.opacity = '0';
  document.body.appendChild(ta);
  ta.select();
  try { document.execCommand('copy'); done(); } catch { prompt('Скопируйте вручную:', text); }
  document.body.removeChild(ta);
}

function studentUrlContent(name) {
  const url = `${location.origin}/?nameInput=${encodeURIComponent(name)}`;
  return `[InternetShortcut]\r\nURL=${url}\r\n`;
}

function safeWindowsName(name) {
  return String(name).replace(/[\\/:*?"<>|]/g, '_').replace(/\s+/g, '_');
}

function downloadBlob(blob, filename) {
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = filename;
  a.click();
  URL.revokeObjectURL(url);
}

async function exportStudentUrlZip(students, zipName) {
  if (typeof JSZip === 'undefined') { alert('JSZip не загружен'); return; }
  const zip = new JSZip();
  students.forEach(s => {
    zip.file(safeWindowsName(s.name) + '.url', studentUrlContent(s.name));
  });
  const blob = await zip.generateAsync({ type: 'blob' });
  downloadBlob(blob, zipName);
}

function copyText(text) {
  const done = () => showToast('Скопировано: ' + text);
  if (navigator.clipboard && window.isSecureContext) {
    navigator.clipboard.writeText(text).then(done).catch(() => fallbackCopy(text, done));
  } else {
    fallbackCopy(text, done);
  }
}

function renderPager(el, page, totalPages, onPage) {
  if (!el) return;
  if (totalPages <= 1) { el.innerHTML = ''; return; }
  let html = `<button ${page === 1 ? 'disabled' : ''} data-nav="-1">‹</button>`;
  for (let i = 1; i <= totalPages; i++) {
    if (totalPages > 9 && i > 2 && i < totalPages - 1 && Math.abs(i - page) > 2) {
      if (i === 3) html += `<button disabled>…</button>`;
      continue;
    }
    html += `<button class="${i === page ? 'active' : ''}" data-page="${i}">${i}</button>`;
  }
  html += `<button ${page === totalPages ? 'disabled' : ''} data-nav="1">›</button>`;
  el.innerHTML = html;
  el._onPage = onPage;
  el._page = page;
  if (!el._bound) {
    el._bound = true;
    el.addEventListener('click', e => {
      const btn = e.target.closest('button');
      if (!btn || btn.disabled) return;
      const p = btn.dataset.page ? parseInt(btn.dataset.page, 10) : el._page + parseInt(btn.dataset.nav, 10);
      if (el._onPage) el._onPage(p);
    });
  }
}

document.addEventListener('click', e => {
  const imgEl = e.target.closest('[data-img]');
  if (imgEl) { e.preventDefault(); showImg(imgEl.dataset.img); return; }
  const out = e.target.closest('[data-action="logout"]');
  if (out) { e.preventDefault(); doLogout(); }
});