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; }

// --- 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' },
    { page: 'journal', label: 'Журнал' },
    { page: 'trash', label: 'Корзина' },
    { page: 'files', label: 'Файлы' },
    { page: 'links', label: 'Ссылки' },
    { page: 'students', label: 'Ученики' },
    { page: 'groups', label: 'Группы' },
  ];
  const adminNav = [
    { page: 'branches', label: 'Филиалы' },
    { page: 'users', label: 'Пользователи' },
    { page: 'audit', label: 'Аудит' },
    { page: 'worker', label: 'Воркер ИИ' },
    { page: 'settings', label: 'Настройки' },
  ];
  const nav = [...base, ...(isAdmin() ? adminNav : [])];
  const userName = currentUser?.name || currentUser?.username || '';
  const roleLabel = isAdmin() ? 'Администратор' : 'Тутор';
  el.innerHTML = `
    <div class="logo">Админ-панель</div>
    <div class="user-box">
      <div class="user-name">${esc(userName)}</div>
      <div class="user-role">${roleLabel}</div>
    </div>
    <nav>
      ${nav.map(n => `<a href="${n.page}.html" class="${n.page === active ? 'active' : ''}">${n.label}</a>`).join('')}
    </nav>
    <div class="bottom">
      <a href="/">На главную</a>
      <a class="logout" href="#" data-action="logout">Выйти</a>
    </div>`;
}

// --- Common UI ---
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(); }
});