function esc(s){return String(s==null?'':s).replace(/&/g,'&').replace(/</g,'<').replace(/>/g,'>').replace(/"/g,'"')}
function fmt(d){return d?d.split('-').reverse().join('.'):'весь период'}
function showImg(src){document.getElementById('lightboxImg').src=src;document.getElementById('lightbox').classList.add('open')}
function isImageFile(name){return /\.(jpe?g|png|gif|webp|bmp|avif|svg|ico)$/i.test(name||'')}
function thumbSrc(p){
  if(!p)return p;
  if(p.startsWith('/uploads/'))return '/uploads/thumb/'+p.slice('/uploads/'.length);
  if(p.includes('/api/files/'))return p+(p.includes('?')?'&':'?')+'thumb=1';
  return p;
}

let countdownInterval = null;
let countdownTarget = null;
let countdownScrollHandler = null;

function formatRemaining(ms) {
  if (ms <= 0) return null;
  const totalSec = Math.floor(ms / 1000);
  const days = Math.floor(totalSec / 86400);
  const hours = Math.floor((totalSec % 86400) / 3600);
  const minutes = Math.floor((totalSec % 3600) / 60);
  const seconds = totalSec % 60;

  const parts = [];
  if (days > 0) parts.push(`${days} ${declension(days, 'день', 'дня', 'дней')}`);
  if (hours > 0) parts.push(`${hours} ${declension(hours, 'час', 'часа', 'часов')}`);
  if (minutes > 0) parts.push(`${minutes} ${declension(minutes, 'минута', 'минуты', 'минут')}`);
  if (days === 0) parts.push(`${seconds} ${declension(seconds, 'секунда', 'секунды', 'секунд')}`);
  return parts.join(' ');
}

function declension(n, one, few, many) {
  const mod10 = n % 10;
  const mod100 = n % 100;
  if (mod100 >= 11 && mod100 <= 19) return many;
  if (mod10 === 1) return one;
  if (mod10 >= 2 && mod10 <= 4) return few;
  return many;
}

function shouldShowCountdown() {
  const hero = document.querySelector('.hero');
  if (!hero) return true;
  return window.scrollY > hero.offsetHeight - 80;
}

function syncCountdownVisibility() {
  const el = document.getElementById('countdown');
  if (!countdownTarget) { el.classList.remove('visible'); return; }
  if (countdownTarget - Date.now() <= 0) { el.classList.remove('visible'); return; }
  if (shouldShowCountdown()) el.classList.add('visible');
  else el.classList.remove('visible');
}

function updateCountdown() {
  const el = document.getElementById('countdown');
  if (!countdownTarget) { el.classList.remove('visible'); return; }
  const now = Date.now();
  const remaining = countdownTarget - now;
  if (remaining <= 0) {
    el.classList.remove('visible');
    if (countdownInterval) { clearInterval(countdownInterval); countdownInterval = null; }
    return;
  }
  const text = formatRemaining(remaining);
  if (!text) { el.classList.remove('visible'); return; }
  el.classList.remove('warn', 'urgent');
  if (remaining < 3600000) el.classList.add('urgent');
  else if (remaining < 86400000) el.classList.add('warn');
  el.querySelector('.cd-text').innerHTML = `Ссылка доступна ещё <strong>${text}</strong>`;
  syncCountdownVisibility();
}

function startCountdown(expiresAt) {
  if (countdownInterval) { clearInterval(countdownInterval); countdownInterval = null; }
  if (countdownScrollHandler) { window.removeEventListener('scroll', countdownScrollHandler); countdownScrollHandler = null; }
  const el = document.getElementById('countdown');
  if (!expiresAt) { el.classList.remove('visible'); return; }
  countdownTarget = new Date(expiresAt).getTime();
  countdownScrollHandler = syncCountdownVisibility;
  window.addEventListener('scroll', countdownScrollHandler, { passive: true });
  updateCountdown();
  countdownInterval = setInterval(updateCountdown, 1000);
}

function fileType(name){
  if(/\.(jpe?g|png|gif|webp|bmp|avif|svg|ico)$/i.test(name||'')) return 'image';
  if(/\.(mp3|wav|ogg|flac|m4a|aac|opus)$/i.test(name||'')) return 'music';
  if(/\.(pptx?|odp|key)$/i.test(name||'')) return 'presentation';
  if(/\.(pdf|docx?|xlsx?|txt|rtf|odt|ods|csv|md)$/i.test(name||'')) return 'document';
  return 'other';
}
function fileIcon(t){
  const icons = {image:'🖼️',music:'🎵',presentation:'📊',document:'📄',other:'📁'};
  return icons[t]||icons.other;
}
function filesHTML(files, password, shareToken){
  if(!files||!files.length)return '';
  const pw = password ? `?password=${encodeURIComponent(password)}` : '';
  return `<div class="files-block">
    <div class="files-label">Работы резидента</div>
    <div class="files">${files.map(f=>{
      const t = fileType(f.name);
      const url = `/api/share/${shareToken}/files/${f.token}${pw}`;
      return `<a class="ftype-${t}" title="${esc(f.name)}" ${isImageFile(f.name)
        ?`href="#" data-img="${esc(url)}"`
        :`href="${url}" download`}>
        <span class="ficon" alt="${esc(f.name)}">${fileIcon(t)}</span>
      </a>`;
    }).join('')}</div>
  </div>`;
}

let currentToken = '';
let currentPassword = null;

async function fetchShareData(token, password) {
  const headers = {};
  if (password) headers['x-share-password'] = password;
  const res = await fetch('/api/share/' + token, { headers });
  const data = await res.json().catch(() => ({}));
  return { ok: res.ok, status: res.status, data };
}

async function loadShare() {
  const token = location.pathname.split('/').filter(Boolean).pop() || '';
  currentToken = token;
  currentPassword = null;

  const tryLoad = async (pwd) => {
    const result = await fetchShareData(token, pwd);
    if (result.ok) {
      renderShare(result.data, pwd);
      return true;
    }
    if (result.status === 401 && result.data.passwordRequired) {
      showPasswordModal();
      return false;
    }
    if (result.status === 410) {
      showError('Срок действия ссылки истёк');
      return true;
    }
    showError('Ссылка не найдена или была удалена');
    return true;
  };

  await tryLoad(null);
}

function showPasswordModal() {
  document.getElementById('passwordInput').value = '';
  document.getElementById('passwordModal').classList.add('open');
  document.getElementById('passwordInput').focus();
}

function hidePasswordModal() {
  document.getElementById('passwordModal').classList.remove('open');
}

async function submitPassword() {
  const pwd = document.getElementById('passwordInput').value;
  if (!pwd) return;
  const result = await fetchShareData(currentToken, pwd);
  if (result.ok) {
    hidePasswordModal();
    currentPassword = pwd;
    renderShare(result.data, pwd);
  } else {
    alert('Неверный пароль');
    document.getElementById('passwordInput').value = '';
    document.getElementById('passwordInput').focus();
  }
}

function showError(msg) {
  document.getElementById('title').textContent = msg;
  document.getElementById('grid').innerHTML = `<div class="empty"><div class="big">🤔</div>${esc(msg)}</div>`;
  document.getElementById('photosBlock').style.display = 'none';
  document.getElementById('shareMessage').style.display = 'none';
  document.getElementById('shareLinkBlock').style.display = 'none';
  document.getElementById('countdown').classList.remove('visible');
  if (countdownInterval) { clearInterval(countdownInterval); countdownInterval = null; }
  if (countdownScrollHandler) { window.removeEventListener('scroll', countdownScrollHandler); countdownScrollHandler = null; }
}

function renderShare(data, password) {
  const heading = data.group_name || data.name || 'Записи занятий';
  document.title = heading;
  document.getElementById('title').textContent = heading;
  const chips = [];
  if (data.group_name) chips.push(`Группа: <b>${esc(data.group_name)}</b>`);
  if (data.date_from || data.date_to) chips.push(`Период: <b>${fmt(data.date_from)}</b> — <b>${fmt(data.date_to)}</b>`);
  document.getElementById('chips').innerHTML = chips.map(c => `<span class="chip">${c}</span>`).join('');

  startCountdown(data.expires_at);

  const msgEl = document.getElementById('shareMessage');
  if (data.message) {
    msgEl.textContent = data.message;
    msgEl.style.display = 'block';
  } else {
    msgEl.style.display = 'none';
  }

  const linkBlock = document.getElementById('shareLinkBlock');
  linkBlock.innerHTML = '';
  if (data.link_url && /^https?:\/\//i.test(data.link_url)) {
    const a = document.createElement('a');
    a.className = 'share-link-btn';
    a.href = data.link_url;
    a.target = '_blank';
    a.rel = 'noopener noreferrer';
    a.textContent = '🔗 Перейти по ссылке';
    linkBlock.appendChild(a);
    linkBlock.style.display = 'block';
  } else {
    linkBlock.style.display = 'none';
  }

  const pb = document.getElementById('photosBlock');
  if (data.show_group_photos && data.photos && data.photos.length) {
    document.getElementById('photosGrid').innerHTML = data.photos.map(p => `
      <a class="gphoto" href="#" data-img="${esc(p.photo_path)}">
        <img src="${thumbSrc(p.photo_path)}" alt="${esc(p.caption || '')}" loading="lazy" decoding="async">
        ${p.caption ? `<div class="gcap">${esc(p.caption)}</div>` : ''}
      </a>
    `).join('');
    pb.style.display = 'block';
  } else {
    pb.style.display = 'none';
  }

  const grid = document.getElementById('grid');
  if (!data.entries.length) {
    grid.innerHTML = '<div class="empty"><div class="big">🎈</div>Записей пока нет</div>';
    return;
  }
  const isAnonymized = !data.show_student_names;
  const showStudentMessage = !!data.show_student_message;
  const showEntryDate = !!data.show_entry_date;
  grid.innerHTML = data.entries.map(e => `
    <div class="card">
      <div class="photo">
        ${e.photo_path
          ? `<img src="${thumbSrc(e.photo_path)}" data-img="${esc(e.photo_path)}" loading="lazy" decoding="async" alt="">`
          : `<div class="no-photo"><svg viewBox="0 0 240 160" preserveAspectRatio="xMidYMid meet" aria-hidden="true"><circle cx="105" cy="48" r="15"/><path d="M74 140 C74 106 88 92 105 92 C122 92 136 106 136 140 Z"/><circle cx="145" cy="58" r="18"/><path d="M108 144 C108 104 124 88 145 88 C166 88 182 104 182 144 Z"/></svg></div>`}
      </div>
      <div class="body">
        ${!isAnonymized ? `<div class="name">${esc(e.student_name)}</div>` : ''}
        ${!isAnonymized && e.group_name ? `<div><span class="group">${esc(e.group_name)}</span></div>` : ''}
        ${showStudentMessage && e.description ? `<div class="desc">${esc(e.description)}</div>` : ''}
        ${filesHTML(e.files, password, currentToken)}
      </div>
      ${showEntryDate ? `<div class="foot">${new Date(e.created_at).toLocaleString('ru',{day:'2-digit',month:'2-digit',year:'numeric',hour:'2-digit',minute:'2-digit'})}</div>` : ''}
    </div>
  `).join('');
}

document.getElementById('lightbox').addEventListener('click', () => document.getElementById('lightbox').classList.remove('open'));
document.getElementById('passwordModal').querySelector('button').addEventListener('click', submitPassword);

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

(async()=>{
  await loadShare();
})();