const PAGE_SIZE = 24;
let page = 1;
let totalPhotos = 0;
let currentPhotos = [];
let groupsLoaded = false;
let studentsLoaded = false;
let sourcesLoaded = false;
let searchTimer = null;

function humanSize(b) {
  if (!b) return '';
  if (b < 1024) return b + ' Б';
  if (b < 1048576) return (b / 1024).toFixed(1) + ' КБ';
  return (b / 1048576).toFixed(1) + ' МБ';
}

function photoLink(p) {
  if (p.source_type === 'entry') return `journal.html#entry-${p.source_id}`;
  if (p.source_type === 'entry_photo') return `journal.html#entry-${p.source_id}`;
  if (p.source_type === 'group_photo') return 'groups.html';
  if (p.source_type === 'student_photo') return 'students.html';
  if (p.source_type === 'module_photo') return 'modules.html';
  return '';
}

function photoCardHTML(p) {
  const url = p.path;
  const meta = [];
  if (p.student_name) meta.push(esc(p.student_name));
  if (p.group_name) meta.push(esc(p.group_name));
  const link = photoLink(p);
  return `
    <div class="ph-card">
      <img src="${esc(thumbSrc(url))}" data-img="${esc(url)}" loading="lazy" decoding="async" alt="">
      <div class="ph-body">
        <span class="ph-badge">${esc(p.source_label)}</span>
        <div class="ph-title">${esc(p.title || 'Без описания')}</div>
        ${meta.length ? `<div class="ph-meta">${meta.join(' · ')}</div>` : ''}
        <div class="ph-time">${fmtFull(p.created_at)}</div>
        ${link ? `<a class="ph-link" href="${link}">Открыть источник →</a>` : ''}
      </div>
    </div>
  `;
}

function renderGrid() {
  const grid = document.getElementById('grid');
  if (!currentPhotos.length) {
    grid.innerHTML = '<div class="empty" style="grid-column:1/-1">Фотографий не найдено</div>';
    return;
  }
  grid.innerHTML = currentPhotos.map(photoCardHTML).join('');
}

async function loadGroupOptions() {
  if (groupsLoaded) return;
  const sel = document.getElementById('groupFilter');
  while (sel.options.length > 1) sel.remove(1);
  const res = await fetch(`${API}/api/groups`, { headers: hdr() });
  const groups = await res.json();
  groups.forEach(g => {
    const o = document.createElement('option');
    o.value = g.id; o.textContent = g.name;
    sel.appendChild(o);
  });
  groupsLoaded = true;
}

async function loadStudentOptions() {
  if (studentsLoaded) return;
  const dl = document.getElementById('studentFilterList');
  const res = await fetch(`${API}/api/students/names`, { headers: hdr() });
  const names = await res.json();
  dl.innerHTML = names.map(n => `<option value="${esc(n)}">`).join('');
  studentsLoaded = true;
}

function fillSourceOptions() {
  if (sourcesLoaded) return;
  const sel = document.getElementById('sourceFilter');
  const labels = [];
  currentPhotos.forEach(p => { if (!labels.includes(p.source_label)) labels.push(p.source_label); });
  const known = ['Главное фото записи', 'Фото записи', 'Фотохроника группы', 'Фото ученика', 'Тема модуля'];
  known.concat(labels.filter(l => !known.includes(l))).forEach(label => {
    const o = document.createElement('option');
    o.value = label; o.textContent = label;
    sel.appendChild(o);
  });
  sourcesLoaded = true;
}

async function loadPhotos() {
  const p = new URLSearchParams();
  const q = document.getElementById('searchInput').value;
  const sn = document.getElementById('studentFilter').value;
  const gid = document.getElementById('groupFilter').value;
  const df = document.getElementById('dateFrom').value;
  const dt = document.getElementById('dateTo').value;
  if (q) p.set('search', q);
  if (sn) p.set('student_name', sn);
  if (gid) p.set('group_id', gid);
  if (df) p.set('date_from', df);
  if (dt) p.set('date_to', dt);
  p.set('limit', PAGE_SIZE);
  p.set('offset', (page - 1) * PAGE_SIZE);
  const res = await fetch(`${API}/api/photos?${p}`, { headers: hdr() });
  if (!res.ok) {
    document.getElementById('grid').innerHTML = '<div class="empty" style="grid-column:1/-1">Не удалось загрузить фотографии</div>';
    return;
  }
  const data = await res.json();
  const srcFilter = document.getElementById('sourceFilter').value;
  currentPhotos = srcFilter ? data.photos.filter(x => x.source_label === srcFilter) : data.photos;
  totalPhotos = srcFilter ? currentPhotos.length : data.total;
  fillSourceOptions();
  renderGrid();
  renderPager(document.getElementById('pager'), page, Math.max(1, Math.ceil(totalPhotos / PAGE_SIZE)), goPage);
}

function goPage(p) {
  page = p;
  loadPhotos();
}

document.getElementById('studentFilter').addEventListener('change', () => { page = 1; loadPhotos(); });
document.getElementById('groupFilter').addEventListener('change', () => { page = 1; loadPhotos(); });
document.getElementById('sourceFilter').addEventListener('change', () => { page = 1; loadPhotos(); });
document.getElementById('dateFrom').addEventListener('change', () => { page = 1; loadPhotos(); });
document.getElementById('dateTo').addEventListener('change', () => { page = 1; loadPhotos(); });
document.getElementById('searchInput').addEventListener('input', () => {
  clearTimeout(searchTimer);
  searchTimer = setTimeout(() => { page = 1; loadPhotos(); }, 300);
});

document.getElementById('imgModal').addEventListener('click', e => e.currentTarget.classList.remove('open'));

(async () => {
  if (await checkAuth()) {
    buildSidebar('photos');
    await loadGroupOptions();
    await loadStudentOptions();
    loadPhotos();
  }
})();