/* Nekochan Gallery — lightbox + keyboard nav */
(function() {
  'use strict';

  const lb       = document.getElementById('lightbox');
  const lbImg    = document.getElementById('lb-img');
  const lbCap    = document.getElementById('lb-caption');
  const lbClose  = document.getElementById('lb-close');
  const lbPrev   = document.getElementById('lb-prev');
  const lbNext   = document.getElementById('lb-next');

  if (!lb) return;

  let items = [];
  let current = 0;

  function open(index) {
    current = index;
    const item = items[current];
    lbImg.src = item.full;
    lbImg.alt = item.caption;
    lbCap.textContent = item.caption;
    lb.classList.add('active');
    document.body.style.overflow = 'hidden';
    lbPrev.style.visibility = current > 0 ? 'visible' : 'hidden';
    lbNext.style.visibility = current < items.length - 1 ? 'visible' : 'hidden';
  }

  function closeLb() {
    lb.classList.remove('active');
    document.body.style.overflow = '';
    lbImg.src = '';
  }

  function prev() { if (current > 0) open(current - 1); }
  function next() { if (current < items.length - 1) open(current + 1); }

  // Build item list from photo grid
  document.querySelectorAll('.photo-thumb-link').forEach(function(a, i) {
    items.push({ full: a.dataset.full, caption: a.dataset.caption || '' });
    a.addEventListener('click', function(e) {
      e.preventDefault();
      open(i);
    });
  });

  lbClose.addEventListener('click', closeLb);
  lbPrev.addEventListener('click', prev);
  lbNext.addEventListener('click', next);

  lb.addEventListener('click', function(e) {
    if (e.target === lb) closeLb();
  });

  document.addEventListener('keydown', function(e) {
    if (!lb.classList.contains('active')) return;
    if (e.key === 'Escape') closeLb();
    if (e.key === 'ArrowLeft') prev();
    if (e.key === 'ArrowRight') next();
  });

  // Touch swipe support
  let touchStartX = null;
  lb.addEventListener('touchstart', function(e) {
    touchStartX = e.touches[0].clientX;
  }, { passive: true });
  lb.addEventListener('touchend', function(e) {
    if (touchStartX === null) return;
    const dx = e.changedTouches[0].clientX - touchStartX;
    if (Math.abs(dx) > 50) { dx < 0 ? next() : prev(); }
    touchStartX = null;
  }, { passive: true });
})();