/**
 * Bildvorschau für Anhänge im Ticket: Ein Klick auf ein Vorschaubild zeigt das Bild groß über der Seite, ohne es herunterzuladen.
 * Pfeil links/rechts (oder die Knöpfe) blättern durch alle Bilder des Tickets, Esc oder ein Klick daneben schließt. Ohne JavaScript
 * öffnet der Link das Bild wie bisher in einem neuen Tab.
 */
(function () {
  'use strict';
  var links = Array.prototype.slice.call(document.querySelectorAll('a[data-lightbox]'));
  if (!links.length) return;

  var EN = /^en/i.test(document.documentElement.lang || '');
  var TXT = EN ? { dialog: 'Image preview', prev: 'Previous image (←)', next: 'Next image (→)', download: '⬇ Download', close: '✕ Close', closeTitle: 'Close (Esc)' }
               : { dialog: 'Bildvorschau', prev: 'Vorheriges Bild (←)', next: 'Nächstes Bild (→)', download: '⬇ Herunterladen', close: '✕ Schließen', closeTitle: 'Schließen (Esc)' };
  var overlay = null, img = null, caption = null, counter = null, index = 0;

  function build() {
    overlay = document.createElement('div');
    overlay.setAttribute('role', 'dialog');
    overlay.setAttribute('aria-modal', 'true');
    overlay.setAttribute('aria-label', TXT.dialog);
    overlay.style.cssText = 'position:fixed;inset:0;z-index:2147483500;background:rgba(2,6,23,.88);display:none;flex-direction:column;align-items:center;justify-content:center;padding:16px;gap:10px';
    img = document.createElement('img');
    img.alt = '';
    img.style.cssText = 'max-width:96vw;max-height:80vh;object-fit:contain;border-radius:6px;background:#fff;box-shadow:0 10px 40px rgba(0,0,0,.5)';
    caption = document.createElement('div');
    caption.style.cssText = 'color:#e2e8f0;font:14px system-ui,sans-serif;text-align:center;max-width:90vw;word-break:break-all';
    counter = document.createElement('span');
    counter.style.cssText = 'color:#94a3b8;margin-left:8px';
    var bar = document.createElement('div');
    bar.style.cssText = 'display:flex;gap:8px;flex-wrap:wrap;justify-content:center';
    function btn(label, title, fn) {
      var b = document.createElement('button');
      b.type = 'button';
      b.textContent = label;
      b.title = title;
      b.style.cssText = 'background:#1e293b;color:#fff;border:1px solid #475569;border-radius:8px;padding:7px 14px;cursor:pointer;font:600 14px system-ui,sans-serif';
      b.addEventListener('click', function (e) { e.stopPropagation(); fn(); });
      return b;
    }
    var download = document.createElement('a');
    download.textContent = TXT.download;
    download.style.cssText = 'background:#1e293b;color:#fff;border:1px solid #475569;border-radius:8px;padding:7px 14px;text-decoration:none;font:600 14px system-ui,sans-serif';
    download.addEventListener('click', function (e) { e.stopPropagation(); });
    overlay._download = download;
    bar.appendChild(btn('‹', TXT.prev, function () { show(index - 1); }));
    bar.appendChild(btn('›', TXT.next, function () { show(index + 1); }));
    bar.appendChild(download);
    bar.appendChild(btn(TXT.close, TXT.closeTitle, close));
    caption.appendChild(document.createTextNode(''));
    overlay.appendChild(img);
    overlay.appendChild(caption);
    overlay.appendChild(bar);
    overlay.addEventListener('click', close);
    document.body.appendChild(overlay);
  }

  function show(i) {
    if (!links.length) return;
    index = (i + links.length) % links.length;
    var a = links[index];
    img.src = a.getAttribute('href');
    img.alt = a.getAttribute('title') || '';
    caption.textContent = a.getAttribute('title') || '';
    counter.textContent = links.length > 1 ? '(' + (index + 1) + ' / ' + links.length + ')' : '';
    caption.appendChild(counter);
    overlay._download.href = a.getAttribute('data-download') || a.getAttribute('href');
    overlay._download.setAttribute('download', a.getAttribute('title') || '');
  }

  function open(i) {
    if (!overlay) build();
    overlay.style.display = 'flex';
    document.body.style.overflow = 'hidden';
    show(i);
  }

  function close() {
    if (!overlay) return;
    overlay.style.display = 'none';
    img.removeAttribute('src');
    document.body.style.overflow = '';
  }

  links.forEach(function (a, i) {
    a.addEventListener('click', function (e) {
      if (e.ctrlKey || e.metaKey || e.shiftKey || e.button === 1) return; // neuer Tab bleibt möglich
      e.preventDefault();
      open(i);
    });
  });

  document.addEventListener('keydown', function (e) {
    if (!overlay || overlay.style.display === 'none') return;
    if (e.key === 'Escape') { e.preventDefault(); close(); }
    else if (e.key === 'ArrowLeft') { e.preventDefault(); show(index - 1); }
    else if (e.key === 'ArrowRight') { e.preventDefault(); show(index + 1); }
  });
})();