// A native modal keeps the underlying page inert and provides keyboard dismissal.
// Links remain useful when JavaScript is unavailable or the browser lacks dialog.
export function installPhotoViewer(doc=document) {
 if(doc.documentElement.dataset.photoViewerInstalled)return;
 if(typeof HTMLDialogElement==='undefined'||typeof HTMLDialogElement.prototype.showModal!=='function')return;
 doc.documentElement.dataset.photoViewerInstalled='true';
 let active=null;
 doc.defaultView?.addEventListener('popstate',()=>active?.close());
 doc.addEventListener('click',event=>{
  if(event.defaultPrevented||event.button!==0||event.ctrlKey||event.metaKey||event.shiftKey||event.altKey)return;
  const trigger=event.target instanceof Element?event.target.closest('a[data-photo-viewer]'):null;
  if(!trigger)return;
  const thumbnail=trigger.querySelector('img');if(!thumbnail)return;
  const url=new URL(trigger.href,doc.baseURI);
  if(url.origin!==location.origin||!/^\/photography\/[a-z0-9/_-]+\.(?:png|jpe?g|webp)$/i.test(url.pathname))return;
  event.preventDefault();if(active)return;
  const dialog=doc.createElement('dialog');dialog.className='ar-photo-viewer';
  const toolbar=doc.createElement('header');toolbar.className='ar-photo-viewer-toolbar';
  const heading=doc.createElement('h2');heading.id='ar-photo-viewer-title';heading.textContent=trigger.dataset.photoModel||trigger.closest('[data-photo-model]')?.dataset.photoModel||'Product image';
  dialog.setAttribute('aria-labelledby',heading.id);
  const actions=doc.createElement('div');actions.className='ar-photo-viewer-actions';
  const button=(label,title)=>{const el=doc.createElement('button');el.type='button';el.textContent=label;el.title=title;return el;};
  const fit=button('Fit','Fit the complete image'),pixels=button('100%','View original image pixels'),close=button('Close ×','Close image viewer');
  fit.setAttribute('aria-pressed','true');pixels.setAttribute('aria-pressed','false');close.setAttribute('aria-label','Close image viewer');
  actions.append(fit,pixels,close);toolbar.append(heading,actions);
  const stage=doc.createElement('div');stage.className='ar-photo-viewer-stage';stage.tabIndex=0;stage.setAttribute('role','region');stage.setAttribute('aria-label','Product image. In 100% view, scroll to inspect the original image.');
  const picture=doc.createElement('img');picture.src=url.href;picture.alt=thumbnail.alt;picture.decoding='async';picture.draggable=false;
  const notice=doc.createElement('p');notice.className='ar-photo-viewer-error';notice.hidden=true;notice.textContent='This image could not be loaded. Close the viewer and try again.';notice.setAttribute('role','status');
  picture.addEventListener('error',()=>{picture.hidden=true;notice.hidden=false;fit.disabled=true;pixels.disabled=true;});
  stage.append(picture,notice);dialog.append(toolbar,stage);doc.body.append(dialog);active=dialog;
  const setNative=native=>{stage.classList.toggle('ar-photo-viewer-native',native);fit.setAttribute('aria-pressed',String(!native));pixels.setAttribute('aria-pressed',String(native));stage.scrollTop=0;stage.scrollLeft=0;};
  fit.addEventListener('click',()=>setNative(false));pixels.addEventListener('click',()=>setNative(true));
  close.addEventListener('click',()=>dialog.close());
  dialog.addEventListener('click',e=>{if(e.target===dialog){const rect=dialog.getBoundingClientRect();if(e.clientX<rect.left||e.clientX>rect.right||e.clientY<rect.top||e.clientY>rect.bottom)dialog.close();}});
  dialog.addEventListener('close',()=>{dialog.remove();doc.documentElement.classList.remove('ar-photo-viewer-open');active=null;if(trigger.isConnected)trigger.focus();},{once:true});
  doc.documentElement.classList.add('ar-photo-viewer-open');dialog.showModal();close.focus();
 });
}
if(typeof document!=='undefined')installPhotoViewer(document);