(function () {
  var currentArtId = null;
  var currentImageIdx = null;

  var mainContent = document.getElementById('main-content');
  var infoOverlay = document.getElementById('info-overlay');
  var infoContent = document.getElementById('info-overlay-content');
  var closeInfo = document.getElementById('close-info');
  var prevArt = document.getElementById('prev-art');
  var nextArt = document.getElementById('next-art');
  var imageOverlay = document.getElementById('image-overlay');
  var fullscreenImage = document.getElementById('fullscreen-image');
  var navHome = document.getElementById('nav-home');
  var navDocs = document.getElementById('nav-docs');
  var homeLink = document.getElementById('home-link');

  function getArtIndex(id) {
    for (var i = 0; i < DATA.arts.length; i++) {
      if (DATA.arts[i].id === id) return i;
    }
    return -1;
  }

  function getArtById(id) {
    for (var i = 0; i < DATA.arts.length; i++) {
      if (DATA.arts[i].id === id) return DATA.arts[i];
    }
    return null;
  }

  function formatParagraphs(text) {
    var parts = text.split('\n\n');
    var result = '';
    for (var i = 0; i < parts.length; i++) {
      var p = parts[i].trim();
      if (p) {
        result += '<p>' + p.replace(/\n/g, '<br>') + '</p>';
      }
    }
    return result;
  }

  function updateUrl() {
    var params = new URLSearchParams();
    if (currentArtId) {
      params.set('view', currentArtId);
      if (currentImageIdx !== null) {
        params.set('img', currentImageIdx);
      }
    }
    var qs = params.toString();
    var url = qs ? '?' + qs : window.location.pathname;
    window.history.replaceState(null, '', url);
  }

  function parseUrl() {
    var params = new URLSearchParams(window.location.search);
    return {
      view: params.get('view'),
      img: params.get('img') !== null ? parseInt(params.get('img'), 10) : null
    };
  }

  function renderMainPage() {
    var html = '<section id="overview">' + formatParagraphs(DATA.overview) + '</section>';
    html += '<section id="gallery"><div class="section-header" style="border-bottom:1px solid #222;padding-bottom:0.5rem;margin-bottom:1.5rem;color:#666;font-size:0.85rem;">ARTWORK</div><div class="art-grid">';

    for (var i = 0; i < DATA.arts.length; i++) {
      var art = DATA.arts[i];
      html += '<div class="art-card" data-art-id="' + art.id + '">' +
        '<img src="' + art.images[0] + '" alt="' + art.title.replace(/"/g, '&quot;') + '" loading="lazy">' +
        '<div class="art-title">' + art.title + '</div></div>';
    }

    html += '</div></section>';
    mainContent.innerHTML = html;

    var cards = document.querySelectorAll('.art-card');
    for (var i = 0; i < cards.length; i++) {
      cards[i].addEventListener('click', function () {
        openInfoOverlay(this.dataset.artId);
      });
    }
  }

  function renderInfoOverlay(artId) {
    var art = getArtById(artId);
    if (!art) return;

    var isMulti = art.images.length > 1;
    var imagesHtml = '';
    for (var i = 0; i < art.images.length; i++) {
      imagesHtml += '<img src="' + art.images[i] + '" alt="' + art.title.replace(/"/g, '&quot;') + ' ' + (i + 1) + '" data-img-index="' + i + '">';
    }

    var html = '<h2>' + art.title + '</h2>' +
      '<div class="overlay-image-container' + (isMulti ? ' multi' : '') + '">' +
      imagesHtml + '</div>' +
      '<div class="description">' + formatParagraphs(art.description) + '</div>';

    infoContent.innerHTML = html;

    var imgs = infoContent.querySelectorAll('.overlay-image-container img');
    for (var i = 0; i < imgs.length; i++) {
      imgs[i].addEventListener('click', function (e) {
        e.stopPropagation();
        openImageOverlay(artId, parseInt(this.dataset.imgIndex, 10));
      });
    }

    var idx = getArtIndex(artId);
    prevArt.style.display = idx > 0 ? 'block' : 'none';
    nextArt.style.display = idx < DATA.arts.length - 1 ? 'block' : 'none';
  }

  function renderDocsView() {
    var html = '<div id="docs-view">' +
      '<div class="docs-tree">' +
      '<div class="folder-label">docs/</div><ul>';

    for (var i = 0; i < DATA.docFiles.length; i++) {
      var doc = DATA.docFiles[i];
      html += '<li data-file="' + doc.filename.replace(/"/g, '&quot;') + '">' +
        doc.filename + '<span class="type-badge">' + (doc.type || '?') + '</span></li>';
    }

    html += '</ul></div>' +
      '<div class="docs-content">' +
      '<pre id="docs-content-pre">Select a file to view</pre>' +
      '</div></div>';

    mainContent.innerHTML = html;

    var items = document.querySelectorAll('.docs-tree li');
    for (var i = 0; i < items.length; i++) {
      items[i].addEventListener('click', function () {
        var active = document.querySelectorAll('.docs-tree li.active');
        for (var j = 0; j < active.length; j++) {
          active[j].classList.remove('active');
        }
        this.classList.add('active');
        var filename = this.dataset.file;
        for (var k = 0; k < DATA.docFiles.length; k++) {
          if (DATA.docFiles[k].filename === filename) {
            document.getElementById('docs-content-pre').textContent = DATA.docFiles[k].raw;
            break;
          }
        }
      });
    }
  }

  function openInfoOverlay(artId, imgIdx) {
    currentArtId = artId;
    currentImageIdx = (imgIdx !== undefined && imgIdx !== null) ? imgIdx : null;
    renderInfoOverlay(artId);
    infoOverlay.classList.remove('hidden');

    if (currentImageIdx !== null) {
      openImageOverlay(artId, currentImageIdx);
    } else {
      imageOverlay.classList.add('hidden');
    }

    updateUrl();
  }

  function closeInfoOverlay() {
    currentArtId = null;
    currentImageIdx = null;
    infoOverlay.classList.add('hidden');
    imageOverlay.classList.add('hidden');
    updateUrl();
  }

  function openImageOverlay(artId, idx) {
    var art = getArtById(artId);
    if (!art || !art.images[idx]) return;

    fullscreenImage.src = art.images[idx];
    imageOverlay.classList.remove('hidden');
    currentImageIdx = idx;
    updateUrl();
  }

  function closeImageOverlay() {
    imageOverlay.classList.add('hidden');
    currentImageIdx = null;
    updateUrl();
  }

  function navigateArt(direction) {
    var idx = getArtIndex(currentArtId);
    if (idx === -1) return;
    var newIdx = idx + direction;
    if (newIdx < 0 || newIdx >= DATA.arts.length) return;
    openInfoOverlay(DATA.arts[newIdx].id);
  }

  function goHome() {
    closeInfoOverlay();
    currentArtId = null;
    currentImageIdx = null;
    renderMainPage();
    updateUrl();
  }

  function goDocs() {
    closeInfoOverlay();
    renderDocsView();
    currentArtId = null;
    currentImageIdx = null;
    updateUrl();
  }

  closeInfo.addEventListener('click', closeInfoOverlay);

  prevArt.addEventListener('click', function () { navigateArt(-1); });
  nextArt.addEventListener('click', function () { navigateArt(1); });

  imageOverlay.addEventListener('click', function (e) {
    if (e.target === imageOverlay || e.target === fullscreenImage) {
      closeImageOverlay();
    }
  });

  navHome.addEventListener('click', function (e) {
    e.preventDefault();
    goHome();
  });

  navDocs.addEventListener('click', function (e) {
    e.preventDefault();
    goDocs();
  });

  homeLink.addEventListener('click', function (e) {
    if (!infoOverlay.classList.contains('hidden') ||
        mainContent.querySelector('#docs-view')) {
      e.preventDefault();
      goHome();
    }
  });

  document.addEventListener('keydown', function (e) {
    if (!infoOverlay.classList.contains('hidden')) {
      if (e.key === 'Escape') {
        if (!imageOverlay.classList.contains('hidden')) {
          closeImageOverlay();
        } else {
          closeInfoOverlay();
        }
      } else if (e.key === 'ArrowLeft') {
        navigateArt(-1);
      } else if (e.key === 'ArrowRight') {
        navigateArt(1);
      }
    }
  });

  function init() {
    var params = parseUrl();

    if (params.view === 'docs') {
      renderDocsView();
    } else if (params.view && getArtById(params.view)) {
      renderMainPage();
      openInfoOverlay(params.view, params.img);
    } else {
      renderMainPage();
    }
  }

  init();
})();