/* ========================================
   G1 Moves — Showcase App
   ======================================== */

(function () {
  'use strict';

  // ------------------------------------
  // State
  // ------------------------------------
  let allClips = [];
  let baseUrl = '';
  let activeCategory = 'all';
  const isMobile = window.matchMedia('(max-width: 480px)').matches;
  const PAGE_SIZE = 12;
  let currentPage = 0;

  // ------------------------------------
  // DOM refs
  // ------------------------------------
  const grid = document.getElementById('clip-grid');
  const emptyState = document.getElementById('empty-state');
  const modal = document.getElementById('pipeline-modal');

  // ------------------------------------
  // Init
  // ------------------------------------
  async function init() {
    try {
      const res = await fetch('data.json');
      const data = await res.json();
      allClips = data.clips;
      baseUrl = data.base_url;
      updateStats(data.stats);
      filterAndRender();
      setupCategoryButtons();
      setupModal();
      setupScrollReveal();
    } catch (err) {
      grid.innerHTML = '<p style="padding:2rem;color:#888;font-family:monospace;">Failed to load data.json</p>';
    }
  }

  // ------------------------------------
  // Stats
  // ------------------------------------
  function updateStats(stats) {
    setText('stat-total', stats.total);
    setText('stat-dance', stats.dance);
    setText('stat-karate', stats.karate);
    setText('stat-bonus', stats.bonus);
    setText('stat-policies', stats.policies);
  }

  function setText(id, value) {
    const el = document.getElementById(id);
    if (el) el.textContent = value;
  }

  // ------------------------------------
  // Filtering & Rendering
  // ------------------------------------
  let filteredClips = [];
  let carouselIndex = 0;

  function filterAndRender() {
    filteredClips = activeCategory === 'all'
      ? allClips.slice()
      : allClips.filter(c => c.category === activeCategory);

    // Prioritize trained models first
    filteredClips.sort(function (a, b) {
      if (a.has_policy && !b.has_policy) return -1;
      if (!a.has_policy && b.has_policy) return 1;
      return 0;
    });

    grid.innerHTML = '';
    currentPage = 0;
    emptyState.classList.toggle('visible', filteredClips.length === 0);

    // Remove any existing pagination
    var oldNav = document.getElementById('page-nav');
    if (oldNav) oldNav.remove();

    if (isMobile) {
      carouselIndex = 0;
      renderCarousel();
    } else {
      renderPage();
    }
  }

  function totalPages() {
    return Math.ceil(filteredClips.length / PAGE_SIZE);
  }

  function renderPage() {
    grid.innerHTML = '';
    var start = currentPage * PAGE_SIZE;
    var end = Math.min(start + PAGE_SIZE, filteredClips.length);
    var pageClips = filteredClips.slice(start, end);

    pageClips.forEach(function (clip, i) {
      var card = createCard(clip, start + i);
      grid.appendChild(card);
    });

    observeLazyImages();
    observeCardReveal();
    updatePageNav();

    // Scroll grid into view on page change
    if (currentPage > 0) {
      grid.scrollIntoView({ behavior: 'smooth', block: 'start' });
    }
  }

  function updatePageNav() {
    var oldNav = document.getElementById('page-nav');
    if (oldNav) oldNav.remove();

    var pages = totalPages();
    if (pages <= 1) return;

    var nav = document.createElement('div');
    nav.id = 'page-nav';
    nav.className = 'page-nav';

    // Prev button
    var prevBtn = document.createElement('button');
    prevBtn.className = 'page-nav-btn';
    prevBtn.disabled = currentPage === 0;
    prevBtn.innerHTML = '<svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="15 18 9 12 15 6"/></svg>';
    prevBtn.setAttribute('aria-label', 'Previous page');
    prevBtn.addEventListener('click', function () {
      if (currentPage > 0) { currentPage--; renderPage(); }
    });

    // Counter
    var counter = document.createElement('span');
    counter.className = 'page-nav-counter';
    counter.textContent = (currentPage + 1) + ' / ' + pages;

    // Next button
    var nextBtn = document.createElement('button');
    nextBtn.className = 'page-nav-btn';
    nextBtn.disabled = currentPage >= pages - 1;
    nextBtn.innerHTML = '<svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="9 18 15 12 9 6"/></svg>';
    nextBtn.setAttribute('aria-label', 'Next page');
    nextBtn.addEventListener('click', function () {
      if (currentPage < pages - 1) { currentPage++; renderPage(); }
    });

    nav.appendChild(prevBtn);
    nav.appendChild(counter);
    nav.appendChild(nextBtn);
    grid.parentNode.insertBefore(nav, grid.nextSibling);
  }

  // ------------------------------------
  // Mobile carousel
  // ------------------------------------
  function renderCarousel() {
    grid.innerHTML = '';
    if (!filteredClips.length) return;

    var wrap = document.createElement('div');
    wrap.className = 'carousel';

    // Counter
    var counter = document.createElement('div');
    counter.className = 'carousel-counter';
    wrap.appendChild(counter);

    // Card container
    var cardWrap = document.createElement('div');
    cardWrap.className = 'carousel-card-wrap';
    wrap.appendChild(cardWrap);

    // Nav buttons
    var nav = document.createElement('div');
    nav.className = 'carousel-nav';
    var prevBtn = document.createElement('button');
    prevBtn.className = 'carousel-btn';
    prevBtn.innerHTML = '&#8249;';
    prevBtn.setAttribute('aria-label', 'Previous');
    var nextBtn = document.createElement('button');
    nextBtn.className = 'carousel-btn';
    nextBtn.innerHTML = '&#8250;';
    nextBtn.setAttribute('aria-label', 'Next');
    nav.appendChild(prevBtn);
    nav.appendChild(nextBtn);
    wrap.appendChild(nav);

    grid.appendChild(wrap);

    function showCard(idx) {
      carouselIndex = idx;
      var clip = filteredClips[idx];
      counter.textContent = (idx + 1) + ' / ' + filteredClips.length;
      prevBtn.disabled = idx === 0;
      nextBtn.disabled = idx === filteredClips.length - 1;

      cardWrap.innerHTML = '';
      var card = createCard(clip, idx);
      card.classList.add('visible');
      cardWrap.appendChild(card);

      // Load preview media immediately
      var lazyMedia = card.querySelector('img[data-src], video[data-src]');
      if (lazyMedia && lazyMedia.dataset.src) {
        lazyMedia.src = lazyMedia.dataset.src;
        lazyMedia.removeAttribute('data-src');
      }
    }

    prevBtn.addEventListener('click', function () {
      if (carouselIndex > 0) showCard(carouselIndex - 1);
    });
    nextBtn.addEventListener('click', function () {
      if (carouselIndex < filteredClips.length - 1) showCard(carouselIndex + 1);
    });

    // Swipe support
    var touchStartX = 0;
    wrap.addEventListener('touchstart', function (e) {
      touchStartX = e.touches[0].clientX;
    }, { passive: true });
    wrap.addEventListener('touchend', function (e) {
      var dx = e.changedTouches[0].clientX - touchStartX;
      if (Math.abs(dx) > 50) {
        if (dx < 0 && carouselIndex < filteredClips.length - 1) showCard(carouselIndex + 1);
        if (dx > 0 && carouselIndex > 0) showCard(carouselIndex - 1);
      }
    }, { passive: true });

    showCard(0);
  }

  // ------------------------------------
  // Card creation
  // ------------------------------------
  function createCard(clip, index) {
    const card = document.createElement('div');
    card.className = 'clip-card';
    card.dataset.clipId = clip.id;

    var viewerUrl = 'viewer.html?clip=' + encodeURIComponent(clip.id) +
      '&category=' + encodeURIComponent(clip.category);

    // Get preview media for cards — use uploaded policy MP4 renders from Space
    var stageData = clip.stages.policy || clip.stages.training || clip.stages.retarget || clip.stages.capture;
    var mediaSrc = stageData ? cardMediaUrl(stageData, clip) : null;
    var isVideo = mediaSrc && mediaSrc.endsWith('.mp4');

    var mediaHtml;
    if (mediaSrc) {
      mediaHtml = isVideo
        ? '<video data-src="' + mediaSrc + '" autoplay muted loop playsinline preload="none" class="lazy-video"></video>'
        : '<img data-src="' + mediaSrc + '" alt="' + escHtml(clip.name) + '" loading="lazy">';
    } else {
      mediaHtml = '<div class="card-placeholder">Not available</div>';
    }

    card.innerHTML =
      '<div class="card-media">' +
        mediaHtml +
        '<div class="card-duration">' + formatDuration(clip.duration) + '</div>' +
        (clip.has_policy ? '<div class="card-badge">TRAINED</div>' : '') +
      '</div>' +
      '<div class="card-info">' +
        '<div class="card-title">' + escHtml(clip.name) + '</div>' +
        '<div class="card-meta">' +
          '<span class="card-category">' + clip.category + '</span>' +
          '<span class="card-separator"></span>' +
          '<span>' + clip.performer + '</span>' +
        '</div>' +
        '<div class="card-actions">' +
          (clip.has_policy
            ? '<a class="card-view-btn" href="' + viewerUrl + '" title="Run policy in browser">' +
              '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polygon points="5 3 19 12 5 21 5 3"/></svg>' +
              'View' +
              '</a>'
            : '') +
        '</div>' +
      '</div>';

    // Media click → open modal
    card.querySelector('.card-media').addEventListener('click', function () {
      openModal(clip);
    });

    return card;
  }

  // ------------------------------------
  // Lazy loading
  // ------------------------------------
  var lazyObserver = null;

  function observeLazyImages() {
    if (!lazyObserver) {
      lazyObserver = new IntersectionObserver(function (entries) {
        entries.forEach(function (entry) {
          if (entry.isIntersecting) {
            var el = entry.target;
            if (el.dataset.src) {
              el.src = el.dataset.src;
            }
            lazyObserver.unobserve(el);
          }
        });
      }, { rootMargin: '300px' });
    }

    var lazyMedia = grid.querySelectorAll('img[data-src], video[data-src]');
    for (var i = 0; i < lazyMedia.length; i++) {
      lazyObserver.observe(lazyMedia[i]);
    }
  }

  // ------------------------------------
  // Card reveal on scroll
  // ------------------------------------
  var revealObserver = null;

  function observeCardReveal() {
    if (!revealObserver) {
      revealObserver = new IntersectionObserver(function (entries) {
        entries.forEach(function (entry) {
          if (entry.isIntersecting) {
            entry.target.classList.add('visible');
            revealObserver.unobserve(entry.target);
          }
        });
      }, { threshold: 0.05, rootMargin: '40px' });
    }

    var cards = grid.querySelectorAll('.clip-card:not(.visible)');
    for (var i = 0; i < cards.length; i++) {
      // Stagger the transition delay
      cards[i].style.transitionDelay = (i * 0.04) + 's';
      revealObserver.observe(cards[i]);
    }
  }

  // ------------------------------------
  // Category buttons
  // ------------------------------------
  function setupCategoryButtons() {
    var btns = document.querySelectorAll('.category-btn');
    for (var i = 0; i < btns.length; i++) {
      btns[i].addEventListener('click', function () {
        setActiveBtn('.category-btn', this);
        activeCategory = this.dataset.category;
        filterAndRender();
      });
    }
  }

  function setActiveBtn(selector, activeEl) {
    var btns = document.querySelectorAll(selector);
    for (var i = 0; i < btns.length; i++) {
      btns[i].classList.toggle('active', btns[i] === activeEl);
    }
  }

  // ------------------------------------
  // Modal
  // ------------------------------------
  function setupModal() {
    var closeBtn = modal.querySelector('.modal-close');
    if (closeBtn) {
      closeBtn.addEventListener('click', closeModal);
    }

    modal.addEventListener('click', function (e) {
      if (e.target === modal) closeModal();
    });

    document.addEventListener('keydown', function (e) {
      if (e.key === 'Escape') closeModal();
    });
  }

  function openModal(clip) {
    var stages = ['capture', 'retarget', 'training', 'policy'];

    modal.querySelector('.modal-title').textContent = clip.name;
    modal.querySelector('.modal-meta').textContent =
      clip.category + '  ·  ' + clip.performer + '  ·  ' +
      formatDuration(clip.duration) + '  ·  ' +
      clip.frames + ' frames @ ' + clip.fps + ' fps';

    var modalGrid = modal.querySelector('.modal-grid');
    modalGrid.innerHTML = stages.map(function (s) {
      var data = clip.stages[s];
      var unavail = !data ? ' unavailable' : '';
      var label = '<div class="modal-stage-label">' + s.toUpperCase() + '</div>';
      var useViewer = s === 'policy' && clip.has_onnx;

      if (useViewer) {
        var iframeSrc = 'viewer.html?clip=' + encodeURIComponent(clip.id) +
          '&category=' + encodeURIComponent(clip.category) + '&embed=1';
        return '<div class="modal-stage">' +
          label +
          '<iframe src="' + iframeSrc + '" style="width:100%;height:100%;border:none;min-height:300px;" allowtransparency="true"></iframe>' +
          '</div>';
      }
      if (data) {
        var src = mediaUrl(data);
        var isVid = src && src.endsWith('.mp4');
        var mediaTag = isVid
          ? '<video src="' + src + '" autoplay muted loop playsinline></video>'
          : '<img src="' + src + '" alt="' + escHtml(clip.name) + ' ' + s + '" loading="lazy">';
        return '<div class="modal-stage' + unavail + '">' +
          label + mediaTag +
          '</div>';
      }
      return '<div class="modal-stage' + unavail + '">' +
        label +
        '<div class="modal-placeholder">Not yet available</div>' +
        '</div>';
    }).join('');

    modal.classList.add('open');
    document.body.style.overflow = 'hidden';
  }

  function closeModal() {
    modal.classList.remove('open');
    document.body.style.overflow = '';
    // Pause modal videos to stop background playback
    var videos = modal.querySelectorAll('video');
    for (var i = 0; i < videos.length; i++) {
      videos[i].pause();
    }
  }

  // ------------------------------------
  // Scroll reveal for sections
  // ------------------------------------
  function setupScrollReveal() {
    var sections = document.querySelectorAll('.reveal');
    if (!sections.length) return;

    var observer = new IntersectionObserver(function (entries) {
      entries.forEach(function (entry) {
        if (entry.isIntersecting) {
          entry.target.classList.add('revealed');
          observer.unobserve(entry.target);
        }
      });
    }, { threshold: 0.1 });

    for (var i = 0; i < sections.length; i++) {
      observer.observe(sections[i]);
    }
  }

  // ------------------------------------
  // Utils
  // ------------------------------------
  function mediaUrl(stageData) {
    var file = stageData.mp4 || stageData.gif;
    if (!file) return null;
    return baseUrl ? baseUrl + '/' + file : file;
  }

  function cardMediaUrl(stageData, clip) {
    // Use Space-hosted policy renders (uploaded by render_all_policies.js)
    if (clip && clip.has_policy) {
      return 'media/' + clip.category + '/' + clip.id + '/policy/' + clip.id + '_policy.mp4';
    }
    var file = stageData.mp4 || stageData.gif;
    if (!file) return null;
    return baseUrl ? baseUrl + '/' + file : file;
  }

  function formatDuration(seconds) {
    var m = Math.floor(seconds / 60);
    var s = Math.round(seconds % 60);
    return m + ':' + (s < 10 ? '0' : '') + s;
  }

  function escHtml(str) {
    var div = document.createElement('div');
    div.textContent = str;
    return div.innerHTML;
  }

  // ------------------------------------
  // Citation copy
  // ------------------------------------
  function initCitation() {
    const btn = document.querySelector('.citation-copy');
    if (!btn) return;
    btn.addEventListener('click', () => {
      const code = document.querySelector('.citation-block code');
      if (!code) return;
      navigator.clipboard.writeText(code.textContent.trim()).then(() => {
        btn.classList.add('copied');
        btn.innerHTML = '<svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="20 6 9 17 4 12"/></svg>';
        setTimeout(() => {
          btn.classList.remove('copied');
          btn.innerHTML = '<svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="9" y="9" width="13" height="13" rx="2" ry="2"/><path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"/></svg>';
        }, 2000);
      });
    });
  }

  // ------------------------------------
  // Boot
  // ------------------------------------
  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', () => { init(); initCitation(); });
  } else {
    init();
    initCitation();
  }
})();