/**
 * AKSRT Page Template
 *
 * Handles template-scoped content interactions: TOC, lightbox,
 * expandable article bodies, and one-shot query cleanup banners.
 *
 * @package AKSRT
 */

(function () {
  'use strict';

  function slugifyHeading(text) {
    return 'heading-' + String(text || '')
      .trim()
      .toLowerCase()
      .replace(/\s+/g, '-')
      .replace(/[^\w\u4e00-\u9fff-]/g, '');
  }

  function initPostToc() {
    // Accept either explicit data-aksrt-toc="1" or any [data-nav] article body.
    var content =
      document.querySelector('.wp-posts-content[data-nav="posts"][data-aksrt-toc="1"]') ||
      document.querySelector('.wp-posts-content[data-nav]') ||
      document.querySelector('[data-nav="posts"]') ||
      document.querySelector('[data-nav]');

    // The article sidebar and mobile drawer share one built-in TOC source.
    var tocWidgets = Array.prototype.slice.call(
      document.querySelectorAll('.posts-nav-box.toc-widget')
    );
    var tocLists = [];
    tocWidgets.forEach(function (box) {
      if (!box.classList.contains('toc-widget')) {
        box.classList.add('toc-widget');
      }
      var list = box.querySelector('.toc-list');
      if (!list) {
        list = document.createElement('ol');
        list.className = 'toc-list';
        box.appendChild(list);
      }
      tocLists.push(list);
    });

    var mobileToggle = document.querySelector('.toc-float-btn');
    var drawer = document.querySelector('.toc-drawer');
    var overlay = document.querySelector('.toc-drawer-overlay');
    var drawerList = drawer ? drawer.querySelector('.toc-list') : null;
    var closeBtn = drawer ? drawer.querySelector('.toc-drawer__close') : null;

    if (!content || content.dataset.aksrtTocBound === '1') return;
    if (!tocLists.length && !drawerList && !mobileToggle) return;

    content.dataset.aksrtTocBound = '1';

    var maxDepth = parseInt(content.dataset.aksrtTocDepth || '3', 10) || 3;
    // zibll section-navs: only fill when heading count > 2 (≥3).
    var MIN_HEADINGS = 3;

    function getHeadings() {
      // zibll scans h1–h4 inside [data-nav]; depth setting still caps lower levels.
      return Array.prototype.slice.call(content.querySelectorAll('h1, h2, h3, h4')).filter(function (heading) {
        if (heading.closest('.no-nav') || heading.classList.contains('item-heading')) {
          return false;
        }
        var level = parseInt((heading.tagName || 'H2').replace('H', ''), 10) || 2;
        // toc_depth is typically 2–4 meaning deepest heading level from h2 baseline;
        // allow h1 always, then h2..h(1+maxDepth) capped at h4.
        if (level === 1) return true;
        return level <= Math.min(4, maxDepth + 1);
      });
    }

    function buildToc(container) {
      if (!container) return false;

      var headings = getHeadings();
      if (headings.length < MIN_HEADINGS) return false;

      var html = '';
      headings.forEach(function (heading) {
        if (!heading.id) {
          heading.id = slugifyHeading(heading.textContent);
        }

        var levelClass = '';
        if (heading.tagName === 'H1') {
          levelClass = 'toc-h1';
        } else if (heading.tagName === 'H3') {
          levelClass = 'toc-h3';
        } else if (heading.tagName === 'H4') {
          levelClass = 'toc-h4';
        }

        html += '<li' + (levelClass ? ' class="' + levelClass + '"' : '') + '><a href="#' + heading.id + '">' + heading.textContent.trim() + '</a></li>';
      });

      container.innerHTML = html;
      return true;
    }

    var hasToc = false;
    tocLists.forEach(function (list) {
      if (buildToc(list)) hasToc = true;
    });
    if (drawerList && tocLists.indexOf(drawerList) === -1) {
      if (buildToc(drawerList)) hasToc = true;
    }

    if (!hasToc) {
      tocWidgets.forEach(function (box) {
        var widget = box.closest('.widget');
        // A built-in TOC is a direct child of the article sidebar.  Its parent
        // is therefore not widget chrome and must never be removed here.
        if (widget && widget !== document.body && widget.querySelectorAll('.posts-nav-box').length <= 1) {
          widget.remove();
        } else {
          box.remove();
        }
      });
      if (mobileToggle) mobileToggle.remove();
      if (drawer) drawer.remove();
      if (overlay) overlay.remove();
      return;
    }

    function closeDrawer() {
      if (drawer) drawer.classList.remove('is-open');
      if (overlay) overlay.classList.remove('is-open');
      document.body.style.overflow = '';
    }

    function openDrawer() {
      if (drawer) drawer.classList.add('is-open');
      if (overlay) overlay.classList.add('is-open');
      document.body.style.overflow = 'hidden';
    }

    function trackActiveHeading() {
      var headings = content.querySelectorAll('h1[id], h2[id], h3[id], h4[id]');
      if (!headings.length) return;

      var activeId = '';
      var fromTop = window.scrollY + 120;
      for (var i = headings.length - 1; i >= 0; i -= 1) {
        if (headings[i].offsetTop <= fromTop) {
          activeId = headings[i].id;
          break;
        }
      }

      document.querySelectorAll('.toc-list a').forEach(function (link) {
        link.classList.toggle('is-active', link.getAttribute('href') === '#' + activeId);
      });
    }

    document.querySelectorAll('.toc-list a').forEach(function (link) {
      link.addEventListener('click', function (event) {
        var target = document.querySelector(link.getAttribute('href'));
        if (!target) return;

        event.preventDefault();
        var top = target.getBoundingClientRect().top + window.pageYOffset - 105;
        window.scrollTo({ top: Math.max(0, top), behavior: 'smooth' });
        closeDrawer();
      });
    });

    if (mobileToggle) mobileToggle.addEventListener('click', openDrawer);
    if (overlay) overlay.addEventListener('click', closeDrawer);
    if (closeBtn) closeBtn.addEventListener('click', closeDrawer);

    window.addEventListener('scroll', trackActiveHeading, { passive: true });
    trackActiveHeading();
  }

  function initLightbox() {
    var overlay = document.getElementById('lightbox-overlay');
    var content = document.querySelector(".wp-posts-content[data-aksrt-lightbox='1'], .entry-content[data-aksrt-lightbox='1']");
    if (!overlay || !content || overlay.dataset.aksrtLightboxBound === '1') return;

    overlay.dataset.aksrtLightboxBound = '1';

    var image = overlay.querySelector('.lightbox-img');
    var caption = overlay.querySelector('.lightbox-caption');
    var closeBtn = overlay.querySelector('.lightbox-close');

    function close() {
      overlay.classList.remove('is-open');
      overlay.setAttribute('aria-hidden', 'true');
      document.body.style.overflow = '';
      if (image) {
        image.src = '';
        image.alt = '';
      }
    }

    content.querySelectorAll('img').forEach(function (img) {
      var link = img.closest('a[href]');
      var linkHref = link ? link.href : '';
      var linksToImage = /\.(?:avif|gif|jpe?g|png|svg|webp)(?:[?#].*)?$/i.test(linkHref);
      if (img.closest('[data-no-lightbox]') || (link && !linksToImage)) return;

      img.classList.add('aksrt-lightbox-target');
      img.addEventListener('click', function (event) {
        if (!image) return;
        if (linksToImage) event.preventDefault();

        image.src = linksToImage
          ? linkHref
          : (img.getAttribute('data-src') || img.getAttribute('data-lazy-src') || img.currentSrc || img.src);
        image.alt = img.alt || '';

        if (caption) {
          var figure = img.closest('figure');
          var figureCaption = figure ? figure.querySelector('figcaption') : null;
          caption.textContent = img.alt || (figureCaption ? figureCaption.textContent : '') || '';
        }

        overlay.classList.add('is-open');
        overlay.setAttribute('aria-hidden', 'false');
        document.body.style.overflow = 'hidden';
        if (closeBtn) closeBtn.focus();
      });
    });

    overlay.addEventListener('click', function (event) {
      if (event.target === overlay || event.target === closeBtn || (event.target.closest && event.target.closest('.lightbox-close'))) {
        close();
      }
    });

    document.addEventListener('keydown', function (event) {
      if (event.key === 'Escape' && overlay.classList.contains('is-open')) {
        close();
      }
    });
  }

  function initContentExpand() {
    // Zibll-style: inject .read-more inside .limit-height and expand on click.
    document.querySelectorAll('.wp-posts-content.limit-height, .limit-height[data-nav]').forEach(function (content) {
      if (content.dataset.aksrtExpandBound === '1') return;
      content.dataset.aksrtExpandBound = '1';

      var customMax = parseInt(content.getAttribute('data-maxheight') || content.dataset.maxheight || '0', 10);
      // data-maxheight may be maxheight-80 (Zibll) or absolute maxheight; prefer style max-height.
      var styleMax = 0;
      if (content.style && content.style.maxHeight) {
        styleMax = parseInt(content.style.maxHeight, 10) || 0;
      }
      var limit = styleMax > 0 ? styleMax : (customMax > 0 ? customMax + 80 : 0);
      if (!(limit > 0) && customMax > 0) {
        limit = customMax;
      }
      if (!(limit > 0)) {
        content.classList.remove('limit-height');
        return;
      }

      if (content.scrollHeight <= limit + 40) {
        content.classList.remove('limit-height');
        content.style.maxHeight = '';
        return;
      }

      content.classList.add('limit-height');
      content.style.maxHeight = limit + 'px';

      if (content.querySelector('.read-more')) return;

      var wrap = document.createElement('div');
      wrap.className = 'read-more';
      var link = document.createElement('a');
      link.href = 'javascript:;';
      link.className = 'read-more-open';
      link.innerHTML = '展开阅读全文<i class="fa ml10 fa-angle-down" aria-hidden="true"></i>';
      wrap.appendChild(link);
      content.appendChild(wrap);

      link.addEventListener('click', function (event) {
        event.preventDefault();
        content.classList.remove('limit-height');
        content.style.maxHeight = '';
        wrap.remove();
      });
    });

    // Compatibility: old external expand buttons.
    document.addEventListener('click', function (event) {
      var open = event.target.closest && event.target.closest('.read-more-open');
      if (!open) return;
      var limitBox = open.closest('.limit-height');
      if (!limitBox) return;
      event.preventDefault();
      limitBox.classList.remove('limit-height');
      limitBox.style.maxHeight = '';
      var more = open.closest('.read-more');
      if (more) more.remove();
    });
  }

  function initFlashQueryCleanup() {
    document.querySelectorAll('[data-aksrt-flash-query]').forEach(function (node) {
      var queryKey = node.getAttribute('data-aksrt-flash-query');
      if (!queryKey || !window.history || typeof window.history.replaceState !== 'function') return;

      var url = new URL(window.location.href);
      if (!url.searchParams.has(queryKey)) return;

      url.searchParams.delete(queryKey);
      window.history.replaceState({}, '', url.toString());
    });
  }

  function init() {
    initPostToc();
    initLightbox();
    initContentExpand();
    initFlashQueryCleanup();
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', init);
  } else {
    init();
  }
})();