/* DBC / BIOTEN V4.0.0 shared interaction finish. */
(function () {
  'use strict';

  const root = document.documentElement;
  const body = document.body;
  if (!body || !body.classList.contains('v400-site')) return;

  const reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  function centerCurrentLocalLink() {
    const selectors = [
      '.about-anchor-nav',
      '.packaging-anchor',
      '.resources-page-nav',
      '.news-business-anchor',
      '.knowledge-anchor-nav',
      '.bioten-product-nav',
      '.pl-anchor-nav',
      '.v245-local-nav',
      '.vp-anchor-nav',
      '.dv2-local-nav__inner',
      '.dv23-journey-nav'
    ];

    selectors.forEach(function (selector) {
      const nav = document.querySelector(selector);
      if (!nav || nav.scrollWidth <= nav.clientWidth + 4) return;
      const active = nav.querySelector('[aria-current], .is-active, a[href="' + window.location.hash + '"]');
      if (!active) return;
      window.requestAnimationFrame(function () {
        active.scrollIntoView({ behavior: 'auto', block: 'nearest', inline: 'center' });
      });
    });
  }

  function setupSectionReveal() {
    if (reduceMotion || !('IntersectionObserver' in window)) return;
    if (body.classList.contains('dbc-home-page') || body.classList.contains('dv24-page')) return;

    const sections = Array.from(document.querySelectorAll('main > section')).slice(1);
    if (!sections.length) return;
    root.classList.add('v400-motion-ready');
    sections.forEach(function (section) { section.classList.add('v400-reveal'); });

    const observer = new IntersectionObserver(function (entries) {
      entries.forEach(function (entry) {
        if (!entry.isIntersecting) return;
        entry.target.classList.add('is-visible');
        observer.unobserve(entry.target);
      });
    }, { rootMargin: '0px 0px -8% 0px', threshold: 0.07 });

    sections.forEach(function (section) { observer.observe(section); });
  }

  function stopDecorativeAutoplayForReducedMotion() {
    if (!reduceMotion) return;
    document.querySelectorAll('[data-v311-gallery]').forEach(function (gallery) {
      const button = gallery.querySelector('[data-v311-action="toggle"]');
      if (!button) return;
      const label = (button.getAttribute('aria-label') || '').toLowerCase();
      if (label.includes('暂停') || label.includes('pause')) button.click();
    });
  }

  function wireHashNavigation() {
    window.addEventListener('hashchange', centerCurrentLocalLink, { passive: true });
    document.addEventListener('click', function (event) {
      const link = event.target.closest('a[href^="#"]');
      if (!link) return;
      window.setTimeout(centerCurrentLocalLink, 80);
    });
  }

  function markExternalLinks() {
    document.querySelectorAll('a[href^="http"]').forEach(function (link) {
      try {
        const target = new URL(link.href, window.location.href);
        if (target.origin === window.location.origin) return;
        if (link.target === '_blank') {
          const rel = new Set((link.rel || '').split(/\s+/).filter(Boolean));
          rel.add('noopener');
          link.rel = Array.from(rel).join(' ');
        }
      } catch (_) {
        /* Invalid user-authored URL remains untouched for the QA script. */
      }
    });
  }

  function init() {
    centerCurrentLocalLink();
    setupSectionReveal();
    stopDecorativeAutoplayForReducedMotion();
    wireHashNavigation();
    markExternalLinks();
  }

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