(function () {
  'use strict';

  var DOMAIN_CONTEXT = {
    'food-beverage': {
      label: '食品与饮料包装',
      returnHref: 'developer-domain-food.html'
    },
    'beauty-care': {
      label: '美妆与个护包装',
      returnHref: 'developer-domain-beauty.html'
    },
    'medical-outer': {
      label: '医药与医疗包装',
      returnHref: 'developer-domain-medical-outer.html'
    },
    'special-performance': {
      label: '特种包装',
      returnHref: 'developer-domain-specialty.html'
    }
  };

  var DOMAIN_ALIAS = {
    food: 'food-beverage',
    beauty: 'beauty-care',
    medical: 'medical-outer',
    specialty: 'special-performance'
  };

  function toArray(list) {
    return Array.prototype.slice.call(list || []);
  }

  function readDomainFromQuery() {
    var params = new URLSearchParams(window.location.search);
    var value = params.get('domain') || '';
    return DOMAIN_CONTEXT[value] ? value : '';
  }

  function readDomainFromHash() {
    var value = window.location.hash.replace(/^#/, '').replace(/^domain-/, '');
    return DOMAIN_ALIAS[value] || (DOMAIN_CONTEXT[value] ? value : '');
  }

  function createContextBar(domain) {
    var context = DOMAIN_CONTEXT[domain];
    if (!context || document.querySelector('[data-dv23-domain-context]')) return;

    var anchor = document.querySelector('.dv2-local-nav') || document.querySelector('.dv2-page-intro');
    if (!anchor || !anchor.parentNode) return;

    var bar = document.createElement('aside');
    var inner = document.createElement('div');
    var label = document.createElement('span');
    var title = document.createElement('strong');
    var note = document.createElement('p');
    var returnLink = document.createElement('a');
    var allLink = document.createElement('a');

    bar.className = 'dv23-context-bar';
    bar.setAttribute('data-dv23-domain-context', domain);
    bar.setAttribute('aria-label', '当前包装领域上下文');
    inner.className = 'dv2-shell dv23-context-bar__inner';
    label.textContent = '当前领域';
    title.textContent = context.label;
    note.textContent = '本页是通用专业底座，内容尚未按领域过滤。';
    returnLink.href = context.returnHref;
    returnLink.textContent = '返回该领域';
    allLink.href = window.location.pathname.split('/').pop() || window.location.pathname;
    allLink.textContent = '查看全部';

    inner.appendChild(label);
    inner.appendChild(title);
    inner.appendChild(note);
    inner.appendChild(returnLink);
    inner.appendChild(allLink);
    bar.appendChild(inner);
    anchor.parentNode.insertBefore(bar, anchor.nextSibling);
    document.body.setAttribute('data-domain-context', domain);
  }

  function initDomainContext() {
    var domain = readDomainFromQuery();
    if (!domain) return;
    createContextBar(domain);
  }

  function initJourneyNavigation() {
    var nav = document.querySelector('[data-dv23-journey-nav]');
    if (!nav) return;

    var links = toArray(nav.querySelectorAll('a[href^="#"]'));
    var items = links.map(function (link) {
      var target = document.querySelector(link.getAttribute('href'));
      return target ? { link: link, target: target } : null;
    }).filter(Boolean);
    if (!items.length) return;

    function activate(target) {
      items.forEach(function (item) {
        if (item.target === target) item.link.setAttribute('aria-current', 'step');
        else item.link.removeAttribute('aria-current');
      });
    }

    activate(items[0].target);

    if (!('IntersectionObserver' in window)) return;
    var observer = new IntersectionObserver(function (entries) {
      var visible = entries.filter(function (entry) { return entry.isIntersecting; });
      if (!visible.length) return;
      visible.sort(function (a, b) { return a.boundingClientRect.top - b.boundingClientRect.top; });
      activate(visible[0].target);
    }, {
      rootMargin: '-28% 0px -58% 0px',
      threshold: 0
    });

    items.forEach(function (item) { observer.observe(item.target); });
  }

  function configureSnapRail(element, label, enabled, reduceMotion) {
    if (!element) return;

    if (enabled) {
      element.classList.add('dv23-snap-rail');
      element.setAttribute('tabindex', '0');
      element.setAttribute('role', 'region');
      if (!element.getAttribute('aria-label')) element.setAttribute('aria-label', label);

      if (!element.hasAttribute('data-dv23-keyboard')) {
        element.setAttribute('data-dv23-keyboard', 'true');
        element.addEventListener('keydown', function (event) {
          if (event.key !== 'ArrowLeft' && event.key !== 'ArrowRight') return;
          event.preventDefault();
          var direction = event.key === 'ArrowRight' ? 1 : -1;
          element.scrollBy({
            left: direction * element.clientWidth * .78,
            behavior: reduceMotion ? 'auto' : 'smooth'
          });
        });
      }
    } else {
      element.classList.remove('dv23-snap-rail');
      element.removeAttribute('tabindex');
      if (element.hasAttribute('aria-label') || element.hasAttribute('aria-labelledby')) {
        element.setAttribute('role', 'group');
      } else {
        element.removeAttribute('role');
      }
    }
  }

  function initSnapRails() {
    var media = window.matchMedia('(max-width: 620px)');
    var reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
    var groups = [
      { selector: '.dv21-progressive-steps', label: '横向浏览五步开发路径' },
      { selector: '.dv2-tool-list', label: '横向浏览开发工具' },
      { selector: '.dv21-deep-links', label: '横向浏览专业模块' },
      { selector: '.dv21-domain-summary', label: '横向浏览领域摘要' }
    ];

    function update() {
      groups.forEach(function (group) {
        toArray(document.querySelectorAll(group.selector)).forEach(function (element) {
          configureSnapRail(element, group.label, media.matches, reduceMotion);
        });
      });
    }

    update();
    if (media.addEventListener) media.addEventListener('change', update);
    else if (media.addListener) media.addListener(update);
  }

  function filterChallenges(domain) {
    var cards = toArray(document.querySelectorAll('[data-challenge-domain]'));
    if (!cards.length || !DOMAIN_CONTEXT[domain]) return;

    var count = 0;
    cards.forEach(function (card) {
      var visible = card.getAttribute('data-challenge-domain') === domain;
      card.hidden = !visible;
      if (visible) count += 1;
    });

    var status = document.querySelector('[data-dv23-challenge-status]');
    if (status) status.textContent = DOMAIN_CONTEXT[domain].label + '：' + count + ' 个公开问题对象';

    var projectLink = document.querySelector('[data-dv23-challenge-project]');
    if (projectLink) projectLink.href = 'sample.html?domain=' + domain;
  }

  function initChallengeFilter() {
    var controls = toArray(document.querySelectorAll('[data-domain-tab]'));
    var cards = toArray(document.querySelectorAll('[data-challenge-domain]'));
    if (!controls.length || !cards.length) return;

    function activeDomain() {
      var hashDomain = readDomainFromHash();
      if (hashDomain) return hashDomain;
      var active = document.querySelector('[data-domain-tab][aria-pressed="true"]');
      var value = active ? active.getAttribute('data-domain-tab') : 'food';
      return DOMAIN_ALIAS[value] || 'food-beverage';
    }

    controls.forEach(function (control) {
      control.addEventListener('click', function () {
        var value = control.getAttribute('data-domain-tab');
        filterChallenges(DOMAIN_ALIAS[value] || value);
      });
      control.addEventListener('keydown', function (event) {
        if (event.key !== 'ArrowLeft' && event.key !== 'ArrowRight' && event.key !== 'Home' && event.key !== 'End') return;
        window.requestAnimationFrame(function () {
          filterChallenges(activeDomain());
        });
      });
    });

    window.addEventListener('hashchange', function () {
      filterChallenges(activeDomain());
    });

    filterChallenges(activeDomain());
  }

  function init() {
    if (!document.body.classList.contains('dv23-page')) return;
    initDomainContext();
    initJourneyNavigation();
    initSnapRails();
    initChallengeFilter();
  }

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