(function () {
  'use strict';

  var LIST_SEL = '[fs-list-element="list"].articles_grid';
  var FILTER_SEL = '.filters_flex.w-dyn-items';

  var snapshotCounts = null;

  function qList() {
    return document.querySelector(LIST_SEL);
  }

  function qFilter() {
    return document.querySelector(FILTER_SEL);
  }

  function articleCategory(article) {
    var tag =
      article.querySelector('.tags_higlight [fs-list-field="category"]') ||
      article.querySelector('[fs-list-field="category"]');
    return tag ? tag.textContent.replace(/\s+/g, ' ').trim() : '';
  }

  function buildCounts() {
    var list = qList();
    var counts = {};
    if (!list) return counts;

    var items = list.querySelectorAll('.article_item.w-dyn-item');
    for (var i = 0; i < items.length; i++) {
      var cat = articleCategory(items[i]);
      if (!cat) continue;
      counts[cat] = (counts[cat] || 0) + 1;
    }
    return counts;
  }

  function totalArticles(counts) {
    var t = 0;
    for (var k in counts) {
      if (Object.prototype.hasOwnProperty.call(counts, k)) t += counts[k];
    }
    return t;
  }

  function captureSnapshotIfPossible() {
    var c = buildCounts();
    if (totalArticles(c) === 0) return false;
    snapshotCounts = c;
    return true;
  }

  function applyFromSnapshot() {
    var filterRoot = qFilter();
    if (!filterRoot) return;

    if (!snapshotCounts) {
      if (!captureSnapshotIfPossible()) return;
    }

    var counts = snapshotCounts;
    var inputs = filterRoot.querySelectorAll(
      'input[fs-list-field="category"][fs-list-value]'
    );

    for (var j = 0; j < inputs.length; j++) {
      var input = inputs[j];
      var val = (input.getAttribute('fs-list-value') || '').trim();
      var label = input.closest('label');
      var sup = label && label.querySelector('.count_items sup');

      var row =
        input.closest('.filter_item.w-dyn-item') ||
        input.closest('.w-dyn-item');

      var n = Object.prototype.hasOwnProperty.call(counts, val) ? counts[val] : 0;

      if (sup) sup.textContent = String(n);

      if (!row) continue;

      if (n === 0) {
        row.setAttribute('hidden', '');
        input.disabled = true;
        input.checked = false;
      } else {
        row.removeAttribute('hidden');
        input.disabled = false;
      }
    }
  }

  function bind() {
    var list = qList();
    var filterRoot = qFilter();
    if (!list || !filterRoot) return false;

    document.addEventListener('fs-cmsload-complete', function () {
      snapshotCounts = null;
      captureSnapshotIfPossible();
      applyFromSnapshot();
    });

    window.addEventListener('pageshow', function () {
      applyFromSnapshot();
    });

    (function waitSnapshot() {
      if (captureSnapshotIfPossible()) {
        applyFromSnapshot();
        return;
      }
      setTimeout(waitSnapshot, 120);
    })();

    return true;
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', function tryBind() {
      if (!bind()) setTimeout(tryBind, 200);
    });
  } else {
    (function tryBind() {
      if (!bind()) setTimeout(tryBind, 200);
    })();
  }
})();