(function () {
  var content = document.querySelector('.content');
  if (!content) return;

  var allHeadings = content.querySelectorAll('h1, h2, h3, h4, h5, h6');
  if (!allHeadings.length) return;

  function copyAnchor(id, item, label, menu) {
    var url = window.location.origin + window.location.pathname + '#' + id;
    function flash() {
      item.textContent = 'Copied!';
      setTimeout(function () {
        item.textContent = label;
        menu.classList.remove('is-open');
      }, 1200);
    }
    function fallback() {
      var ta = document.createElement('textarea');
      ta.value = url;
      ta.setAttribute('readonly', '');
      ta.style.position = 'fixed';
      ta.style.opacity = '0';
      document.body.appendChild(ta);
      ta.select();
      var ok = false;
      try { ok = document.execCommand('copy'); } catch (e) { ok = false; }
      document.body.removeChild(ta);
      if (ok) flash();
      else openModal({
        title: 'Copy anchor link',
        body: 'Could not copy automatically. URL:\n' + url,
        confirm: { label: 'OK', onConfirm: function () { closeModal(); } }
      });
    }
    if (navigator.clipboard && navigator.clipboard.writeText) {
      navigator.clipboard.writeText(url).then(flash, fallback);
    } else {
      fallback();
    }
  }

  function addTask(sectionIndex, headingId) {
    var input = document.createElement('input');
    input.type = 'text';
    input.className = 'modal-input';
    input.placeholder = 'Task description';
    var ctrl = openModal({
      title: 'Add task',
      body: input,
      confirm: {
        label: 'ADD',
        initiallyDisabled: true,
        onConfirm: function () {
          var text = input.value.trim();
          if (!text) return;
          var action = window.location.pathname + '?addtask=' + sectionIndex;
          var target = window.location.pathname + '#' + headingId;
          closeModal();
          postReplace(action, 'text=' + encodeURIComponent(text), target);
        }
      }
    });
    input.addEventListener('input', function () {
      ctrl.setConfirmDisabled(input.value.trim() === '');
    });
  }

  allHeadings.forEach(function (h, i) {
    if (!h.id) return;
    var tag = h.tagName.toLowerCase();
    if (tag !== 'h2' && tag !== 'h3' && tag !== 'h4') return;

    var sectionIndex = i + 1;

    var wrap = document.createElement('span');
    wrap.className = 'dropdown heading-anchor';

    var trigger = document.createElement('button');
    trigger.type = 'button';
    trigger.className = 'dropdown-toggle';
    trigger.setAttribute('aria-haspopup', 'menu');
    trigger.setAttribute('aria-label', 'Section actions');
    trigger.textContent = '#';

    var menu = document.createElement('div');
    menu.className = 'dropdown-menu';

    var copyLabel = 'Copy anchor link';
    var copyBtn = document.createElement('button');
    copyBtn.type = 'button';
    copyBtn.className = 'btn btn-tool btn-block';
    copyBtn.dataset.action = 'copy-anchor';
    copyBtn.textContent = copyLabel;
    copyBtn.addEventListener('click', function (e) {
      e.stopPropagation();
      copyAnchor(h.id, copyBtn, copyLabel, menu);
    });

    var addBtn = document.createElement('button');
    addBtn.type = 'button';
    addBtn.className = 'btn btn-tool btn-block';
    addBtn.dataset.action = 'add-task';
    addBtn.textContent = 'Add task';
    addBtn.addEventListener('click', function () { addTask(sectionIndex, h.id); });

    menu.appendChild(copyBtn);
    menu.appendChild(addBtn);
    wrap.appendChild(trigger);
    wrap.appendChild(menu);
    h.insertBefore(wrap, h.firstChild);

    wireDropdown(trigger);
  });
}());