(function (root, factory) {
  const createMobileSearchModal = factory();
  if (typeof module !== 'undefined' && module.exports) module.exports = createMobileSearchModal;
  else root.createMobileSearchModal = createMobileSearchModal;
})(typeof globalThis !== 'undefined' ? globalThis : this, function () {
  const FOCUSABLE = [
    'a[href]', 'button', 'input', 'select', 'textarea',
    '[tabindex]:not([tabindex="-1"])', '[contenteditable="true"]',
  ].join(',');

  return function createMobileSearchModal(options) {
    const documentRef = options.document;
    const backgrounds = Array.from(options.backgrounds || [
      documentRef.querySelector?.('body > header'),
      documentRef.querySelector?.('main'),
      documentRef.querySelector?.('#mobile-task-dock'),
    ]).filter(Boolean);
    let surface = null;
    let opener = null;
    let priorInert = null;

    function focusable() {
      if (!surface || typeof surface.querySelectorAll !== 'function') return [];
      return Array.from(surface.querySelectorAll(FOCUSABLE)).filter(element =>
        !element.disabled && !element.hidden && element.getAttribute?.('aria-hidden') !== 'true' &&
        (typeof element.matches !== 'function' || element.matches(':not([hidden])')) &&
        (typeof element.getClientRects !== 'function' || element.getClientRects().length > 0)
      );
    }

    function focus(element) {
      if (element?.isConnected !== false && typeof element?.focus === 'function') element.focus();
    }

    function onKeydown(event) {
      if (!surface || event.key !== 'Tab') return;
      const controls = focusable();
      if (!controls.length) {
        event.preventDefault();
        return;
      }
      const first = controls[0];
      const last = controls[controls.length - 1];
      if (event.shiftKey && documentRef.activeElement === first) {
        event.preventDefault();
        focus(last);
      } else if (!event.shiftKey && documentRef.activeElement === last) {
        event.preventDefault();
        focus(first);
      } else if (!controls.includes(documentRef.activeElement)) {
        event.preventDefault();
        focus(event.shiftKey ? last : first);
      }
    }

    function transition(nextSurface, transitionOptions = {}) {
      surface = nextSurface;
      focus(transitionOptions.initialFocus || focusable()[0]);
    }

    function activate(nextSurface, activateOptions = {}) {
      if (!surface) {
        opener = activateOptions.opener || documentRef.activeElement || null;
        priorInert = backgrounds.map(element => element.inert === true);
        backgrounds.forEach(element => { element.inert = true; });
      }
      transition(nextSurface, activateOptions);
    }

    function deactivate() {
      if (!surface) return;
      backgrounds.forEach((element, index) => { element.inert = priorInert[index]; });
      surface = null;
      priorInert = null;
      const restore = opener;
      opener = null;
      focus(restore);
    }

    documentRef.addEventListener('keydown', onKeydown);
    return { activate, transition, deactivate, current: () => surface };
  };
});