(function (window, document) {
  'use strict';

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

  function dayTokenLocal() {
    var now = new Date();
    var year = String(now.getFullYear());
    var month = String(now.getMonth() + 1).padStart(2, '0');
    var day = String(now.getDate()).padStart(2, '0');
    return year + '-' + month + '-' + day;
  }

  function storageKey(viewerId, dayToken) {
    return 'taskCertEscOverlayAck:v1:' + viewerId + ':' + dayToken;
  }

  function hasAck(key) {
    try {
      return window.localStorage.getItem(key) === '1';
    } catch (error) {
      return false;
    }
  }

  function setAck(key) {
    try {
      window.localStorage.setItem(key, '1');
      return true;
    } catch (error) {
      return false;
    }
  }

  function closeAndCleanup(root, overlay) {
    if (overlay) {
      overlay.hidden = true;
    }
    document.body.classList.remove('task-cert-user-escalation-overlay-open');
    if (root && root.parentNode) {
      root.parentNode.removeChild(root);
    }
  }

  function initEscalationOverlay(root) {
    if (!(root instanceof window.HTMLElement)) {
      return;
    }
    if (root.dataset.overlayInit === '1') {
      return;
    }
    root.dataset.overlayInit = '1';

    var overlay = root.querySelector('.task-cert-user-escalation-overlay');
    if (!(overlay instanceof window.HTMLElement)) {
      closeAndCleanup(root, null);
      return;
    }

    var viewerId = parseInt(root.getAttribute('data-viewer-id') || '0', 10);
    if (!viewerId || viewerId <= 0) {
      closeAndCleanup(root, overlay);
      return;
    }

    var key = storageKey(viewerId, dayTokenLocal());
    if (hasAck(key)) {
      closeAndCleanup(root, overlay);
      return;
    }

    var myTasksUrl = root.getAttribute('data-my-tasks-url') || '';
    var myTasksLink = root.querySelector('[data-overlay-my-tasks]');
    var ackButton = root.querySelector('[data-overlay-ack]');

    if (myTasksLink instanceof window.HTMLAnchorElement && myTasksUrl !== '') {
      myTasksLink.href = myTasksUrl;
    }

    overlay.hidden = false;
    document.body.classList.add('task-cert-user-escalation-overlay-open');

    if (ackButton instanceof window.HTMLButtonElement) {
      ackButton.focus();
      ackButton.addEventListener('click', function () {
        setAck(key);
        closeAndCleanup(root, overlay);
      });
    }

    if (myTasksLink instanceof window.HTMLAnchorElement) {
      myTasksLink.addEventListener('click', function () {
        setAck(key);
      });
    }
  }

  function autoInit() {
    var roots = toArray(document.querySelectorAll('[data-task-cert-escalation-overlay]'));
    if (roots.length === 0) {
      return;
    }

    var primary = roots[0];
    for (var i = 1; i < roots.length; i += 1) {
      if (roots[i] && roots[i].parentNode) {
        roots[i].parentNode.removeChild(roots[i]);
      }
    }

    initEscalationOverlay(primary);
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', autoInit);
  } else {
    autoInit();
  }
})(window, document);