text: // This file is part of Moodle - http://moodle.org/
  //
  // Moodle is free software: you can redistribute it and/or modify
  // it under the terms of the GNU General Public License as published by
  // the Free Software Foundation, either version 3 of the License, or
  // (at your option) any later version.
  //
  // Moodle is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  // GNU General Public License for more details.
  //
  // You should have received a copy of the GNU General Public License
  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  
  /**
   * Notification manager for in-page notifications in Moodle.
   *
   * @module     core/notification
   * @copyright  2015 Damyon Wiese <damyon@moodle.com>
   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
   * @since      2.9
   */
  import Pending from 'core/pending';
  import Log from 'core/log';
  
  let currentContextId = M.cfg.contextid;
  
  const notificationTypes = {
      success:  'core/notification_success',
      info:     'core/notification_info',
      warning:  'core/notification_warning',
      error:    'core/notification_error',
  };
  
  const notificationRegionId = 'user-notifications';
  
  const Selectors = {
      notificationRegion: `#${notificationRegionId}`,
      fallbackRegionParents: [
          '#region-main',
          '[role="main"]',
          'body',
      ],
  };
  
  const setupTargetRegion = () => {
      let targetRegion = getNotificationRegion();
      if (targetRegion) {
          return false;
      }
  
      const newRegion = document.createElement('span');
      newRegion.id = notificationRegionId;
  
      return Selectors.fallbackRegionParents.some(selector => {
          const targetRegion = document.querySelector(selector);
  
          if (targetRegion) {
              targetRegion.prepend(newRegion);
              return true;
          }
  
          return false;
      });
  };
  
  /**
   * A notification object displayed to a user.
   *
   * @typedef  {Object} Notification
   * @property {string} message       The body of the notification
   * @property {string} type          The type of notification to add (error, warning, info, success).
   * @property {Boolean} closebutton  Whether to show the close button.
   * @property {Boolean} announce     Whether to announce to screen readers.
   */
  
  /**
   * Poll the server for any new notifications.
   *
   * @method
   * @returns {Promise}
   */
  export const fetchNotifications = async() => {
      const Ajax = await import('core/ajax');
  
      return Ajax.call([{
          methodname: 'core_fetch_notifications',
          args: {
              contextid: currentContextId
          }
      }])[0]
      .then(addNotifications);
  };
  
  /**
   * Add all of the supplied notifications.
   *
   * @method
   * @param {Notification[]} notifications The list of notificaitons
   * @returns {Promise}
   */
  const addNotifications = notifications => {
      if (!notifications.length) {
          return Promise.resolve();
      }
  
      const pendingPromise = new Pending('core/notification:addNotifications');
      notifications.forEach(notification => renderNotification(notification.template, notification.variables));
  
      return pendingPromise.resolve();
  };
  
  /**
   * Add a notification to the page.
   *
   * Note: This does not cause the notification to be added to the session.
   *
   * @method
   * @param {Notification} notification The notification to add.
   * @returns {Promise}
   */
  export const addNotification = notification => {
      const pendingPromise = new Pending('core/notification:addNotifications');
  
      let template = notificationTypes.error;
  
      notification = {
          closebutton:    true,
          announce:       true,
          type:           'error',
          ...notification,
      };
  
      if (notification.template) {
          template = notification.template;
          delete notification.template;
      } else if (notification.type) {
          if (typeof notificationTypes[notification.type] !== 'undefined') {
              template = notificationTypes[notification.type];
          }
          delete notification.type;
      }
  
      return renderNotification(template, notification)
      .then(pendingPromise.resolve);
  };
  
  const renderNotification = async(template, variables) => {
      if (typeof variables.message === 'undefined' || !variables.message) {
          Log.debug('Notification received without content. Skipping.');
          return;
      }
  
      const pendingPromise = new Pending('core/notification:renderNotification');
      const Templates = await import('core/templates');
  
      Templates.renderForPromise(template, variables)
      .then(({html, js = ''}) => {
          Templates.prependNodeContents(getNotificationRegion(), html, js);
  
          return;
      })
      .then(pendingPromise.resolve)
      .catch(exception);
  };
  
  const getNotificationRegion = () => document.querySelector(Selectors.notificationRegion);
  
  /**
   * Alert dialogue.
   *
   * @method
   * @param {String|Promise} title
   * @param {String|Promise} message
   * @param {String|Promise} cancelText
   * @returns {Promise}
   */
  export const alert = async(title, message, cancelText) => {
      var pendingPromise = new Pending('core/notification:alert');
  
      const ModalFactory = await import('core/modal_factory');
  
      return ModalFactory.create({
          type: ModalFactory.types.ALERT,
          body: message,
          title: title,
          buttons: {
              cancel: cancelText,
          },
          removeOnClose: true,
      })
      .then(function(modal) {
          modal.show();
  
          pendingPromise.resolve();
          return modal;
      });
  };
  
  /**
   * The confirm has now been replaced with a save and cancel dialogue.
   *
   * @method
   * @param {String|Promise} title
   * @param {String|Promise} question
   * @param {String|Promise} saveLabel
   * @param {String|Promise} noLabel
   * @param {String|Promise} saveCallback
   * @param {String|Promise} cancelCallback
   * @returns {Promise}
   */
  export const confirm = (title, question, saveLabel, noLabel, saveCallback, cancelCallback) =>
          saveCancel(title, question, saveLabel, saveCallback, cancelCallback);
  
  /**
   * The Save and Cancel dialogue helper.
   *
   * @method
   * @param {String|Promise} title
   * @param {String|Promise} question
   * @param {String|Promise} saveLabel
   * @param {String|Promise} saveCallback
   * @param {String|Promise} cancelCallback
   * @returns {Promise}
   */
  export const saveCancel = async(title, question, saveLabel, saveCallback, cancelCallback) => {
      const pendingPromise = new Pending('core/notification:confirm');
  
      const [
          ModalFactory,
          ModalEvents,
      ] = await Promise.all([
          import('core/modal_factory'),
          import('core/modal_events'),
      ]);
  
      return ModalFactory.create({
          type: ModalFactory.types.SAVE_CANCEL,
          title: title,
          body: question,
          buttons: {
              // Note: The noLabel is no longer supported.
              save: saveLabel,
          },
          removeOnClose: true,
      })
      .then(function(modal) {
          modal.show();
  
          modal.getRoot().on(ModalEvents.save, saveCallback);
          modal.getRoot().on(ModalEvents.cancel, cancelCallback);
          pendingPromise.resolve();
  
          return modal;
      });
  };
  
  /**
   * Wrap M.core.exception.
   *
   * @method
   * @param {Error} ex
   */
  export const exception = async ex => {
      const pendingPromise = new Pending('core/notification:displayException');
  
      // Fudge some parameters.
      if (!ex.stack) {
          ex.stack = '';
      }
  
      if (ex.debuginfo) {
          ex.stack += ex.debuginfo + '\n';
      }
  
      if (!ex.backtrace && ex.stacktrace) {
          ex.backtrace = ex.stacktrace;
      }
  
      if (ex.backtrace) {
          ex.stack += ex.backtrace;
          const ln = ex.backtrace.match(/line ([^ ]*) of/);
          const fn = ex.backtrace.match(/ of ([^:]*): /);
          if (ln && ln[1]) {
              ex.lineNumber = ln[1];
          }
          if (fn && fn[1]) {
              ex.fileName = fn[1];
              if (ex.fileName.length > 30) {
                  ex.fileName = '...' + ex.fileName.substr(ex.fileName.length - 27);
              }
          }
      }
  
      if (typeof ex.name === 'undefined' && ex.errorcode) {
          ex.name = ex.errorcode;
      }
  
      const Y = await import('core/yui');
      Y.use('moodle-core-notification-exception', function() {
          var modal = new M.core.exception(ex);
  
          modal.show();
  
          pendingPromise.resolve();
      });
  };
  
  /**
   * Initialise the page for the suppled context, and displaying the supplied notifications.
   *
   * @method
   * @param {Number} contextId
   * @param {Notification[]} notificationList
   */
  export const init = (contextId, notificationList) => {
      currentContextId = contextId;
  
      // Setup the message target region if it isn't setup already
      setupTargetRegion();
  
      // Add provided notifications.
      addNotifications(notificationList);
  };
  
  // To maintain backwards compatability we export default here.
  export default {
      init,
      fetchNotifications,
      addNotification,
      alert,
      confirm,
      saveCancel,
      exception,
  };
  