/**
 * @file
 * A Backbone view for the aural feedback of the toolbar.
 */

(function(Backbone, Drupal) {
  Drupal.toolbar.ToolbarAuralView = Backbone.View.extend(
    /** @lends Drupal.toolbar.ToolbarAuralView# */ {
      /**
       * Backbone view for the aural feedback of the toolbar.
       *
       * @constructs
       *
       * @augments Backbone.View
       *
       * @param {object} options
       *   Options for the view.
       * @param {object} options.strings
       *   Various strings to use in the view.
       */
      initialize(options) {
        this.strings = options.strings;

        this.listenTo(
          this.model,
          'change:orientation',
          this.onOrientationChange,
        );
        this.listenTo(this.model, 'change:activeTray', this.onActiveTrayChange);
      },

      /**
       * Announces an orientation change.
       *
       * @param {Drupal.toolbar.ToolbarModel} model
       *   The toolbar model in question.
       * @param {string} orientation
       *   The new value of the orientation attribute in the model.
       */
      onOrientationChange(model, orientation) {
        Drupal.announce(
          Drupal.t('Tray orientation changed to @orientation.', {
            '@orientation': orientation,
          }),
        );
      },

      /**
       * Announces a changed active tray.
       *
       * @param {Drupal.toolbar.ToolbarModel} model
       *   The toolbar model in question.
       * @param {HTMLElement} tray
       *   The new value of the tray attribute in the model.
       */
      onActiveTrayChange(model, tray) {
        const relevantTray =
          tray === null ? model.previous('activeTray') : tray;
        // Current activeTray and previous activeTray are empty, no state change
        // to announce.
        if (!relevantTray) {
          return;
        }
        const action = tray === null ? Drupal.t('closed') : Drupal.t('opened');
        const trayNameElement = relevantTray.querySelector(
          '.toolbar-tray-name',
        );
        let text;
        if (trayNameElement !== null) {
          text = Drupal.t('Tray "@tray" @action.', {
            '@tray': trayNameElement.textContent,
            '@action': action,
          });
        } else {
          text = Drupal.t('Tray @action.', { '@action': action });
        }
        Drupal.announce(text);
      },
    },
  );
})(Backbone, Drupal);
