/**
 * @file
 * Adds default classes to buttons for styling purposes.
 */

(function ($, { tabbable, isTabbable }) {
  $.widget('ui.dialog', $.ui.dialog, {
    options: {
      buttonClass: 'button',
      buttonPrimaryClass: 'button--primary',
    },
    _createButtons() {
      const opts = this.options;
      let primaryIndex;
      let index;
      const il = opts.buttons.length;
      for (index = 0; index < il; index++) {
        if (
          opts.buttons[index].primary &&
          opts.buttons[index].primary === true
        ) {
          primaryIndex = index;
          delete opts.buttons[index].primary;
          break;
        }
      }
      this._super();
      const $buttons = this.uiButtonSet.children().addClass(opts.buttonClass);
      if (typeof primaryIndex !== 'undefined') {
        $buttons.eq(index).addClass(opts.buttonPrimaryClass);
      }
    },
    // Override jQuery UI's `_focusTabbable()` so finding tabbable elements uses
    // the core/tabbable library instead of jQuery UI's `:tabbable` selector.
    _focusTabbable() {
      // Set focus to the first match:

      // 1. An element that was focused previously.
      let hasFocus = this._focusedElement ? this._focusedElement.get(0) : null;

      // 2. First element inside the dialog matching [autofocus].
      if (!hasFocus) {
        hasFocus = this.element.find('[autofocus]').get(0);
      }

      // 3. Tabbable element inside the content element.
      // 4. Tabbable element inside the buttonpane.
      if (!hasFocus) {
        const $elements = [this.element, this.uiDialogButtonPane];
        for (let i = 0; i < $elements.length; i++) {
          const element = $elements[i].get(0);
          if (element) {
            const elementTabbable = tabbable(element);
            hasFocus = elementTabbable.length ? elementTabbable[0] : null;
          }
          if (hasFocus) {
            break;
          }
        }
      }

      // 5. The close button.
      if (!hasFocus) {
        const closeBtn = this.uiDialogTitlebarClose.get(0);
        hasFocus = closeBtn && isTabbable(closeBtn) ? closeBtn : null;
      }

      // 6. The dialog itself.
      if (!hasFocus) {
        hasFocus = this.uiDialog.get(0);
      }
      $(hasFocus).eq(0).trigger('focus');
    },
  });
})(jQuery, window.tabbable);