.-.-.-.-.-

<?php
/**
 * @package   ats
 * @copyright Copyright (c)2011-2022 Nicholas K. Dionysopoulos / Akeeba Ltd
 * @license   GNU General Public License version 3, or later
 */

defined('_JEXEC') or die();

use FOF40\Container\Container;
use Joomla\CMS\Plugin\CMSPlugin;
use Joomla\CMS\User\User as JUser;

class plgAtsUsergroups extends CMSPlugin
{

/** @var array Joomla groups per user ID */
	private static $groupsPerUser = [];
	private static $groupNames = [];

public function __construct(&$subject, $config = [])
	{
		parent::__construct($subject, $config);

if (!defined('FOF40_INCLUDED') && !@include_once(JPATH_LIBRARIES . '/fof40/include.php'))
		{
			throw new RuntimeException('This extension requires FOF 4.', 500);
		}

// Prime the cache for group names
		$container = Container::getInstance('com_ats');
		$db        = $container->db;

$query            = $db->getQuery(true)
			->select([$db->qn('id'), $db->qn('title')])
			->from($db->qn('#__usergroups'));
		self::$groupNames = $db->setQuery($query)->loadObjectList('id');
	}

/**
	 * Get a list of Joomla groups for a particular user account.
	 *
	 * @param   JUser  $user  The user to check
	 *
	 * @return  array  An object with arrays for user groups
	 */
	public function onAtsGetUserGroupsList(JUser $user = null)
	{
		if ($user->username == 'system')
		{
			return [];
		}

if (!array_key_exists($user->id, self::$groupsPerUser) && ($user->id <= 0))
		{
			self::$groupsPerUser[$user->id] = [];
		}

if (!array_key_exists($user->id, self::$groupsPerUser))
		{
			$groups = [];

foreach ($user->groups as $group)
			{
				if (!isset(self::$groupNames[$group]))
				{
					continue;
				}

$groups[] = self::$groupNames[$group]->title;
			}

self::$groupsPerUser[$user->id] = $groups;
		}

return self::$groupsPerUser[$user->id];
	}
}

/var/www/consult-e-syn/public_html/plugins/ats/usergroups/usergroups.php