User::getUserHeads

public function getUserHeads(int $userId): array
{
	$heads = [];
	$userDepartments = $this->getUserDepartmentChains($userId);

	foreach ($userDepartments as $chain)
	{
		foreach ($chain as $deptId)
		{
			$departmentHead = $this->getDepartmentHead($deptId);

			if (!$departmentHead || $departmentHead === $userId)
			{
				continue;
			}

			$heads[] = $departmentHead;
			break;
		}
	}

	return array_unique($heads);
}