public function getAvailableRoles()
    {
        Piwik::checkUserHasSomeAdminAccess();

        $response = array();

        foreach ($this->roleProvider->getAllRoles() as $role) {
            $response[] = array(
                'id' => $role->getId(),
                'name' => $role->getName(),
                'description' => $role->getDescription(),
                'helpUrl' => $role->getHelpUrl(),
            );
        }

        return $response;
    }