Is it possible to add new facebook users to a group?

/**
 * LOGIN
 *
 * If you wanted to do any custom checks in the database for the user,
 * here is where you'd do it. For example, below you can see the basic calls to retrieve
 * the user id using the $user object passed in to the method then get the user profile data
 * 
 * @param      obj     $user       The user object
 * @param      obj     $options    The login options
 * @return     bool    true/false  The 'success' for login
 */
function onUserLogin($user, $options)
{
    //Get App & User
    $app =& JFactory::getApplication();
       
    //only run in site
    if($app->isSite()){
       //INIT some vars to use
       //Get the user ID with helper method and the $user object
       $userId = intval(JUserHelper::getUserId($user['username']));

       //Get Profile with helper method and userId
       $profile = JUserHelper::getProfile($userId);        

       // Check the users groups against the configured Investor/Creator groups to get login redirect
       $redirect = $this->runCrowdfundingLoginOverrides($userId);
       
       // Only redirect if the config is not empty (fallback to default behaviour)
       if($redirect != ""){
           // Get config to pass in the site's SEF setting in redirect
           $config = JFactory::getConfig();
           
           // Set the redirect 
           $app->setUserState(
               'users.login.form.return', 
               JRoute::_($redirect, false, $config->get('usesecure'))
           );
       }//END IF redirect isn't empty
    }// END IF IN SITE
   
   //RETURN
   return true;
}

/**
* Get the custom user/group data to use
* 
* Method to get the Custom Crowdfunding user groups & their custom redirect urls for each from config
* and compare with the users current groups to determine the redirect
* 
* As its name suggests, this method (function) You could conceivably add additional 'sub' routines in here to get additional info &
* 'Do' stuff with it. You could do this by writing your logic (code) or 'trigger'
* other public or private methods (in this file) - both of which are demonstrated in the
* function 'runCrowdfundingLoginOverrides($userId, $userGroups)'.
* 
* Please see bottom of this file for examples.
* 
* @param   integer     $userId         The user id whose groups to chec
* @return  bool        true/false      True on success/False on fail
*/
public function runCrowdfundingLoginOverrides($userId)
{   // INIT Vars 
    $return=""; // to return
   
    // Login Type - first OR any
    $loginType = "any";
    
    // Groups
    $userGroups = JUserHelper::getUserGroups($userId);
    
    // Get the configured custom user groups to check against;
    $check = array(
       "custom_groups" => array(
              $this->params->get('investor_group', 2),
              $this->params->get('creator_group', 3)
       ),
       "first" => array(
              $this->params->get('investor_group', 2) => $this->params->get('investorredirect1', ''), 
              $this->params->get('creator_group', 3) => $this->params->get('creatorredirect1', '')    
       ),
       "any" => array(
              $this->params->get('investor_group', 2) => $this->params->get('investorredirect2', ''), 
              $this->params->get('creator_group', 3) => $this->params->get('creatorredirect2', '')
       )
    );    
       
    // Get user type
    $profile = JUserHelper::getProfile($userId);
    $userType = ((int)$profile->profile['usertype'] > 0) ? (int)$profile->profile['usertype'] : 0;
    $otherGroup = ((int)$userType > 0 && (int)$userType == $check['custom_groups'][0]) ? $check['custom_groups'][1] : $check['custom_groups'][0];
    
    // =============== Check & Set the user's groups =====================//
    // Check usergroups is array & not empty 
    if(is_array($userGroups) && !empty($userGroups)){        
           // The user is in their correct group
           if($userType > 0){
               if(in_array($userType, $userGroups)){
                   //Check if they are alo in the opposing group
                   if(in_array($otherGroup, $userGroups)){
                       JUserHelper::removeUserFromGroup($userId, $otherGroup);
                       //unset($userGroups[$otherGroup]);
                   }
               }else{// User isn't in their correct group
                   // Add the user to their group
                   JUserHelper::addUserToGroup($userId, $userType);
                   //$userGroups[$userType] = $userType;
                   
                   //Remove from opposing
                   if(in_array($otherGroup, $userGroups)){
                       JUserHelper::removeUserFromGroup($userId, $otherGroup);
                       //unset($userGroups[$otherGroup]);
                   }
               }
           }else{
                // User Doesn't have a usertype set - ADD IT based on their group
               //If creator
               if(in_array($this->params->get('creator_group', 3), $userGroups))
                   // Add to creator type
                   $profile->profile['usertype'] = $this->params->get('creator_group', 3);
               
               //If investor
               if(in_array($this->params->get('investor_group', 2), $userGroups))
                   //Set to investor type
                   $profile->profile['usertype'] = $this->params->get('investor_group', 2);
               
               // RESET usertype var
               $userType = ((int)$profile->profile['usertype'] > 0) ? (int)$profile->profile['usertype'] : 0;
               if($userType > 0)  // if their field is set
                   // Set the Group based on the usertype field
                   JUserHelper::addUserToGroup($userId, $userType);
               
           }//END Else (usertype <= 0)
   }//END IF $userGroups is array and not empty
   
   else{ //The user is not in any groups - check if they have a usertype in profile info and add to that group
       if($userType > 0){
           // Add the user to their group
           JUserHelper::addUserToGroup($userId, $userType);
       }else{
           // Add the users to the default Registration Group
           jimport('joomla.application.component.helper');
           $config = JComponentHelper::getParams('com_users');
           // Default to Registered.
           $defaultUserGroup = $config->get('new_usertype', 2);
           JUserHelper::addUserToGroup($userId, $defaultUserGroup);
       }
   }
           
   // Get the groups again        
   $userGroups = JUserHelper::getUserGroups($userId);
   
   // Get fresh session/user object
   $session = JFactory::getSession();
   $session->set('user', new JUser($userId));
   $user = JFactory::getUser($userId);

   //Check if this is the first login or not and set $loginType
   if($user->guest || $user->lastvisitDate == "0000-00-00 00:00:00" || $user->lastvisitDate == NULL){
       $loginType = "first";
   }
   
   //Check the user groups again now we've added/removed
   if(is_array($userGroups) && !empty($userGroups)){
       //Loop through the users groups to check which group they are in
       foreach($userGroups as $k => $v){
           if(in_array($k, $check['custom_groups'])) //&& $g = $userType
               $return = $check[$loginType][$k];
       }
   }

   // Return $return
   return $return;
}