CakePHP + Facebook

I am trying to implement facebook Connect to my cakephp Application. i am using Nick's Facebook Plugin.

I wanna implement it this way

1. When a user Visits the Site he should be able to login via Registration on the site or Facebook Connect
2. Existing users should be able to connect their account to their FB account
3. People who first time login to the site using FB Connect and dont have an account on the site. should be redirected to a page where they have to enter details to complete the profile.

What i have done - I have followed the instruction of Nick to implement it and when i click Login - it connects to my app. but i dont understand how to create a username and password associated with the Fb Connect Id. and user it against the FB token.

Apparently I'm doing the same thing a little before you... ;-)

Here's a method for Facebook login I'm using (slightly redacted and annotated):

public function facebook($authorize = null) {
    App::import('Lib', 'Facebook.FB');
    $Fb = new FB();

    $session = $Fb->getSession();

    // not logged into Facebook and not a callback either,
    // sending user over to Facebook to log in
    if (!$session && !$authorize) {
        $params = array(
            'req_perms'  => /* the permissions you require */,
            'next'       => Router::url(array('action' => 'facebook', 'authorize'), true),
            'cancel_url' => Router::url(array('action' => 'login'), true)
        );
        $this->redirect($Fb->getLoginUrl($params));
    }

    // user is coming back from Facebook login,
    // assume we have a valid Facebook session
    $userInfo = $Fb->api('/me');

    if (!$userInfo) {
        // nope, login failed or something went wrong, aborting
        $this->Session->setFlash('Facebook login failed');
        $this->redirect(array('action' => 'login'));
    }

    $user = array(
        'User' => array(
            'firstname'       => $userInfo['first_name'],
            'lastname'        => $userInfo['last_name'],
            'username'        => trim(parse_url($userInfo['link'], PHP_URL_PATH), '/'),
            'email'           => $userInfo['email'],
            'email_validated' => $userInfo['verified']
        ),
        'Oauth' => array(
            'provider'        => 'facebook',
            'provider_uid'    => $userInfo['id']
        )
    );

    $this->oauthLogin($user);
}

This gives me an array with all the user details I could grab from Facebook and invokes ::oauthLogin, which either logs the user in with the given information or asks the user to fill in missing details and/or creates a new user record in the database. The most important part you get from the Facebook API is the $userInfo['id'] and/or email address, either of which you can use to identify the user in your database. If you're using the AuthComponent, you can "manually" log in the user using $this->Auth->login($user_id), where $user_id is the id of the user in your own database.

private function oauthLogin($data) {
    $this->User->create();

    // do we already know about these credentials?
    $oauth = $this->User->Oauth->find('first', array('conditions' => $data['Oauth']));

    if ($oauth) {
        // yes we do, let's try to log this user in
        if (empty($oauth['User']['id']) || !$this->Auth->login($oauth['User']['id'])) {
            $this->Session->setFlash('Login failed');
        }
        $this->redirect('/');
    }

    // no we don't, let's see if we know this email address already
    if (!empty($data['User']['email'])) {
        $user = $this->User->find('first', array('conditions' => array('email' => $data['User']['email'])));
        if ($user) {
            // yes we do! let's store all data in the session
            // and ask the user to associate his accounts

            $data['User'] = array_merge($data['User'], $user['User']);
            $data['Oauth']['user_id'] = $user['User']['id'];

            $this->Session->write('Oauth.associate_accounts', $data);
            $this->redirect(array('action' => 'oauth_associate_accounts'));
        }
    }

    // no, this is a new user, let's ask him to register        
    $this->Session->write('Oauth.register', $data);
    $this->redirect(array('action' => 'oauth_register'));
}