Facebook Login/Signup Example - with account merging

config.php

// Facebook
define('FB_APP_ID', '375664735854032');
define('FB_APP_SECRET', '7fe05d4179b32e5925a96f85c777fa64');

example.php

// require_once(LIB_DIR . 'social/facebook/facebook.php');

... 

// get logged in fb user
$facebook = new Facebook(array(
                    'appId' => FB_APP_ID,
                    'secret' => FB_APP_SECRET,
));

// get logged in fb user id
$userId = $facebook->getUser();
// get array of user info
$user = $facebook->api('/me');

LIB.Facebook.js

var LIB = LIB || {};

LIB.Facebook = {};

LIB.Facebook.appId = 0;

LIB.Facebook.permissions = 'email';

LIB.Facebook.jsLoaded = false;

LIB.Facebook.load = function(appId, locale) {
    LIB.Facebook.appId = appId;
    if(locale == null) {
        locale = 'en_US';
    }
    window.fbAsyncInit = function() {
        LIB.Facebook.init();
    };
  
    (function(d){
        var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
        if (d.getElementById(id)) {
            return;
        }
        js = d.createElement('script');
        js.id = id;
        js.async = true;
        js.src = "//connect.facebook.net/en_US/all.js#xfbml=1&appId=" + LIB.Facebook.appId;
        ref.parentNode.insertBefore(js, ref);
    }(document));
    
}

LIB.Facebook.init = function() {
    FB.init({
        appId      : LIB.Facebook.appId ,
        status     : true, 
        cookie     : true,
        xfbml      : true,
        oauth      : true
    });
    FB.Event.subscribe('auth.login', function(response) {
        LIB.Facebook.onlogin();
    // alert("FB login");
    //      window.location.reload();
    });
    FB.Event.subscribe('auth.logout', function(response) {
        //    alert("FB logout");
        //  window.location.reload();
        });
}; 

/**
 * 
 * response:
 *     authResponse:
 *          accessToken
 *          userID
 *          expiresIn
 *          signedRequest
 *     status
 */
LIB.Facebook.login = function(success, fail) {
    FB.login(function(response) {     
        if(response.status == 'connected') {
            if(success) {
                success();
            }
            //window.location = redirect;
            //LIB.Facebook.onlogin(redirect);
            return true;
        } else {
            if(fail) {
                fail();
            }
            return false;
        }
    }, {
        scope : LIB.Facebook.permissions
    }
    );
}

LIB.Facebook.onlogout = function() {
    window.location = LIB.BASE_URL + 'user/logout';
}


LIB.Facebook.onlogin = function() {
    $.post(LIB.BASE_URL + "json/user/fb/login", function(json) {
        //alert(json.status + "  msg:  " + json.msg + "  data:" + json.data);
        if(json.status == 'OK') {
            if(redirect == null ) {
                redirect = LIB.BASE_URL;
            }
            window.location = redirect;
        } else {
            $("#login_error_msg").html(json.msg);
        }
    },"json");
}
/*
LIB.Facebook.autoLogin = function() {
  //  alert("ON LOGIN");
    $.post(LIB.BASE_URL + "json/user/fb/login", function(json) {
       // alert(json.status + "  msg:  " + json.msg + "  data:" + json.data);
        if(json.status == 'OK') {
            window.location.reload()
        }
    },"json");
}
*/

User.php

// add these function in User.php


    public function fbLogin() {
        // See if there is a user from a cookie
        $user = $this->facebook->getUser();
        if ($user) {
            try {
                $profile = $this->facebook->api('/me');
                $email = $profile['email'];
                $facebook_id = $profile['id'];
                $djname = "DJ " . $profile['first_name'] . " " . $profile['last_name'];

                if ($this->fbIdUnique($facebook_id)) { // new facebook user, handle that
                    // return fail('Facebook Signup disabled for now');
                    // Proceed knowing you have a logged in user who's authenticated.
                    if ($this->emailUnique($email)) { // completely new user
                        //$email, $password, $password_confirm, $tos, $djname, $facebook_id = 0, $twitter_id = 0
                        $ret = $this->signup($email, null, null, 1, $djname, $facebook_id, 0);
                        if ($ret['status'] == 'OK') { // successfully created a new user via FB, now log in
                            return $this->fbLogin();
                        } else {
                            return fail('Succesfully connected to Facebook, Error occured while creating Streamix account');
                        }
                    } else { // user with this email exists, so merge accounts
                        $ret = $this->update(array('facebook_id'))->where('email = :email')->execute(array('facebook_id' => $facebook_id, 'email' => $email));
                        if ($ret['status'] == 'OK') { // successfully merged accounts, now log in
                            return $this->fbLogin();
                        } else {
                            return fail('Succesfully connected to Facebook, Error occured while merging existing Streamix account with Facebook account');
                        }
                    }
                } else { // existing facebook user so, just log in
                    Session::set('facebook_id', $facebook_id);
                    $ret = $this->select()->where(" facebook_id = :facebook_id ")->execute(array('facebook_id' => $facebook_id));
                    if ($ret['status'] == 'OK' && count($ret['data']) == 1) {
                        $this->info['info'] = $ret['data'][0];
                    } else {
                        return fail('An unexpected error occured when logging in via Facebook');
                    }
                    $this->loginSuccess();
                    return success('Logged in!');
                }
            } catch (FacebookApiException $e) {
                return fail('Error occured in Facebook API, please try again later.');
            }
        } else {
            return fail('You do not appear to be logged into Facebook');
        }
        return fail('You do not appear to be logged into Facebook');
    }



    public function fbIdUnique($facebook_id) {
        $info = $this->select(array('id'))->where("facebook_id = :facebook_id")->execute(array('facebook_id' => $facebook_id));
        if ($info['status'] == 'OK') {
            if (count($info['data'])) {
                return false;
            }
        } else {
            return false;
        }
        return true;
    }

view.php

// have this javascript on the signup/signin page, modify as needed

// in header
LIB.Facebook.load('<?php echo FB_APP_ID; ?>', '<?php echo Session::get('locale'); ?>');

$(document).ready(function() {

        $("#login_button").click(function() {
            LIB.Facebook.login(function() {
                $("#login").submit();
            },
            function() {
                alert("facebook login failed");
            });
        });


});