___________________________________
  
                    Light PHP wrapper for the OAuth 2.0
                    ___________________________________


AUTHOR & CONTACT
================

Charron Pierrick
    - pierrick@webstart.fr

Berejeb Anis
    - anis.berejeb@gmail.com

    
DOCUMENTATION & DOWNLOAD
========================

Latest version is available on github at :
    - https://github.com/adoy/PHP-OAuth2

Documentation can be found on : 
    - https://github.com/adoy/PHP-OAuth2


LICENSE
=======

This Code is released under the GNU LGPL

Please do not change the header of the file(s).

This library is free software; you can redistribute it and/or modify it 
under the terms of the GNU Lesser General Public License as published 
by the Free Software Foundation; either version 2 of the License, or 
(at your option) any later version.

This library is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU Lesser General Public License for more details.


How can I use it ?
==================

// Change path
require('Client.php');
require('GrantType/IGrantType.php');
require('GrantType/AuthorizationCode.php');

// beware: "const" can't be define in a function or if statement.
const CLIENT_ID     = 'your client id';
const CLIENT_SECRET = 'your client secret';

// Please be aware that you can not specify a redirector for the redirect_uri.
// http://tools.ietf.org/html/draft-ietf-oauth-v2-22#section-10.15

const REDIRECT_URI           = 'http://url/of/this.php';
const AUTHORIZATION_ENDPOINT = 'https://graph.facebook.com/oauth/authorize';
const TOKEN_ENDPOINT         = 'https://graph.facebook.com/oauth/access_token';

$client = new OAuth2\Client(CLIENT_ID, CLIENT_SECRET);
if (!isset($_REQUEST['code']))
{

    // state are recommanded in draft #23
    $_SESSION['state'] = md5(uniqid(rand(), TRUE)); // CRSF protection

    $auth_url = $client->getAuthenticationUrl(AUTHORIZATION_ENDPOINT, array(
        'redirect_uri' => REDIRECT_URI,
        'state' => $_SESSION['state']
    ));

    header('Location: ' . $auth_url);
    die(); 

}
else
{
    if ($_REQUEST['state'] == $_SESSION['state']) {

        $params = array(
            'code' => $_GET['code'], 
            'client_id' => $client->getClientId(),
            'redirect_uri' => REDIRECT_URI
        );

        $response = $client->getAccessToken(TOKEN_ENDPOINT, 'authorization_code', $params);

        if (!isset($response['result']['error'])) {

            $info = $response['result'];

            // @todo $info should be saved for further usage (access_token)

            $client->setAccessToken($info['access_token']);

            // Recommendations (security):
            // Don't pass access_token in URL, use HTTP message headers instead
            // Not sure facebook support this.
            // $client->setAccessTokenType(OAuth2\Client::ACCESS_TOKEN_BEARER);

            $response = $client->fetch('https://graph.facebook.com/me');
            var_dump($response, $response['result']);

        } else {
            die($response['result']['error']);
        }
    } else {
        die('Invalid state');
    }
}

How can I add a new Grant Type ? 
================================
Simply write a new class in the namespace OAuth2\GrantType. You can place the class file under GrantType. 
Here is an example :

namespace OAuth2\GrantType;

/**
 * MyCustomGrantType Grant Type 
 */
class MyCustomGrantType implements IGrantType
{
    /**
     * Defines the Grant Type
     * 
     * @var string  Defaults to 'my_custom_grant_type'. 
     */
    const GRANT_TYPE = 'my_custom_grant_type';

    /**
     * Adds a specific Handling of the parameters
     * 
     * @return array of Specific parameters to be sent.
     * @param  mixed  $parameters the parameters array (passed by reference)
     */
    public function validateParameters(&$parameters)
    {
        if (!isset($parameters['first_mandatory_parameter']))
        {
            throw new \Exception('The \'first_mandatory_parameter\' parameter must be defined for the Password grant type');
        }
        elseif (!isset($parameters['second_mandatory_parameter']))
        {
            throw new \Exception('The \'seconde_mandatory_parameter\' parameter must be defined for the Password grant type');
        }
    }
}

call the OAuth client getAccessToken with the grantType you defined in the GRANT_TYPE constant, As following : 
$response = $client->getAccessToken(TOKEN_ENDPOINT, 'my_custom_grant_type', $params);