<?php
/*!
* HybridAuth
* http://hybridauth.sourceforge.net | http://github.com/hybridauth/hybridauth
* (c) 2009-2012, HybridAuth authors | http://hybridauth.sourceforge.net/licenses.html
*/

// A service client for the OAuth 2 flow.
// v0.1
class OAuth2Client
{
    public $api_base_url     = "";
    public $authorize_url    = "";
    public $token_url        = "";
    public $token_info_url   = "";

    public $client_id        = "" ;
    public $client_secret    = "" ;
    public $redirect_uri     = "" ;
    public $access_token     = "" ;
    public $refresh_token    = "" ;

    public $access_token_expires_in = "" ;
    public $access_token_expires_at = "" ;

    //--

    public $sign_token_name          = "access_token";
    public $decode_json              = true;
    public $curl_time_out            = 30;
    public $curl_connect_time_out    = 30;
    public $curl_ssl_verifypeer      = false;
    public $curl_header              = array();
    public $curl_useragent           = "OAuth/2 Simple PHP Client v0.1; HybridAuth http://hybridauth.sourceforge.net/";
    public $curl_authenticate_method = "POST";
        public $curl_proxy               = null;

    //--

    public $http_code             = "";
    public $http_info             = "";

    //--

    public function __construct( $client_id = false, $client_secret = false, $redirect_uri='' )
    {
        $this->client_id     = $client_id;
        $this->client_secret = $client_secret;
        $this->redirect_uri  = $redirect_uri;
    }

    public function authorizeUrl( $extras = array() )
    {
        $params = array(
            "client_id"     => $this->client_id,
            "redirect_uri"  => $this->redirect_uri,
            "response_type" => "code"
        );

        if( count($extras) )
            foreach( $extras as $k=>$v )
                $params[$k] = $v;

        return $this->authorize_url . "?" . http_build_query( $params );
    }

    public function authenticate( $code )
    {
        $params = array(
            "client_id"     => $this->client_id,
            "client_secret" => $this->client_secret,
            "grant_type"    => "authorization_code",
            "redirect_uri"  => $this->redirect_uri,
            "code"          => $code
        );

        $response = $this->request( $this->token_url, $params, $this->curl_authenticate_method );

        $response = $this->parseRequestResult( $response );

        if ( ! $response || ! isset( $response->access_token ) ) {
            throw new Exception( "The Authorization Service has return: " . $response->error );
        }

        if( isset( $response->access_token  ) )  $this->access_token           = $response->access_token;
        if( isset( $response->refresh_token ) ) $this->refresh_token           = $response->refresh_token;
        if( isset( $response->expires_in    ) ) $this->access_token_expires_in = $response->expires_in;

        // calculate when the access token expire
        if ( isset($response->expires_in)) {
            $this->access_token_expires_at = time() + $response->expires_in;
        }

        return $response;
    }

    public function authenticated()
    {
        if ($this->access_token) {
            if ($this->token_info_url && $this->refresh_token) {
                // check if this access token has expired,
                $tokeninfo = $this->tokenInfo( $this->access_token );

                // if yes, access_token has expired, then ask for a new one
                if ( $tokeninfo && isset( $tokeninfo->error ) ) {
                    $response = $this->refreshToken( $this->refresh_token );

                    // if wrong response
                    if ( ! isset( $response->access_token ) || ! $response->access_token ) {
                        throw new Exception( "The Authorization Service has return an invalid response while requesting a new access token. given up!" );
                    }

                    // set new access_token
                    $this->access_token = $response->access_token;
                }
            }

            return true;
        }

        return false;
    }

    /**
    * Format and sign an oauth for provider api
    */
    public function api( $url, $method = "GET", $parameters = array() )
    {
        if ( strrpos($url, 'http://') !== 0 && strrpos($url, 'https://') !== 0 ) {
            $url = $this->api_base_url . $url;
        }

        $parameters[$this->sign_token_name] = $this->access_token;
        $response = null;

        switch ($method) {
            case 'GET'  : $response = $this->request( $url, $parameters, "GET"  ); break;
            case 'POST' : $response = $this->request( $url, $parameters, "POST" ); break;
        }

        if ($response && $this->decode_json) {
            $response = json_decode( $response );
        }

        return $response;
    }

    /**
    * GET wrappwer for provider apis request
    */
    public function get( $url, $parameters = array() )
    {
        return $this->api( $url, 'GET', $parameters );
    }

    /**
    * POST wreapper for provider apis request
    */
    public function post( $url, $parameters = array() )
    {
        return $this->api( $url, 'POST', $parameters );
    }

    // -- tokens

    public function tokenInfo($accesstoken)
    {
        $params['access_token'] = $this->access_token;
        $response = $this->request( $this->token_info_url, $params );

        return $this->parseRequestResult( $response );
    }

    public function refreshToken( $parameters = array() )
    {
        $params = array(
            "client_id"     => $this->client_id,
            "client_secret" => $this->client_secret,
            "grant_type"    => "refresh_token"
        );

        foreach ($parameters as $k=>$v) {
            $params[$k] = $v;
        }

        $response = $this->request( $this->token_url, $params, "POST" );

        return $this->parseRequestResult( $response );
    }

    // -- utilities

    private function request( $url, $params=false, $type="GET" )
    {
        Hybrid_Logger::info( "Enter OAuth2Client::request( $url )" );
        Hybrid_Logger::debug( "OAuth2Client::request(). dump request params: ", serialize( $params ) );

        if ($type == "GET") {
            $url = $url . ( strpos( $url, '?' ) ? '&' : '?' ) . http_build_query( $params );
        }

        $this->http_info = array();
        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL            , $url );
        curl_setopt($ch, CURLOPT_RETURNTRANSFER , 1 );
        curl_setopt($ch, CURLOPT_TIMEOUT        , $this->curl_time_out );
        curl_setopt($ch, CURLOPT_USERAGENT      , $this->curl_useragent );
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT , $this->curl_connect_time_out );
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER , $this->curl_ssl_verifypeer );
        curl_setopt($ch, CURLOPT_HTTPHEADER     , $this->curl_header );

        if ($this->curl_proxy) {
            curl_setopt( $ch, CURLOPT_PROXY        , $this->curl_proxy);
        }

        if ($type == "POST") {
            curl_setopt($ch, CURLOPT_POST, 1);
            if($params) curl_setopt( $ch, CURLOPT_POSTFIELDS, $params );
        }

        $response = curl_exec($ch);
        Hybrid_Logger::debug( "OAuth2Client::request(). dump request info: ", serialize( curl_getinfo($ch) ) );
        Hybrid_Logger::debug( "OAuth2Client::request(). dump request result: ", serialize( $response ) );

        $this->http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $this->http_info = array_merge($this->http_info, curl_getinfo($ch));

        curl_close ($ch);

        return $response;
    }

    private function parseRequestResult( $result )
    {
        if( json_decode( $result ) ) return json_decode( $result );

        parse_str( $result, $ouput );

        $result = new StdClass();

        foreach( $ouput as $k => $v )
            $result->$k = $v;

        return $result;
    }
}
