<?php

/**
 * Twitter OAuth class
 */
if ( !class_exists( 'TwitterOAuth' ) ) {

  class TwitterOAuth {

    /* Contains the last HTTP status code returned. */

    public $http_code;
    /* Contains the last API call. */
    public $url;
    /* Set up the API root URL. */
    public $host           = "https://api.twitter.com/1.1/";
    /* Set timeout default. */
    public $timeout        = 30;
    /* Set connect timeout. */
    public $connecttimeout = 30;
    /* Verify SSL Cert. */
    public $ssl_verifypeer = FALSE;
    /* Respons format. */
    public $format         = 'json';
    /* Decode returned json data. */
    public $decode_json    = TRUE;
    /* Contains the last HTTP headers returned. */
    public $http_info;
    /* Set the useragnet. */
    public $useragent      = 'TwitterOAuth v0.2.0-beta2';

    /* Immediately retry the API call if the response was not successful. */
    //public $retry = TRUE;

    /**
     * Set API URLS
     */
    function accessTokenURL() {
      return 'https://api.twitter.com/oauth/access_token';

    }

    function authenticateURL() {
      return 'https://api.twitter.com/oauth/authenticate';

    }

    function authorizeURL() {
      return 'https://api.twitter.com/oauth/authorize';

    }

    function requestTokenURL() {
      return 'https://api.twitter.com/oauth/request_token';

    }

    /**
     * Debug helpers
     */
    function lastStatusCode() {
      return $this->http_status;

    }

    function lastAPICall() {
      return $this->last_api_call;

    }

    /**
     * construct TwitterOAuth object
     */
    function __construct( $consumer_key , $consumer_secret , $oauth_token = NULL , $oauth_token_secret = NULL ) {
      $this->sha1_method = new OAuthSignatureMethod_HMAC_SHA1();
      $this->consumer    = new OAuthConsumer( $consumer_key , $consumer_secret );
      if ( !empty( $oauth_token ) && !empty( $oauth_token_secret ) ) {
        $this->token = new OAuthConsumer( $oauth_token , $oauth_token_secret );
      }
      else {
        $this->token = NULL;
      }

    }

    /**
     * Get a request_token from Twitter
     *
     * @returns a key/value array containing oauth_token and oauth_token_secret
     */
    function getRequestToken( $oauth_callback ) {
      $parameters = array( );
      $parameters['oauth_callback'] = $oauth_callback;
      $request                      = $this->oAuthRequest( $this->requestTokenURL() , 'GET' , $parameters );
      $token                        = OAuthUtil::parse_parameters( $request );
      $this->token                  = new OAuthConsumer( $token['oauth_token'] , $token['oauth_token_secret'] );
      return $token;

    }

    /**
     * Get the authorize URL
     *
     * @returns a string
     */
    function getAuthorizeURL( $token , $sign_in_with_twitter = TRUE ) {
      if ( is_array( $token ) ) {
        $token = $token['oauth_token'];
      }
      if ( empty( $sign_in_with_twitter ) ) {
        return $this->authorizeURL() . "?oauth_token={$token}";
      }
      else {
        return $this->authenticateURL() . "?oauth_token={$token}";
      }

    }

    /**
     * Exchange request token and secret for an access token and
     * secret, to sign API calls.
     *
     * @returns array("oauth_token" => "the-access-token",
     *                "oauth_token_secret" => "the-access-secret",
     *                "user_id" => "9436992",
     *                "screen_name" => "abraham")
     */
    function getAccessToken( $oauth_verifier ) {
      $parameters = array( );
      $parameters['oauth_verifier'] = $oauth_verifier;
      $request                      = $this->oAuthRequest( $this->accessTokenURL() , 'GET' , $parameters );
      $token                        = OAuthUtil::parse_parameters( $request );
      $this->token                  = new OAuthConsumer( $token['oauth_token'] , $token['oauth_token_secret'] );
      return $token;

    }

    /**
     * One time exchange of username and password for access token and secret.
     *
     * @returns array("oauth_token" => "the-access-token",
     *                "oauth_token_secret" => "the-access-secret",
     *                "user_id" => "9436992",
     *                "screen_name" => "abraham",
     *                "x_auth_expires" => "0")
     */
    function getXAuthToken( $username , $password ) {
      $parameters = array( );
      $parameters['x_auth_username'] = $username;
      $parameters['x_auth_password'] = $password;
      $parameters['x_auth_mode']     = 'client_auth';
      $request                       = $this->oAuthRequest( $this->accessTokenURL() , 'POST' , $parameters );
      $token                         = OAuthUtil::parse_parameters( $request );
      $this->token                   = new OAuthConsumer( $token['oauth_token'] , $token['oauth_token_secret'] );
      return $token;

    }

    /**
     * GET wrapper for oAuthRequest.
     */
    function get( $url , $parameters = array( ) ) {
      $response = $this->oAuthRequest( $url , 'GET' , $parameters );
      if ( $this->format === 'json' && $this->decode_json ) {
        return json_decode( $response );
      }
      return $response;

    }

    /**
     * POST wrapper for oAuthRequest.
     */
    function post( $url , $parameters = array( ) ) {
      $response = $this->oAuthRequest( $url , 'POST' , $parameters );
      if ( $this->format === 'json' && $this->decode_json ) {
        return json_decode( $response );
      }
      return $response;

    }

    /**
     * DELETE wrapper for oAuthReqeust.
     */
    function delete( $url , $parameters = array( ) ) {
      $response = $this->oAuthRequest( $url , 'DELETE' , $parameters );
      if ( $this->format === 'json' && $this->decode_json ) {
        return json_decode( $response );
      }
      return $response;

    }

    /**
     * Format and sign an OAuth / API request
     */
    function oAuthRequest( $url , $method , $parameters ) {
      if ( strrpos( $url , 'https://' ) !== 0 && strrpos( $url , 'http://' ) !== 0 ) {
        $url     = "{$this->host}{$url}.{$this->format}";
      }
      $request = OAuthRequest::from_consumer_and_token( $this->consumer , $this->token , $method , $url , $parameters );
      $request->sign_request( $this->sha1_method , $this->consumer , $this->token );
      switch ( $method ) {
        case 'GET':
          return $this->http( $request->to_url() , 'GET' );
        default:
          return $this->http( $request->get_normalized_http_url() , $method , $request->to_postdata() );
      }

    }

    /**
     * Make an HTTP request
     *
     * @return API results
     */
    function http( $url , $method , $postfields = NULL ) {
      $this->http_info = array( );
      $ci = curl_init();
      /* Curl settings */
      curl_setopt( $ci , CURLOPT_USERAGENT , $this->useragent );
      curl_setopt( $ci , CURLOPT_CONNECTTIMEOUT , $this->connecttimeout );
      curl_setopt( $ci , CURLOPT_TIMEOUT , $this->timeout );
      curl_setopt( $ci , CURLOPT_RETURNTRANSFER , TRUE );
      curl_setopt( $ci , CURLOPT_HTTPHEADER , array( 'Expect:' ) );
      curl_setopt( $ci , CURLOPT_SSL_VERIFYPEER , $this->ssl_verifypeer );
      curl_setopt( $ci , CURLOPT_HEADERFUNCTION , array( $this , 'getHeader' ) );
      curl_setopt( $ci , CURLOPT_HEADER , FALSE );

      switch ( $method ) {
        case 'POST':
          curl_setopt( $ci , CURLOPT_POST , TRUE );
          if ( !empty( $postfields ) ) {
            curl_setopt( $ci , CURLOPT_POSTFIELDS , $postfields );
          }
          break;
        case 'DELETE':
          curl_setopt( $ci , CURLOPT_CUSTOMREQUEST , 'DELETE' );
          if ( !empty( $postfields ) ) {
            $url = "{$url}?{$postfields}";
          }
      }

      curl_setopt( $ci , CURLOPT_URL , $url );
      $response        = curl_exec( $ci );
      $this->http_code = curl_getinfo( $ci , CURLINFO_HTTP_CODE );
      $this->http_info = array_merge( $this->http_info , curl_getinfo( $ci ) );
      $this->url       = $url;
      curl_close( $ci );
      return $response;

    }

    /**
     * Get the header info to store.
     */
    function getHeader( $ch , $header ) {
      $i = strpos( $header , ':' );
      if ( !empty( $i ) ) {
        $key                     = str_replace( '-' , '_' , strtolower( substr( $header , 0 , $i ) ) );
        $value                   = trim( substr( $header , $i + 2 ) );
        $this->http_header[$key] = $value;
      }
      return strlen( $header );

    }

  }

}