/EpiFoursquare.php

<?php
/*
 *  Class to integrate with Foursquare's API.
 *    Authenticated calls are done using OAuth and require access tokens for a user.
 *    API calls which do not require authentication do not require tokens
 * 
 *  Full documentation available on github
 *    http://wiki.github.com/jmathai/foursquare-async
 * 
 *  @author Jaisen Mathai <jaisen@jmathai.com>
 */
class EpiFoursquare
{
  protected $clientId, $clientSecret, $accessToken;
  protected $requestTokenUrl= 'https://foursquare.com/oauth2/authenticate';
  protected $accessTokenUrl = 'https://foursquare.com/oauth2/access_token';
  protected $authorizeUrl   = 'https://foursquare.com/oauth/authorize';
  protected $apiUrl         = 'https://api.foursquare.com';
  protected $userAgent      = 'EpiFoursquare (http://github.com/jmathai/foursquare-async/tree/)';
  protected $apiVersion     = 'v2';
  protected $isAsynchronous = false;
  protected $followLocation = false;
  protected $connectionTimeout = 5;
  protected $requestTimeout = 30;
  protected $debug = false;
  protected $verifyCert = false;

  public function getAccessToken($code, $redirectUri)
  {
    $params = array('client_id' => $this->clientId, 'client_secret' => $this->clientSecret, 'grant_type' => 'authorization_code', 'redirect_uri' => $redirectUri, 'code' => $code);
    $qs = http_build_query($params);
    return $this->request('GET', "{$this->accessTokenUrl}", $params);
  }

  public function getAuthorizeUrl($redirectUri)
  {
    $params = array('client_id' => $this->clientId, 'response_type' => 'code', 'redirect_uri' => $redirectUri);
    $qs = http_build_query($params);
    return "{$this->requestTokenUrl}?{$qs}";
  }

  public function setAccessToken($accessToken)
  {
    $this->accessToken = $accessToken;
  }

  public function setTimeout($requestTimeout = null, $connectionTimeout = null)
  {
    if($requestTimeout !== null)
      $this->requestTimeout = floatval($requestTimeout);
    if($connectionTimeout !== null)
      $this->connectionTimeout = floatval($connectionTimeout);
  }

  public function useApiVersion($version = null)
  {
    $this->apiVersion = $version;
  }

  public function useAsynchronous($async = true)
  {
    $this->isAsynchronous = (bool)$async;
  }

  // Public api interface for most calls GET/POST/DELETE
  public function delete($endpoint, $params = null)
  {
    return $this->request('DELETE', $endpoint, $params);
  }

  public function get($endpoint, $params = null)
  {
    return $this->request('GET', $endpoint, $params);
  }

  public function post($endpoint, $params = null)
  {
    return $this->request('POST', $endpoint, $params);
  }

  public function __construct($clientId = null, $clientSecret = null, $accessToken = null)
  {
    $this->clientId = $clientId;
    $this->clientSecret = $clientSecret;
    $this->accessToken = $accessToken;
  }

  private function getApiUrl($endpoint)
  {
    if(!empty($this->apiVersion))
      return "{$this->apiUrl}/{$this->apiVersion}{$endpoint}";
    else
      return "{$this->apiUrl}{$endpoint}";
  }

  private function request($method, $endpoint, $params = null)
  {
    if(preg_match('#^https?://#', $endpoint))
      $url = $endpoint;
    else
      $url = $this->getApiUrl($endpoint);

    if($this->accessToken)
    {
      $params['oauth_token'] = $this->accessToken;
    }
    else
    {
      $params['client_id'] = $this->clientId;
      $params['client_secret'] = $this->clientSecret;
    }

    if($method === 'GET')
      $url .= is_null($params) ? '' : '?'.http_build_query($params, '', '&');
    $ch  = curl_init($url);
    //print_r($url);exit;
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Expect:'));
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, $this->verifyCert);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_TIMEOUT, $this->requestTimeout);
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
    if($method === 'POST' && $params !== null)
    {
      curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($params));
    }

    $resp = new EpiFoursquareJson(EpiCurl::getInstance()->addCurl($ch), $this->debug);
    if(!$this->isAsynchronous)
      $resp->responseText;

    return $resp;
  }
}

class EpiFoursquareJson implements ArrayAccess, Countable, IteratorAggregate
{
  private $debug;
  private $__resp;
  public function __construct($response, $debug = false)
  {
    $this->__resp = $response;
    $this->debug  = $debug;
  }

  // ensure that calls complete by blocking for results, NOOP if already returned
  public function __destruct()
  {
    $this->responseText;
  }

  // Implementation of the IteratorAggregate::getIterator() to support foreach ($this as $...)
  public function getIterator ()
  {
    if ($this->__obj) {
      return new ArrayIterator($this->__obj);
    } else {
      return new ArrayIterator($this->response);
    }
  }

  // Implementation of Countable::count() to support count($this)
  public function count ()
  {
    return count($this->response);
  }
  
  // Next four functions are to support ArrayAccess interface
  // 1
  public function offsetSet($offset, $value) 
  {
    $this->response[$offset] = $value;
  }

  // 2
  public function offsetExists($offset) 
  {
    return isset($this->response[$offset]);
  }
  
  // 3
  public function offsetUnset($offset) 
  {
    unset($this->response[$offset]);
  }

  // 4
  public function offsetGet($offset) 
  {
    return isset($this->response[$offset]) ? $this->response[$offset] : null;
  }

  public function __get($name)
  {
    $accessible = array('responseText'=>1,'headers'=>1,'code'=>1);
    $this->responseText = $this->__resp->data;
    $this->headers      = $this->__resp->headers;
    $this->code         = $this->__resp->code;
    if(isset($accessible[$name]) && $accessible[$name])
      return $this->$name;
    elseif(($this->code < 200 || $this->code >= 400) && !isset($accessible[$name]))
      EpiFoursquareException::raise($this->__resp, $this->debug);

    // Call appears ok so we can fill in the response
    $this->response     = json_decode($this->responseText, 1);
    $this->__obj        = json_decode($this->responseText);

    if(gettype($this->__obj) === 'object')
    {
      foreach($this->__obj as $k => $v)
      {
        $this->$k = $v;
      }
    }

    if (property_exists($this, $name)) {
      return $this->$name;
    }
    return null;
  }

  public function __isset($name)
  {
    $value = self::__get($name);
    return !empty($name);
  }
}

class EpiFoursquareException extends Exception 
{
  public static function raise($response, $debug)
  {
    $message = $response->data;
 
    switch($response->code)
    {
      case 400:
        throw new EpiFoursquareBadRequestException($message, $response->code);
      case 401:
        throw new EpiFoursquareNotAuthorizedException($message, $response->code);
      case 403:
        throw new EpiFoursquareForbiddenException($message, $response->code);
      case 404:
        throw new EpiFoursquareNotFoundException($message, $response->code);
      default:
        throw new EpiFoursquareException($message, $response->code);
    }
  }
}
class EpiFoursquareBadRequestException extends EpiFoursquareException{}
class EpiFoursquareNotAuthorizedException extends EpiFoursquareException{}
class EpiFoursquareForbiddenException extends EpiFoursquareException{}
class EpiFoursquareNotFoundException extends EpiFoursquareException{}