<?php
/*
 +--------------------------------------------------------------------+
 | CiviCRM version 4.6                                                |
 +--------------------------------------------------------------------+
 | Copyright CiviCRM LLC (c) 2004-2014                                |
 +--------------------------------------------------------------------+
 | This file is a part of CiviCRM.                                    |
 |                                                                    |
 | CiviCRM is free software; you can copy, modify, and distribute it  |
 | under the terms of the GNU Affero General Public License           |
 | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
 |                                                                    |
 | CiviCRM 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 Affero General Public License for more details.        |
 |                                                                    |
 | You should have received a copy of the GNU Affero General Public   |
 | License and the CiviCRM Licensing Exception along                  |
 | with this program; if not, contact CiviCRM LLC                     |
 | at info[AT]civicrm[DOT]org. If you have questions about the        |
 | GNU Affero General Public License or the licensing of CiviCRM,     |
 | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
 +--------------------------------------------------------------------+
*/

/**
 *
 * @package CRM
 * @copyright CiviCRM LLC (c) 2004-2014
 * $Id$
 *
 */
class CRM_Utils_ReCAPTCHA {

  protected $_captcha = NULL;

  protected $_name = NULL;

  protected $_url = NULL;

  protected $_phrase = NULL;

  /**
   * We only need one instance of this object. So we use the singleton
   * pattern and cache the instance in this variable
   *
   * @var object
   * @static
   */
  static private $_singleton = NULL;

  /**
   * Singleton function used to manage this object
   *
   * @param string the key to permit session scope's
   *
   * @return object
   * @static
   *
   */
  public static function &singleton() {
    if (self::$_singleton === NULL) {
      self::$_singleton = new CRM_Utils_ReCAPTCHA();
    }
    return self::$_singleton;
  }

  /**
   *
   */
  public function __construct() {}

  /**
   * Add element to form
   *
   */
  public static function add(&$form) {
    $error  = NULL;
    $config = CRM_Core_Config::singleton();
    $useSSL = FALSE;
    if ( !function_exists( 'recaptcha_get_html' ) ) {
      require_once 'packages/recaptcha/recaptchalib.php';
    }

    // See if we are using SSL
    if (CRM_Utils_System::isSSL()) {
      $useSSL = TRUE;
    }
    $html = recaptcha_get_html($config->recaptchaPublicKey, $error, $useSSL);

    $form->assign('recaptchaHTML', $html);
    $form->assign('recaptchaOptions', $config->recaptchaOptions);
    $form->add(
      'text',
      'recaptcha_challenge_field',
      NULL,
      NULL,
      TRUE
    );
    $form->add(
      'hidden',
      'recaptcha_response_field',
      'manual_challenge'
    );

    $form->registerRule('recaptcha', 'callback', 'validate', 'CRM_Utils_ReCAPTCHA');
    $form->addRule(
      'recaptcha_challenge_field',
      ts('Input text must match the phrase in the image. Please review the image and re-enter matching text.'),
      'recaptcha',
      $form
    );
  }

  /**
   * @param $value
   * @param CRM_Core_Form $form
   *
   * @return mixed
   */
  public static function validate($value, $form) {
    $config = CRM_Core_Config::singleton();

    $resp = recaptcha_check_answer($config->recaptchaPrivateKey,
      $_SERVER['REMOTE_ADDR'],
      $_POST["recaptcha_challenge_field"],
      $_POST["recaptcha_response_field"]
    );
    return $resp->is_valid;
  }
}