<?php
/**
 * @link http://bakery.cakephp.org/articles/view/recaptcha-component-helper-for-cakephp
 */
 class RecaptchaComponent extends Object {
    public $publickey = '';
    public $privatekey= '';
    
    public $is_valid = false;
    public $error = "";
    
    public function startup(&$controller){
        $this->publickey = Configure::read('Service.recaptcha_public_key');
        $this->privatekey = Configure::read('Service.recaptcha_private_key');

        Configure::write("Recaptcha.apiServer","http://api.recaptcha.net");
        Configure::write("Recaptcha.apiSecureServer","https://api-secure.recaptcha.net");
        Configure::write("Recaptcha.verifyServer","api-verify.recaptcha.net");
        Configure::write("Recaptcha.pubKey", $this->publickey);
        Configure::write("Recaptcha.privateKey", $this->privatekey);
        
        $this->controller =& $controller;
        $this->controller->helpers[] = "Recaptcha";
    }
    
    public function valid($form){
        if (isset($form['recaptcha_challenge_field']) && isset($form['recaptcha_response_field'])){
            if($this->recaptcha_check_answer(
                $this->privatekey, 
                $_SERVER["REMOTE_ADDR"],
                $form['recaptcha_challenge_field'], 
                $form['recaptcha_response_field']
            ) == 0)
                return false;

            if ($this->is_valid)
                return true;
        }
        return false;
    }
    
    /**
      * Calls an HTTP POST function to verify if the user's guess was correct
      * @param string $privkey
      * @param string $remoteip
      * @param string $challenge
      * @param string $response
      * @param array $extra_params an array of extra variables to post to the server
      * @return ReCaptchaResponse
      */
    public function recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array()){
        if ($privkey == null || $privkey == ''){
            die ("To use reCAPTCHA you must get an API key from <a href='http://recaptcha.net/api/getkey'>http://recaptcha.net/api/getkey</a>");
        }
    
        if ($remoteip == null || $remoteip == ''){
            die ("For security reasons, you must pass the remote ip to reCAPTCHA");
        }        
            
            //discard spam submissions
            if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) {
                    $this->is_valid = false;
                    $this->error = 'incorrect-captcha-sol';
                    return 0;
            }

            $response = $this->_recaptcha_http_post(Configure::read('Recaptcha.verifyServer'), "/verify",
                                              array (
                                                     'privatekey' => $privkey,
                                                     'remoteip' => $remoteip,
                                                     'challenge' => $challenge,
                                                     'response' => $response
                                                     ) + $extra_params
                                              );
    
            $answers = explode ("\n", $response [1]);
            
            if (trim ($answers [0]) == 'true') {
                    $this->is_valid = true;
                    return 1;
            }else{
                    $this->is_valid = false;
                    $this->error = $answers [1];
                    return 0;
            }
    }
    
    
    /**
     * Submits an HTTP POST to a reCAPTCHA server
     * @param string $host
     * @param string $path
     * @param array $data
     * @param int port
     * @return array response
     */
    protected function _recaptcha_http_post($host, $path, $data, $port = 80) {

        $req = $this->_recaptcha_qsencode ($data);

        $http_request  = "POST $path HTTP/1.0\r\n";
        $http_request .= "Host: $host\r\n";
        $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
        $http_request .= "Content-Length: " . strlen($req) . "\r\n";
        $http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
        $http_request .= "\r\n";
        $http_request .= $req;

        $response = '';
        if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {
                die ('Could not open socket');
        }

        fwrite($fs, $http_request);

        while ( !feof($fs) )
                $response .= fgets($fs, 1160); // One TCP-IP packet
        fclose($fs);
        $response = explode("\r\n\r\n", $response, 2);

        return $response;
    }
    
    
    /**
     * Encodes the given data into a query string format
     * @param $data - array of string elements to be encoded
     * @return string - encoded request
     */
    protected function _recaptcha_qsencode ($data) {
        $req = "";
        foreach ( $data as $key => $value )
                $req .= $key . '=' . urlencode( stripslashes($value) ) . '&';

        // Cut the last '&'
        $req=substr($req,0,strlen($req)-1);
        return $req;
    }
}
?>