<?php

/**
* Akismet anti-comment spam service
*
* The class in this package allows use of the {@link http://akismet.com Akismet} anti-comment spam service in any PHP5 application.
*
* This service performs a number of checks on submitted data and returns whether or not the data is likely to be spam.
*
* Please note that in order to use this class, you must have a vaild {@link http://wordpress.com/api-keys/ WordPress API key}.  They are free for non/small-profit types and getting one will only take a couple of minutes.  
*
* For commercial use, please {@link http://akismet.com/commercial/ visit the Akismet commercial licensing page}.
*
* Please be aware that this class is PHP5 only.  Attempts to run it under PHP4 will most likely fail.
*
* See the Akismet class documentation page linked to below for usage information.
*
* @package Akismet
* @author Alex Potsides, {@link http://www.achingbrain.net http://www.achingbrain.net}
* @version 0.1
* @copyright Alex Potsides, {@link http://www.achingbrain.net http://www.achingbrain.net}
* @license http://www.gnu.org/licenses/gpl.html GNU General Public License
*/

/**
*    The Akismet PHP5 Class
*
*  This class takes the functionality from the Akismet WordPress plugin written by {@link http://photomatt.net/ Matt Mullenweg} and allows it to be integrated into any PHP5 application or website.
*
*  The original plugin is {@link http://akismet.com/download/ available on the Akismet website}.
*
*  <b>Usage:</b>
*  <code>
*    $akismet = new Akismet('http://www.example.com/blog/', 'aoeu1aoue');
*    $akismet->setCommentAuthor($name);
*    $akismet->setCommentAuthorEmail($email);
*    $akismet->setCommentAuthorURL($url);
*    $akismet->setCommentContent($comment);
*    $akismet->setPermalink('http://www.example.com/blog/alex/someurl/');
*    if($akismet->isCommentSpam())
*      // store the comment but mark it as spam (in case of a mis-diagnosis)
*    else
*      // store the comment normally
*  </code>
*
*    @package    akismet
*    @name        Akismet
*    @version    0.2
*  @author        Alex Potsides
*  @link        http://www.achingbrain.net/
*/
class Akismet
{
    protected $version = '0.2';
    protected $wordPressAPIKey;
    protected $blogURL;
    protected $comment;
    protected $apiPort;
    protected $akismetServer;
    protected $akismetVersion;
    
    // This prevents some potentially sensitive information from being sent accross the wire.
    protected $ignore = array('HTTP_COOKIE', 
    'HTTP_X_FORWARDED_FOR', 
    'HTTP_X_FORWARDED_HOST', 
    'HTTP_MAX_FORWARDS', 
    'HTTP_X_FORWARDED_SERVER', 
    'REDIRECT_STATUS', 
    'SERVER_PORT', 
    'PATH',
    'DOCUMENT_ROOT',
    'SERVER_ADMIN',
    'QUERY_STRING',
    'PHP_SELF' );
    
    
    /**
    *    @throws    Exception    An exception is thrown if your API key is invalid.
    *    @param    string    Your WordPress API key.
    *    @param    string    $blogURL            The URL of your blog.
    */
    public function __construct($blogURL, $wordPressAPIKey)
    {
        $this->blogURL = $blogURL;
        $this->wordPressAPIKey = $wordPressAPIKey;
        
        // Set some default values
        $this->apiPort = 80;
        $this->akismetServer = 'rest.akismet.com';
        $this->akismetVersion = '1.1';
        
        // Start to populate the comment data
        $this->comment['blog'] = $blogURL;
        $this->comment['user_agent'] = $_SERVER['HTTP_USER_AGENT'];
        $this->comment['referrer'] = $_SERVER['HTTP_REFERER'];
        
        // This is necessary if the server PHP5 is running on has been set up to run PHP4 and
        // PHP5 concurently and is actually running through a separate proxy al a these instructions:
        // http://www.schlitt.info/applications/blog/archives/83_How_to_run_PHP4_and_PHP_5_parallel.html
        // and http://wiki.coggeshall.org/37.html
        // Otherwise the user_ip appears as the IP address of the PHP4 server passing the requests to the 
        // PHP5 one...
        $this->comment['user_ip'] = $_SERVER['REMOTE_ADDR'] != getenv('SERVER_ADDR') ? $_SERVER['REMOTE_ADDR'] : getenv('HTTP_X_FORWARDED_FOR');
        
        // Check to see if the key is valid
        $response = $this->http_post('key=' . $this->wordPressAPIKey . '&blog=' . $this->blogURL, $this->akismetServer, '/' . $this->akismetVersion . '/verify-key');
        
        if($response[1] != 'valid')
        {
            // Whoops, no it's not.  Throw an exception as we can't proceed without a valid API key.
            throw new Exception('Invalid API key.  Please obtain one from http://wordpress.com/api-keys/');
        }
    }
    
    protected function http_post($request, $host, $path)
    {
        $http_request  = "POST " . $path . " HTTP/1.1\r\n";
        $http_request .= "Host: " . $host . "\r\n";
        $http_request .= "Content-Type: application/x-www-form-urlencoded; charset=utf-8\r\n";
        $http_request .= "Content-Length: " . strlen($request) . "\r\n";
        $http_request .= "User-Agent: Akismet PHP5 Class " . $this->version . " | Akismet/1.11\r\n";
        $http_request .= "\r\n";
        $http_request .= $request;
        $socketWriteRead = new SocketWriteRead($host, $this->apiPort, $http_request);
        $socketWriteRead->send();
        
        return explode("\r\n\r\n", $socketWriteRead->getResponse(), 2);
    }
    
    // Formats the data for transmission    echo $sql;
    protected function getQueryString()
    {
        foreach($_SERVER as $key => $value)
        {
            if(!in_array($key, $this->ignore))
            {
                if($key == 'REMOTE_ADDR')
                {
                    $this->comment[$key] = $this->comment['user_ip'];
                }
                else
                {
                    $this->comment[$key] = $value;
                }
            }
        }
        
        $query_string = '';
        
        foreach($this->comment as $key => $data)
        {
            if (!is_array($data)) {
                $query_string .= $key . '=' . urlencode(stripslashes($data)) . '&';
            }
        }
        
        return $query_string;
    }
    
    /**
    *    Tests for spam.
    *
    *    Uses the web service provided by {@link http://www.akismet.com Akismet} to see whether or not the submitted comment is spam.  Returns a boolean value.
    *
    *    @return        bool    True if the comment is spam, false if not
    */
    public function isCommentSpam()
    {
        $response = $this->http_post($this->getQueryString(), $this->wordPressAPIKey . '.rest.akismet.com', '/' . $this->akismetVersion . '/comment-check');
        
        return ($response[1] == 'true');
    }
    
    /**
    *    Submit spam that is incorrectly tagged as ham.
    *
    *    Using this function will make you a good citizen as it helps Akismet to learn from its mistakes.  This will improve the service for everybody.
    */
    public function submitSpam()
    {
        $this->http_post($this->getQueryString(), $this->wordPressAPIKey . '.' . $this->akismetServer, '/' . $this->akismetVersion . '/submit-spam');
    }
    
    /**
    *    Submit ham that is incorrectly tagged as spam.
    *
    *    Using this function will make you a good citizen as it helps Akismet to learn from its mistakes.  This will improve the service for everybody.
    */
    public function submitHam()
    {
        $this->http_post($this->getQueryString(), $this->wordPressAPIKey . '.' . $this->akismetServer, '/' . $this->akismetVersion . '/submit-ham');
    }
    
    /**
    *    To override the user IP address when submitting spam/ham later on
    *
    *    @param string $userip    An IP address.  Optional.
    */
    public function setUserIP($userip)
    {
        $this->comment['user_ip'] = $userip;
    }
    
    /**
    *    To override the referring page when submitting spam/ham later on
    *
    *    @param string $referrer    The referring page.  Optional.
    */
    public function setReferrer($referrer)
    {
        $this->comment['referrer'] = $referrer;
    }
    
    /**
    *    A permanent URL referencing the blog post the comment was submitted to.
    *
    *    @param string $permalink    The URL.  Optional.
    */
    public function setPermalink($permalink)
    {
        $this->comment['permalink'] = $permalink;
    }
    
    /**
    *    The type of comment being submitted.  
    *
    *    May be blank, comment, trackback, pingback, or a made up value like "registration" or "wiki".
    */
    public function setCommentType($commentType)
    {
        $this->comment['comment_type'] = $commentType;
    }
    
    /**
    *    The name that the author submitted with the comment.
    */
    public function setCommentAuthor($commentAuthor)
    {
        $this->comment['comment_author'] = $commentAuthor;
    }
    
    /**
    *    The email address that the author submitted with the comment.
    *
    *    The address is assumed to be valid.
    */
    public function setCommentAuthorEmail($authorEmail)
    {
        $this->comment['comment_author_email'] = $authorEmail;
    }
    
    /**
    *    The URL that the author submitted with the comment.
    */    
    public function setCommentAuthorURL($authorURL)
    {
        $this->comment['comment_author_url'] = $authorURL;
    }
    
    /**
    *    The comment's body text.
    */
    public function setCommentContent($commentBody)
    {
        $this->comment['comment_content'] = $commentBody;
    }
    
    /**
    *    Defaults to 80
    */
    public function setAPIPort($apiPort)
    {
        $this->apiPort = $apiPort;
    }
    
    /**
    *    Defaults to rest.akismet.com
    */
    public function setAkismetServer($akismetServer)
    {
        $this->akismetServer = $akismetServer;
    }
    
    /**
    *    Defaults to '1.1'
    */
    public function setAkismetVersion($akismetVersion)
    {
        $this->akismetVersion = $akismetVersion;
    }
}

/**
*    Utility class used by Akismet
*
*  This class is used by Akismet to do the actual sending and receiving of data.  It opens a connection to a remote host, sends some data and the reads the response and makes it available to the calling program.
*
*  The code that makes up this class originates in the Akismet WordPress plugin, which is {@link http://akismet.com/download/ available on the Akismet website}.
*
*    N.B. It is not necessary to call this class directly to use the Akismet class.  This is included here mainly out of a sense of completeness.
*
*    @package    akismet
*    @name        SocketWriteRead
*    @version    0.1
*  @author        Alex Potsides
*  @link        http://www.achingbrain.net/
*/
class SocketWriteRead
{
    protected $host;
    protected $port;
    protected $request;
    protected $response;
    protected $responseLength;
    protected $errorNumber;
    protected $errorString;
    
    /**
    *    @param    string    $host            The host to send/receive data.
    *    @param    int        $port            The port on the remote host.
    *    @param    string    $request        The data to send.
    *    @param    int        $responseLength    The amount of data to read.  Defaults to 1160 bytes.
    */
    public function __construct($host, $port, $request, $responseLength = 1160)
    {
        $this->host = $host;
        $this->port = $port;
        $this->request = $request;
        $this->responseLength = $responseLength;
        $this->errorNumber = 0;
        $this->errorString = '';
    }
    
    /**
    *  Sends the data to the remote host.
    *
    * @throws    An exception is thrown if a connection cannot be made to the remote host.
    */
    public function send()
    {
        $this->response = '';
        
        $fs = fsockopen($this->host, $this->port, $this->errorNumber, $this->errorString, 3);
        
        if($this->errorNumber != 0)
        {
            throw new Exception('Error connecting to host: ' . $this->host . ' Error number: ' . $this->errorNumber . ' Error message: ' . $this->errorString);
        }
        
        if($fs !== false)
        {
            @fwrite($fs, $this->request);
            
            while(!feof($fs))
            {
                $this->response .= fgets($fs, $this->responseLength);
            }
            
            fclose($fs);
        }
        
    }
    
    /**
    *  Returns the server response text
    *
    *  @return    string
    */
    public function getResponse()
    {
        return $this->response;
    }
    
    /**
    *    Returns the error number
    *
    *    If there was no error, 0 will be returned.
    *
    *    @return int
    */
    public function getErrorNumner()
    {
        return $this->errorNumber;
    }
    
    /**
    *    Returns the error string
    *
    *    If there was no error, an empty string will be returned.
    *
    *    @return string
    */
    public function getErrorString()
    {
        return $this->errorString;
    }
}
?>