<?php

/*

  Class: Comments

  

  Used to interface with the storage mechanism.

  

  This instance supports XML.

*/

class Comments extends DataLayer {

  private $filename;

  private $handle;



  /*

    Function: __construct

    

    Sets the filename, gets a file resource handle, and locks the XML file.

  */

  public function __construct() {

    $this->filename = realpath(dirname(__FILE__) . '/' . JB_XML_FILENAME);

    $this->handle = @fopen($this->filename, 'r+') or die('<p><strong>Error:</strong> Could not open XML file. Make sure your server has correct permissions.</p>');

    flock($this->handle, LOCK_EX);

  }

  

  public function __destruct() {

    @flock($this->handle, LOCK_UN);

    @fclose($this->handle);

  }

  /*

    Function: getContents

    

    Gets contents from the XML file.

    

    Returns:

      String

  */

  private function getContents() {

    $contents = fread($this->handle, filesize($this->filename)) or die('Can\'t read file.');

    fseek($this->handle, 0);

    return (string) $contents;

  } 

  

  /*

    Function: putContents

    

    Writes to the XML file.

    

    Parameters:

      $contents - string to write to the XML file.

  */

  private function putContents($contents) {

    if (strlen($contents) > 25) {
      ftruncate($this->handle, 0);
      fwrite($this->handle, $contents) or die('Could not write to file.');
    }

  }

  

  /*

    Function: deleteComment

    

    Deletes a comment given the comment ID.

    

    Parameters:

      id - comment ID

  */

  public function deleteComment($id) {

    $xml = new DOMDocument();

    $xml->validateOnParse=true;

    $xml->loadXML($this->getContents(true));

    $message = $xml->getElementById($id);

    $parentNode = $message->parentNode;

    $parentNode->removeChild($message);

    $this->putContents($xml->saveXML());

  }

  

  /*

    Function: deleteSpam

    

    Deletes all comments classified as spam.

  */

  public function deleteSpam() {

    $xml = new DOMDocument();

    $xml->validateOnParse=true;

    $xml->loadXML($this->getContents(true));

    $xpath = new DOMXPath($xml);

    $spams = $xpath->query("/messages/message[spam=1]");

    foreach ($spams as $spam){

      $parentNode = $spam->parentNode;

      $parentNode->removeChild($spam);

    }

    $this->putContents($xml->saveXML());

  }

  

  /*

    Function: addComment

    

    Adds a comment.

    

    Parameters:

      $data - associative array of data, must contain 'name', 'website', 'comment', 'date', 'user_ip', 'user_agent', and 'spam'.

      

    Returns:

      ID of the new comment. 

  */

  public function addComment($data) {

    $xml = new SimpleXMLElement($this->getContents(true));

    $message = $xml->addChild('message');

    $id = $this->generateID();

    $message->addAttribute('mID', $id);

    foreach ($data as $key => $value) {

      $message->addChild($key, htmlspecialchars($value, ENT_QUOTES));

    }

    $this->putContents($xml->asXML());

    

    return $id;

  }

  

  /*

    Function: reclassifyComment

    

    Marks comment as spam or not spam given its current classification.

    

    Parameters:

     $id - comment ID

  */

  public function reclassifyComment($id) {

    $xml = new SimpleXMLElement($this->getContents(true));

    $message = $xml->xpath("/messages/message[@mID='$id']");

    $message = $message[0];

    if ((int) $message->spam) {

      $new_type = 'ham';

      $new_value = 0;

    } else {

      $new_type = 'spam';

      $new_value = 1;

    }

    $message->spam = $new_value;

    

    $this->notifyAkismet($message, $new_type);

    

    $this->putContents($xml->asXML());

  }

  

  /*

    Function: getCount

    

    Gets the number of the specified type of comments.

    

    Parameters:

      $filter - type of comments, 0 for ham, 1 for spam

      

    Returns:

      Number

  */

  public function getCount($filter) {

    $xml = new SimpleXMLElement($this->getContents());

    return count($xml->xpath("/messages/message[spam=$filter]"));

  }

  

  /*

    Function: getComments

    

    Gets all comments of specified type.

    

    Parameters:

      $filter - type of comment, 1 for spam, 0 for ham

      $limit - single value will get last [value] comments, array['upper'] and array['lower'] will get a range

    

    Returns:

      Multi-dimensional array

  */

  public function getComments($filter, $limit = null) {

    $xml = new SimpleXMLElement($this->getContents());

    $comments = $xml->xpath("//message[spam=$filter]");

    if (isset($limit)) {

      if (is_array($limit)) {

        if ($limit['lower'] < 0) $limit['lower'] = 0;

        $show = abs($limit['lower'] - $limit['upper']);

        $comments = array_slice($comments, $limit['lower'], $show);

      } else {

        $end = count($comments) - $limit;

        $end = ($end < 0) ? 0 : $end;

        $comments = array_slice($comments, $end);

      }

    }

    $data = array();

    foreach ($comments as $key => $message) {

      $data[$key]['name'] = (string)$message->name;

      $data[$key]['website'] = (string)$message->website;

      $data[$key]['comment'] = (string)$message->comment;

      $data[$key]['date'] = (string)$message->date;

      $data[$key]['id'] = (string)$message['mID'];

    }

    return array_reverse($data);

  }

  

  /*

    Function: notifyAkismet

    

    Called when a comment is reclassified.

    

    Parameters:

      $obj - comment array

      $type - new type, 'spam' or 'ham'

  */

  protected function notifyAkismet($obj, $type) {

    if (JB_AKISMET_KEY != '') {

      if ((string) $obj->user_ip != '' && (string) $obj->user_agent != '') {

      

        $vars = array();

        $vars['user_ip'] = (string) $obj->user_ip;

        $vars['user_agent'] = (string) $obj->user_agent;

        $vars['comment_content'] = (string) $obj->comment;

        $vars['comment_author'] = (string) $obj->name;

        $vars['comment_author_url'] = (string) $obj->website;

      

        $akismet = new MicroAkismet(JB_AKISMET_KEY, JB_GUESTBOOK_URL, 'JibberBook/' . JB_VERSION . ' | microakismet/' . JB_MA_VERSION);

        $akismet->$type($vars);

      }

    }

  }

}

?>