<?php
# -- BEGIN LICENSE BLOCK ----------------------------------
#
# This file is part of Dotclear 2.
#
# Copyright (c) 2003-2008 Olivier Meunier and contributors
# Licensed under the GPL version 2.0 license.
# See LICENSE file or
# http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
#
# -- END LICENSE BLOCK ------------------------------------

class dcFilterFairTrackbacks extends dcSpamFilter
{
	public $name = 'Fair Trackbacks';
	public $has_gui = false;
	public $active = true;
	public $order = -10;
	
	public function __construct(&$core)
	{
		parent::__construct($core);
	}
	
	protected function setInfo()
	{
		$this->description = __('Checks trackback source for a link to the post');
	}
	
	
	public function isSpam($type,$author,$email,$site,$ip,$content,$post_id,&$status)
	{
		if ($type != 'trackback') {
			return;
		}
		
		try
		{
			$default_parse = array('scheme'=>'','host'=>'','path'=>'','query'=>'');
			$S = array_merge($default_parse,parse_url($site));
			
			if ($S['scheme'] != 'http' || !$S['host'] || !$S['path']) {
				throw new Exception('Invalid URL');
			}
			
			# Check incomink link page
			$post = $this->core->blog->getPosts(array('post_id' => $post_id));
			$post_url = $post->getURL();
			$P = array_merge($default_parse,parse_url($post_url));
			
			if ($post_url == $site) {
				throw new Exception('Same source and destination');
			}
			
			$o = netHttp::initClient($site,$path);
			$o->setTimeout(3);
			$o->get($path);
			
			# Trackback source does not return 200 status code
			if ($o->getStatus() != 200) {
				throw new Exception('Invalid Status Code');
			}
			
			$tb_page = $o->getContent();
			
			# Do we find a link to post in trackback source?
			if ($S['host'] == $P['host']) {
				$pattern = $P['path'].($P['query'] ? '?'.$P['query'] : '');
			} else {
				$pattern = $post_url;
			}
			$pattern = preg_quote($pattern,'/');
			
			if (!preg_match('/'.$pattern.'/',$tb_page)) {
				throw new Exception('Unfair');
			}
		}
		catch (Exception $e)
		{
			throw new Exception('Trackback not allowed for this URL.');
		}
	}
}
?>