<?php

/*
// +----------------------------------------------------------------------+
// | SimpleCloak                                                          |
// | Class for cloaking content                                           |
// | http://www.SEOEgghead.com                                            |
// +----------------------------------------------------------------------+
// | Copyright (c) 2005-2006 Jaimie Sirovich and Cristian Darie           |
// +----------------------------------------------------------------------+
*/

// load configuration file
require_once('config.inc.php');

class SimpleCloak
{  
  // returns the confidence level
  function isSpider($spider_name = '', $check_uas = true, $check_ips = true)
  {
    // default confidence level to 0
    $confidence = 0;
    
    // matching user agent?    
    if ($check_uas)
      if (SimpleCloak::_get(0, $spider_name, 'UA', $_SERVER['HTTP_USER_AGENT'])) 
        $confidence += 2;
  
    // matching IP?    
    if ($check_ips)
      if (SimpleCloak::_get(0, $spider_name, 'IP', '', $_SERVER['REMOTE_ADDR'])) 
        $confidence += 3;     
    
    // return confidence level
    return $confidence;
  }
  
  // retrieve cloaking data filtered by the supplied parameters
  function _get($id = 0, $spider_name = '', $record_type = '', 
               $value = '', $wildcard_value = '')
  {
    // by default, retrieve all records
    $q = " SELECT cloak_data.* FROM cloak_data WHERE TRUE ";
           
    // add filters
    if ($id) {
      $id = (int) $id;
      $q .= " AND id = $id ";
    }     
    if ($spider_name) {
      $spider_name = mysql_escape_string($spider_name);
      $q .= " AND spider_name = '$spider_name' ";
    }      
    if ($record_type) {            
      $record_type = mysql_escape_string($record_type);
      $q .= " AND record_type = '$record_type' ";
    }      
    if ($value) {  
      $value = mysql_escape_string($value);
      $q .= " AND value = '$value' ";
    }
    if ($wildcard_value) {
      $wildcard_value = mysql_escape_string($wildcard_value);
      $q .= " AND '$wildcard_value' LIKE CONCAT(value, '%') ";
    }
    
    // Connect to MySQL server
    $dbLink = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD)
                    or die("Could not connect: " . mysql_error());

    // Connect to the seophp database 
    mysql_select_db(DB_DATABASE) or die("Could not select database");
          
    // execute the query
    $tmp = mysql_query($q);
    
    // close database connection 
    mysql_close($dbLink);       
      
    // return the results as an associative array
    $rows = array();
    while ($_x = mysql_fetch_assoc($tmp)) {
      $rows[] = $_x;
    }
    return $rows;
  }  
  
  // updates the entire database with fresh spider data, but only if our data is
  // more than 7 days old, and if the online version from iplists.org has changed
  function updateAll()
  {      
    // Connect to MySQL server
    $dbLink = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD)
                    or die("Could not connect: " . mysql_error());

    // Connect to the seophp database 
    mysql_select_db(DB_DATABASE) or die("Could not select database");

    // retrieve last update information from database
    $q = "SELECT cloak_update.* FROM cloak_update";
    $tmp = mysql_query($q);
    $updated = mysql_fetch_assoc($tmp);    
    $db_version = $updated['version']; 
    $updated_on = $updated ['updated_on'];
 
    // get the latest update more recent than 7 days, don't attempt an update    
    if (isset($updated_on) && 
        (strtotime($updated_on) > strtotime("-604800 seconds"))) 
    {
      // close database connection 
      mysql_close($dbLink);
      // return false to indicate an update wasn't performed
      return false;
    }
 
    // read the latest iplists version     
    $version_url = 'http://www.iplists.com/nw/version.php';
    $latest_version = mysql_escape_string(file_get_contents($version_url));

    // if no updated version information was retrieved, abort
    if (!$latest_version) 
    {
      // return false to indicate an update wasn't performed
      return false;
    }
    
    // save the update data
    $q = "DELETE FROM cloak_update";
    mysql_query($q);
    $q = "INSERT INTO cloak_update (version, updated_on) " . 
         "VALUES('$latest_version', NOW())";
    mysql_query($q);
    
    // if we already have the current data, don't attempt an update 
    if ($latest_version == $db_version) 
    {
      // close database connection 
      mysql_close($dbLink);
      // return false to indicate an update wasn't performed
      return false;
    }
 
    // update the database
    SimpleCloak::_updateCloakingDB('google', 
                                  'http://www.iplists.com/nw/google.txt');
    SimpleCloak::_updateCloakingDB('yahoo', 
                                  'http://www.iplists.com/nw/inktomi.txt');
    SimpleCloak::_updateCloakingDB('msn', 
                                  'http://www.iplists.com/nw/msn.txt');
    SimpleCloak::_updateCloakingDB('ask', 
                                  'http://www.iplists.com/nw/askjeeves.txt');
    SimpleCloak::_updateCloakingDB('altavista', 
                                  'http://www.iplists.com/nw/altavista.txt');
    SimpleCloak::_updateCloakingDB('lycos', 
                                  'http://www.iplists.com/nw/lycos.txt');
    SimpleCloak::_updateCloakingDB('wisenut', 
                                  'http://www.iplists.com/nw/wisenut.txt');

    // close connection 
    mysql_close($dbLink);

    // return true to indicate a successful update
    return true;
  }
  
  // update the database for the mentioned spider, by reading the provided URL
  function _updateCloakingDB($spider_name, $url, 
      $ua_regex = '/^# UA "(.*)"$/m', $ip_regex = '/^([0-9.]+)$/m')
  {
    // use cURL to read the data from $url
    // NOTE: additional settings are required when accessing the web through a proxy
    $ch = curl_init();    
    curl_setopt ($ch, CURLOPT_URL, $url);
    curl_setopt ($ch, CURLOPT_HEADER, 1);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt ($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt ($ch, CURLOPT_TIMEOUT, 60);
    $result = curl_exec($ch);
    curl_close($ch);
       
    // use _parseListURL to parse the list of IPs and user agents
    $lists = SimpleCloak::_parseListURL($result, $ua_regex, $ip_regex);
    
    // if the user agents and IPs weren't retrieved, we cancel the update 
    if (!$lists['ua_list'] || !$lists['ip_list']) return;

    // lock the cloack_data table to avoid concurrency problems
    mysql_query('LOCK TABLES cloak_data WRITE');
    
    // delete all the existing data for $spider_name
    SimpleCloak::_deleteSpiderData($spider_name);

    // insert the list of user agents for the spider
    foreach ($lists['ua_list'] as $ua) {
      SimpleCloak::_insertSpiderData($spider_name, 'UA', $ua);
    }

    // insert the list of IPs for the spider
    foreach ($lists['ip_list'] as $ip) {
      SimpleCloak::_insertSpiderData($spider_name, 'IP', $ip);
    }
    
    // release the table lock
    mysql_query('UNLOCK TABLES');
  }
  
  // helper function used to parse lists of user agents and IPs
  function _parseListURL($data, $ua_regex, $ip_regex)
  {
    $ua_list_ret = preg_match_all($ua_regex, $data, $ua_list);
    $ip_list_ret = preg_match_all($ip_regex, $data, $ip_list);
    return array('ua_list' => $ua_list[1], 'ip_list' => $ip_list[1]);  
  }

  // inserts a new row of data to the cloaking table
  function _insertSpiderData($spider_name, $record_type, $value)
  {
    // escape input data
    $spider_name = mysql_escape_string($spider_name);
    $record_type = mysql_escape_string($record_type);
    $value = mysql_escape_string($value);

    // build and execute the INSERT query
    $q  = "INSERT INTO cloak_data (spider_name, record_type, value) " . 
          "VALUES ('$spider_name', '$record_type', '$value')";
    mysql_query($q);            
  }
  
  // delete the cloaking data for the mentioned spider
  function _deleteSpiderData($spider_name)
  { 
    // escape input data
    $spider_name = mysql_escape_string($spider_name);

    // build and execute the DELETE query
    $q = "DELETE FROM cloak_data WHERE spider_name='$spider_name'";
    mysql_query($q);  
  }
}
?>