<?php
/**
 * Link script. Gets redirects to the correct page_id 
 * 
 * @author Bert Hofmänner, www.hofmaenner.ch
 * @version 22.03.2006
 */

// set headers to avoid cache
header("Expires: Mon, 16 Apr 1973 05:08:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");

include("config.php");

$error= false;

$page = CFG_ENGINE . "?";
$var = array();

$to = isset($_GET["to"]) ? str_replace("'", "", $_GET["to"]) : false;
$where = $to ? "name='" . $to . "'" : "page_id=" . CFG_HOMEPAGE_ID ;
$error = $to ? false : true;

$sql="select page_id from page where " . $where;
if (!$result=mysql_query($sql)){
	die ("Error: Can't find page");
}

if ($row=mysql_fetch_row($result)){
    $to=$row[0];
} else {
    $to = CFG_HOMEPAGE_ID;
	$error = true;
}

/******************************************************************************
 * get the variables of the http_referer
 *****************************************************************************/

if (isset($_SERVER["HTTP_REFERER"])){
    // $query[1] is the variable part
    $query=explode("?", $_SERVER["HTTP_REFERER"] );
} else {
    $query=array();
}

// if query has no attributes!
if (sizeof($query)>1){;
    $pairs = explode("&", $query[1]);
    for ($i=0; $i < count($pairs); $i++){
    // split key and value
        $query[$i]= explode("=", $pairs[$i]);
        list($key, $val) = $query[$i];
        switch ($key){
            case "page_id":
            case "cmd":
            case "login_msg":
                // do nothing on page_id, cmd and login_msg
                break;
            default:
                $var [$key] = $val;
                break;
        }
    } // end for -> no more pairs left
} else {
    // there were no variables
    $page.="page_id=$to&";
}

/******************************************************************************
 * get the variables of the query string
 *****************************************************************************/

// read the variables of the link
$query = "";
$pairs = explode("&", $_SERVER["QUERY_STRING"]);

for ($i=0; $i < count($pairs); $i++){
    $query[$i]= explode("=", $pairs[$i]);
    list($key, $val) = $query[$i];
    switch ($key){
		case "eng":
        case "page_id":
        case "to":
            // do nothing on to, page_id and eng
            break;
        default:
            $var [$key] = $val;
            break;
    }
}

/******************************************************************************
 * build link
 *****************************************************************************/
 
$page .= "page_id=" . $to . "&";

while (list($key, $val)= each($var)){
    $page .= "$key=$val&";
}

$page = substr($page, 0, strlen($page)-1);

header("Location: $page" . ($error ? "&error=link" : "") );

?>