Helly's router

<?php
/*
=================================
			H E L L Y
---------------------------------
 @author  : Fesor
 @email   : fesors@gmail.com
 @homepage: http://helly.fesor.ru
 @version : 0.8 RC1
 @date    : 07.08.2009
=================================
*/

class router
{
	
	private static $uri, $params, $route, $app;
	
	function __construct()
	{
		
		/* Match URI string */
		//on htaccess isn't in use 
		if( strpos( $_SERVER['REQUEST_URI'], $_SERVER['SCRIPT_NAME'] ) !== false )
			self::$uri = substr( $_SERVER['REQUEST_URI'], strlen( $_SERVER['SCRIPT_NAME'] )+1 );
		else
			self::$uri = substr( $_SERVER['REQUEST_URI'], strlen(substr(ROOT, strlen($_SERVER['DOCUMENT_ROOT']))) );
		
		$uriSegments = explode('/', self::$uri);
		self::$uri = array();
		foreach($uriSegments as $segment)
			if($segment !== '')
				self::$uri[] = $segment;
		
		//Check for Page param
		if(self::$uri[count(self::$uri)-2] == 'page' AND is_numeric(self::$uri[count(self::$uri)-1]))
		{
			$_GET['page'] = self::$uri[count(self::$uri)-1];
			unset(self::$uri[count(self::$uri)-1]);
			unset(self::$uri[count(self::$uri)-2]);
		}
		//Match application
		$apps = system::getConfig('apps');
		if(isset($apps[self::$uri[0]]))
		{
			self::$app = $apps[self::$uri[0]];
			unset(self::$uri[0]);
		}
		else
			self::$app = system::getConfig('defaultApp');
		
		self::$uri = implode('/', self::$uri).'/';
		
		
		if(self::$uri == '/')
			self::$route = (system::getConfig('defaultController', self::$app) == null ? self::$app:system::getConfig('defaultController', self::$app)).'/index';
		elseif(preg_match("/^([A-Za-z0-9\-\_]+)\.html\/$/Uis",self::$uri,$matches))
		{
			self::$route = 'page/show';
			$_GET['name'] = $matches[1];
			self::$app = 'pages';
		}
		else{
			$rules = system::getConfig('routing', self::$app);
			if(!is_array($rules))
				self::http404();
			
			foreach($rules['rules'] as $template=>$route)
			{
				if( $find = preg_match(self::makePattern($template), self::$uri, $matches) )
				{
					self::$route = $route;
					
					foreach(self::$params as $key=>$value)
						$_GET[$key] = $matches[$key];
					break;
				}
			}
				
		}
		
	}
	
	public function getAppName()
	{
		return self::$app;
	}
	
	public function getRoute()
	{
		return self::$route;
	}
	
	public function getURIstring()
	{
		return self::$uri;
	}
	
	private function makePattern($pattern)
	{
		if(preg_match_all('/<(\w+):?(.*?)?>/',$pattern,$matches))
			self::$params=array_combine($matches[1],$matches[2]);
		else
			self::$params=array();
		$p=rtrim($pattern,'*');
		$append=$p!==$pattern;
		$p=trim($p,'/');
		$template=preg_replace('/<(\w+):?.*?>/','<$1>',$p);	
		if(($pos=strpos($p,'<'))!==false)
			$signature=substr($p,0,$pos);
		else
			$signature=$p;
		$tr['/']='\\/';
		foreach(self::$params as $key=>$value)
			$tr["<$key>"]="(?P<$key>".($value!==''?$value:'[^\/]+').')';	
		$pattern='/^'.strtr($template,$tr).'\/';
		if($append)
			$pattern.='/u';
		else
			$pattern.='$/u';

		return $pattern."is";
	}
	
	public static function http404()
	{
		header("HTTP/1.0 404 Not Found");
		die("<h1>404 Error</h1>\n<p>".system::message('Page not found!')."</p>");
	}
	
}