<?php

$url_patterns =array();

function add_url_handler($pattern, $handler=null, $override=true) {
	global $url_patterns;
	if (is_array($pattern)) {
		if (is_null($handler))
			foreach($pattern as $p => $h)
				add_url_handler($p, $h, $override);
		else
			foreach($pattern as $p)
				add_url_handler($p, $handler, $override);
	}
	else {
		if (!isset($url_patterns[$pattern])) {
			$url_patterns[$pattern] = $handler;
		}
		elseif ($override) {
			logging('DEBUG', "URL : override pattern '$pattern' with handler '$handler' (old handler = '".$url_patterns[$pattern]."')");
			$url_patterns[$pattern] = $handler;
		}
		else {
			logging('DEBUG', "URL : pattern '$pattern' already defined : do not override.");
		}
	}
}

/*
 * Error 404 page
 */
function error_404($url_infos=array()) {
        display_template('error_404.tpl', "Oups ! Page introuvable");
	exit();
}

$_404_url_handler = 'error_404';
function set_404_url_handler($handler=null) {
        global $_404_url_handler;
        $_404_url_handler = $handler;
}


/*
 * URL patterns :
 *
 *   array (
 *     '[URL pattern]' => '[handler]',
 *     [...]
 *   )
 *
 *  Example :
 *
 *   array (
 *     '#get/(?P<name>[a-zA-Z0-9]+)$#' => 'get_by_name',
 *     '#get/status/(?P<status>pending|archived)$#' => 'get_by_status',
 *     '#get/all$#' => 'get_all',
 *   )
 *
 *  Return example (for the last one previous URL pattern) :
 *
 *  return : array (
 *             'handler' => 'get',
 *             'current_page' => 'get/[name]',
 *             'name' => [name],
 *           )
 *
 */
function get_current_url_handler($url_patterns=null, $default_page=false) {
	global $_404_url_handler;
	if (is_null($url_patterns))
		global $url_patterns;
	$current_page = get_current_page();
	if ($current_page === false) {
		logging('FATAL', 'Impossible de déterminer la page demandée. Si le problème persiste, merci de prendre contact avec le support.');
		exit();
	}
	if (!is_array($url_patterns)) {
		logging('FATAL', 'URL : No URL patterns provided !');
		exit();
	}

	logging('DEBUG', "URL : current page = '$current_page'");
	logging('DEBUG', "URL : check current page with the following URL patterns :\n - ".implode("\n - ", array_keys($url_patterns)));
	foreach ($url_patterns as $pattern => $handler) {
		$m = url_match($pattern, $current_page);
		if (is_array($m)) {
			$m['handler'] = $handler;
			$m['current_page'] = $current_page;
			// Reset last redirect
			if (isset($_SESSION['last_redirect']))
				unset($_SESSION['last_redirect']);
			logging('DEBUG', "URL : result :\n".print_r($m, 1));
			return $m;
		}
	}
	if ($default_page !== false) {
		logging('DEBUG', "Current page match with no pattern. Redirect to default page ('$default_page')");
		redirect($default_page);
		exit();
	}
	elseif ($_404_url_handler) {
    logging('DEBUG', "Current page match with no pattern. Use error 404 handler.");
    return array('handler' => $_404_url_handler);
  }
	return False;
}

function url_match($pattern, $current_page=false) {
	if ($current_page === false) {
		$current_page = get_current_page();
		if (!$current_page) return False;
	}
	if (preg_match($pattern, $current_page, $m)) {
		logging('DEBUG', "URL : Match found with pattern '$pattern' :\n\t".str_replace("\n", "\n\t", print_r($m, 1)));
		return $m;
	}
	return False;
}

function get_current_page() {
	if (isset($_REQUEST['go']))
		return $_REQUEST['go'];
	else
		return detect_current_page();
}

function detect_current_page() {
	logging('DEBUG', "URL : request URI = '".$_SERVER['REQUEST_URI']."'");

	$base = get_rewrite_base();
	logging('DEBUG', "URL : rewrite base = '$base'");

	if ($_SERVER['REQUEST_URI'] == $base)
		return '';

	if (substr($_SERVER['REQUEST_URI'], 0, strlen($base)) != $base) {
		logging('ERROR', "URL : request URI (".$_SERVER['REQUEST_URI'].") does not start with rewrite base ($base)");
		return False;
	}

	$current_page = substr($_SERVER['REQUEST_URI'], strlen($base));

	// URL contain params ?
	$params_start = strpos($current_page, '?');
	if ($params_start !== false)
		// Params detected, remove it

		// No page / currrent page start by '?' ?
		if ($params_start == 0)
			return '';
		else
			return substr($current_page, 0, $params_start);

	return $current_page;
}

function get_rewrite_base() {
	global $public_root_url;
	if (preg_match('|^https?://[^/]+/(.*)$|', $public_root_url, $m))
		return '/'.remove_trailing_slash($m[1]).'/';
	elseif (preg_match('|^/(.*)$|', $public_root_url, $m))
		return '/'.remove_trailing_slash($m[1]).'/';
	return '/';
}

function redirect($go=false) {
	global $public_root_url;

	if ($go===false)
		$go = "";

	if (preg_match('#^https?://#',$go))
		$url = $go;
	elseif (isset($public_root_url) && $public_root_url) {
		// Check $public_root_url end
		if (substr($public_root_url, -1)=='/') {
			$public_root_url=substr($public_root_url, 0, -1);
		}
		$url="$public_root_url/$go";
	}
	else
		$url="/$go";

	// Prevent loop
	if (isset($_SESSION['last_redirect']) && $_SESSION['last_redirect'] == $url)
		logging('FATAL', 'Impossible de déterminer la page demandée (boucle). Si le problème persiste, merci de prendre contact avec le support.');
	else
		$_SESSION['last_redirect'] = $url;

	logging('DEBUG',"redirect($go) => Redirect to : <$url>");
	header("Location: $url");
	exit();
}

function handle_url($url_patterns=null, $default_url=null) {
	global $smarty;
	if (is_null($url_patterns)) global $url_patterns;
	if (is_null($default_url)) global $default_url;

	global $url_info;
	$url_info = get_current_url_handler();

	if (!is_array($url_info))
		logging('FATAL', "Une problème est survenu en interprétant l'URL de la page demandée.");

	if (!function_exists($url_info['handler'])) {
		logging('ERROR', "URL handler function ".$url_info['handler']."() does not exists !");
		logging('FATAL', "Cette requête ne peut être traitée.");
	}

	if (isset($smarty) && $smarty)
		$smarty -> assign('url_info', $url_info);

	try {
		return call_user_func($url_info['handler'], $url_info);
	}
	catch (Exception $e) {
		log_exception($e, "An exception occured running URL handler function ".$url_info['handler']."()");
		logging('FATAL', "Cette requête n'a put être traitée correctement.");
	}
}

function remove_trailing_slash($url) {
	if ($url == '/')
		return $url;
	elseif (substr($url, -1) == '/')
		return substr($url, 0, -1);
	return $url;
}

function check_ajax_request($session_key=null) {
	global $ajax, $debug_ajax;
	$ajax=true;

	if (is_null($session_key) && isset($_REQUEST['session_key']))
		$session_key = $_REQUEST['session_key'];

	if ($_SESSION['session_key'] != $session_key) {
		fatal_error('Invalid request');
	}

	if ($debug_ajax)
		logging('DEBUG',"Ajax Request : ".vardump($_REQUEST));
}