<?php

#  Copyright (C) 2005 Jason Woofenden
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#  
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#  
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.


# return our best guess at the url used to access this page, without the path or query string
function this_url_sans_path() {
	if(strtolower($_SERVER['HTTPS']) == 'on' || strtolower($_SERVER['HTTPS']) == 'yes') {
		$url = 'https';
		$expected_port = 443;
	} else {
		$url = 'http';
		$expected_port = 80;
	}

	$url .= '://';
	if($_SERVER['HTTP_HOST']) {
		$url .= $_SERVER['HTTP_HOST'];
	} else {
		$url .= $_SERVER['SERVER_NAME'];
		if($_SERVER['SERVER_PORT'] != $expected_port) {
			$url .= ':' . $_SERVER['SERVER_PORT'];
		}
	}

	return $url;
}

# just the hostname, no port number
function this_host() {
	if($_SERVER['HTTP_HOST']) {
		$host = $_SERVER['HTTP_HOST'];
		$p = strpos($host, ':');
		if($p) {
			$host = substr($host, 0, $p);
		}
		return $host;
	} else {
		return $_SERVER['SERVER_NAME'];
	}
}


# return our best guess at the url used to access this page
function this_url() {
	$url = this_url_sans_path();

	$url .= $_SERVER['REQUEST_URI'];

	return $url;
}

# sends an HTTP redirect
#
# $url can be:
#   1) a full URL
#   2) an absolute path
#   3) a filename (you can pass a directory/file.html and such, but "../" prefix is not supported yet)
function redirect($url, $status = '302 Moved Temporarily', $message = '') {
	if(!strpos($url, ':')) {
		while(substr($url, 0, 2) == './') {
			$url = substr($url, 2);
		}
		if(substr($url, 0, 1) == '/') {
			$url = this_url_sans_path() . $url;
		} else {
			$url = preg_replace('|/[^/]*$|', "/$url", this_url());
		}
	}
			
	if(function_exists('session_save_messages')) {
		if(function_exists('atexit_now')) {
			atexit_now();
		}
		session_save_messages();
	}

	header("HTTP/1.0 $status");
	header("Location: $url");
	echo($message);
	exit();
}

# output http headers to allow caching of this page forever
function http_cache_forever($cache_control = 'public') {
	header('Last-Modified: '.gmdate('D, d M Y H:i:s', 5025) . ' GMT'); # long time ago
	header("Cache-Control: $cache_control");
	header('Expires: ' . gmdate('D, d M Y H:i:s',time()+31536000) . ' GMT'); # rfc 2616 says not to go more than a year in the future
}

?>