<?php
  /**
   * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  class OC_Request {
  	/**
  	 * @brief Check overwrite condition
  	 * @returns bool
  	 */
  	private static function isOverwriteCondition($type = '') {
  		$regex = '/' . OC_Config::getValue('overwritecondaddr', '')  . '/';
  		return $regex === '//' or preg_match($regex, $_SERVER['REMOTE_ADDR']) === 1
  			or ($type !== 'protocol' and OC_Config::getValue('forcessl', false));
  	}
  
  	/**
  	 * @brief Returns the server host
  	 * @returns string the server host
  	 *
  	 * Returns the server host, even if the website uses one or more
  	 * reverse proxies
  	 */
  	public static function serverHost() {
  		if(OC::$CLI) {
  			return 'localhost';
  		}
  		if(OC_Config::getValue('overwritehost', '') !== '' and self::isOverwriteCondition()) {
  			return OC_Config::getValue('overwritehost');
  		}
  		if (isset($_SERVER['HTTP_X_FORWARDED_HOST'])) {
  			if (strpos($_SERVER['HTTP_X_FORWARDED_HOST'], ",") !== false) {
  				$host = trim(array_pop(explode(",", $_SERVER['HTTP_X_FORWARDED_HOST'])));
  			}
  			else{
  				$host=$_SERVER['HTTP_X_FORWARDED_HOST'];
  			}
  		}
  		else{
  			if (isset($_SERVER['HTTP_HOST'])) {
  				return $_SERVER['HTTP_HOST'];
  			}
  			if (isset($_SERVER['SERVER_NAME'])) {
  				return $_SERVER['SERVER_NAME'];
  			}
  			return 'localhost';
  		}
  		return $host;
  	}
  
  
  	/**
  	* @brief Returns the server protocol
  	* @returns string the server protocol
  	*
  	* Returns the server protocol. It respects reverse proxy servers and load balancers
  	*/
  	public static function serverProtocol() {
  		if(OC_Config::getValue('overwriteprotocol', '') !== '' and self::isOverwriteCondition('protocol')) {
  			return OC_Config::getValue('overwriteprotocol');
  		}
  		if (isset($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
  			$proto = strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']);
  		}else{
  			if(isset($_SERVER['HTTPS']) and !empty($_SERVER['HTTPS']) and ($_SERVER['HTTPS']!='off')) {
  				$proto = 'https';
  			}else{
  				$proto = 'http';
  			}
  		}
  		return $proto;
  	}
  
  	/**
  	 * @brief Returns the request uri
  	 * @returns string the request uri
  	 *
  	 * Returns the request uri, even if the website uses one or more
  	 * reverse proxies
  	 */
  	public static function requestUri() {
  		$uri = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : '';
  		if (OC_Config::getValue('overwritewebroot', '') !== '' and self::isOverwriteCondition()) {
  			$uri = self::scriptName() . substr($uri, strlen($_SERVER['SCRIPT_NAME']));
  		}
  		return $uri;
  	}
  
  	/**
  	 * @brief Returns the script name
  	 * @returns string the script name
  	 *
  	 * Returns the script name, even if the website uses one or more
  	 * reverse proxies
  	 */
  	public static function scriptName() {
  		$name = $_SERVER['SCRIPT_NAME'];
  		if (OC_Config::getValue('overwritewebroot', '') !== '' and self::isOverwriteCondition()) {
  			$serverroot = str_replace("\\", '/', substr(__DIR__, 0, -4));
  			$suburi = str_replace("\\", "/", substr(realpath($_SERVER["SCRIPT_FILENAME"]), strlen($serverroot)));
  			$name = OC_Config::getValue('overwritewebroot', '') . $suburi;
  		}
  		return $name;
  	}
  
  	/**
  	 * @brief get Path info from request
  	 * @returns string Path info or false when not found
  	 */
  	public static function getPathInfo() {
  		if (array_key_exists('PATH_INFO', $_SERVER)) {
  			$path_info = $_SERVER['PATH_INFO'];
  		}else{
  			$path_info = self::getRawPathInfo();
  			// following is taken from Sabre_DAV_URLUtil::decodePathSegment
  			$path_info = rawurldecode($path_info);
  			$encoding = mb_detect_encoding($path_info, array('UTF-8', 'ISO-8859-1'));
  
  			switch($encoding) {
  
  				case 'ISO-8859-1' :
  					$path_info = utf8_encode($path_info);
  
  			}
  			// end copy
  		}
  		return $path_info;
  	}
  
  	/**
  	 * @brief get Path info from request, not urldecoded
  	 * @returns string Path info or false when not found
  	 */
  	public static function getRawPathInfo() {
  		$path_info = substr($_SERVER['REQUEST_URI'], strlen($_SERVER['SCRIPT_NAME']));
  		// Remove the query string from REQUEST_URI
  		if ($pos = strpos($path_info, '?')) {
  			$path_info = substr($path_info, 0, $pos);
  		}
  		return $path_info;
  	}
  
  	/**
  	 * @brief Check if this is a no-cache request
  	 * @returns boolean true for no-cache
  	 */
  	static public function isNoCache() {
  		if (!isset($_SERVER['HTTP_CACHE_CONTROL'])) {
  			return false;
  		}
  		return $_SERVER['HTTP_CACHE_CONTROL'] == 'no-cache';
  	}
  
  	/**
  	 * @brief Check if the requestor understands gzip
  	 * @returns boolean true for gzip encoding supported
  	 */
  	static public function acceptGZip() {
  		if (!isset($_SERVER['HTTP_ACCEPT_ENCODING'])) {
  			return false;
  		}
  		$HTTP_ACCEPT_ENCODING = $_SERVER["HTTP_ACCEPT_ENCODING"];
  		if( strpos($HTTP_ACCEPT_ENCODING, 'x-gzip') !== false )
  			return 'x-gzip';
  		else if( strpos($HTTP_ACCEPT_ENCODING, 'gzip') !== false )
  			return 'gzip';
  		return false;
  	}
  
  	/**
  	 * @brief Check if the requester sent along an mtime
  	 * @returns false or an mtime
  	 */
  	static public function hasModificationTime () {
  		if (isset($_SERVER['HTTP_X_OC_MTIME'])) {
  			return $_SERVER['HTTP_X_OC_MTIME'];
  		} else {
  			return false;
  		}
  	}
  }