<?php
/**
 * CHttpRequest and CCookieCollection class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */


/**
 * CHttpRequest encapsulates the $_SERVER variable and resolves its inconsistency among different Web servers.
 *
 * CHttpRequest also manages the cookies sent from and sent to the user.
 * By setting {@link enableCookieValidation} to true,
 * cookies sent from the user will be validated to see if they are tampered.
 * The property {@link getCookies cookies} returns the collection of cookies.
 * For more details, see {@link CCookieCollection}.
 *
 * CHttpRequest is a default application component loaded by {@link CWebApplication}. It can be
 * accessed via {@link CWebApplication::getRequest()}.
 *
 * @property string $url Part of the request URL after the host info.
 * @property string $hostInfo Schema and hostname part (with port number if needed) of the request URL (e.g. http://www.yiiframework.com).
 * @property string $baseUrl The relative URL for the application.
 * @property string $scriptUrl The relative URL of the entry script.
 * @property string $pathInfo Part of the request URL that is after the entry script and before the question mark.
 * Note, the returned pathinfo is decoded starting from 1.1.4.
 * Prior to 1.1.4, whether it is decoded or not depends on the server configuration
 * (in most cases it is not decoded).
 * @property string $requestUri The request URI portion for the currently requested URL.
 * @property string $queryString Part of the request URL that is after the question mark.
 * @property boolean $isSecureConnection If the request is sent via secure channel (https).
 * @property string $requestType Request type, such as GET, POST, HEAD, PUT, DELETE.
 * @property boolean $isPostRequest Whether this is a POST request.
 * @property boolean $isDeleteRequest Whether this is a DELETE request.
 * @property boolean $isPutRequest Whether this is a PUT request.
 * @property boolean $isAjaxRequest Whether this is an AJAX (XMLHttpRequest) request.
 * @property boolean $isFlashRequest Whether this is an Adobe Flash or Adobe Flex request.
 * @property string $serverName Server name.
 * @property integer $serverPort Server port number.
 * @property string $urlReferrer URL referrer, null if not present.
 * @property string $userAgent User agent, null if not present.
 * @property string $userHostAddress User IP address.
 * @property string $userHost User host name, null if cannot be determined.
 * @property string $scriptFile Entry script file path (processed w/ realpath()).
 * @property array $browser User browser capabilities.
 * @property string $acceptTypes User browser accept types, null if not present.
 * @property integer $port Port number for insecure requests.
 * @property integer $securePort Port number for secure requests.
 * @property CCookieCollection $cookies The cookie collection.
 * @property string $preferredLanguage The user preferred language.
 * @property string $csrfToken The random token for CSRF validation.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id$
 * @package system.web
 * @since 1.0
 */
class CHttpRequest extends CApplicationComponent
{
	/**
	 * @var boolean whether cookies should be validated to ensure they are not tampered. Defaults to false.
	 */
	public $enableCookieValidation=false;
	/**
	 * @var boolean whether to enable CSRF (Cross-Site Request Forgery) validation. Defaults to false.
	 * By setting this property to true, forms submitted to an Yii Web application must be originated
	 * from the same application. If not, a 400 HTTP exception will be raised.
	 * Note, this feature requires that the user client accepts cookie.
	 * You also need to use {@link CHtml::form} or {@link CHtml::statefulForm} to generate
	 * the needed HTML forms in your pages.
	 * @see http://seclab.stanford.edu/websec/csrf/csrf.pdf
	 */
	public $enableCsrfValidation=false;
	/**
	 * @var string the name of the token used to prevent CSRF. Defaults to 'YII_CSRF_TOKEN'.
	 * This property is effectively only when {@link enableCsrfValidation} is true.
	 */
	public $csrfTokenName='YII_CSRF_TOKEN';
	/**
	 * @var array the property values (in name-value pairs) used to initialize the CSRF cookie.
	 * Any property of {@link CHttpCookie} may be initialized.
	 * This property is effective only when {@link enableCsrfValidation} is true.
	 */
	public $csrfCookie;

	private $_requestUri;
	private $_pathInfo;
	private $_scriptFile;
	private $_scriptUrl;
	private $_hostInfo;
	private $_baseUrl;
	private $_cookies;
	private $_preferredLanguage;
	private $_csrfToken;
	private $_deleteParams;
	private $_putParams;

	/**
	 * Initializes the application component.
	 * This method overrides the parent implementation by preprocessing
	 * the user request data.
	 */
	public function init()
	{
		parent::init();
		$this->normalizeRequest();
	}

	/**
	 * Normalizes the request data.
	 * This method strips off slashes in request data if get_magic_quotes_gpc() returns true.
	 * It also performs CSRF validation if {@link enableCsrfValidation} is true.
	 */
	protected function normalizeRequest()
	{
		// normalize request
		if(function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc())
		{
			if(isset($_GET))
				$_GET=$this->stripSlashes($_GET);
			if(isset($_POST))
				$_POST=$this->stripSlashes($_POST);
			if(isset($_REQUEST))
				$_REQUEST=$this->stripSlashes($_REQUEST);
			if(isset($_COOKIE))
				$_COOKIE=$this->stripSlashes($_COOKIE);
		}

		if($this->enableCsrfValidation)
			Yii::app()->attachEventHandler('onBeginRequest',array($this,'validateCsrfToken'));
	}


	/**
	 * Strips slashes from input data.
	 * This method is applied when magic quotes is enabled.
	 * @param mixed $data input data to be processed
	 * @return mixed processed data
	 */
	public function stripSlashes(&$data)
	{
		return is_array($data)?array_map(array($this,'stripSlashes'),$data):stripslashes($data);
	}

	/**
	 * Returns the named GET or POST parameter value.
	 * If the GET or POST parameter does not exist, the second parameter to this method will be returned.
	 * If both GET and POST contains such a named parameter, the GET parameter takes precedence.
	 * @param string $name the GET parameter name
	 * @param mixed $defaultValue the default parameter value if the GET parameter does not exist.
	 * @return mixed the GET parameter value
	 * @see getQuery
	 * @see getPost
	 */
	public function getParam($name,$defaultValue=null)
	{
		return isset($_GET[$name]) ? $_GET[$name] : (isset($_POST[$name]) ? $_POST[$name] : $defaultValue);
	}

	/**
	 * Returns the named GET parameter value.
	 * If the GET parameter does not exist, the second parameter to this method will be returned.
	 * @param string $name the GET parameter name
	 * @param mixed $defaultValue the default parameter value if the GET parameter does not exist.
	 * @return mixed the GET parameter value
	 * @see getPost
	 * @see getParam
	 */
	public function getQuery($name,$defaultValue=null)
	{
		return isset($_GET[$name]) ? $_GET[$name] : $defaultValue;
	}

	/**
	 * Returns the named POST parameter value.
	 * If the POST parameter does not exist, the second parameter to this method will be returned.
	 * @param string $name the POST parameter name
	 * @param mixed $defaultValue the default parameter value if the POST parameter does not exist.
	 * @return mixed the POST parameter value
	 * @see getParam
	 * @see getQuery
	 */
	public function getPost($name,$defaultValue=null)
	{
		return isset($_POST[$name]) ? $_POST[$name] : $defaultValue;
	}

	/**
	 * Returns the named DELETE parameter value.
	 * If the DELETE parameter does not exist or if the current request is not a DELETE request,
	 * the second parameter to this method will be returned.
	 * If the DELETE request was tunneled through POST via _method parameter, the POST parameter
	 * will be returned instead (available since version 1.1.11).
	 * @param string $name the DELETE parameter name
	 * @param mixed $defaultValue the default parameter value if the DELETE parameter does not exist.
	 * @return mixed the DELETE parameter value
	 * @since 1.1.7
	 */
	public function getDelete($name,$defaultValue=null)
	{
		if($this->getIsDeleteViaPostRequest())
			return $this->getPost($name, $defaultValue);

		if($this->_deleteParams===null)
			$this->_deleteParams=$this->getIsDeleteRequest() ? $this->getRestParams() : array();
		return isset($this->_deleteParams[$name]) ? $this->_deleteParams[$name] : $defaultValue;
	}

	/**
	 * Returns the named PUT parameter value.
	 * If the PUT parameter does not exist or if the current request is not a PUT request,
	 * the second parameter to this method will be returned.
	 * If the PUT request was tunneled through POST via _method parameter, the POST parameter
	 * will be returned instead (available since version 1.1.11).
	 * @param string $name the PUT parameter name
	 * @param mixed $defaultValue the default parameter value if the PUT parameter does not exist.
	 * @return mixed the PUT parameter value
	 * @since 1.1.7
	 */
	public function getPut($name,$defaultValue=null)
	{
		if($this->getIsPutViaPostReqest())
			return $this->getPost($name, $defaultValue);

		if($this->_putParams===null)
			$this->_putParams=$this->getIsPutRequest() ? $this->getRestParams() : array();
		return isset($this->_putParams[$name]) ? $this->_putParams[$name] : $defaultValue;
	}

	/**
	 * Returns the PUT or DELETE request parameters.
	 * @return array the request parameters
	 * @since 1.1.7
	 */
	protected function getRestParams()
	{
		$result=array();
		if(function_exists('mb_parse_str'))
			mb_parse_str(file_get_contents('php://input'), $result);
		else
			parse_str(file_get_contents('php://input'), $result);
		return $result;
	}

	/**
	 * Returns the currently requested URL.
	 * This is the same as {@link getRequestUri}.
	 * @return string part of the request URL after the host info.
	 */
	public function getUrl()
	{
		return $this->getRequestUri();
	}

	/**
	 * Returns the schema and host part of the application URL.
	 * The returned URL does not have an ending slash.
	 * By default this is determined based on the user request information.
	 * You may explicitly specify it by setting the {@link setHostInfo hostInfo} property.
	 * @param string $schema schema to use (e.g. http, https). If empty, the schema used for the current request will be used.
	 * @return string schema and hostname part (with port number if needed) of the request URL (e.g. http://www.yiiframework.com)
	 * @see setHostInfo
	 */
	public function getHostInfo($schema='')
	{
		if($this->_hostInfo===null)
		{
			if($secure=$this->getIsSecureConnection())
				$http='https';
			else
				$http='http';
			if(isset($_SERVER['HTTP_HOST']))
				$this->_hostInfo=$http.'://'.$_SERVER['HTTP_HOST'];
			else
			{
				$this->_hostInfo=$http.'://'.$_SERVER['SERVER_NAME'];
				$port=$secure ? $this->getSecurePort() : $this->getPort();
				if(($port!==80 && !$secure) || ($port!==443 && $secure))
					$this->_hostInfo.=':'.$port;
			}
		}
		if($schema!=='')
		{
			$secure=$this->getIsSecureConnection();
			if($secure && $schema==='https' || !$secure && $schema==='http')
				return $this->_hostInfo;

			$port=$schema==='https' ? $this->getSecurePort() : $this->getPort();
			if($port!==80 && $schema==='http' || $port!==443 && $schema==='https')
				$port=':'.$port;
			else
				$port='';

			$pos=strpos($this->_hostInfo,':');
			return $schema.substr($this->_hostInfo,$pos,strcspn($this->_hostInfo,':',$pos+1)+1).$port;
		}
		else
			return $this->_hostInfo;
	}

	/**
	 * Sets the schema and host part of the application URL.
	 * This setter is provided in case the schema and hostname cannot be determined
	 * on certain Web servers.
	 * @param string $value the schema and host part of the application URL.
	 */
	public function setHostInfo($value)
	{
		$this->_hostInfo=rtrim($value,'/');
	}

	/**
	 * Returns the relative URL for the application.
	 * This is similar to {@link getScriptUrl scriptUrl} except that
	 * it does not have the script file name, and the ending slashes are stripped off.
	 * @param boolean $absolute whether to return an absolute URL. Defaults to false, meaning returning a relative one.
	 * @return string the relative URL for the application
	 * @see setScriptUrl
	 */
	public function getBaseUrl($absolute=false)
	{
		if($this->_baseUrl===null)
			$this->_baseUrl=rtrim(dirname($this->getScriptUrl()),'\\/');
		return $absolute ? $this->getHostInfo() . $this->_baseUrl : $this->_baseUrl;
	}

	/**
	 * Sets the relative URL for the application.
	 * By default the URL is determined based on the entry script URL.
	 * This setter is provided in case you want to change this behavior.
	 * @param string $value the relative URL for the application
	 */
	public function setBaseUrl($value)
	{
		$this->_baseUrl=$value;
	}

	/**
	 * Returns the relative URL of the entry script.
	 * The implementation of this method referenced Zend_Controller_Request_Http in Zend Framework.
	 * @return string the relative URL of the entry script.
	 */
	public function getScriptUrl()
	{
		if($this->_scriptUrl===null)
		{
			$scriptName=basename($_SERVER['SCRIPT_FILENAME']);
			if(basename($_SERVER['SCRIPT_NAME'])===$scriptName)
				$this->_scriptUrl=$_SERVER['SCRIPT_NAME'];
			else if(basename($_SERVER['PHP_SELF'])===$scriptName)
				$this->_scriptUrl=$_SERVER['PHP_SELF'];
			else if(isset($_SERVER['ORIG_SCRIPT_NAME']) && basename($_SERVER['ORIG_SCRIPT_NAME'])===$scriptName)
				$this->_scriptUrl=$_SERVER['ORIG_SCRIPT_NAME'];
			else if(($pos=strpos($_SERVER['PHP_SELF'],'/'.$scriptName))!==false)
				$this->_scriptUrl=substr($_SERVER['SCRIPT_NAME'],0,$pos).'/'.$scriptName;
			else if(isset($_SERVER['DOCUMENT_ROOT']) && strpos($_SERVER['SCRIPT_FILENAME'],$_SERVER['DOCUMENT_ROOT'])===0)
				$this->_scriptUrl=str_replace('\\','/',str_replace($_SERVER['DOCUMENT_ROOT'],'',$_SERVER['SCRIPT_FILENAME']));
			else
				throw new CException(Yii::t('yii','CHttpRequest is unable to determine the entry script URL.'));
		}
		return $this->_scriptUrl;
	}

	/**
	 * Sets the relative URL for the application entry script.
	 * This setter is provided in case the entry script URL cannot be determined
	 * on certain Web servers.
	 * @param string $value the relative URL for the application entry script.
	 */
	public function setScriptUrl($value)
	{
		$this->_scriptUrl='/'.trim($value,'/');
	}

	/**
	 * Returns the path info of the currently requested URL.
	 * This refers to the part that is after the entry script and before the question mark.
	 * The starting and ending slashes are stripped off.
	 * @return string part of the request URL that is after the entry script and before the question mark.
	 * Note, the returned pathinfo is decoded starting from 1.1.4.
	 * Prior to 1.1.4, whether it is decoded or not depends on the server configuration
	 * (in most cases it is not decoded).
	 * @throws CException if the request URI cannot be determined due to improper server configuration
	 */
	public function getPathInfo()
	{
		if($this->_pathInfo===null)
		{
			$pathInfo=$this->getRequestUri();

			if(($pos=strpos($pathInfo,'?'))!==false)
			   $pathInfo=substr($pathInfo,0,$pos);

			$pathInfo=$this->decodePathInfo($pathInfo);

			$scriptUrl=$this->getScriptUrl();
			$baseUrl=$this->getBaseUrl();
			if(strpos($pathInfo,$scriptUrl)===0)
				$pathInfo=substr($pathInfo,strlen($scriptUrl));
			else if($baseUrl==='' || strpos($pathInfo,$baseUrl)===0)
				$pathInfo=substr($pathInfo,strlen($baseUrl));
			else if(strpos($_SERVER['PHP_SELF'],$scriptUrl)===0)
				$pathInfo=substr($_SERVER['PHP_SELF'],strlen($scriptUrl));
			else
				throw new CException(Yii::t('yii','CHttpRequest is unable to determine the path info of the request.'));

			$this->_pathInfo=trim($pathInfo,'/');
		}
		return $this->_pathInfo;
	}

	/**
	 * Decodes the path info.
	 * This method is an improved variant of the native urldecode() function and used in {@link getPathInfo getPathInfo()} to
	 * decode the path part of the request URI. You may override this method to change the way the path info is being decoded.
	 * @param string $pathInfo encoded path info
	 * @return string decoded path info
	 * @since 1.1.10
	 */
	protected function decodePathInfo($pathInfo)
	{
		$pathInfo = urldecode($pathInfo);

		// is it UTF-8?
		// http://w3.org/International/questions/qa-forms-utf-8.html
		if(preg_match('%^(?:
		   [\x09\x0A\x0D\x20-\x7E]            # ASCII
		 | [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte
		 | \xE0[\xA0-\xBF][\x80-\xBF]         # excluding overlongs
		 | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte
		 | \xED[\x80-\x9F][\x80-\xBF]         # excluding surrogates
		 | \xF0[\x90-\xBF][\x80-\xBF]{2}      # planes 1-3
		 | [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15
		 | \xF4[\x80-\x8F][\x80-\xBF]{2}      # plane 16
		)*$%xs', $pathInfo))
		{
			return $pathInfo;
		}
		else
		{
			return utf8_encode($pathInfo);
		}
	}

	/**
	 * Returns the request URI portion for the currently requested URL.
	 * This refers to the portion that is after the {@link hostInfo host info} part.
	 * It includes the {@link queryString query string} part if any.
	 * The implementation of this method referenced Zend_Controller_Request_Http in Zend Framework.
	 * @return string the request URI portion for the currently requested URL.
	 * @throws CException if the request URI cannot be determined due to improper server configuration
	 */
	public function getRequestUri()
	{
		if($this->_requestUri===null)
		{
			if(isset($_SERVER['HTTP_X_REWRITE_URL'])) // IIS
				$this->_requestUri=$_SERVER['HTTP_X_REWRITE_URL'];
			else if(isset($_SERVER['REQUEST_URI']))
			{
				$this->_requestUri=$_SERVER['REQUEST_URI'];
				if(!empty($_SERVER['HTTP_HOST']))
				{
					if(strpos($this->_requestUri,$_SERVER['HTTP_HOST'])!==false)
						$this->_requestUri=preg_replace('/^\w+:\/\/[^\/]+/','',$this->_requestUri);
				}
				else
					$this->_requestUri=preg_replace('/^(http|https):\/\/[^\/]+/i','',$this->_requestUri);
			}
			else if(isset($_SERVER['ORIG_PATH_INFO']))  // IIS 5.0 CGI
			{
				$this->_requestUri=$_SERVER['ORIG_PATH_INFO'];
				if(!empty($_SERVER['QUERY_STRING']))
					$this->_requestUri.='?'.$_SERVER['QUERY_STRING'];
			}
			else
				throw new CException(Yii::t('yii','CHttpRequest is unable to determine the request URI.'));
		}

		return $this->_requestUri;
	}

	/**
	 * Returns part of the request URL that is after the question mark.
	 * @return string part of the request URL that is after the question mark
	 */
	public function getQueryString()
	{
		return isset($_SERVER['QUERY_STRING'])?$_SERVER['QUERY_STRING']:'';
	}

	/**
	 * Return if the request is sent via secure channel (https).
	 * @return boolean if the request is sent via secure channel (https)
	 */
	public function getIsSecureConnection()
	{
		return isset($_SERVER['HTTPS']) && !strcasecmp($_SERVER['HTTPS'],'on');
	}

	/**
	 * Returns the request type, such as GET, POST, HEAD, PUT, DELETE.
	 * Request type can be manually set in POST requests with a parameter named _method. Useful 
	 * for RESTful request from older browsers which do not support PUT or DELETE 
	 * natively (available since version 1.1.11).
	 * @return string request type, such as GET, POST, HEAD, PUT, DELETE.
	 */
	public function getRequestType()
	{
		if(isset($_POST['_method']))
			return strtoupper($_POST['_method']);

		return strtoupper(isset($_SERVER['REQUEST_METHOD'])?$_SERVER['REQUEST_METHOD']:'GET');
	}

	/**
	 * Returns whether this is a POST request.
	 * @return boolean whether this is a POST request.
	 */
	public function getIsPostRequest()
	{
		return isset($_SERVER['REQUEST_METHOD']) && !strcasecmp($_SERVER['REQUEST_METHOD'],'POST');
	}

	/**
	 * Returns whether this is a DELETE request.
	 * @return boolean whether this is a DELETE request.
	 * @since 1.1.7
	 */
	public function getIsDeleteRequest()
	{
		return (isset($_SERVER['REQUEST_METHOD']) && !strcasecmp($_SERVER['REQUEST_METHOD'],'DELETE')) || $this->getIsDeleteViaPostRequest();
	}

	/**
	 * Returns whether this is a DELETE request which was tunneled through POST.
	 * @return boolean whether this is a DELETE request tunneled through POST.
	 * @since 1.1.11
	 */
	protected function getIsDeleteViaPostRequest()
	{
		return isset($_POST['_method']) && !strcasecmp($_POST['_method'],'DELETE');
	}

	/**
	 * Returns whether this is a PUT request.
	 * @return boolean whether this is a PUT request.
	 * @since 1.1.7
	 */
	public function getIsPutRequest()
	{
		return (isset($_SERVER['REQUEST_METHOD']) && !strcasecmp($_SERVER['REQUEST_METHOD'],'PUT')) || $this->getIsPutViaPostReqest();
	}

	/**
	 * Returns whether this is a PUT request which was tunneled through POST.
	 * @return boolean whether this is a PUT request tunneled through POST.
	 * @since 1.1.11
	 */	
	protected function getIsPutViaPostReqest()
	{
		return isset($_POST['_method']) && !strcasecmp($_POST['_method'],'PUT');
	}

	/**
	 * Returns whether this is an AJAX (XMLHttpRequest) request.
	 * @return boolean whether this is an AJAX (XMLHttpRequest) request.
	 */
	public function getIsAjaxRequest()
	{
		return isset($_SERVER['HTTP_X_REQUESTED_WITH']) && $_SERVER['HTTP_X_REQUESTED_WITH']==='XMLHttpRequest';
	}

	/**
	 * Returns whether this is an Adobe Flash or Adobe Flex request.
	 * @return boolean whether this is an Adobe Flash or Adobe Flex request.
	 * @since 1.1.11
	 */
	public function getIsFlashRequest()
	{
		return isset($_SERVER['HTTP_USER_AGENT']) && (stripos($_SERVER['HTTP_USER_AGENT'],'Shockwave')!==false || stripos($_SERVER['HTTP_USER_AGENT'],'Flash')!==false);
	}

	/**
	 * Returns the server name.
	 * @return string server name
	 */
	public function getServerName()
	{
		return $_SERVER['SERVER_NAME'];
	}

	/**
	 * Returns the server port number.
	 * @return integer server port number
	 */
	public function getServerPort()
	{
		return $_SERVER['SERVER_PORT'];
	}

	/**
	 * Returns the URL referrer, null if not present
	 * @return string URL referrer, null if not present
	 */
	public function getUrlReferrer()
	{
		return isset($_SERVER['HTTP_REFERER'])?$_SERVER['HTTP_REFERER']:null;
	}

	/**
	 * Returns the user agent, null if not present.
	 * @return string user agent, null if not present
	 */
	public function getUserAgent()
	{
		return isset($_SERVER['HTTP_USER_AGENT'])?$_SERVER['HTTP_USER_AGENT']:null;
	}

	/**
	 * Returns the user IP address.
	 * @return string user IP address
	 */
	public function getUserHostAddress()
	{
		return isset($_SERVER['REMOTE_ADDR'])?$_SERVER['REMOTE_ADDR']:'127.0.0.1';
	}

	/**
	 * Returns the user host name, null if it cannot be determined.
	 * @return string user host name, null if cannot be determined
	 */
	public function getUserHost()
	{
		return isset($_SERVER['REMOTE_HOST'])?$_SERVER['REMOTE_HOST']:null;
	}

	/**
	 * Returns entry script file path.
	 * @return string entry script file path (processed w/ realpath())
	 */
	public function getScriptFile()
	{
		if($this->_scriptFile!==null)
			return $this->_scriptFile;
		else
			return $this->_scriptFile=realpath($_SERVER['SCRIPT_FILENAME']);
	}

	/**
	 * Returns information about the capabilities of user browser.
	 * @param string $userAgent the user agent to be analyzed. Defaults to null, meaning using the
	 * current User-Agent HTTP header information.
	 * @return array user browser capabilities.
	 * @see http://www.php.net/manual/en/function.get-browser.php
	 */
	public function getBrowser($userAgent=null)
	{
		return get_browser($userAgent,true);
	}

	/**
	 * Returns user browser accept types, null if not present.
	 * @return string user browser accept types, null if not present
	 */
	public function getAcceptTypes()
	{
		return isset($_SERVER['HTTP_ACCEPT'])?$_SERVER['HTTP_ACCEPT']:null;
	}

	private $_port;

 	/**
	 * Returns the port to use for insecure requests.
	 * Defaults to 80, or the port specified by the server if the current
	 * request is insecure.
	 * You may explicitly specify it by setting the {@link setPort port} property.
	 * @return integer port number for insecure requests.
	 * @see setPort
	 * @since 1.1.3
	 */
	public function getPort()
	{
		if($this->_port===null)
			$this->_port=!$this->getIsSecureConnection() && isset($_SERVER['SERVER_PORT']) ? (int)$_SERVER['SERVER_PORT'] : 80;
		return $this->_port;
	}

	/**
	 * Sets the port to use for insecure requests.
	 * This setter is provided in case a custom port is necessary for certain
	 * server configurations.
	 * @param integer $value port number.
	 * @since 1.1.3
	 */
	public function setPort($value)
	{
		$this->_port=(int)$value;
		$this->_hostInfo=null;
	}

	private $_securePort;

	/**
	 * Returns the port to use for secure requests.
	 * Defaults to 443, or the port specified by the server if the current
	 * request is secure.
	 * You may explicitly specify it by setting the {@link setSecurePort securePort} property.
	 * @return integer port number for secure requests.
	 * @see setSecurePort
	 * @since 1.1.3
	 */
	public function getSecurePort()
	{
		if($this->_securePort===null)
			$this->_securePort=$this->getIsSecureConnection() && isset($_SERVER['SERVER_PORT']) ? (int)$_SERVER['SERVER_PORT'] : 443;
		return $this->_securePort;
	}

	/**
	 * Sets the port to use for secure requests.
	 * This setter is provided in case a custom port is necessary for certain
	 * server configurations.
	 * @param integer $value port number.
	 * @since 1.1.3
	 */
	public function setSecurePort($value)
	{
		$this->_securePort=(int)$value;
		$this->_hostInfo=null;
	}

	/**
	 * Returns the cookie collection.
	 * The result can be used like an associative array. Adding {@link CHttpCookie} objects
	 * to the collection will send the cookies to the client; and removing the objects
	 * from the collection will delete those cookies on the client.
	 * @return CCookieCollection the cookie collection.
	 */
	public function getCookies()
	{
		if($this->_cookies!==null)
			return $this->_cookies;
		else
			return $this->_cookies=new CCookieCollection($this);
	}

	/**
	 * Redirects the browser to the specified URL.
	 * @param string $url URL to be redirected to. If the URL is a relative one, the base URL of
	 * the application will be inserted at the beginning.
	 * @param boolean $terminate whether to terminate the current application
	 * @param integer $statusCode the HTTP status code. Defaults to 302. See {@link http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html}
	 * for details about HTTP status code.
	 */
	public function redirect($url,$terminate=true,$statusCode=302)
	{
		if(strpos($url,'/')===0)
			$url=$this->getHostInfo().$url;
		header('Location: '.$url, true, $statusCode);
		if($terminate)
			Yii::app()->end();
	}

	/**
	 * Returns the user preferred language.
	 * The returned language ID will be canonicalized using {@link CLocale::getCanonicalID}.
	 * This method returns false if the user does not have language preference.
	 * @return string the user preferred language.
	 */
	public function getPreferredLanguage()
	{
		if($this->_preferredLanguage===null)
		{
			if(isset($_SERVER['HTTP_ACCEPT_LANGUAGE']) && ($n=preg_match_all('/([\w\-_]+)\s*(;\s*q\s*=\s*(\d*\.\d*))?/',$_SERVER['HTTP_ACCEPT_LANGUAGE'],$matches))>0)
			{
				$languages=array();
				for($i=0;$i<$n;++$i)
					$languages[$matches[1][$i]]=empty($matches[3][$i]) ? 1.0 : floatval($matches[3][$i]);
				arsort($languages);
				foreach($languages as $language=>$pref)
					return $this->_preferredLanguage=CLocale::getCanonicalID($language);
			}
			return $this->_preferredLanguage=false;
		}
		return $this->_preferredLanguage;
	}

	/**
	 * Sends a file to user.
	 * @param string $fileName file name
	 * @param string $content content to be set.
	 * @param string $mimeType mime type of the content. If null, it will be guessed automatically based on the given file name.
	 * @param boolean $terminate whether to terminate the current application after calling this method
	 */
	public function sendFile($fileName,$content,$mimeType=null,$terminate=true)
	{
		if($mimeType===null)
		{
			if(($mimeType=CFileHelper::getMimeTypeByExtension($fileName))===null)
				$mimeType='text/plain';
		}
		header('Pragma: public');
		header('Expires: 0');
		header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
		header("Content-type: $mimeType");
		if(ob_get_length()===false)
			header('Content-Length: '.(function_exists('mb_strlen') ? mb_strlen($content,'8bit') : strlen($content)));
		header("Content-Disposition: attachment; filename=\"$fileName\"");
		header('Content-Transfer-Encoding: binary');

		if($terminate)
		{
			// clean up the application first because the file downloading could take long time
			// which may cause timeout of some resources (such as DB connection)
			Yii::app()->end(0,false);
			echo $content;
			exit(0);
		}
		else
			echo $content;
	}

	/**
	 * Sends existing file to a browser as a download using x-sendfile.
	 *
	 * X-Sendfile is a feature allowing a web application to redirect the request for a file to the webserver
	 * that in turn processes the request, this way eliminating the need to perform tasks like reading the file
	 * and sending it to the user. When dealing with a lot of files (or very big files) this can lead to a great
	 * increase in performance as the web application is allowed to terminate earlier while the webserver is
	 * handling the request.
	 *
	 * The request is sent to the server through a special non-standard HTTP-header.
	 * When the web server encounters the presence of such header it will discard all output and send the file
	 * specified by that header using web server internals including all optimizations like caching-headers.
	 *
	 * As this header directive is non-standard different directives exists for different web servers applications:
	 * <ul>
	 * <li>Apache: {@link http://tn123.org/mod_xsendfile X-Sendfile}</li>
	 * <li>Lighttpd v1.4: {@link http://redmine.lighttpd.net/projects/lighttpd/wiki/X-LIGHTTPD-send-file X-LIGHTTPD-send-file}</li>
	 * <li>Lighttpd v1.5: {@link http://redmine.lighttpd.net/projects/lighttpd/wiki/X-LIGHTTPD-send-file X-Sendfile}</li>
	 * <li>Nginx: {@link http://wiki.nginx.org/XSendfile X-Accel-Redirect}</li>
	 * <li>Cherokee: {@link http://www.cherokee-project.com/doc/other_goodies.html#x-sendfile X-Sendfile and X-Accel-Redirect}</li>
	 * </ul>
	 * So for this method to work the X-SENDFILE option/module should be enabled by the web server and
	 * a proper xHeader should be sent.
	 *
	 * <b>Note:</b>
	 * This option allows to download files that are not under web folders, and even files that are otherwise protected (deny from all) like .htaccess
	 *
	 * <b>Side effects</b>:
	 * If this option is disabled by the web server, when this method is called a download configuration dialog
	 * will open but the downloaded file will have 0 bytes.
	 *
	 * <b>Example</b>:
	 * <pre>
	 * <?php
	 *    Yii::app()->request->xSendFile('/home/user/Pictures/picture1.jpg',array(
	 *        'saveName'=>'image1.jpg',
	 *        'mimeType'=>'image/jpeg',
	 *        'terminate'=>false,
	 *    ));
	 * ?>
	 * </pre>
	 * @param string $filePath file name with full path
	 * @param array $options additional options:
	 * <ul>
	 * <li>saveName: file name shown to the user, if not set real file name will be used</li>
	 * <li>mimeType: mime type of the file, if not set it will be guessed automatically based on the file name, if set to null no content-type header will be sent.</li>
	 * <li>xHeader: appropriate x-sendfile header, defaults to "X-Sendfile"</li>
	 * <li>terminate: whether to terminate the current application after calling this method, defaults to true</li>
	 * <li>forceDownload: specifies whether the file will be downloaded or shown inline, defaults to true. (Since version 1.1.9.)</li>
	 * <li>addHeaders: an array of additional http headers in header-value pairs (available since version 1.1.10)</li>
	 * </ul>
	 */
	public function xSendFile($filePath, $options=array())
	{
		if(!isset($options['forceDownload']) || $options['forceDownload'])
			$disposition='attachment';
		else
			$disposition='inline';

		if(!isset($options['saveName']))
			$options['saveName']=basename($filePath);

		if(!isset($options['mimeType']))
		{
			if(($options['mimeType']=CFileHelper::getMimeTypeByExtension($filePath))===null)
				$options['mimeType']='text/plain';
		}

		if(!isset($options['xHeader']))
			$options['xHeader']='X-Sendfile';

		if($options['mimeType'] !== null)
			header('Content-type: '.$options['mimeType']);
		header('Content-Disposition: '.$disposition.'; filename="'.$options['saveName'].'"');
		if(isset($options['addHeaders']))
		{
			foreach($options['addHeaders'] as $header=>$value)
				header($header.': '.$value);
		}
		header(trim($options['xHeader']).': '.$filePath);

		if(!isset($options['terminate']) || $options['terminate'])
			Yii::app()->end();
	}

	/**
	 * Returns the random token used to perform CSRF validation.
	 * The token will be read from cookie first. If not found, a new token
	 * will be generated.
	 * @return string the random token for CSRF validation.
	 * @see enableCsrfValidation
	 */
	public function getCsrfToken()
	{
		if($this->_csrfToken===null)
		{
			$cookie=$this->getCookies()->itemAt($this->csrfTokenName);
			if(!$cookie || ($this->_csrfToken=$cookie->value)==null)
			{
				$cookie=$this->createCsrfCookie();
				$this->_csrfToken=$cookie->value;
				$this->getCookies()->add($cookie->name,$cookie);
			}
		}

		return $this->_csrfToken;
	}

	/**
	 * Creates a cookie with a randomly generated CSRF token.
	 * Initial values specified in {@link csrfCookie} will be applied
	 * to the generated cookie.
	 * @return CHttpCookie the generated cookie
	 * @see enableCsrfValidation
	 */
	protected function createCsrfCookie()
	{
		$cookie=new CHttpCookie($this->csrfTokenName,sha1(uniqid(mt_rand(),true)));
		if(is_array($this->csrfCookie))
		{
			foreach($this->csrfCookie as $name=>$value)
				$cookie->$name=$value;
		}
		return $cookie;
	}

	/**
	 * Performs the CSRF validation.
	 * This is the event handler responding to {@link CApplication::onBeginRequest}.
	 * The default implementation will compare the CSRF token obtained
	 * from a cookie and from a POST field. If they are different, a CSRF attack is detected.
	 * @param CEvent $event event parameter
	 * @throws CHttpException if the validation fails
	 */
	public function validateCsrfToken($event)
	{
		if($this->getIsPostRequest())
		{
			// only validate POST requests
			$cookies=$this->getCookies();
			if($cookies->contains($this->csrfTokenName) && isset($_POST[$this->csrfTokenName]))
			{
				$tokenFromCookie=$cookies->itemAt($this->csrfTokenName)->value;
				$tokenFromPost=$_POST[$this->csrfTokenName];
				$valid=$tokenFromCookie===$tokenFromPost;
			}
			else
				$valid=false;
			if(!$valid)
				throw new CHttpException(400,Yii::t('yii','The CSRF token could not be verified.'));
		}
	}
}


/**
 * CCookieCollection implements a collection class to store cookies.
 *
 * You normally access it via {@link CHttpRequest::getCookies()}.
 *
 * Since CCookieCollection extends from {@link CMap}, it can be used
 * like an associative array as follows:
 * <pre>
 * $cookies[$name]=new CHttpCookie($name,$value); // sends a cookie
 * $value=$cookies[$name]->value; // reads a cookie value
 * unset($cookies[$name]);  // removes a cookie
 * </pre>
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id$
 * @package system.web
 * @since 1.0
 */
class CCookieCollection extends CMap
{
	private $_request;
	private $_initialized=false;

	/**
	 * Constructor.
	 * @param CHttpRequest $request owner of this collection.
	 */
	public function __construct(CHttpRequest $request)
	{
		$this->_request=$request;
		$this->copyfrom($this->getCookies());
		$this->_initialized=true;
	}

	/**
	 * @return CHttpRequest the request instance
	 */
	public function getRequest()
	{
		return $this->_request;
	}

	/**
	 * @return array list of validated cookies
	 */
	protected function getCookies()
	{
		$cookies=array();
		if($this->_request->enableCookieValidation)
		{
			$sm=Yii::app()->getSecurityManager();
			foreach($_COOKIE as $name=>$value)
			{
				if(is_string($value) && ($value=$sm->validateData($value))!==false)
					$cookies[$name]=new CHttpCookie($name,@unserialize($value));
			}
		}
		else
		{
			foreach($_COOKIE as $name=>$value)
				$cookies[$name]=new CHttpCookie($name,$value);
		}
		return $cookies;
	}

	/**
	 * Adds a cookie with the specified name.
	 * This overrides the parent implementation by performing additional
	 * operations for each newly added CHttpCookie object.
	 * @param mixed $name Cookie name.
	 * @param CHttpCookie $cookie Cookie object.
	 * @throws CException if the item to be inserted is not a CHttpCookie object.
	 */
	public function add($name,$cookie)
	{
		if($cookie instanceof CHttpCookie)
		{
			$this->remove($name);
			parent::add($name,$cookie);
			if($this->_initialized)
				$this->addCookie($cookie);
		}
		else
			throw new CException(Yii::t('yii','CHttpCookieCollection can only hold CHttpCookie objects.'));
	}

	/**
	 * Removes a cookie with the specified name.
	 * This overrides the parent implementation by performing additional
	 * cleanup work when removing a CHttpCookie object.
	 * @param mixed $name Cookie name.
	 * @return CHttpCookie The removed cookie object.
	 */
	public function remove($name)
	{
		if(($cookie=parent::remove($name))!==null)
		{
			if($this->_initialized)
				$this->removeCookie($cookie);
		}
		return $cookie;
	}

	/**
	 * Sends a cookie.
	 * @param CHttpCookie $cookie cookie to be sent
	 */
	protected function addCookie($cookie)
	{
		$value=$cookie->value;
		if($this->_request->enableCookieValidation)
			$value=Yii::app()->getSecurityManager()->hashData(serialize($value));
		if(version_compare(PHP_VERSION,'5.2.0','>='))
			setcookie($cookie->name,$value,$cookie->expire,$cookie->path,$cookie->domain,$cookie->secure,$cookie->httpOnly);
		else
			setcookie($cookie->name,$value,$cookie->expire,$cookie->path,$cookie->domain,$cookie->secure);
	}

	/**
	 * Deletes a cookie.
	 * @param CHttpCookie $cookie cookie to be deleted
	 */
	protected function removeCookie($cookie)
	{
		if(version_compare(PHP_VERSION,'5.2.0','>='))
			setcookie($cookie->name,null,0,$cookie->path,$cookie->domain,$cookie->secure,$cookie->httpOnly);
		else
			setcookie($cookie->name,null,0,$cookie->path,$cookie->domain,$cookie->secure);
	}
}