<?php
/**
 * THttpSession class
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.pradosoft.com/
 * @copyright Copyright &copy; 2005 PradoSoft
 * @license http://www.pradosoft.com/license/
 * @version $Revision: $  $Date: $
 * @package System.Web
 */

/**
 * THttpSession class
 *
 * THttpSession provides session-level data management and the related configurations.
 * To start the session, call {@open}; to complete and send out session data, call {@close};
 * to destroy the session, call {@destroy}. If AutoStart is true, then the session
 * will be started once the session module is loaded and initialized.
 *
 * To access data stored in session, use the Items property. For example,
 * <code>
 *   $session=new THttpSession;
 *   $session->open();
 *   foreach($session->Items as $key=>$value)
 *       ; // read data in session
 *   $session->Items['key']=$data; // store new data into session
 * </code>
 *
 * The following configurations are available for session:
 * AutoStart, Cookie, CacheExpire, CacheLimiter, SavePath, Storage, GCProbability, CookieUsage, Timeout.
 * See the corresponding setter and getter documentation for more information.
 * Note, these properties must be set before the session is started.
 *
 * THttpSession can be inherited with customized session storage method.
 * Override {@link _open}, {@link _close}, {@link _read}, {@link _write}, {@link _destroy} and {@link _gc}
 * and set Storage as 'user' to store session using methods other than files and shared memory.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Revision: $  $Date: $
 * @package System.Web
 * @since 3.0
 */
class THttpSession extends TComponent implements IModule
{
	/**
	 * @var string ID of this module
	 */
	private $_id;
	/**
	 * @var THttpSessionCollection list of session variables
	 */
	private $_items;
	/**
	 * @var boolean whether this module has been initialized
	 */
	private $_initialized=false;
	/**
	 * @var boolean whether the session has started
	 */
	private $_started=false;
	/**
	 * @var boolean whether the session should be started when the module is initialized
	 */
	private $_autoStart=false;
	/**
	 * @var THttpCookie cookie to be used to store session ID and other data
	 */
	private $_cookie=null;

	/**
	 * Initializes the module.
	 * This method is required by IModule.
	 * If AutoStart is true, the session will be started.
	 * @param IApplication prado application instance
	 */
	public function init($application,$config)
	{
		if($this->_autoStart)
			session_start();
		$this->_initialized=true;
	}

	/**
	 * Starts the session if it has not started yet.
	 */
	public function open()
	{
		if(!$this->_started)
		{
			if($this->_cookie!==null)
				session_set_cookie_params($this->_cookie->getExpire(),$this->_cookie->getPath(),$this->_cookie->getDomain(),$this->_cookie->getSecure());
			session_start();
			$this->_started=true;
		}
	}

	/**
	 * Ends the current session and store session data.
	 */
	public function close()
	{
		if($this->_started)
		{
			session_write_close();
			$this->_started=false;
		}
	}

	/**
	 * Destroys all data registered to a session.
	 */
	public function destroy()
	{
		if($this->_started)
		{
			session_destroy();
			$this->_started=false;
		}
	}

	/**
	 * @return string the ID of this session module (not session ID)
	 */
	public function getID()
	{
		return $this->_id;
	}

	/**
	 * @param string the ID of this session module (not session ID)
	 */
	public function setID($value)
	{
		$this->_id=$value;
	}

	/**
	 * @return THttpSessionCollection list of session variables
	 */
	public function getItems()
	{
		if($this->_items===null)
			$this->_items=new THttpSessionCollection($_SESSION);
		return $this->_items;
	}

	/**
	 * @return boolean whether the session has started
	 */
	public function getIsStarted()
	{
		return $this->_started;
	}

	/**
	 * @return string the current session ID
	 */
	public function getSessionID()
	{
		return session_id();
	}

	/**
	 * @param string the session ID for the current session
	 * @throws TInvalidOperationException if session is started already
	 */
	public function setSessionID($value)
	{
		if($this->_started)
			throw new TInvalidOperationException('httpsession_sessionid_unchangeable');
		else
			session_id($value);
	}

	/**
	 * @return string the current session name
	 */
	public function getSessionName()
	{
		return session_name();
	}

	/**
	 * @param string the session name for the current session, must be an alphanumeric string, defaults to PHPSESSID
	 * @throws TInvalidOperationException if session is started already
	 */
	public function setSessionName($value)
	{
		if($this->_started)
			throw new TInvalidOperationException('httpsession_sessionname_unchangeable');
		else if(ctype_alnum($value))
			session_name($value);
		else
			throw new TInvalidDataValueException('httpsession_sessionname_invalid',$name);
	}

	/**
	 * @return string the current session save path, defaults to '/tmp'.
	 */
	public function getSavePath()
	{
		return session_save_path();
	}

	/**
	 * @param string the current session save path
	 * @throws TInvalidOperationException if session is started already
	 */
	public function setSavePath($value)
	{
		if($this->_started)
			throw new TInvalidOperationException('httpsession_cachelimiter_unchangeable');
		else if(is_dir($value))
			session_save_path($value);
		else
			throw new TInvalidDataValueException('httpsession_savepath_invalid',$value);
	}

	/**
	 * @return string (files|mm|user) storage mode of session, defaults to 'files'.
	 */
	public function getStorage()
	{
		return session_module_name();
	}

	/**
	 * @param string (files|mm|user) storage mode of session. By default, the session
	 * data is stored in files. You may change to shared memory (mm) for better performance.
	 * Or you may choose your own storage (user). If you do so, make sure you
	 * override {@link _open}, {@link _close}, {@link _read}, {@link _write},
	 * {@link _destroy}, and {@link _gc}.
	 * @throws TInvalidOperationException if session is started already
	 */
	public function setStorage($value)
	{
		if($this->_started)
			throw new TInvalidOperationException('httpsession_storage_unchangeable');
		else
		{
			$value=TPropertyValue::ensureEnum($value,array('files','mm','user'));
			if($value==='user')
				session_set_save_handler(array($this,'_open'),array($this,'_close'),array($this,'_read'),array($this,'_write'),array($this,'_destroy'),array($this,'_gc'));
			session_module_name($value);
		}
	}

	/**
	 * @return THttpCookie cookie that will be used to store session ID
	 */
	public function getCookie()
	{
		if($this->_cookie===null)
			$this->_cookie=new THttpCookie($this->getSessionName(),$this->getSessionID());
		return $this->_cookie;
	}

	/**
	 * @return string (none|allow|only) how to use cookie to store session ID
	 *               'none' means not using cookie, 'allow' means using cookie, and 'only' means using cookie only, defaults to 'allow'.
	 */
	public function getCookieMode()
	{
		if(ini_get('session.use_cookies')==='0')
			return 'none';
		else if(ini_get('session.use_only_cookies')==='0')
			return 'allow';
		else
			return 'only';
	}

	/**
	 * @param string (none|allow|only) how to use cookie to store session ID
	 *               'none' means not using cookie, 'allow' means using cookie, and 'only' means using cookie only.
	 * @throws TInvalidOperationException if session is started already
	 */
	public function setCookieMode($value)
	{
		if($this->_started)
			throw new TInvalidOperationException('httpsession_cookiemode_unchangeable');
		else
		{
			$value=TPropertyValue::ensureEnum($value,array('none','allow','only'));
			if($value==='none')
				ini_set('session.use_cookies','0');
			else if($value==='allow')
			{
				ini_set('session.use_cookies','1');
				ini_set('session.use_only_cookies','0');
			}
			else
			{
				ini_set('session.use_cookies','1');
				ini_set('session.use_only_cookies','1');
			}
		}
	}

	/**
	 * @return boolean whether the session should be automatically started when the session module is initialized, defaults to false.
	 */
	public function getAutoStart()
	{
		return $this->_autoStart;
	}

	/**
	 * @param boolean whether the session should be automatically started when the session module is initialized, defaults to false.
	 * @throws TInvalidOperationException if session is started already
	 */
	public function setAutoStart($value)
	{
		if($this->_initialized)
			throw new TInvalidOperationException('httpsession_autostart_unchangeable');
		else
			$this->_autoStart=TPropertyValue::ensureBoolean($value);
	}

	/**
	 * @return integer the probability (percentage) that the gc (garbage collection) process is started on every session initialization, defaults to 1 meaning 1% chance.
	 */
	public function getGCProbability()
	{
		return TPropertyValue::ensureInteger(ini_get('session.gc_probability'));
	}

	/**
	 * @param integer the probability (percentage) that the gc (garbage collection) process is started on every session initialization.
	 * @throws TInvalidOperationException if session is started already
	 * @throws TInvalidDataValueException if the value is beyond [0,100].
	 */
	public function setGCProbability($value)
	{
		if($this->_started)
			throw new TInvalidOperationException('httpsession_gcprobability_unchangeable');
		else
		{
			$value=TPropertyValue::ensureInteger($value);
			if($value>=0 && $value<=100)
			{
				ini_set('session.gc_probability',$value);
				ini_set('session.gc_divisor','100');
			}
			else
				throw new TInvalidDataValueException('httpsession_gcprobability_invalid',$value);
		}
	}

	/**
	 * @return boolean whether transparent sid support is enabled or not, defaults to false.
	 */
	public function getUseTransparentSessionID()
	{
		return ini_get('session.use_trans_sid')==='1'?true:false;
	}

	/**
	 * @param boolean whether transparent sid support is enabled or not.
	 */
	public function setUseTransparentSessionID($value)
	{
		if($this->_started)
			throw new TInvalidOperationException('httpsession_transid_unchangeable');
		else
			ini_set('session.use_only_cookies',TPropertyValue::ensureBoolean($value)?'1':'0');
	}

	/**
	 * @return integer the number of seconds after which data will be seen as 'garbage' and cleaned up, defaults to 1440 seconds.
	 */
	public function getTimeout()
	{
		return TPropertyValue::ensureInteger(ini_get('session.gc_maxlifetime'));
	}

	/**
	 * @param integer the number of seconds after which data will be seen as 'garbage' and cleaned up
	 * @throws TInvalidOperationException if session is started already
	 */
	public function setTimeout($value)
	{
		if($this->_started)
			throw new TInvalidOperationException('httpsession_maxlifetime_unchangeable');
		else
			ini_set('session.gc_maxlifetime',$value);
	}

	/**
	 * Session open handler.
	 * This method should be overriden if session Storage is set as 'user'.
	 * @param string session save path
	 * @param string session name
	 * @return boolean whether session is opened successfully
	 */
	public function _open($savePath,$sessionName)
	{
		return true;
	}

	/**
	 * Session close handler.
	 * This method should be overriden if session Storage is set as 'user'.
	 * @return boolean whether session is closed successfully
	 */
	public function _close()
	{
		return true;
	}

	/**
	 * Session read handler.
	 * This method should be overriden if session Storage is set as 'user'.
	 * @param string session ID
	 * @return string the session data
	 */
	public function _read($id)
	{
		return '';
	}

	/**
	 * Session write handler.
	 * This method should be overriden if session Storage is set as 'user'.
	 * @param string session ID
	 * @param string session data
	 * @return boolean whether session write is successful
	 */
	public function _write($id,$data)
	{
		return true;
	}

	/**
	 * Session destroy handler.
	 * This method should be overriden if session Storage is set as 'user'.
	 * @param string session ID
	 * @return boolean whether session is destroyed successfully
	 */
	public function _destroy($id)
	{
		return true;
	}

	/**
	 * Session GC (garbage collection) handler.
	 * This method should be overriden if session Storage is set as 'user'.
	 * @param integer the number of seconds after which data will be seen as 'garbage' and cleaned up.
	 * @return boolean whether session is GCed successfully
	 */
	public function _gc($maxLifetime)
	{
		return true;
	}
}

/**
 * THttpSessionCollection class.
 *
 * THttpSessionCollection implements a collection class to store session data items.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Revision: $  $Date: $
 * @package System.Web
 * @since 3.0
 */
class THttpSessionCollection extends TMap
{
	/**
	 * @var boolean whether the initial session data has been loaded into the collection
	 */
	private $_initialized=false;

	/**
	 * Constructor.
	 * Initializes the list with an array or an iterable object.
	 * @param array|Iterator the intial data.
	 */
	public function __construct($data=null)
	{
		parent::__construct($data);
		$this->_initialized=true;
	}

	/**
	 * Adds the item into session.
	 * This method will be invoked whenever an item is added to the collection.
	 */
	protected function addedItem($key,$value)
	{
		if($this->_initialized)
			$_SESSION[$key]=$value;
	}

	/**
	 * Removes the item from session.
	 * This method will be invoked whenever an item is removed from the collection.
	 */
	protected function removedItem($key,$value)
	{
		unset($_SESSION[$key]);
	}
}
?>