<?php
/**
 * This file contains the iwp_session class
 *
 * @version $Id$
 * 
 *
 * @package IWP
 * @subpackage IWP_API
 */

/**
 * Session Class
 * This is a static class. It is used when dealing with session variables.
 * It uses a unique key to store everything in so the data is not accessible by a different application or by a IWP in another diretory																																**
 *
 * @package IWP
 * @subpackage IWP_API
 */
class iwp_session {
	/**
	 * Instance
	 * This static variable holds the current instance of this object being loaded.
	 * So using the getInstance function anywhere will return the very same instance.
	 *
	 * @var iwp_session Instance
	 */
	public static $Instance;

	/**
	 * getInstance
	 * This is a static function that sets up the class instance and stores it to the static variable. It will then return that instantiation in the future.
	 *
	 * @return iwp_session Returns the instantiated object
	 **/
	public static function getInstance(){
		if(!isset(self::$Instance)){
			self::$Instance = new self();
		}
		return self::$Instance;
	}

	/**
	 * This is the key that is used to store the data. It should be a unique key set for this website.
	 *
	 * @var string
	 */
	static private $SessionKey = null;

	/**
	 * This function creates the session and does any other processes needed when intializing. This needs to be explicitly called, it is not called by a constructor.
	 *
	 * @return void Doesn't return anything.
	 */
	public static function start($sessionId=null){
		// Setting the timeout to 0
		session_set_cookie_params(0);
		if(!is_null($sessionId)) {
			session_id($sessionId);
			session_start();
		} else {
			session_start();
		}
	}

	function console_log($err){
	if(is_array($err)){
		ob_start();
		print_r($err);
		$err = ob_get_contents();
		ob_end_clean();
	}

	if(is_bool($err)){
		if($err === true) {
			$err = "true";
		} else {
			$err = "false";
		}
	}

	$err = $err ."\n\n";
	file_put_contents(dirname(dirname(__FILE__)). '/tmp/log.txt', $err, FILE_APPEND);
}

	/**
	 * Sets variables through a name/value pair
	 *
	 * @param string $name The name of the variable
	 * @param string $value The value of the variable
	 *
	 * @return void Doesn't return anything.
	 */
	public static function Set($name, $value){
		$_SESSION[self::$SessionKey][$name] = $value;
	}

	/**
	 * Gets the value of a session variable by its name
	 *
	 * @param string $name The name of the variable to retrieve
	 *
	 * @return mixed The value of the stored session variable
	 */
	public static function Get($name=null){
		if(isset($_SESSION[self::$SessionKey][$name])){
			return $_SESSION[self::$SessionKey][$name];
		}
		return false;
	}

	/**
	 * Deletes a session variable via its key/name
	 *
	 * @param string $name The name of the variable to delete
	 *
	 * @return void Doesn't return anything.
	 */
	public static function Kill($name){
		$_SESSION[self::$SessionKey][$name] = '';
		unset($_SESSION[self::$SessionKey][$name]);
	}

	/**
	 * Checks to see if a specified session variable exists
	 *
	 * @param string $name The name of the variable to check exists
	 *
	 * @return boolean True if the variable exists, false otherwise
	 */

	public static function Exists($name=null){
		if(isset($_SESSION[self::$SessionKey][$name])){
			return true;
		}else{
			return false;
		}
	}

	/**
	 * This function sets the unique key used by the class for storing the session variables
	 *
	 * @param string $key The unique key used -- must only be alplha numeric charaters (a md5 hash is perfect)
	 *
	 * @return void Doesn't return anything.
	 *
	 * @see $SessionKey
	 */
	public static function SetKey($key){
		self::$SessionKey = iwp_validation::FilterAlphaNumeric($key);
	}

	/**
	 * Returns the current session key.
	 *
	 * @return string The current session key.
	 */
	public static function GetKey () {
		return self::$SessionKey;
	}
}