<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
/**
 * Code Igniter
 *
 * An open source application development framework for PHP 4.3.2 or newer
 *
 * @package		CodeIgniter
 * @author		Rick Ellis
 * @copyright	Copyright (c) 2006, pMachine, Inc.
 * @license		http://www.codeignitor.com/user_guide/license.html
 * @link		http://www.codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * Session Class
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Sessions
 * @author		Jeremy Bush
 */
class CI_Session {

	var $CI;
	var $now;
	var $encryption		= TRUE;
	var $use_database	= FALSE;
	var $session_table	= FALSE;
	var $sess_length	= 7200;
	var $sess_cookie	= 'ci_session';
	var $userdata		= array();
	var $gc_probability	= 5;


	/**
	 * Session Constructor
	 *
	 * The constructor runs the session routines automatically
	 * whenever the class is instantiated.
	 */		
	function CI_Session()
	{
		$this->CI =& get_instance();

		log_message('debug', "Session Class Initialized");
		$this->sess_run();
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Run the session routines
	 *
	 * @access	public
	 * @return	void
	 */		
	function sess_run()
	{
		/*
		 *  Set the "now" time
		 *
		 * It can either set to GMT or time(). The pref
		 * is set in the config file.  If the developer
		 * is doing any sort of time localization they
		 * might want to set the session time to GMT so
		 * they can offset the "last_activity" and
		 * "last_visit" times based on each user's locale.
		 *
		 */
		if (strtolower($this->CI->config->item('time_reference')) == 'gmt')
		{
			$now = time();
			$this->now = mktime(gmdate("H", $now), gmdate("i", $now), gmdate("s", $now), gmdate("m", $now), gmdate("d", $now), gmdate("Y", $now));
	
			if (strlen($this->now) < 10)
			{
				$this->now = time();
				log_message('error', 'The session class could not set a proper GMT timestamp so the local time() value was used.');
			}
		}
		else
		{
			$this->now = time();
		}
		
		/*
		 *  Set the session length
		 *
		 * If the session expiration is set to zero in
		 * the config file we'll set the expiration
		 * two years from now.
		 *
		 */
		$expiration = $this->CI->config->item('sess_expiration');
		
		if (is_numeric($expiration))
		{
			if ($expiration > 0)
			{
				$this->sess_length = $this->CI->config->item('sess_expiration');
			}
			else
			{
				$this->sess_length = (60*60*24*365*2);
			}
		}
		
		// Do we need encryption?
		$this->encryption = $this->CI->config->item('sess_encrypt_cookie');
	
		if ($this->encryption == TRUE)	
		{
			$this->CI->load->library('encrypt');
		}		

		// Are we using a database?
		if ($this->CI->config->item('sess_use_database') === TRUE AND $this->CI->config->item('sess_table_name') != '')
		{
			$this->use_database = TRUE;
			$this->session_table = $this->CI->config->item('sess_table_name');
			$this->CI->load->database();
		}
		
		// Set the cookie name
		if ($this->CI->config->item('sess_cookie_name') != FALSE)
		{
			$this->sess_cookie = $this->CI->config->item('cookie_prefix').$this->CI->config->item('sess_cookie_name');
		}
	
		/*
		 *  Fetch the current session
		 *
		 * If a session doesn't exist we'll create
		 * a new one.  If it does, we'll update it.
		 *
		 */
		if ( ! $this->sess_read())
		{
			$this->sess_create();
		}
		else
		{	
			$this->sess_fetch();
		}
		
		// Delete expired sessions if necessary
		if ($this->use_database === TRUE)
		{		
			$this->sess_gc();
		}	
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Fetch the current session data if it exists
	 *
	 * @access	public
	 * @return	bool
			}
	 */
	function sess_read()
	{	
		// Fetch the session ID
		
		$session_id = get_cookie('ci_session');
		
		if ($session_id === FALSE)
		{
			return FALSE;
		}
			
		$this->CI->db->from('ci_sessions')->where('session_id', $session_id);
		$query = $this->CI->db->get();
		
		// No valid session in the db
		if (count($query->result() == 0))
		{
			$this->sess_destroy();
			return false;
		}
		
		$session_data = $query->result();
		$session_data = $session_data[0];
		$session_data = unserialize($session_data->extras);
		echo "sess_read():<pre>" . print_r($session_data, true) . "</pre>";
		
		// Is the session current?
		if (($session_data['extras'] + $this->sess_length) < $this->now)
		{
			echo "not current session";  die;
			$this->sess_destroy();
			return FALSE;
		}
		
		// Does the IP Match?
		if ($session_data['ip_address'] != $this->CI->input->ip_address())
		{
			echo "no ip match";  die;
			$this->sess_destroy();
			return FALSE;
		}
		
		// Does the User Agent Match?
		if ($session_data['user_agent'] != substr($this->CI->input->user_agent(), 0, 50))
		{
			echo "no user agent match";  die;
			$this->sess_destroy();
			return FALSE;
		}
		
		$this->userdata = $session_data;
		echo "set_userdata: " . $this->CI->input->cookie($this->sess_cookie);
		return true;
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Write the session cookie
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_write($session_id)
	{								
		$cookie = array(	'name' 	=> 'ci_session',
							'value'	=> $session_id,
							'expire'=> 0,
							'domain'=> $this->CI->config->item('cookie_domain'));
		set_cookie($cookie);
		echo "created new session";
	}
	
	/**
	 * Write the session data
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_write_data()
	{								
		unset($this->userdata['session_id']);
		$this->CI->db->update('ci_sessions', $this->userdata, array('session_id' => get_cookie($this->CI->config->item('sess_cookie_name'))));
	}
		
	// --------------------------------------------------------------------
	
	/**
	 * Create a new empty session
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_create()
	{	
		$this->CI->load->library('user_agent');
		$sessid = '';
		while (strlen($sessid) < 32)
		{
			$sessid .= mt_rand(0, mt_getrandmax());
		}
		
		$session_id = sha1(uniqid($sessid, TRUE));
	
		$this->userdata = array(
							'session_id' 	=> $session_id,
							'extras'		=> serialize(array('ip_address'	=> $this->CI->input->ip_address(),
													'user_agent'	=> $this->CI->agent->agent_string(),
													'last_activity'	=> time()))
							);
		
		
		// Save the session in the DB
		
		$this->CI->db->insert('ci_sessions', $this->userdata);
			
		// Write the cookie	
		$this->sess_write($session_id);
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Assign the session values to userdata
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_fetch()
	{	
		echo "sess_fetch: " . $this->CI->input->cookie($this->sess_cookie);
		
		$this->CI->db->from('ci_sessions')->where('session_id', $this->CI->input->cookie($this->sess_cookie));
		$session_data = $this->CI->db->get();
		$session_data = $session_data->result();
		$session_data = $session_data[0];
		
		foreach (unserialize($session_data->extras) as $key => $value)
			$this->userdata[$key] = $value;

	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Destroy the current session
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_destroy()
	{
		setcookie(
					$this->sess_cookie,
					addslashes(serialize(array())),
					($this->now - 31500000),
					$this->CI->config->item('cookie_path'),
					$this->CI->config->item('cookie_domain'),
					0
				);
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Garbage collection
	 *
	 * This deletes expired session rows from database
	 * if the probability percentage is met
	 *
	 * @access	public
	 * @return	void
	 */
	function sess_gc()
	{
		srand(time());
		if ((rand() % 100) < $this->gc_probability)
		{
			$expire = $this->now - $this->sess_length;
			
			$this->CI->db->where("last_activity < {$expire}");
			$this->CI->db->delete($this->session_table);

			log_message('debug', 'Session garbage collection performed.');
		}
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Fetch a specific item (or all items) form  the session array
	 *
	 * @access	public
	 * @param	string
	 * @return	string or array
	 */		
	function userdata($item = null)
	{
		echo "userdata: " . $this->CI->input->cookie($this->sess_cookie);
		
		if ($item == null)
			return unserialize($this->userdata['extras']);
		else
			return ( ! isset($this->userdata[$item])) ? FALSE : $this->userdata[$item];
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Add or change data in the "userdata" array
	 *
	 * @access	public
	 * @param	mixed
	 * @param	string
	 * @return	void
	 */		
	function set_userdata($newdata = array(), $newval = '')
	{
		echo "set_userdata: " . $this->CI->input->cookie($this->sess_cookie);
		
		if (is_string($newdata))
		{
			$newdata = array($newdata => $newval);
		}
	
		if (count($newdata) > 0)
		{
			foreach ($newdata as $key => $val)
			{
				$this->userdata['extras'][$key] = $val;
			}
		}
	
		$this->sess_write_data();
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Delete a session variable from the "userdata" array
	 *
	 * @access	array
	 * @return	void
	 */		
	function unset_userdata($newdata = array())
	{
		if (is_string($newdata))
		{
			$newdata = array($newdata => '');
		}
	
		if (count($newdata) > 0)
		{
			foreach ($newdata as $key => $val)
			{
				unset($this->userdata[$key]);
			}
		}
	
		$this->sess_write();
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Strip slashes
	 *
	 * @access	public
	 * @param	mixed
	 * @return	mixed
	 */
	 function strip_slashes($vals)
	 {
	 	if (is_array($vals))
	 	{	
	 		foreach ($vals as $key=>$val)
	 		{
	 			$vals[$key] = $this->strip_slashes($val);
	 		}
	 	}
	 	else
	 	{
	 		$vals = stripslashes($vals);
	 	}
	 	
	 	return $vals;
	}

}
// END Session Class
?>