<?php
/**
 *  
 * @author  Benjamin Gillissen <hide@address.com>
 * 
 *	**************************************************************

	Copyright (C) 2009  Benjamin Gillissen
	
	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.
	
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details at:
	http://www.gnu.org/copyleft/gpl.html

 *	**************************************************************
 */
class sess_db extends sess {
	
	private $DBOBJ;
	
	public function __construct($SESSRef){
		if ( !isset($conf['cookref']) ){
			$conf['cookref'] = NULL;
		} elseif (! isset($conf['timeout']) ){
			$conf['timeout'] = 60*15;
		} elseif (! isset($conf['lifetime']) ){
			$conf['lifetime'] = 0;
		}
		parent::__construct($SESSRef);
		$cnf = configs::get('sessions', $SESSRef, 'CNF');
		$this->DBOBJ = new dbobject($cnf);
	}
	
	public function __destruct(){ 
		errors::raise('DB sessions destruct', CORE_LOG_NOTICE, 'SESS');
		$this->store();
		$this->clearcache();//unset cache
		unset($this);
	}
	
	public function start(){
		if ( $this->restoreid() ){ //sessid could be restored from cookies
			if ( FALSE !== $this->exists() ){
				//sess restoration, return true or false,
				return $this->load();	//known sessid we load it
			}
		}
		$this->genid();
		$r = $this->exportid();
		if ( CORE::isError($r) ){ 
			return errors::getnew('Session ID could not be stored on client side :'.$r->getmsg(), CORE_LOG_ERROR, 'SESS'); 
		}
		if ( FALSE === $this->creat() ){
			return errors::getnew('Session data could not be stored on server side.', CORE_LOG_ERROR, 'SESS'); 
		}
		errors::raise('Session has been created : '.$this->get_sessid(), CORE_LOG_NOTICE, 'SESS'); 
		if ( FALSE === $this->exists() ){
			errors::raise('Session has been created BUT do not exists', CORE_LOG_WARNING, 'SESS'); 
		}
		
		//new sess created we return NULL
		return NULL;
	}
	
	public function store(){
		if ( !isset($this->DBOBJ) ){ return FALSE;	}
		$arg=Array('id'=>$this->get_sessid(), 'sessref'=>$this->SESSRef,'data'=>$this->storedata(), 'time'=>time() );
		return $this->DBOBJ->dbquery($arg, __FUNCTION__);
	}
	
	public function cleanup(){
		if ( !isset($this->DBOBJ) ){ return FALSE;	}
		$lifetime = configs::get('sessions', $this->SESSRef, 'lifetime');
		if ( $lifetime == 0 ){ 
			$lt = 0;
		} else {
			$lt = (time()-$lifetime);
		}
		$timeout  = configs::get('sessions', $this->SESSRef, 'timeout');
		$arg=Array('lt'=>$lt, 'to'=>(time()-$timeout), 'sessref'=>$this->SESSRef);
		unset($lt, $lifetime, $timeout);
		return $this->DBOBJ->dbquery($arg, __FUNCTION__);
	}
	
	public function tocleanup(){
		if ( !isset($this->DBOBJ) ){ return FALSE;	}
		$lifetime = configs::get('sessions', $this->SESSRef, 'lifetime');
		$timeout  = configs::get('sessions', $this->SESSRef, 'timeout');
		if ( $lifetime == 0 AND $timeout == 0 ){
			errors::raise('This sessions will never drop any session !', CORE_LOG_WARNING, 'SESS');
			fclose($hdl);$hdl=TRUE;return FALSE;
		}
		if ( $lifetime == 0 ){ 
			$lt = 0;
		} else {
			$lt = (time()-$lifetime);
		}
		$arg=Array('lt'=>$lt, 'to'=>(time()-$timeout), 'sessref'=>$this->SESSRef);
		unset($lt, $lifetime, $timeout);
		return $this->DBOBJ->dbquery($arg, __FUNCTION__, 'sessid');
	}
	
	public function destroy(){
		if ( !isset($this->DBOBJ) ){ return FALSE;	}
		$arg=Array('id'=>$this->get_sessid(), 'sessref'=>$this->SESSRef);
		return $this->DBOBJ->dbquery($arg, __FUNCTION__);
	}
	
	private function exists($sessid=NULL){
		if ( !isset($this->DBOBJ) ){ return FALSE;	}
		if ( $sessid === NULL ){ $sessid = $this->get_sessid(); }
		$arg=Array('id'=>$sessid, 'sessref'=>$this->SESSRef);
		return $this->DBOBJ->dbquery($arg, __FUNCTION__);
	}
	
	private function creat($sessid=NULL){
		if ( !isset($this->DBOBJ) ){ return FALSE;	}
		if ( $sessid === NULL ){ $sessid = $this->get_sessid(); }
		$arg=Array('id'=>$sessid, 'time'=>time(), 'sessref'=>$this->SESSRef);
		return $this->DBOBJ->dbquery($arg, __FUNCTION__);
	}
	
	private function load($sessid=NULL){
		if ( !isset($this->DBOBJ) ){ return FALSE;	}
		if ( $sessid === NULL ){ $sessid = $this->get_sessid(); }
		$arg=Array('id'=>$sessid, 'sessref'=>$this->SESSRef);
		return $this->restoredata( $this->DBOBJ->dbquery($arg, __FUNCTION__, 'data') );
	}
}