final class DatabaseManager{

    private $hostname;
    private $username;
    private $password;
    private $database;
    private $active_record = "true";
    private $active_group = "default";
    private $dbdriver = "mysqli";
    private $dbprefix = "";
    private $pconnect = false;
    private $db_debug = true;
    private $cache_on = TRUE;
    private $cachedir = "";
    private $char_set = "latin1";
    private $dbcollat = "latin1_swedish_ci";
    private $cipher;

    private static $instance;

    protected function __construct($hostname,$username,$database){

        $this->setCipher(Cipher::getInstance());

        $this->setHostname($hostname);
        $this->setUsername($username);
        $this->setDatabase($database);
    }

    public static function initDatabase($hostname = null,$username = null,$database = null,$force_load = false){
        if(self::$instance === null OR $force_load == true){
            self::$instance = new self($hostname,$username,$database);
        }

        return self::$instance;
    }

    public function &exportConfigCI(){
        //$config = get_object_vars($this); it don't return by ref
        $config_ci = array();

        //foreach($config as $i=>$c){
        //    $config_ci[$this->getActiveGroup()][$i] = $c;
        //}

        $config_ci[$this->getActiveGroup()]['username'] = &$this->getUsername();
        $config_ci[$this->getActiveGroup()]['password'] = &$this->getPassword();
    //the same to all attribs

        return $config_ci;
    }

    public function &getUsername(){
       return $this->username;
    }

    public function &getPassword(){
       return $this->password;
    }

  //the same to all gets
}