Automatic Code

<?php
class Autocode
{

    public function code_increment($prefix='',$count=4,$last_kode='')
    {
        $output='';
        $next='';
        if(empty($last_kode))
        {
            $order=1;
            $next=sprintf("%0".$count."s",$order);
            $output=$prefix.$next;
        }else{
            $lenght_prefix=strlen($prefix);
            $next=(int) substr($last_kode,$lenght_prefix,$count);
            $next++;
            $next=sprintf("%0".$count."s",$next);
            $output=$prefix.$next;
        }
        return $output;
    }

    public function code_date($prefix='',$format='Ymd',$timezone='Asia/Jakarta')
    {
        date_default_timezone_set($timezone);
        $date=date($format);
        $generate=$prefix.$date;
        return $generate;
    }

    public function code_random($prefix='',$length=20,$alphabet=FALSE)
    {
        $output='';
        if(empty($alphabet) || $alphabet==FALSE)
        {
            $output= substr(str_shuffle("0123456789"), 0, $length);
        }else{
            $output= substr(str_shuffle("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"), 0, $length);
        }

        $generate=$prefix.$output;
        return $generate;
    }
}

//TEST
<?php
require_once('Autocode.php');
//RANDOM
echo "----RANDOM----".'<br/>';
echo "----WITHOUT PREFIX".'<br/>';
echo $this->autocode->code_random('',10,TRUE).'<br/>';
echo "----PREFIX".'<br/>';
echo $this->autocode->code_random("CR-",40,TRUE).'<br/>';
$random=$this->autocode->code_random("CR-",40,TRUE);
echo strtoupper($random).'<br/>';
echo '<p>&nbsp;</p>';

//DATE
echo "----DATE----".'<br/>';
echo "----WITHOUT PREFIX".'<br/>';
echo $this->autocode->code_date('','Ymd').'<br/>';
echo "----PREFIX".'<br/>';
echo $this->autocode->code_date("CD/",'YmdH').'<br/>';
echo $this->autocode->code_date("CD/",'dmYHis').'<br/>';
echo '<p>&nbsp;</p>';

//INCREMENT
echo "----INCREMENT----".'<br/>';
$last_code="CI-2345677";
$count=7; //523049 6 character
echo "----WITHOUT PREFIX".'<br/>';
echo $this->autocode->code_increment('',6).'<br/>';
echo "----PREFIX Last Code ".$last_code.'<br/>';
echo $this->autocode->code_increment('CI-',$count,$last_code);
?>