salahh logic?

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class Cart extends CI_Controller {
/*
salah logika mas.. kayaknya salah target array

*/
    public function show(){
        $cart= array(
            'barangs'=> $this->cart->contents(),
            'total'=> $this->cart->total()
        );
        foreach($cart['barangs'] AS $id=>$data){ //$keys['values']
// foreach untuk perulangan data yang dinamis, berubah sesuai jumlah data yang ada
            //$cart['price'] =
            $cart['barangs']['price'] =
                number_format($data['price'], 2, ',', '.');
            //$cart['subtotal']
            $cart['barangs']['subtotal'] =
             number_format($data['subtotal'], 2, ',', '.');
        }
        $cart['total'] = number_format($cart['total'], 2, ',', '.');

        $content= array(
            'content'=> $this->parser->parse('cart_view', $cart, true)
        );
        $this->parser->parse('template', $content);
    }

//=====================


    function __construct() {
        parent::__construct();
        $this->load->model('barang_model');
        $this->load->model('cart_model');
        $this->load->library("cart");
    }
    public function index(){
        $this->show();
    }

    public function how_shop(){
        $content= array(
            'content'=> $this->load->view('cara_belanja', '', true)
        );
        $this->parser->parse('template', $content);
    }
    public function add($barang_id){
        $rows= $this->barang_model->buy_select($barang_id)->row_array();
        $data= array(
            'id'=> $rows['id'],
            'qty'=> 1,
            'price'=> $rows['price'],
            'name'=> $rows['name'],
            'options'=> array()
        );
        $this->cart->insert($data);
        $this->show();
    }
    public function edit(){
        $data=array();
        foreach ($this->cart->contents() as $items){
            $data = array_merge(
                    $data,
                    array(
                        array(
                            'rowid'=> $this->input->post('rowid_'.$items['rowid']),
                            'qty'=> $this->input->post('qty_'.$items['rowid'])
                        )
                    )
            );
        }
        $this->cart->update($data);
        $this->show();
    }

    public function finished(){
        /*
        $this->cart->destroy();
        redirect('barang/show');
        */
        if(!is_login()){
            redirect('customer/form_login');
        }else{
            if(count($this->cart->contents())>0){
                $cart_number= $this->get_cart_number();
                $cart= array(
                            'header' => array(
                                        'cart_nomor' => $cart_number,
                                        'cart_customer_id' => $this->session->userdata('customer_id'),
                                        'cart_tanggal' => mdate("%Y-%m-%d %H:%i:%s", time())
                            ),
                            'detail' => array()
                );
                $i=0;
                foreach($this->cart->contents() AS $cart_detail){
                    $cart['detail'][$i]['cart_nomor']=$cart_number;
                    $cart['detail'][$i]['cart_barang_id']=$cart_detail['id'];
                    $cart['detail'][$i]['cart_barang_qty']=$cart_detail['qty'];
                    $cart['detail'][$i]['cart_barang_harga']=$cart_detail['price'];
                    $i++;
                }
                $this->cart_model->insert($cart);
                $this->cart->destroy();
                $content= array(
                            'content' => "<h2>Transaksi selesai, silakan lakukan pembayaran</h2>"
                );
                $this->parser->parse('template', $content);
            }else{
                redirect();
            }
        }
    }
    private function get_cart_number(){
        $customer_id= $this->session->userdata('customer_id');
        $count_cart= $this->cart_model->select_where($customer_id)->num_rows()+1;
        $cart_number= $customer_id.$count_cart;
        return $cart_number;
    }
}