FP_Pembelian_VM

public class Pembelian extends Transaction
{
    private int amount;
    private int pilihan_item;
    private Keypad keypad;
    private ItemDispenser itemDispenser;

    public Pembelian( int userCardNumber, Screen VMScreen,
        BankDatabase VMBankDatabase, Keypad VMKeypad,
        ItemDispenser VMItemDispenser, int pilihan )
    {
        super( userCardNumber, VMScreen, VMBankDatabase );

        keypad = VMKeypad;
        itemDispenser = VMItemDispenser;
        pilihan_item = pilihan - 1;
    }

    @Override
    public void execute()
    {
        boolean itemDispensed = false;
        double availableBalance;

        BankDatabase bankDatabase = getBankDatabase();
        Screen screen = getScreen();

        do
        {
            amount = displayMenuOfAmounts();
            availableBalance =
                bankDatabase.getAvailableBalance( getCardNumber() );

                if ( amount <= availableBalance )
                {
                    if ( itemDispenser.isStockAvailable( pilihan_item ) )
                    {
                        bankDatabase.debit( getCardNumber(), amount );

                        itemDispenser.dispenseItem( pilihan_item );
                        itemDispensed = true;

                        screen.displayMessageLine( "\nBarang anda telah dikeluarkan." +
                                "Silahkan ambil barang anda sekarang." );
                        screen.displayMessage( "\nSaldo anda : ");
                        availableBalance =
                            bankDatabase.getAvailableBalance( getCardNumber() );
                        screen.displayRupiahAmount( availableBalance );
                    }
                    else
                    {
                        screen.displayMessageLine( "\nMohon maaf stok barang yang anda pilih telah habis."
                               + "\n\n Silahkan pilih barang yang lain" );
                    }
                }

                else
                {
                    screen.displayMessageLine("\n Mohon maaf saldo anda tidak mencukupi. ");
                    screen.displayMessage("\n Saldo anda : ");
                    screen.displayRupiahAmount( availableBalance );
                }

            return;
        } while ( !itemDispensed );
    }

    private int displayMenuOfAmounts()
    {
        int HargaItem = 0;
        int[] amounts = { 2500, 4000, 6000 };

        switch ( pilihan_item )
        {
            case 0:
            case 1:
            case 2:
                HargaItem = amounts[ pilihan_item ];
                break;
        }

        return HargaItem;
    }
}