public class Withdrawal extends Transaction
{
    // instance variables - replace the example below with your own
    private int accountNumber;
    private Keypad keypad;
    private CashDispenser cashDispenser;

    private final static int CANCELED = 6;


    /**
     * Constructor for objects of class Withdrawal
     */
    public Withdrawal(int userAccountNumber, Screen atmScreen, BankDatabase atmBankDatabase, Keypad atmKeypad, CashDispenser atmCashDispenser)
    {
        super(userAccountNumber,atmScreen,atmBankDatabase);
        keypad = atmKeypad;
        cashDispenser = atmCashDispenser;
    }
    @Override
    /**
     * An example of a method - replace this comment with your own
     *
     * @param  y  a sample parameter for a method
     * @return    the sum of x and y
     */
    public void execute()
    {
        boolean cashDispended = false;
        double availableBalance;

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

        do{
            amount = displayMenuOfAmounts();
            if(amount!=CANCELED){
                availableBalance = bankDatabase.getAvailableBalance(getAccountNumber());
                if(amount <= availableBalance){
                    if(cashdispenser.isSufficientCashAvailable(amount)){
                        bankDatabase.debit(getAccountNumber(),amount);
                        cashDispenser.dispenserCash(amount);
                        casDispensed = true;

                        screen.displayMessageLine("\nYour cash has been"+"dispenser.Please take your cash now.");
                    }
                    else screen.displayMessageLine("\nInsufficient cash available in the ATM."+"\n\nPlease choose a smaller amount.");
                }
                else{
                    screen.displayMessageLine("\nInsufficient funds in your account."+"\n\nPlease choose a smaller amount.");
                }
            }
            else{
                screen.displayMessageLine("\nCanceling transaction...");
                return;
            }
        }
        while(!cashDispensed);
    }
    private int displayMenuOfAmounts(){
        int userChoice = 0;
        Screen screen = getScreen();
        int[] amounts = {0,20,40,60,100,200};
        while(userChoice == 0){
            screen.displayMessageLine("\nWithdrawal Menu:");
            screen.displayMessageLine("1-$20");
            screen.displayMessageLine("2-$40");
            screen.displayMessageLine("3-$60");
            screen.displayMessageLine("4-$100");
            screen.displayMessageLine("5-$200");
            screen.displayMessageLine("6-Cancel transaction");
            screen.displayMessage("\nChoose a withdrawal amount:");

            int input = keypad.getInput();

            switch(input){
                case 1:
                case 2:
                case 3:
                case 4:
                case 5:
                    userChoice = amounts[input];
                    break;
                case CANCELED:
                    userChoice = CANCELED;
                    break;
                default:
                    screen.displayMessageLine("\nInvalid selection.Try again.");
                }
            }
            return userChoice;
        }
    }