Atm.java

import java.util.Scanner;

public class Atm {
    private Bank bank;

    public Atm(Bank bank){
        this.bank = bank;
    }

    public void start(){
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter account number: ");
        int accountNumber = scanner.nextInt();
        System.out.print("Enter pin: ");
        int pin = scanner.nextInt();

        Account account = bank.authenticateUser(accountNumber, pin);

        if(account == null){
            System.out.println("Invalid Credentials!");
            return;
        }

        while(true){
            System.out.println("----------------");
            System.out.println("1. Withdraw");
            System.out.println("2. Deposit");
            System.out.println("3. Check Balance");
            System.out.println("4. Exit");
            System.out.println("----------------");
            System.out.println();

            System.out.print("Enter choice: ");
            int choice = scanner.nextInt();

            switch(choice){
                case 1:
                    System.out.print("Enter amount: ");
                    double amount = scanner.nextDouble();

                    account.withdraw(amount);
                    break;
                case 2:
                    System.out.print("Enter amount: ");
                    double am = scanner.nextDouble();

                    account.deposit(am);
                    break;
                case 3:
                    account.display();
                    break;
                case 4:
                    System.out.println("Session Ended!");
                    return;
                default:
                    System.out.println("Invalid Choice!");
            }
        }
    }
}