switchExample.js

const readline = require("readline");

const input = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

// Simple in-memory accounts database for demo
const accounts = {
    "12345": { pin: "1111", balance: 2000.0, name: "Chinwe" },
    "67890": { pin: "2222", balance: 2555.5, name: "Oracle" }
};

// Prompt user for their ATM details
input.question("Enter your account number: ", (accountNumber) => {
    input.question("Enter your PIN: ", (pin) => {
        const account = accounts[accountNumber];
        if (!account) {
            console.log("Account not found.");
            input.close();
            return;
        }
        if (account.pin !== pin) {
            console.log("Incorrect PIN.");
            input.close();
            return;
        }
        console.log(`Welcome, ${account.name}!`);
        atmMachine(account);
    });
});

function atmMachine(account) {
    function showMenu() {
        input.question("\nChoose an option:\n1) Check balance\n2) Withdraw\n3) Exit\nEnter choice: ", (choice) => {
            switch (choice.trim()) {
                case "1":
                    console.log(`Your balance: $${account.balance.toFixed(2)}`);
                    showMenu();
                    break;
                case "2":
                    input.question("Enter amount to withdraw: ", (amtStr) => {
                        const amt = parseFloat(amtStr);
                        if (isNaN(amt) || amt <= 0) {
                            console.log("Invalid amount.");
                            showMenu();
                        } else if (amt > account.balance) {
                            console.log("Insufficient funds.");
                            showMenu();
                        } else {
                            account.balance -= amt;
                            console.log(`Success! New balance: $${account.balance.toFixed(2)}`);
                            showMenu();
                        }
                    });
                    break;
                case "3":
                    console.log("Thank you. Goodbye.");
                    input.close();
                    break;
                default:
                    console.log("Invalid choice.");
                    showMenu();
            }
        });
    }
    showMenu();
}