public class Ticketing {
    static int tickets = 10;
    static double sellPrice = 9.9;
    static double earned = 0;
    static int buyTickets = 0;
    public static void main(String[] args) {
        int menuId = 0;

        do {
            printMenu();
            System.out.print("Enter Menu Function: ");
            menuId = Input.readInt();
            switch (menuId) {
                case 1:
                    sellTickets();
                    break;
                case 2:
                    ticketsLeft();
                    break;
                case 3:
                   cashReister();
                    break;
                case 0:
                    endingProcess();
                    break;
                default:
                    System.out.println("Unknown Menu Function");
                    break;
            }
        } while (menuId != 0);
    }
    private static void sellTickets() {
        if (tickets <= 0) {
                System.out.println("No tickets left for sale");
                return;
            } else
                do {
                    System.out.println("Enter amount of tickets to be bought: ");
                    buyTickets = Input.readInt();
                    if (buyTickets > 0) {
                        if (tickets - buyTickets >= 0) {
                            double price = Math.round(sellPrice * buyTickets * 100) / 100d;
                            earned += price;
                            System.out.printf("Sell Price: %.2f\n", price);
                            tickets -= buyTickets;
                            return;
                        } else {
                            System.out.println("Not enough tickets left");
                            return;
                        }
                    }
                } while (buyTickets > 0 && tickets > 0);
        }
    private static void ticketsLeft(){
        System.out.printf("%d Tickets left\n", tickets);
    }
    private static void cashReister(){
        System.out.printf("The Cash Register contains %.2f €\n", Math.round(earned * 100) / 100d);
    }
    private static void endingProcess (){
        System.out.printf("%d Tickets left\n", tickets);
        System.out.printf("The Cash Register contains %.2f €\n", Math.round(earned * 100) / 100d);
        System.out.println("Bye!");
    }
    private static void printMenu() {
        System.out.println("Main Menu: ");
        System.out.println("  1) Sell Tickets");
        System.out.println("  2) Show Tickets Left");
        System.out.println("  3) Show Balance");
        System.out.println("  0) Exit");
    }
}