Hotel Booking

interface Room {
    String getRoomNumber();
    RoomType getRoomType();
    double getPrice();
    boolean isAvailable(Date startDate, Date endDate);
    void addBooking(Booking booking);
}

interface Booking {
    String getId();
    Guest getGuest();
    Room getRoom();
    Date getStartDate();
    Date getEndDate();
    void cancel();
    boolean conflictsWith(Date startDate, Date endDate);
}

interface Payment {
    boolean processPayment();
    boolean refundPayment();
}

interface Service {
    String getDescription();
    double getCost();
    void provideService(Guest guest);
}

interface Hotel {
    void addRoom(Room room);
    List<Room> getAvailableRooms(Date startDate, Date endDate);
}

class StandardRoom implements Room {
    private String roomNumber;
    private RoomType type;
    private double price;
    private List<Booking> bookings;

    public StandardRoom(String roomNumber, RoomType type, double price) {
        this.roomNumber = roomNumber;
        this.type = type;
        this.price = price;
        this.bookings = new ArrayList<>();
    }

    @Override
    public String getRoomNumber() {
        return roomNumber;
    }

    @Override
    public RoomType getRoomType() {
        return type;
    }

    @Override
    public double getPrice() {
        return price;
    }

    @Override
    public boolean isAvailable(Date startDate, Date endDate) {
        for (Booking booking : bookings) {
            if (booking.conflictsWith(startDate, endDate)) {
                return false;
            }
        }
        return true;
    }

    @Override
    public void addBooking(Booking booking) {
        bookings.add(booking);
    }
}

class RoomBooking implements Booking {
    private String id;
    private Guest guest;
    private Room room;
    private Date startDate;
    private Date endDate;
    private boolean isCancelled;

    public RoomBooking(String id, Guest guest, Room room, Date startDate, Date endDate) {
        this.id = id;
        this.guest = guest;
        this.room = room;
        this.startDate = startDate;
        this.endDate = endDate;
        this.isCancelled = false;
    }

    @Override
    public String getId() {
        return id;
    }

    @Override
    public Guest getGuest() {
        return guest;
    }

    @Override
    public Room getRoom() {
        return room;
    }

    @Override
    public Date getStartDate() {
        return startDate;
    }

    @Override
    public Date getEndDate() {
        return endDate;
    }

    @Override
    public void cancel() {
        this.isCancelled = true;
        System.out.println("Booking cancelled successfully.");
    }

    @Override
    public boolean conflictsWith(Date startDate, Date endDate) {
        if (isCancelled) {
            return false;
        }
        return !(endDate.before(this.startDate) || startDate.after(this.endDate));
    }
}

class BookingPayment implements Payment {
    private String id;
    private Booking booking;
    private double amount;
    private String paymentMethod;
    private boolean isProcessed;

    public BookingPayment(String id, Booking booking, double amount, String paymentMethod) {
        this.id = id;
        this.booking = booking;
        this.amount = amount;
        this.paymentMethod = paymentMethod;
        this.isProcessed = false;
    }

    @Override
    public boolean processPayment() {
        if (!isProcessed) {
            // Payment processing logic
            System.out.println("Payment processed for amount: " + amount);
            isProcessed = true;
            return true;
        }
        return false;
    }

    @Override
    public boolean refundPayment() {
        if (isProcessed) {
            // Refund logic
            System.out.println("Payment refunded for amount: " + amount);
            isProcessed = false;
            return true;
        }
        return false;
    }
}

class HotelService implements Service {
    private String id;
    private String description;
    private double cost;

    public HotelService(String id, String description, double cost) {
        this.id = id;
        this.description = description;
        this.cost = cost;
    }

    @Override
    public String getDescription() {
        return description;
    }

    @Override
    public double getCost() {
        return cost;
    }

    @Override
    public void provideService(Guest guest) {
        System.out.println("Service provided to guest: " + guest.getName());
    }
}

class HotelImpl implements Hotel {
    private String id;
    private String name;
    private String location;
    private List<Room> rooms;

    public HotelImpl(String id, String name, String location) {
        this.id = id;
        this.name = name;
        this.location = location;
        this.rooms = new ArrayList<>();
    }

    @Override
    public void addRoom(Room room) {
        rooms.add(room);
    }

    @Override
    public List<Room> getAvailableRooms(Date startDate, Date endDate) {
        List<Room> availableRooms = new ArrayList<>();
        for (Room room : rooms) {
            if (room.isAvailable(startDate, endDate)) {
                availableRooms.add(room);
            }
        }
        return availableRooms;
    }
}

class Guest {
    private String id;
    private String name;

    public Guest(String id, String name) {
        this.id = id;
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public Booking makeBooking(Hotel hotel, Room room, Date startDate, Date endDate) {
        if (room.isAvailable(startDate, endDate)) {
            Booking booking = new RoomBooking(UUID.randomUUID().toString(), this, room, startDate, endDate);
            room.addBooking(booking);
            System.out.println("Booking made successfully.");
            return booking;
        } else {
            System.out.println("Room is not available for the selected dates.");
            return null;
        }
    }

    public void cancelBooking(Booking booking) {
        booking.cancel();
    }
}

public class HotelManagementSystem {
    public static void main(String[] args) {
        // Create hotel
        Hotel hotel = new HotelImpl("H1", "The Grand Hotel", "New York");

        // Create rooms
        Room room1 = new StandardRoom("101", RoomType.SINGLE, 100.0);
        Room room2 = new StandardRoom("102", RoomType.DOUBLE, 150.0);
        hotel.addRoom(room1);
        hotel.addRoom(room2);

        // Create guest
        Guest guest = new Guest("G1", "Alice");

        // Make a booking
        Calendar cal = Calendar.getInstance();
        cal.set(2024, Calendar.AUGUST, 20);
        Date startDate = cal.getTime();
        cal.set(2024, Calendar.AUGUST, 25);
        Date endDate = cal.getTime();

        Booking booking = guest.makeBooking(hotel, room1, startDate, endDate);

        // Process payment
        Payment payment = new BookingPayment("P1", booking, room1.getPrice() * 5, "Credit Card");
        payment.processPayment();

        // Provide a service
        Service roomService = new HotelService("S1", "Room Service", 20.0);
        roomService.provideService(guest);

        // Cancel booking and refund payment
        if (booking != null) {
            guest.cancelBooking(booking);
            payment.refundPayment();
        }
    }
}