using System;

using System.Collections.Generic;

using System.Linq;

using SimpleInjector;

​

public class Program

{

    public static void Main()

    {        

        Console.WriteLine("Setup the container");

        Container container = new Container();

        container.Register<Hotel>();

        // Task 1: configure dependencies

        container.Register<IRoomAllocator, LeastRecentlyUsedRoomManager>();

        container.Collection.Register<Room>(new List<Room> {

            new Room(1, new DateTime(2021, 10, 20), true),

            new Room(2, new DateTime(2021, 10, 22), false),

            new Room(3, new DateTime(2021, 10, 21), false),

        });

        container.Verify();

        Console.WriteLine("Run the system");

        var hotel = container.GetInstance<Hotel>();

        hotel.BookRoom();

    }

}

​

​

public class Hotel

{

    private IRoomAllocator roomAllocator;

    private IPaymentCalculator paymentCalculator;

    public Hotel(IRoomAllocator roomAllocator, IEnumerable<Room> rooms) {

        this.roomAllocator = roomAllocator;

        this.rooms = rooms;

    }

    private IEnumerable<Room> rooms;

    public Room BookRoom()

    {

        Console.WriteLine("Start booking a room");

        return roomAllocator.GetFreeRoom(rooms);

    }

}

​

public interface IRoomAllocator

{

    Room GetFreeRoom(IEnumerable<Room> rooms);

}

​

public interface IPaymentCalculator

{

    float CalculateSalary();

}

​

public class Room

{

    public int Number { get; private set; }

    public DateTime LastUsedAt { get; set; }

    public bool Booked { get; set; }

    public Room(int number, DateTime lastUsedAt, bool booked)

    {

        Number = number;

        LastUsedAt = lastUsedAt;

        Booked = booked;

    }

}

​

public class LeastRecentlyUsedRoomManager : IRoomAllocator

{

    public Room GetFreeRoom(IEnumerable<Room> rooms)

    {

        // Task 2: implement allocators

        var room = rooms.OrderBy(r => r.LastUsedAt).First();

        room.Booked = true;

        return room;

    }

}

​

public class NearestFrontDeskRoom : IRoomAllocator

{

    public Room GetFreeRoom(IEnumerable<Room> rooms)

    {

        // Task 2: implement allocators

        var room = rooms.OrderBy(r => r.Number).First(r => (r.Booked != true));

        room.Booked = true;

        return room;

    }

}