using System;

using System.Reactive.Subjects; 

using System.Reactive.Linq;

using System.Collections.Generic;

​

public class Program

{

    static Subject<UnitModel> m_whenDeviceChanged = new();

    static Dictionary<string, UnitModel> m_units = new();

    public static void Main()

    {

        Console.WriteLine($"Hello World {DateTime.Now}");

        m_whenDeviceChanged.GroupBy(u => u.Name)

            .Select(g => g.DistinctUntilChanged().Throttle(TimeSpan.FromSeconds(1))).Subscribe(u => OnDeviceUpdated(u));

​

        ConsoleKeyInfo k;                                       

                                                        for(int i=0; i<10; ++i)

                                                        {

                                                            System.Threading.Thread.Sleep(1000);

                                                            //k = Console.ReadKey();

                                                            //var name = k.KeyChar.ToString();

                                                            var name = (i % 3).ToString();

                                                            if (m_units.ContainsKey(name))

                                                            {

                                                                Console.WriteLine($"update {name}");

                                                                var unit = m_units[name];

                                                                unit.State++;

                                                                m_whenDeviceChanged.OnNext(unit);

                                                            }

                                                            else

                                                            {

                                                                Console.WriteLine($"add {name}");

                                                                var newUnit = new UnitModel(){Name = name};

                                                                m_units[name] = newUnit;

                                                                m_whenDeviceChanged.OnNext(newUnit);

                                                            }

                                                        }

        //while(k.Key != ConsoleKey.Escape);

        Console.WriteLine("Bye");

    }

    private static void OnDeviceUpdated(IObservable<UnitModel> unitObs)

    {

        Console.WriteLine($"{DateTime.Now} Subscribe to");

        unitObs.Subscribe(OnDeviceUpdated);

    }

​

    private static void OnDeviceUpdated(UnitModel unit)

    {

        Console.WriteLine($"{DateTime.Now} Unit changed {unit.Name}-{unit.State}");

    }

}

​

public record UnitModel

{

    public string Name {get;set;}

    public int State{get;set;}

}