using System;

using System.Collections.Generic;

​

public abstract class OnBoardComputer

{

    public string Name { get; protected set; }

    public bool IsLandingGearRaised { get; set; }

    public bool IsInManualMode { get; set; }

​

    public event LandingGearHandler OnLandingGearRaisedEvent;

    public delegate void LandingGearHandler(OnBoardComputer computer);

    public void OnLandingGearRaised()

    {

        if (OnLandingGearRaisedEvent != null) OnLandingGearRaisedEvent(this);

    }

​

    public event ManualModeHandler OnManualModeEvent;

    public delegate void ManualModeHandler(OnBoardComputer computer);

    public void OnManualMode()

    {

        if (OnManualModeEvent != null) OnManualModeEvent(this);

    }

​

    public Stack<ICommand> Journal = new Stack<ICommand>();

​

    public bool ExecuteCommand(ICommand command)

    {

        if (command.Execute(this))

        {

            Journal.Push(command);

            return true;

        }

        return false;

    }

}

​

public interface ICommand

{

    bool Execute(OnBoardComputer computer);

}

​

public class RaiseLandingGear : ICommand

{

    public bool Execute(OnBoardComputer computer)

    {

        // check if raised

        if (!computer.IsLandingGearRaised)

        {

            // check the speed

​

            // check height

​

            // check the angle

​

            // check aircraft specific rules

            if (computer is Boeing) { /* ... */ }

            if (computer is Cesna) { /* ... */ }

​

            // check ...

​

            // check ...

​

            // events go here

            computer.OnLandingGearRaised();

            return true;

        }

​

        return false;

    }

}

​

public class LowLandingGear : ICommand

{

    public bool Execute(OnBoardComputer computer)

    {

        // check if raised

        if (computer.IsLandingGearRaised)

        {

            // check the speed

​

            // check height

​

            // check the angle

​

            // check aircraft specific rules

            if (computer is Boeing) { /* ... */ }

            if (computer is Cesna) { /* ... */ }

​

            // check ...

​

            // check ...

​

            // events go here

            // computer.OnSomeEvent();

            return true;

        }

​

        return false;

    }

}

​

public class SwitchToManual : ICommand

{

    public bool Execute(OnBoardComputer computer)

    {

        // check if in manual

        if (!computer.IsInManualMode)

        {

​

            // check some other complex things

​

            // check aircraft specific rules

            if (computer is Boeing) { /* ... */ }

            if (computer is Cesna) { /* ... */ }

​

            // check ...

​

            // check ...

            // events go here

            computer.OnManualMode();

            return true;

        }

​

        return false;

    }

}

​

public class SwitchToAutopilot : ICommand

{

    public bool Execute(OnBoardComputer computer)

    {

        // check if in manual

        if (computer.IsInManualMode)

        {

​

            // check some other complex things

​

            // check aircraft specific rules

            if (computer is Boeing) { /* ... */ }

            if (computer is Cesna) { /* ... */ }

​

            // check ...

​

            // check ...

            // events go here

            // computer.OnSomeEvent();

            return true;

        }

​

        return false;

    }

}

​

public class Boeing : OnBoardComputer

{

​

    public Boeing()

    {

        Name = "Boeing";

    }

}

​

public class Cesna : OnBoardComputer

{

​

    public Cesna()

    {

        Name = "Cesna";

    }

}

​

public class Program

{

    public static void Main()

    {

        var boeing = new Boeing();

        var cesna = new Cesna();

​

        // subscribe to events

        boeing.OnManualModeEvent += computer => Console.WriteLine(computer.Name + " is on manual");

        cesna.OnLandingGearRaisedEvent += computer => Console.WriteLine(computer.Name + " raised landing gear");

​

        // initiate some actions

        boeing.ExecuteCommand(new SwitchToManual());

        cesna.ExecuteCommand(new RaiseLandingGear());

    }

}