mediator pattern C# example

Program.cs

// абстрактный базовый класс-"коллега"
abstract class BodyPart
{
    protected Brain brain; // ссылка на медиатор

    public BodyPart(Brain brain)
    {
        this.brain = brain;
    }

    public abstract void Changed();
}

// "коллеги"
class Ear : BodyPart
{
    private string? sounds;

    public Ear(Brain brain) : base(brain) { }

    public void HearSomething()
    {
        Console.WriteLine("Enter what you hear (try to type \"cool\" or \"stupid\"): ");
        sounds = Console.ReadLine();

        Changed();
    }

    public string? GetSounds()
    {
        return sounds;
    }

    public override void Changed()
    {
        brain.SomethingHappenedToBodyPart(this);
    }
}

class Eye : BodyPart
{
    public Eye(Brain brain) : base(brain) { }

    public override void Changed()
    {
        // throw new NotImplementedException();
    }
}

class Face : BodyPart
{
    public Face(Brain brain) : base(brain) { }

    public override void Changed()
    {
        // throw new NotImplementedException();
    }

    public void Smile()
    {
        Console.WriteLine("FACE: Smiling :)");
    }
}

class Hand : BodyPart
{
    private bool isSoft;
    private bool isHurting;

    public Hand(Brain brain) : base(brain) { }

    public void FeelSomething()
    {
        Console.WriteLine("What you feel is soft? (Yes/No) ");
        string? answer = Console.ReadLine();

        if (answer != null && answer.Length > 0 && Char.ToLower(answer[0]) == 'y')
        {
            isSoft = true;
        }

        Console.WriteLine("What you feel is hurting? (Yes/No) ");
        answer = Console.ReadLine();

        if (answer != null && answer.Length > 0 && Char.ToLower(answer[0]) == 'y')
        {
            isHurting = true;
        }

        Changed();
    }

    public void HitPersonNearYou()
    {
        Console.WriteLine("HAND: Just hit offender...");
    }

    public void Embrace()
    {
        Console.WriteLine("HAND: Embracing what is in front of you...");
    }

    public bool DoesItHurt()
    {
        return isHurting;
    }

    public bool IsItNice()
    {
        return !isHurting && isSoft;
    }

    public override void Changed()
    {
        brain.SomethingHappenedToBodyPart(this);
    }
}

class Leg : BodyPart
{
    public Leg(Brain brain) : base(brain) { }

    public override void Changed()
    {
        // throw new NotImplementedException();
    }

    public void Kick()
    {
        Console.WriteLine("LEG: Just kicked offender in front of you...");
    }

    public void StepBack()
    {
        Console.WriteLine("LEG: Stepping back...");
    }

    public void StepForward()
    {
        Console.WriteLine("LEG: Stepping forward...");
    }
}

// медиатор
class Brain
{
    public Ear? ear;
    public Eye? eye;
    public Face? face;
    public Hand? hand;
    public Leg? leg;

    public Brain()
    {
        CreateBodyParts();
    }

    private void CreateBodyParts()
    {
        ear = new Ear(this);
        eye = new Eye(this);
        face = new Face(this);
        hand = new Hand(this);
        leg = new Leg(this);
    }

    public void SomethingHappenedToBodyPart(BodyPart bodyPart)
    {
        if (bodyPart is Ear)
        {
            string? heardSounds = ((Ear)bodyPart).GetSounds();

            if (heardSounds.Contains("stupid"))
            {
                leg?.StepForward();
                hand?.HitPersonNearYou();
                leg?.Kick();
            }
            else if (heardSounds.Contains("cool"))
            {
                face?.Smile();
            }
            else
            {
                Console.WriteLine("OK, I give you another try");
            }
        }
        else if (bodyPart is Eye)
        {
            Console.WriteLine("Brain can analyze what you see and can react appropriately using different body parts");
        }
        else if (bodyPart is Hand)
        {
            Hand? h = bodyPart as Hand;

            if (h.DoesItHurt())
            {
                leg?.StepBack();
            }
            else if (h.IsItNice())
            {
                leg?.StepForward();
                h.Embrace();
            }
            else
            {
                Console.WriteLine("OK, you can touch this :)");
            }
        }
        else if (bodyPart is Leg)
        {
            Console.WriteLine("Leg can also feel something if you would like it to");
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        Brain brain = new Brain();

        Ear? ear = brain.ear;
        Eye? eye = brain.eye;
        Hand? hand = brain.hand;
        Leg? leg = brain.leg;

        ear?.HearSomething();
        hand?.FeelSomething();

        Console.ReadKey();
    }
}