SimonGame.cs

using System;

namespace Simon;

public enum GameState
{
    Start,
    NextLevel,
    Win,
    GameOver,
}

public class SimonEventArgs : EventArgs
{
    public GameState GameState { get; set; }
    public SimonEventArgs(GameState state)
    {
        GameState = state;
    }
}

public class SimonGame
{
    static int MAX_LEVELS = 25;
    static int NUM_BUTTONS = 4;

    public delegate void GameStateChangedDelegate(object sender, SimonEventArgs e);
    public event GameStateChangedDelegate OnGameStateChanged = delegate { };

    public int Level { get; set; }

    int currentStep;
    int[] Steps = new int[MAX_LEVELS];

    Random rand = new Random((int)DateTime.Now.Ticks);

    public void Reset()
    {
        OnGameStateChanged(this, new SimonEventArgs(GameState.Start));
        Level = 1;
        currentStep = 0;
        NextLevel();
    }

    public int[] GetStepsForLevel()
    {
        var steps = new int[Level];
        for (int i = 0; i < Level; i++)
            steps[i] = Steps[i];
        return steps;
    }

    public void EnterStep(int step)
    {
        if (Steps[currentStep] == step)
        {
            currentStep++;
        }
        else
        {
            OnGameStateChanged(this, new SimonEventArgs(GameState.GameOver));
            Reset();
        }
        if (currentStep == Level)
        {
            NextLevel();
        }
    }

    void NextLevel()
    {
        currentStep = 0;
        Level++;
        if (Level >= MAX_LEVELS)
        {
            OnGameStateChanged(this, new SimonEventArgs(GameState.Win));
            Reset();
            return;
        }
        var level = string.Empty;
        for (int i = 0; i < Level; i++)
        {
            Steps[i] = rand.Next(NUM_BUTTONS);
            level += Steps[i] + ", ";
        }
        OnGameStateChanged(this, new SimonEventArgs(GameState.NextLevel));
    }
}