Engine-Pong/Shared/Behaviours/PongManagerBehaviour.cs

using System;

using Microsoft.Xna.Framework.Input;

using Syntriax.Engine.Core;
using Syntriax.Engine.Core.Debug;
using Syntriax.Engine.Network;
using Syntriax.Engine.Systems.Input;

namespace Pong.Behaviours;

public class PongManagerBehaviour : Behaviour, INetworkEntity, IFirstFrameUpdate,
    IPacketListenerServer<PongManagerBehaviour.RequestStartPacket>,
    IPacketListenerClient<PongManagerBehaviour.ScorePacket>
{
    public Action<PongManagerBehaviour>? OnReset { get; set; } = null;
    public Action<PongManagerBehaviour>? OnFinished { get; set; } = null;
    public Action<PongManagerBehaviour>? OnScoreUpdated { get; set; } = null;

    private Random random = new();
    private BallBehaviour ball = null!;

    private INetworkCommunicatorClient? networkClient = null!;
    private INetworkCommunicatorServer? networkServer = null;
    private ILogger? logger = null;

    public int ScoreLeft { get; private set; } = 0;
    public int ScoreRight { get; private set; } = 0;
    public int ScoreSum => ScoreLeft + ScoreRight;

    public int WinScore { get; } = 5;

    public PongManagerBehaviour() => WinScore = 5;
    public PongManagerBehaviour(int winScore) => WinScore = winScore;

    public void FirstActiveFrame()
    {
        IButtonInputs<Keys>? buttonInputs = Universe.FindBehaviour<IButtonInputs<Keys>>();
        buttonInputs?.RegisterOnRelease(Keys.Space, (_, _1) => networkClient?.SendToServer(new RequestStartPacket()));

        ball = Universe.FindRequiredBehaviour<BallBehaviour>();
        networkClient = Universe.FindBehaviour<INetworkCommunicatorClient>();
        networkServer = Universe.FindBehaviour<INetworkCommunicatorServer>();
        logger = Universe.FindBehaviour<ILogger>();
    }

    public void ScoreToLeft()
    {
        ScoreLeft++;
        OnScoreUpdated?.Invoke(this);

        PostScoreUpdate();
    }

    public void ScoreToRight()
    {
        ScoreRight++;
        OnScoreUpdated?.Invoke(this);

        PostScoreUpdate();
    }

    public void Reset()
    {
        ScoreLeft = ScoreRight = 0;

        PostScoreUpdate();

        OnReset?.Invoke(this);
    }

    private void PostScoreUpdate()
    {
        ball.ResetBall();

        if (networkServer is not null)
        {
            networkServer.SendToAll(new ScorePacket(this));
            logger?.Log(this, $"Sending score update packet to all: {ScoreLeft} - {ScoreRight}");
        }

        int halfwayScore = (int)(WinScore * .5f);
        if (ScoreLeft > halfwayScore || ScoreRight > halfwayScore)
        {
            OnFinished?.Invoke(this);
            logger?.Log(this, $"Game finished");
            return;
        }

        ball.LaunchBall(GetBallLaunchDirection());
    }

    private Vector2D GetBallLaunchDirection()
    {
        const float AllowedRadians = 45f * Syntriax.Engine.Core.Math.DegreeToRadian;
        float rotation = (float)random.NextDouble() * 2f * AllowedRadians - AllowedRadians;
        bool isBackwards = (random.Next() % 2) == 1;
        return Vector2D.Right.Rotate(isBackwards ? rotation + Syntriax.Engine.Core.Math.Pi : rotation);
    }

    void IPacketListenerClient<ScorePacket>.OnClientPacketArrived(IConnection sender, ScorePacket packet)
    {
        ScoreLeft = packet.Left;
        ScoreRight = packet.Right;

        OnScoreUpdated?.Invoke(this);
        logger?.Log(this, $"Client score update packet arrived: {packet.Left} - {packet.Right}");
    }

    void IPacketListenerServer<RequestStartPacket>.OnServerPacketArrived(IConnection sender, RequestStartPacket packet)
    {
        logger?.Log(this, $"{sender} requested start");
        if (ball.RigidBody.Velocity.MagnitudeSquared > 0.01f)
            return;

        Reset();
        ball.LaunchBall(GetBallLaunchDirection());
        logger?.Log(this, $"Game started");
    }

    private class RequestStartPacket : INetworkPacket;
    private class ScorePacket : INetworkPacket
    {
        public int Left { get; set; }
        public int Right { get; set; }

        public ScorePacket() { }
        public ScorePacket(PongManagerBehaviour pongManagerBehaviour)
        {
            Left = pongManagerBehaviour.ScoreLeft;
            Right = pongManagerBehaviour.ScoreRight;
        }
    }
}