Engine-Pong/Game/Network/NetworkBase.cs

using System;
using System.Collections.Generic;

using LiteNetLib;
using LiteNetLib.Utils;

using Syntriax.Engine.Core;
using Syntriax.Engine.Core.Abstract;
using Syntriax.Engine.Network.Abstract;

namespace Syntriax.Engine.Network;

public abstract class NetworkBase : BehaviourOverride, INetworkCommunicator
{
    public EventBasedNetListener Listener { get; private set; } = null!;
    public NetManager Manager { get; private set; } = null!;

    public NetworkBase()
    {
        Priority = 10;

        Listener = new EventBasedNetListener();
        Manager = new NetManager(Listener);

        Listener.NetworkReceiveEvent += NetworkReceiveEvent;
    }

    public void PollEvents() => Manager.PollEvents();
    public void Stop() => Manager.Stop();

    protected override void OnUpdate() => PollEvents();
    protected override void OnFinalize() => Stop();

    private readonly Dictionary<string, Action<NetPacketReader, NetPeer>> callbacks = new(32);

    private void NetworkReceiveEvent(NetPeer peer, NetPacketReader reader, byte channel, DeliveryMethod deliveryMethod)
    {
        if (callbacks.TryGetValue(reader.GetString(), out var action))
            action?.Invoke(reader, peer);

        reader.Recycle();
    }

    public void RegisterEntityListener(IEntity entity, Action<NetPacketReader, NetPeer> onDataReceived)
    {
        if (callbacks.ContainsKey(entity.Id))
            return;

        callbacks.Add(entity.Id, onDataReceived);
        entity.OnIdChanged += OnEntityIdChanged;
    }

    public void UnregisterEntityListener(IEntity entity)
    {
        if (!callbacks.Remove(entity.Id))
            return;

        entity.OnIdChanged -= OnEntityIdChanged;
    }

    public NetDataWriter GetMessageWriter(IEntity entity)
    {
        NetDataWriter netDataWriter = GetEntityWriter(entity);
        netDataWriter.Put((int)MessageType.Message);
        return netDataWriter;
    }

    public NetDataWriter GetEntityWriter(IEntity entity)
    {
        NetDataWriter netDataWriter = new();
        netDataWriter.Put(entity.Id);
        return netDataWriter;
    }

    private void OnEntityIdChanged(IEntity entity, string previousId)
    {
        var action = callbacks[previousId];
        callbacks.Remove(previousId);
        callbacks.Add(entity.Id, action);
    }
}