using Unity.Entities;
using Unity.NetCode;
using Unity.Networking.Transport;
using Unity.Burst;
using UnityEngine;

[UpdateInGroup(typeof(ServerSimulationSystemGroup))]
public class IntRpcReceiver : SystemBase
{
  protected override void OnUpdate()
  {
    var system = World.GetOrCreateSystem<BeginInitializationEntityCommandBufferSystem>();
    var buffer = system.CreateCommandBuffer();

    // On the server, go through ever entity with a 'IntRpc' that we
    // are _not_ sending
    Entities.WithNone<SendRpcCommandRequestComponent>().ForEach((Entity entity, in IntRpc request, in ReceiveRpcCommandRequestComponent requestSource) => {
        Debug.Log(request.message);

        // Once we process the message, delete it
        buffer.DestroyEntity(entity);
    }).WithoutBurst().Run();

    system.AddJobHandleForProducer(this.Dependency);
  }
}

[UpdateInGroup(typeof(ClientSimulationSystemGroup))]
public class IntRpcSender : RpcCommandRequestSystem<IntRpc>
{
  // This class doesn't need a body. The parent class takes
  // care of transmitting 'IntRpc's.
}

[BurstCompile]
public struct IntRpc : IRpcCommand
{
    public int message;

    // All this serialization stuff seems like boilerplate, but
    // I don't know how to get rid of it yet.
    public void Deserialize(ref DataStreamReader reader)
    {
      message = reader.ReadInt();
    }

    public void Serialize(ref DataStreamWriter writer)
    {
      writer.WriteInt(message);
    }

    [BurstCompile]
    private static void InvokeExecute(ref RpcExecutor.Parameters parameters)
    {
        RpcExecutor.ExecuteCreateRequestComponent<IntRpc>(ref parameters);
    }

    static PortableFunctionPointer<RpcExecutor.ExecuteDelegate>
      InvokeExecuteFunctionPointer =
      new PortableFunctionPointer<RpcExecutor.ExecuteDelegate>(InvokeExecute);

    public PortableFunctionPointer<RpcExecutor.ExecuteDelegate> CompileExecute()
    {
        return InvokeExecuteFunctionPointer;
    }
}

/* Sending the RPC:
  var request = EntityManager.CreateEntity();
  EntityManager.AddComponent<IntRpc>(request);
  EntityManager.AddComponent<SendRpcCommandRequestComponent>(request);
  EntityManager.SetComponentData(request, new SendRpcCommandRequestComponent {
    TargetConnection = // The entity to send the RPC to. Must have a 'NetworkIdComponent' component
  });
  EntityManager.SetComponentData(request, new IntRpc {
    message = 123, // The actual payload of the RPC
  });
*/