using Engine.Core;

namespace Engine.Systems.Network;

/// <summary>
/// Basic network behaviour that supports both client & server behaviour. Finds both 
/// the <see cref="INetworkCommunicatorClient"/> and the <see cref="INetworkCommunicatorServer"/> 
/// in the universe in it's first active frame. Recommended to use <see cref="ClientBehaviour"/> or <see cref="ServerBehaviour"/>
/// <br/> 
/// Disclaimer: It implements <see cref="IFirstFrameUpdate"/> and <see cref="ILastFrameUpdate"/> in virtual methods.
/// </summary>
public class CommonNetworkBehaviour : Behaviour, IFirstFrameUpdate, ILastFrameUpdate
{
    protected INetworkCommunicatorServer? server = null!;
    protected INetworkCommunicatorClient? client = null!;

    protected bool IsServer { get; private set; } = false;
    protected bool IsClient { get; private set; } = false;

    public INetworkCommunicatorServer Server => server ?? throw new Core.Exceptions.NotFoundException($"Universe does not contain a {nameof(INetworkCommunicatorServer)}");
    public INetworkCommunicatorClient Client => client ?? throw new Core.Exceptions.NotFoundException($"Universe does not contain a {nameof(INetworkCommunicatorClient)}");

    public virtual void FirstActiveFrame()
    {
        client = Universe.FindBehaviour<INetworkCommunicatorClient>();
        server = Universe.FindBehaviour<INetworkCommunicatorServer>();

        IsServer = server is not null;
        IsClient = client is not null;
    }

    public virtual void LastActiveFrame()
    {
        client = null!;
        server = null!;

        IsServer = false;
        IsClient = false;
    }
}