using System.Collections.Generic;

using Syntriax.Engine.Core;

namespace Syntriax.Engine.Network;

public class NetworkManager : UniverseObject, INetworkManager
{
    private INetworkCommunicator networkCommunicator = null!;
    public INetworkCommunicator NetworkCommunicator
    {
        get => networkCommunicator;
        set
        {
            if (networkCommunicator == value)
                return;

            var previousCommunicator = networkCommunicator;
            networkCommunicator = value;

            if (previousCommunicator is not null) previousCommunicator.OnPacketReceived -= OnPacketReceived;
            if (networkCommunicator is not null) networkCommunicator.OnPacketReceived += OnPacketReceived;
        }
    }

    private readonly Dictionary<string, INetworkEntity> _networkEntities = [];
    public IReadOnlyDictionary<string, INetworkEntity> NetworkEntities => _networkEntities;

    private readonly BehaviourCollector<INetworkEntity> _networkEntityCollector = new();
    public IBehaviourCollector<INetworkEntity> NetworkEntityCollector => _networkEntityCollector;

    public NetworkManager()
    {
        _networkEntityCollector.OnCollected += OnCollected;
        _networkEntityCollector.OnRemoved += OnRemoved;
    }

    private void OnPacketReceived(INetworkCommunicator sender, object packet, string from)
    {
        if (packet is not EntityDataPacket entityDataPacket)
            return;

        _networkEntities[entityDataPacket.Entity].ReceiveData(entityDataPacket.Data);
    }

    private void OnCollected(IBehaviourCollector<INetworkEntity> sender, INetworkEntity behaviourCollected)
    {
        if (!_networkEntities.TryAdd(behaviourCollected.Id, behaviourCollected))
            throw new($"Unable to add {behaviourCollected.Id} to {nameof(NetworkManager)}");
    }

    private void OnRemoved(IBehaviourCollector<INetworkEntity> sender, INetworkEntity behaviourRemoved)
    {
        _networkEntities.Remove(behaviourRemoved.Id);
    }

    protected override void OnEnteringUniverse(IUniverse universe) => _networkEntityCollector.Assign(universe);
    protected override void OnExitingUniverse(IUniverse universe) => _networkEntityCollector.Unassign();
}