using System.Collections.Generic;
using Syntriax.Engine.Core;

namespace Syntriax.Engine.Integration.MonoGame;

public class LoadContentManager : Behaviour, IFirstFrameUpdate
{
    // We use Ascending order because we are using reverse for loop to call them
    private static Comparer<IBehaviour> SortByAscendingPriority() => Comparer<IBehaviour>.Create((x, y) => x.Priority.CompareTo(y.Priority));

    private readonly ActiveBehaviourCollectorSorted<ILoadContent> loadContents = new() { SortBy = SortByAscendingPriority() };
    private readonly List<ILoadContent> toCallLoadContents = new(32);

    private MonoGameWindowContainer monoGameWindowContainer = null!;

    public void FirstActiveFrame()
    {
        monoGameWindowContainer = Universe.FindRequiredBehaviour<MonoGameWindowContainer>();
    }

    protected override void OnEnteredUniverse(IUniverse universe)
    {
        loadContents.Assign(universe);

        universe.OnPreUpdate.AddListener(OnPreUpdate);
    }

    protected override void OnExitedUniverse(IUniverse universe)
    {
        loadContents.Unassign();

        universe.OnPreUpdate.RemoveListener(OnPreUpdate);
    }

    private void OnPreUpdate(IUniverse sender, IUniverse.UpdateArguments args)
    {
        for (int i = toCallLoadContents.Count - 1; i >= 0; i--)
        {
            toCallLoadContents[i].LoadContent(monoGameWindowContainer.Window.Content);
            toCallLoadContents.RemoveAt(i);
        }
    }

    private void OnFirstFrameCollected(IBehaviourCollector<ILoadContent> sender, IBehaviourCollector<ILoadContent>.BehaviourCollectedArguments args)
    {
        toCallLoadContents.Add(args.BehaviourCollected);
    }

    public LoadContentManager()
    {
        loadContents.OnCollected.AddListener(OnFirstFrameCollected);
    }
}