using System.Collections.Generic;

using Apos.Shapes;

using Syntriax.Engine.Core;
using Syntriax.Engine.Integration.MonoGame;

namespace Pong.Behaviours;

public class ShapeBatcher : BehaviourBase, IFirstFrameUpdate, IDraw
{
    private static Comparer<IBehaviour> SortByPriority() => Comparer<IBehaviour>.Create((x, y) => y.Priority.CompareTo(x.Priority));
    private ShapeBatch shapeBatch = null!;
    private MonoGameCamera2DBehaviour camera2D = null!;
    private readonly ActiveBehaviourCollectorSorted<IDrawableShape> drawableShapes = new() { SortBy = SortByPriority() };

    public void FirstActiveFrame()
    {
        MonoGameWindowContainer windowContainer = BehaviourController.UniverseObject.Universe.FindRequiredBehaviour<MonoGameWindowContainer>();
        camera2D = BehaviourController.UniverseObject.Universe.FindRequiredBehaviour<MonoGameCamera2DBehaviour>();

        shapeBatch = new(windowContainer.Window.GraphicsDevice, windowContainer.Window.Content);

        drawableShapes.Unassign();
        drawableShapes.Assign(Universe);
    }

    public void Draw()
    {
        shapeBatch.Begin(camera2D.MatrixTransform);
        for (int i = drawableShapes.Count - 1; i >= 0; i--)
            drawableShapes[i].Draw(shapeBatch);
        shapeBatch.End();
    }
}