using System.Collections.Generic;

using Microsoft.Xna.Framework;

using Syntriax.Engine.Core;

namespace Syntriax.Engine.Integration.MonoGame;

public class TriangleBatcher : BehaviourBase, ITriangleBatch, IFirstFrameUpdate, IDraw
{
    private static Comparer<IBehaviour> SortByAscendingPriority() => Comparer<IBehaviour>.Create((x, y) => x.Priority.CompareTo(y.Priority));

    private TriangleBatch triangleBatch = null!;
    private MonoGameCamera2DBehaviour camera2D = null!;
    private readonly ActiveBehaviourCollectorSorted<IDrawableTriangle> drawableShapes = new() { SortBy = SortByAscendingPriority() };

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

        triangleBatch = new(windowContainer.Window.GraphicsDevice);
        drawableShapes.Unassign();
        drawableShapes.Assign(BehaviourController.UniverseObject.Universe);
    }

    public void Draw()
    {
        triangleBatch.Begin(camera2D.MatrixTransform);
        for (int i = 0; i < drawableShapes.Count; i++)
            drawableShapes[i].Draw(triangleBatch);
        triangleBatch.End();
    }

    public void Begin(Matrix? view = null, Matrix? projection = null) => triangleBatch.Begin(view, projection);
    public void Draw(Triangle triangle, ColorRGBA colorRGBA) => triangleBatch.Draw(triangle, colorRGBA);
    public void End() => triangleBatch.End();
}