using System.Collections.Generic;
using Microsoft.Xna.Framework.Graphics;

namespace Kav
{
    public class Scene
    {
        private PointLight[] pointLights = new PointLight[4];
        private List<Model> models = new List<Model>();

        public void AddPointLight(int index, PointLight light)
        {
            pointLights[index] = light;
        }

        public void AddModel(Model model)
        {
            models.Add(model);
        }

        public void Render(GraphicsDevice graphicsDevice, Camera camera)
        {
            var view = camera.View;
            var projection = camera.Projection;

            foreach (var model in models)
            {
                foreach (var modelMesh in model.Meshes)
                {
                    foreach (var meshPart in modelMesh.MeshParts)
                    {
                        graphicsDevice.SetVertexBuffer(meshPart.VertexBuffer);
                        graphicsDevice.Indices = meshPart.IndexBuffer;

                        if (meshPart.Effect is TransformEffect transformEffect)
                        {
                            transformEffect.World = model.Transform;
                            transformEffect.View = view;
                            transformEffect.Projection = projection;
                        }

                        if (meshPart.Effect is PointLightEffect pointLightEffect)
                        {
                            for (int i = 0; i < pointLights.Length; i++)
                            {
                                pointLightEffect.PointLights[i] = pointLights[i];
                            }
                        }

                        foreach (var pass in meshPart.Effect.CurrentTechnique.Passes)
                        {
                            pass.Apply();

                            graphicsDevice.DrawIndexedPrimitives(
                                PrimitiveType.TriangleList,
                                0,
                                0,
                                meshPart.VertexBuffer.VertexCount,
                                0,
                                meshPart.Triangles.Length
                            );
                        }
                    }
                }
            }
        }
    }
}