using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Azimuth;
using Annulus;
using Annulus.SweptCollisionDetection;
using Blacklight.Core;

namespace Lodestone.TestBed.Demos
{
    public class SquareBounce : Demo
    {
        Universe universe = new Universe();
        List<Entity> entities = new List<Entity>();
        
        public override void Initialize()
        {
            universe.Settings.Gravity = new Vector(0, -500);

            var platform = new SimplePolygon(new Vector[]
            {
                new Vector(-1000, 10),
                new Vector(-1000, -10),
                new Vector( 1000, -10),
                new Vector( 1000, 10),
            });

            entities.Add(Entity.BuildFromPolygon(platform));

            var box = new SimplePolygon(new Vector[]
            {
                new Vector(-10, -10),
                new Vector( 10, -10),
                new Vector( 10,  10),
                new Vector(-10,  10),
            });

            var boxEntity = Entity.BuildFromPolygon(box);
            boxEntity.PhysicsBody.SetMotion(0, new Annulus.SweptCollisionDetection.Motion
            {
                InitialPosition = new Vector(0, 1000),
            });
            boxEntity.PhysicsBody.Mass = 10;
            boxEntity.PhysicsBody.MomentOfInertiaRatio = 1;

            entities.Add(boxEntity);

            entities.ForEach(entity =>
            {
                universe.AddBody(entity.PhysicsBody);
            });
        }

        public override void Shutdown()
        {

        }

        public override void Step(Scalar timeStep)
        {
            universe.Step(timeStep);
        }

        public override Scene Draw()
        {
            var returnMe = new Scene();
            var cel = new Cel();
            returnMe.Cels.Add(cel);

            foreach (var entity in entities)
            {
                var transform = entity.PhysicsBody.TransformAt(0);
                var drawable = entity.DrawPrimitive;

                cel.AddEntity(new Blacklight.Core.Entity
                {
                    drawable = drawable,
                    modelToWorld = transform,
                });
            }

            return returnMe;
        }

        public override string Description { get {
            return "This demo shows a diamond bouncing on a box.";
        } }
    }
}