using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Raytracer.utils;

namespace Raytracer.shapes
{
    class Cube : Shape
    {
        private Vector3 pos_;
        private float size_;
        private CubeFace[] faces_;
        private CubeFace inter_face_;

        public Cube(Material mat, Vector3 pos, float s) : base(mat)
        {
            pos_ = pos;
            size_ = s;

            //faces_ = new CubeFace[6];

            Vector3 a = new Vector3(pos.X - s / 2, pos.Y + s / 2, pos.Z - s / 2);
            Vector3 b = new Vector3(pos.X + s / 2, pos.Y + s / 2, pos.Z - s / 2);
            Vector3 c = new Vector3(pos.X + s / 2, pos.Y + s / 2, pos.Z + s / 2);
            Vector3 d = new Vector3(pos.X - s / 2, pos.Y + s / 2, pos.Z + s / 2);

            Vector3 ah = new Vector3(pos.X - s / 2, pos.Y - s / 2, pos.Z - s / 2);
            Vector3 bh = new Vector3(pos.X + s / 2, pos.Y - s / 2, pos.Z - s / 2);
            Vector3 ch = new Vector3(pos.X + s / 2, pos.Y - s / 2, pos.Z + s / 2);
            Vector3 dh = new Vector3(pos.X - s / 2, pos.Y - s / 2, pos.Z + s / 2);


            CubeFace c0 = new CubeFace(mat, ah, bh, a);

            CubeFace c1 = new CubeFace(mat, bh, ch, b);

            CubeFace c2 = new CubeFace(mat, ch, dh, c);

            CubeFace c3 = new CubeFace(mat, dh, ah, d);

            CubeFace sol = new CubeFace(mat, a, b, d);

            CubeFace toit = new CubeFace(mat, bh, ah, bh);


            faces_ = new CubeFace[] { toit, sol, c0, c1,c2,c3 };


            // First face of the cube.
            //faces_[0] = new CubeFace(mat, new Vector3(pos.X + s / 2, pos.Y + s / 2, pos.Z - s / 2), new Vector3(pos.X + s / 2, pos.Y - s / 2, pos.Z - s / 2), new Vector3(pos.X - s / 2, pos.Y + s / 2, pos.Z - s / 2));


        }

        public override Vector3 intersect(Ray ray)
        {
            inter_face_ = null;
            foreach (CubeFace cf in faces_)
            {
                if (cf.intersect(ray) != null)
                {
                    if (inter_face_ != null)
                    {
                        if ((inter_face_.intersect(ray).norm()) > (cf.intersect(ray)).norm())
                        {
                            inter_face_ = cf;
                        }
                    }
                    else
                    {
                        inter_face_ = cf;
                    }
                }

            }

            if (inter_face_ != null)
            {
                return inter_face_.intersect(ray);
            }
            else
            {
                return null;
            }

        }

        public override Vector3 normal_at_point(Vector3 point)
        {
            return inter_face_.normal_at_point(point);
        }
    }
}