using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using CommonLang.Geometry.SceneGraph2D;
using System.Drawing.Drawing2D;
using CommonLang.Geometry;
using System.Drawing;

namespace CommonFroms.SceneGraph2D
{
    public class Win32SceneGraphFactory : Factory
    {
        public static void Init()
        {
            if (Instance == null) { new Win32SceneGraphFactory(); }
        }
        private Win32SceneGraphFactory() { }
        public override ITransform CreateTransform()
        {
            return new Win32Transform();
        }
    }

    public class Win32Graphics : IGraphics
    {
        public readonly Graphics gfx;

        private Stack<GraphicsState> state_stack = new Stack<GraphicsState>();

        public Win32Graphics(Graphics g)
        {
            this.gfx = g;
        }
        public void PopTransform()
        {
            gfx.Restore(state_stack.Pop());
        }
        public void PushTransform()
        {
            state_stack.Push(gfx.Save());
        }
        public void Transform(ITransform trans)
        {
            (trans as Win32Transform).Apply(gfx);
        }
    }

    public class Win32Transform : ITransform
    {
        private Vector2 translation = new Vector2();
        private float rotation = 0f;
        private Vector2 scale = new Vector2(1f, 1f);

        public Vector2 Translation
        {
            get { return translation; }
            set { translation = value; }
        }
        public float Rotation
        {
            get { return rotation; }
            set { rotation = value; }
        }
        public Vector2 Scale
        {
            get { return scale; }
            set { scale = value; }
        }

        internal void Apply(System.Drawing.Drawing2D.Matrix trans)
        {
            trans.Translate(translation.X, translation.Y);
            trans.Rotate(rotation);
            trans.Scale(scale.X, scale.Y);
        }
        internal void Invert(System.Drawing.Drawing2D.Matrix trans)
        {
            trans.Scale(1f / scale.X, 1f / scale.Y);
            trans.Rotate(-rotation);
            trans.Translate(-translation.X, -translation.Y);
        }
        internal void Apply(Graphics gfx)
        {
            gfx.TranslateTransform(translation.X, translation.Y);
            gfx.RotateTransform(rotation);
            gfx.ScaleTransform(scale.X, scale.Y);
        }



        public void LocalToParent(Vector2[] local)
        {
            var pts = new PointF[local.Length];
            for (int i = 0; i < local.Length; i++) { pts[i] = new PointF(local[i].X, local[i].Y); }
            var mtx = new System.Drawing.Drawing2D.Matrix();
            this.Apply(mtx);
            mtx.TransformPoints(pts);
            for (int i = 0; i < local.Length; i++) { local[i] = new Vector2(pts[i].X, pts[i].Y); }
        }

        public void ParentToLocal(Vector2[] parent)
        {
            var pts = new PointF[parent.Length];
            for (int i = 0; i < parent.Length; i++) { pts[i] = new PointF(parent[i].X, parent[i].Y); }
            var mtx = new System.Drawing.Drawing2D.Matrix();
            this.Invert(mtx);
            mtx.TransformPoints(pts);
            for (int i = 0; i < parent.Length; i++) { parent[i] = new Vector2(pts[i].X, pts[i].Y); }
        }

    }
}