using BansheeEngine;

namespace BansheeEditor
{
    public sealed class ScaleHandle : DefaultHandle
    {
        private const float SMALL_CUBE_SIZE = 0.175f;
        private const float CENTER_CUBE_SIZE = 0.33f;

        private Vector3 delta;

        private HandleSliderLine xAxis;
        private HandleSliderLine yAxis;
        private HandleSliderLine zAxis;

        public Vector3 Delta
        {
            get { return delta; }
        }

        internal override bool IsDragged()
        {
            return xAxis.State == HandleSlider.StateType.Active ||
                    yAxis.State == HandleSlider.StateType.Active ||
                    zAxis.State == HandleSlider.StateType.Active;
        }

        public ScaleHandle()
        {
            xAxis = new HandleSliderLine(this, Vector3.xAxis, 1.0f);
            yAxis = new HandleSliderLine(this, Vector3.yAxis, 1.0f);
            zAxis = new HandleSliderLine(this, Vector3.zAxis, 1.0f);
        }

        protected override void PreInput()
        {
            xAxis.Position = position;
            yAxis.Position = position;
            zAxis.Position = position;

            xAxis.Rotation = rotation;
            yAxis.Rotation = rotation;
            zAxis.Rotation = rotation;
        }

        protected override void PostInput()
        {
            delta = Vector3.zero;

            delta += xAxis.Delta * GetXDir();
            delta += yAxis.Delta * GetYDir();
            delta += zAxis.Delta * GetZDir();
        }

        protected override void Draw()
        {
            HandleDrawing.SetTransform(Matrix4.TRS(Position, Rotation, Vector3.one));
            float handleSize = Handles.GetHandleSize(EditorApplication.SceneViewCamera, position);

            // Draw 1D sliders
            Vector3 smallCubeExtents = new Vector3(SMALL_CUBE_SIZE*0.5f, SMALL_CUBE_SIZE*0.5f, SMALL_CUBE_SIZE*0.5f);
            Color axisHover = new Color(0.8f, 0.8f, 0.8f, 1.0f);

            if (xAxis.State == HandleSlider.StateType.Active)
                HandleDrawing.SetColor(Color.white);
            else if (xAxis.State == HandleSlider.StateType.Hover)
                HandleDrawing.SetColor(Color.red * axisHover);
            else
                HandleDrawing.SetColor(Color.red);

            Vector3 xCubeOffset = Vector3.xAxis * SMALL_CUBE_SIZE * 0.5f;
            Vector3 xCubeStart = Vector3.xAxis - xCubeOffset;
            
            HandleDrawing.DrawLine(Vector3.zero, xCubeStart, handleSize);
            HandleDrawing.DrawCube(xCubeStart + xCubeOffset, smallCubeExtents, handleSize);

            if (yAxis.State == HandleSlider.StateType.Active)
                HandleDrawing.SetColor(Color.white);
            else if (yAxis.State == HandleSlider.StateType.Hover)
                HandleDrawing.SetColor(Color.green * axisHover);
            else
                HandleDrawing.SetColor(Color.green);

            Vector3 yCubeOffset = Vector3.yAxis * SMALL_CUBE_SIZE * 0.5f;
            Vector3 yCubeStart = Vector3.yAxis - yCubeOffset;

            HandleDrawing.DrawLine(Vector3.zero, yCubeStart, handleSize);
            HandleDrawing.DrawCube(yCubeStart + yCubeOffset, smallCubeExtents, handleSize);

            if (zAxis.State == HandleSlider.StateType.Active)
                HandleDrawing.SetColor(Color.white);
            else if (zAxis.State == HandleSlider.StateType.Hover)
                HandleDrawing.SetColor(Color.blue * axisHover);
            else
                HandleDrawing.SetColor(Color.blue);

            Vector3 zCubeOffset = Vector3.zAxis * SMALL_CUBE_SIZE * 0.5f;
            Vector3 zCubeStart = Vector3.zAxis - zCubeOffset;

            HandleDrawing.DrawLine(Vector3.zero, zCubeStart, handleSize);
            HandleDrawing.DrawCube(zCubeStart + zCubeOffset, smallCubeExtents, handleSize);

            // TODO - Draw free scale handle
        }

        private Vector3 GetXDir()
        {
            return rotation.Rotate(Vector3.xAxis);
        }

        private Vector3 GetYDir()
        {
            return rotation.Rotate(Vector3.yAxis);
        }

        private Vector3 GetZDir()
        {
            return rotation.Rotate(Vector3.zAxis);
        }
    }
}