using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using OpenTK;
using OpenTK.Graphics.OpenGL;

namespace bbiwarg.Graphics
{
    class OutputWindow : GameWindow
    {
        private VideoHandle videoHandle;
        private uint depthTextureID;
        private uint edgeTextureID;

        public OutputWindow(VideoHandle videoHandle): base(3 * videoHandle.getWidth(), 2 * videoHandle.getHeight())
        {
            this.videoHandle = videoHandle;
        }

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
            Title = "BBIWARG - Output";
            GL.ClearColor(Color.Black);

            // transparency
            GL.Enable(EnableCap.Blend);
            GL.BlendEquation(BlendEquationMode.Max);

            //Depth Test 
            GL.Enable(EnableCap.DepthTest);

            // Textures
            GL.Enable(EnableCap.Texture2D);

            //depthTexture
            GL.GenTextures(1, out depthTextureID);
            GL.BindTexture(TextureTarget.Texture2D, depthTextureID);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);

            //edgetexture
            GL.GenTextures(1, out edgeTextureID);
            GL.BindTexture(TextureTarget.Texture2D, edgeTextureID);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
        }

        protected override void OnResize(EventArgs e)
        {
            base.OnResize(e);
            GL.Viewport(ClientRectangle.X, ClientRectangle.Y, ClientRectangle.Width, ClientRectangle.Height);
            Matrix4 projection = Matrix4.CreatePerspectiveFieldOfView((float)Math.PI / 3, Width / (float)Height, 0.01f, 3.0f);
            GL.MatrixMode(MatrixMode.Projection);
            GL.LoadMatrix(ref projection);
        }

        protected override void OnRenderFrame(FrameEventArgs e)
        {
            
            base.OnRenderFrame(e);
            GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
            Matrix4 modelview = Matrix4.LookAt(Vector3.Zero, -Vector3.UnitZ, Vector3.UnitY);
            GL.MatrixMode(MatrixMode.Modelview);
            GL.LoadMatrix(ref modelview);
            Stopwatch sw = new Stopwatch();
            sw.Start();

            videoHandle.nextFrame();

            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds);
            //draw textures
            DepthImage depthImage = videoHandle.getDepthImage();
            Int16 minDepth = 0;// depthImage.getMinDepth();
            Int16 maxDepth = 400;// depthImage.getMaxDerivative();
            Int64 minMaxInterval = (Int16) Math.Max(maxDepth - minDepth, 1);
            Int16[] depthTextureData = new Int16[3 * depthImage.getWidth() * depthImage.getHeight()];
            Int16[] edgeTextureData = new Int16[3 * depthImage.getWidth() * depthImage.getHeight()];
            int index = 0;

            for (int y = 0; y < depthImage.getHeight(); ++y)
            {
                for (int x = 0; x < depthImage.getWidth(); ++x)
                {
                    //depthTexture
                    Int16 depth = Math.Min(depthImage.getDepthAt(x, y), maxDepth);
                    Int16 scaledDepth =  (Int16)(Int16.MaxValue - (((int)depth - minDepth) * (int)Int16.MaxValue / minMaxInterval));
                    depthTextureData[index] = scaledDepth;
                    depthTextureData[index + 1] = scaledDepth;
                    depthTextureData[index + 2] = scaledDepth;

                    //edgeTexture
                    Int16 edge = depthImage.getEdgeAt(x, y);
                    Int16 fingerPoint;
                    if (depthImage.isFingerPoint(x, y)) fingerPoint = Int16.MaxValue;
                    else fingerPoint = 0;

                    edgeTextureData[index] = fingerPoint;
                    edgeTextureData[index + 1] = fingerPoint;
                    edgeTextureData[index + 2] = edge;

                    index += 3;
                }
            }

            GL.Enable(EnableCap.Texture2D);
            GL.BindTexture(TextureTarget.Texture2D, depthTextureID);
            GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgb, videoHandle.getWidth(), videoHandle.getHeight(), 0, PixelFormat.Rgb, PixelType.Short, depthTextureData);
            float size = 0.5f;
            float size_2 = (float) (size / 2.0f);
            GL.Begin(PrimitiveType.Quads);
            GL.Color3(1.0, 1.0, 1.0);
            GL.TexCoord2(0.0, 0.0); GL.Vertex3(0, size_2, -0.5);
            GL.TexCoord2(1.0, 0.0); GL.Vertex3(size, size_2, -0.5);
            GL.TexCoord2(1.0, 1.0); GL.Vertex3(size, -size_2, -0.5);
            GL.TexCoord2(0.0, 1.0); GL.Vertex3(0, -size_2, -0.5);
            GL.End();

            GL.Enable(EnableCap.Texture2D);
            GL.BindTexture(TextureTarget.Texture2D, edgeTextureID);
            GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgb, videoHandle.getWidth(), videoHandle.getHeight(), 0, PixelFormat.Rgb, PixelType.Short, edgeTextureData);
            GL.Begin(PrimitiveType.Quads);
            GL.Color3(1.0, 1.0, 1.0);
            GL.TexCoord2(0.0, 0.0); GL.Vertex3(0, -size/2.0, -0.5);
            GL.TexCoord2(-1.0, 0.0); GL.Vertex3(-size, -size/2.0, -0.5);
            GL.TexCoord2(-1.0, -1.0); GL.Vertex3(-size, size/2.0, -0.5);
            GL.TexCoord2(0.0, -1.0); GL.Vertex3(0, size/2.0, -0.5);
            GL.End();


            SwapBuffers();
        }

    }
}