using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using OpenTK;
using OpenTK.Graphics.OpenGL;
using System.Drawing;
using System.Diagnostics;
using MathNet.Numerics.LinearAlgebra.Single;
using bbiwarg.Graphics.GraphicElements2D;
using bbiwarg.InputProviders;
using bbiwarg.Images;
using bbiwarg.Helpers;
using bbiwarg.VideoHandles;

namespace bbiwarg.Graphics
{
    class Output2D: GameWindow
    {
        private VideoHandle videoHandle;
        private uint textureId;

        public Output2D(VideoHandle videoHandle): base(3 * 320, 3 * 240)
        {
            this.videoHandle = videoHandle;
        }

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

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

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

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

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

        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);

            videoHandle.nextFrame();

            Stopwatch sw = new Stopwatch();
            sw.Start();

            short[] textureData = new short[3 * videoHandle.getWidth() * videoHandle.getHeight()];
            int index = 0;
            short minDepth = videoHandle.getHandImage().getMinDepth();
            short maxDepth = videoHandle.getHandImage().getMaxDepth();
            
            for (int y = 0; y < videoHandle.getHeight(); ++y)
            {
                for (int x = 0; x < videoHandle.getWidth(); ++x)
                {
                    short depth = videoHandle.getHandImage().getDepth(x, y);
                    short diff = (short) Math.Max(maxDepth - minDepth, 1);
                    short scaledDepth = (short) (Int16.MaxValue - (((int) depth - minDepth) * (int) Int16.MaxValue / diff));
                    textureData[index] = scaledDepth;
                    textureData[index + 1] = scaledDepth;
                    textureData[index + 2] = scaledDepth;
                    index += 3;
                }
            }

            // draw histogram
            GL.Disable(EnableCap.Texture2D);
            int[] histogram = videoHandle.getSmoothedHistogram();
            int maxValue = 0;
            for (int i = 0; i < histogram.Length; ++i)
            {
                if (histogram[i] > maxValue)
                    maxValue = histogram[i];
            }

            Int16[] segmentationDepth = videoHandle.getSegementationDepth();

            GL.Begin(PrimitiveType.LineStrip);
            GL.Color3(0, 0, 1.0);
            GL.LineWidth(5.0f);
            for (int i = 0; i < histogram.Length; ++i)
            {
                if (i > segmentationDepth[0]) GL.Color3(Color.Yellow);
                if (i > segmentationDepth[1]) GL.Color3(Color.Red);
                if (i > segmentationDepth[2]) GL.Color3(Color.Silver);
                
                GL.Vertex3(-0.25 + i * (0.5 / histogram.Length), -0.25 + histogram[i] * (0.5 / (maxValue - 5)), -0.5);
            }
            GL.End();

            // draw texture
            GL.Enable(EnableCap.Texture2D);
            GL.BindTexture(TextureTarget.Texture2D, textureId);
            GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgb, videoHandle.getWidth(), videoHandle.getHeight(), 0,
                          PixelFormat.Rgb, PixelType.Short, textureData);

            float size_2 = 0.5f / 2.0f;
            GL.Begin(PrimitiveType.Quads);
            GL.Color3(1.0, 1.0, 1.0);
            GL.TexCoord2(0.0, 0.0); GL.Vertex3(-size_2,  size_2, -0.5);
            GL.TexCoord2(1.0, 0.0); GL.Vertex3( size_2,  size_2, -0.5);
            GL.TexCoord2(1.0, 1.0); GL.Vertex3( size_2, -size_2, -0.5);
            GL.TexCoord2(0.0, 1.0); GL.Vertex3(-size_2, -size_2, -0.5);
            GL.End();

            sw.Stop();
            Console.WriteLine(sw.ElapsedMilliseconds);

            SwapBuffers();
        }

        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);
        }
    }
}