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;
using MathNet.Numerics.LinearAlgebra.Single;
using bbiwarg.DataSource;


namespace bbiwarg.Graphics
{
    class Output : GameWindow
    {
        private IVideoDataSource source;
        
        private uint imageBufferId, pointBufferId;

        public Output(IVideoDataSource source)
        {
            this.source = source;
        }

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

            initBuffers();
        }

        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);

            source.releaseFrame();
            source.updateFrame();

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

            GL.EnableClientState(ArrayCap.VertexArray);
            GL.EnableClientState(ArrayCap.ColorArray);

            GL.BindBuffer(BufferTarget.ArrayBuffer, imageBufferId);
            source.setVertexBuffer(GL.MapBuffer(BufferTarget.ArrayBuffer, BufferAccess.WriteOnly));
            source.createVertexArray();
            GL.UnmapBuffer(BufferTarget.ArrayBuffer);

            GL.VertexPointer(3, VertexPointerType.Float, 3 * sizeof(float) + 4 * sizeof(byte), IntPtr.Zero);
            GL.ColorPointer(4, ColorPointerType.UnsignedByte, 3 * sizeof(float) + 4 * sizeof(byte), 3 * sizeof(float));

            ImageData data = source.getImageData();

            GL.PointSize(3.0f);
            GL.DrawArrays(PrimitiveType.Points, 0, data.getHeight() * data.getWidth());


            // draw points
            float[] pointData;
            
            DetectionStatus[] fingerStatus = source.getFingerStatus(1);
            int numFingersDetected = 0;
            for (int i = 0; i < fingerStatus.Length; ++i)
            {
                if (fingerStatus[i] == DetectionStatus.Detected || fingerStatus[i] == DetectionStatus.Tracked)
                    ++numFingersDetected;
            }

            pointData = new float[(4 + 3) * (1 + numFingersDetected)];
            Color y = Color.Yellow;
            Vector palmPosition = source.getPalmPosition3D(1);

            pointData[0] = palmPosition[0];
            pointData[1] = palmPosition[2];
            pointData[2] = -palmPosition[1];

            pointData[3] = y.R / 255.0f;
            pointData[4] = y.G / 255.0f;
            pointData[5] = y.B / 255.0f;
            pointData[6] = y.A / 255.0f;

            int index = 7;
            Vector[] fingerPositions = source.getFingerTipPositions3D(1);
            for (int i = 0; i < fingerStatus.Length; ++i)
            {
                if (fingerStatus[i] == DetectionStatus.Detected || fingerStatus[i] == DetectionStatus.Tracked)
                {
                    pointData[index + 0] = fingerPositions[i][0];
                    pointData[index + 1] = fingerPositions[i][2];
                    pointData[index + 2] = -fingerPositions[i][1];

                    pointData[index + 3] = y.R / 255.0f;
                    pointData[index + 4] = y.G / 255.0f;
                    pointData[index + 5] = y.B / 255.0f;
                    pointData[index + 6] = y.A / 255.0f;
                    index += 7;
                }
            }

            GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
            GL.BindBuffer(BufferTarget.ArrayBuffer, pointBufferId);
            GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(pointData.Length * sizeof(float)), pointData, BufferUsageHint.DynamicDraw);
            GL.VertexPointer(3, VertexPointerType.Float, (4 + 3) * sizeof(float), IntPtr.Zero);
            GL.ColorPointer(4, ColorPointerType.Float, (4 + 3) * sizeof(float), 3 * sizeof(float));

            GL.PointSize(10f);
            GL.DrawArrays(PrimitiveType.Points, 0, pointData.Length / (4 + 3));

            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);
        }

        private void initBuffers()
        {
            GL.GenBuffers(1, out imageBufferId);
            GL.GenBuffers(1, out pointBufferId);

            ImageData data = source.getImageData();

            GL.BindBuffer(BufferTarget.ArrayBuffer, imageBufferId);
            GL.BufferData(BufferTarget.ArrayBuffer, 
                          (IntPtr)((3 * sizeof(float) + 4  * sizeof(byte)) * data.getWidth() * data.getHeight()), 
                          IntPtr.Zero, BufferUsageHint.StreamDraw);
        } 
    }
}