using System;
using System.Collections.Generic;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;

namespace Veldrid.Common.Plot
{
    public class DataReViewPlot : BaseVeldridRender,IZoomRender
    {
        public float HScale { get; set; } = 1;
        public float VScale { get; set; } = 1;
        public float HOffset { get; set; }
        public float VOffset { get; set; }
        public bool ZoomEnbled { get; set; } = true;
        struct ProjView
        {
            public Matrix4x4 Proj;
            public Matrix4x4 View;
        }
        private ProjView projView;
        Pipeline pipeline;
        private PlotInfo plotInfo;
        DeviceBuffer plotInfoBuffer;
        DeviceBuffer projViewBuffer;
        DeviceBuffer dataBuffer;
        ResourceLayout dataLayout;
        ResourceSet dataSet;
        ResourceLayout infoLayout;
        ResourceSet infoSet;
        Shader[] shaders;




        private Info info;
        private object locker = new object();
        public DataReViewPlot(VeldridContent control) : base(control)
        {
        }
        internal override void DisposeResources()
        {
            base.DisposeResources();
            pipeline?.Dispose();
            plotInfoBuffer?.Dispose();
            projViewBuffer?.Dispose();
            dataBuffer?.Dispose();
            dataLayout?.Dispose();
            dataSet?.Dispose();
            infoLayout?.Dispose();
            infoSet?.Dispose();
            resultBuffer?.Dispose();
            cpuBuffer?.Dispose();
        }
        internal override void CreateResources()
        {
            base.CreateResources();
            plotInfoBuffer = ResourceFactory.CreateBuffer(new BufferDescription((uint)Unsafe.SizeOf<Info>(), BufferUsage.UniformBuffer));
            projViewBuffer = ResourceFactory.CreateBuffer(new BufferDescription((uint)Unsafe.SizeOf<ProjView>(), BufferUsage.UniformBuffer));
            infoLayout = ResourceFactory.CreateResourceLayout(new ResourceLayoutDescription(
                new ResourceLayoutElementDescription("InfoBuffer", ResourceKind.UniformBuffer, ShaderStages.Vertex),
                new ResourceLayoutElementDescription("ProjView", ResourceKind.UniformBuffer, ShaderStages.Vertex)));
            infoSet = ResourceFactory.CreateResourceSet(new ResourceSetDescription(infoLayout, plotInfoBuffer, projViewBuffer));
            shaders = CreateShader("DataReViewPlot");
            


            CreateBuffer(100);
        }
        public Vector2 WindowScale { get; set; } = Vector2.One;
        public void SetData(IntPtr ptr,uint bytescount)
        {
            if(dataBuffer.SizeInBytes<bytescount)
            {
                CreateBuffer(bytescount);
            }
            GraphicsDevice.UpdateBuffer(dataBuffer, 0, ptr, bytescount);
        }
        public void SetData(float[] datas)
        {
            if (datas == null || datas.Length == 0) return;
            uint bytescount = (uint)(datas.Length * Unsafe.SizeOf<float>());
            if (dataBuffer.SizeInBytes < bytescount)
            {
                CreateBuffer(bytescount);
            }
            GraphicsDevice.UpdateBuffer(dataBuffer, 0, datas);
        }
        private void CreateBuffer(uint bytescount)
        {
            dataBuffer?.Dispose();
            dataLayout?.Dispose();
            dataSet?.Dispose();
            pipeline?.Dispose();
            dataBuffer = ResourceFactory.CreateBuffer(new BufferDescription(bytescount, BufferUsage.StructuredBufferReadWrite,(uint)Unsafe.SizeOf<float>()));
            dataLayout = ResourceFactory.CreateResourceLayout(new ResourceLayoutDescription(new ResourceLayoutElementDescription("DataBuffer", ResourceKind.StructuredBufferReadOnly, ShaderStages.Vertex)));
            dataSet = ResourceFactory.CreateResourceSet(new ResourceSetDescription(dataLayout, dataBuffer));
            pipeline = CreatePipLine(PrimitiveTopology.LineStrip, new[] { dataLayout, infoLayout }, Array.Empty<VertexLayoutDescription>(), shaders);

        }
        internal override void DrawData()
        {
            base.DrawData();
            if (PlotInfos == null || PlotInfos.Length == 0 || TotalCount == 0) return;
            projView.Proj = base.OrthographicMatrix;
            projView.View = GetLineMatrix(HScale,VScale,HOffset/(MainSwapchainBuffer.Width/ WindowScale.X)*2 * (Rectangle.Width/MainSwapchainBuffer.Width),VOffset/(MainSwapchainBuffer.Height/ WindowScale.Y)*2*(Rectangle.Width/MainSwapchainBuffer.Width));
            CommandList.UpdateBuffer(projViewBuffer,0, projView);
            CommandList.SetFramebuffer(MainSwapchainBuffer);
            CommandList.SetPipeline(pipeline);
            CommandList.SetGraphicsResourceSet(0, dataSet);
            CommandList.SetGraphicsResourceSet(1, infoSet);
            info.PlotCount = (uint)PlotInfos.Length;
            for (uint i=0;i<PlotInfos.Length;i++)
            {
                if (!PlotInfos[i].Visibily) continue;
                info.Color = PlotInfos[i].Color;
                info.Interval = Range.XLenght / TotalCount;
                info.PlotDataLenght = TotalCount;
                info.PlotIndex = i;
                CommandList.UpdateBuffer(plotInfoBuffer, 0, info);
                CommandList.Draw(TotalCount);
            }
        }

        DeviceBuffer resultBuffer;
        DeviceBuffer cpuBuffer;
        
        public PlotInfo[] PlotInfos { get; set; } = new PlotInfo[0];
        public uint TotalCount { get; set; }
        [StructLayout(LayoutKind.Sequential,Pack =1)]
        struct Info
        {
            public RgbaFloat Color;
            public uint PlotCount;
            public float Interval;
            public uint PlotIndex;
            public uint PlotDataLenght;
        }
    }
    public class PlotInfo
    {
        public RgbaFloat Color;
        public bool Visibily;
        public string Name = string.Empty;
    }
}