using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Drawing.Imaging;
using System.IO;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Runtime.Versioning;
using AntVortice.Helpers;

using Vortice;
using Vortice.DXGI;
using Vortice.Direct3D11;
using ID3D11Device = Vortice.Direct3D11.ID3D11Device;
using MapFlags = Vortice.Direct3D11.MapFlags;
using Vortice.Direct3D;
using SharpGen.Runtime;

namespace SharpDX_Test
{
    public class CaptureScreenVortice
    {

        public enum DPI_AWARENESS_CONTEXT
        {
            DPI_AWARENESS_CONTEXT_DEFAULT = 0, 
            DPI_AWARENESS_CONTEXT_UNAWARE = -1, 
            DPI_AWARENESS_CONTEXT_SYSTEM_AWARE = -2, 
            DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE = -3,
            DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 = -4,
            DPI_AWARENESS_CONTEXT_UNAWARE_GDISCALED = -5, 
        }

        // for Windows 10 version RS2 and above
        [DllImport("user32.dll", SetLastError = true)]
        [ResourceExposure(ResourceScope.None)]
        public static extern bool SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT dpiFlag);

        [DllImport("msvcrt.dll", EntryPoint = "memcpy_s", CallingConvention = CallingConvention.Cdecl, SetLastError = false)]
        public static extern IntPtr memcpy(IntPtr dest, ulong dstLen, IntPtr src, ulong srcLen);


        private static readonly FeatureLevel[] s_featureLevelsNoLevel11 = new[]
       {
            FeatureLevel.Level_11_0,
            FeatureLevel.Level_10_1,
            FeatureLevel.Level_10_0
        };

        public static readonly ResultDescriptor WaitTimeout 
                = new ResultDescriptor(-2005270489, "Vortice.DXGI", "DXGI_ERROR_WAIT_TIMEOUT", "WaitTimeout");


        // TODO: Split into multiple functions later
        public Bitmap CaptureScreen()
        {
            // Application.SetHighDpiMode(HighDpiMode.PerMonitorV2);
            // SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT.DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);

            // # of graphics card adapter
            const int numAdapter = 0;

            // # of output device (i.e. monitor)
            const int numOutput = 0; // 0 = primary? , 1 = secondary?

            // For DuplicateOutput to succeed, you must create pDevice
            // from SharpDX.DXGI.Factory1 or a later version of a DXGI factory interface that
            // inherits from SharpDX.DXGI.Factory1
            // Create DXGI Factory1
            DXGI.CreateDXGIFactory1(out IDXGIFactory1 factory); // contains video card adapters

            var adapter = factory.GetAdapter1(numAdapter); // EnumAdapters1(numAdapter), graphics card

            // Create device from Adapter
            var grakaDevice = D3D11Helper.CreateDevice(adapter);
			// => D3D11.D3D11CreateDevice(adapter, DriverType.Unknown
            //, DeviceCreationFlags.None, null, out ID3D11Device grakaDevice,
            // out FeatureLevel fl, out ID3D11DeviceContext context);
			
			
            var monitor = adapter.GetOutput(numOutput); // EnumOutputs(numOutput)

            var monitor_op1 = monitor.QueryInterface<IDXGIOutput1>();
            var monitor_op5 = monitor.QueryInterface<IDXGIOutput5>();

            var bounds = monitor.Description.DesktopCoordinates;
            var width = bounds.Right - bounds.Left;
            var height = bounds.Bottom - bounds.Top;

            // Create Staging texture CPU-accessible
            var textureDesc = new Texture2DDescription
            {
                CpuAccessFlags = CpuAccessFlags.Read,
                BindFlags = BindFlags.None,
                Format = Format.B8G8R8A8_UNorm, // Format.B8G8R8A8_UNorm, B8G8R8A8_UNorm_SRgb
                Width = width,
                Height = height,
                OptionFlags = ResourceOptionFlags.None,
                MipLevels = 1,
                ArraySize = 1,
                SampleDescription = { Count = 1, Quality = 0 },
                Usage = Vortice.Direct3D11.Usage.Staging
            };
            var cpuScreenTexture = grakaDevice.CreateTexture2D(textureDesc);

            // must be set before DuplicateOutput1
            // SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT.DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);

            // var duplicatedOutput = monitor_op1.DuplicateOutput(grakaDevice);
            // IDXGIOutput5::DuplicateOutput1 is supposed to be faster, doesnt convert the image

            var duplicatedOutput = monitor_op1.DuplicateOutput(grakaDevice);
            //var duplicatedOutput = monitor_op5.DuplicateOutput1(grakaDevice, new Format[] { Format.B8G8R8A8_UNorm });

            Bitmap bitmap = null;
            IDXGIResource gpuScreenResource;

            // has tons of information
            OutduplFrameInfo duplicateFrameInformation;

            // first frame is black?
            duplicatedOutput.AcquireNextFrame(10000, out duplicateFrameInformation, out gpuScreenResource);
            duplicatedOutput.ReleaseFrame();

            gpuScreenResource.Dispose();

            var sw = new Stopwatch();

            //To correct visual effects, an application must
            //     process the move region data before it processes the dirty rectangles
            // IDXGIOutputDuplication::GetFrameMoveRects,
            // IDXGIOutputDuplication::GetFrameDirtyRects, 
            // IDXGIOutputDuplication::GetFramePointerShape
            for (int k = 0; k < 5; k++)
            {
                try
                {
                    // Try to get changed frame within given time
                    // will wait until the picture has changed...
                    duplicatedOutput.AcquireNextFrame(10000, out duplicateFrameInformation, out gpuScreenResource);

                    sw.Start();

                    // gpuScreenTexture contains the Format of current screen (GPU)
                    // copy resource from GPU (gpuScreenTexture) into memory that can be accessed by the CPU
                    using (var gpuScreenTexture = gpuScreenResource.QueryInterface<ID3D11Texture2D>())
                        grakaDevice.ImmediateContext.CopyResource(gpuScreenTexture, cpuScreenTexture);

                    // CopyResource could silently fail?

                    duplicatedOutput.ReleaseFrame(); // should be close to AcquireNextFrame

                    var d = duplicateFrameInformation;
                    Debug.WriteLine($"changes {d.AccumulatedFrames} b: {d.TotalMetadataBufferSize}");

                    // Create Drawing.Bitmap
                    bitmap = new Bitmap(width, height, PixelFormat.Format32bppArgb);
                    var boundsRect = new Rectangle(0, 0, width, height);

                    // Copy pixels from screen capture Texture to GDI bitmap
                    var mapDest = bitmap.LockBits(boundsRect, ImageLockMode.WriteOnly, bitmap.PixelFormat);

                    var dstPtr = mapDest.Scan0;
                    var stride = mapDest.Stride;

                    var dstLen = (ulong)(height * stride);

                    // Get the desktop capture texture
                    // denies the GPU access to that subresource
                    var mapSource = grakaDevice.ImmediateContext.Map(cpuScreenTexture, 0, Map.Read, MapFlags.None);
                
                    var srcPtr = mapSource.PData;
                    var srcLen = (ulong)mapSource.DepthPitch;

                    var testArr = new byte[srcLen];
                    // TODO: Error Here
                    Marshal.Copy(srcPtr, testArr, 0, (int)srcLen);
                    // testArr is empty byte[] { 0,0,0,0,0,0,0 } why?

                    //memcpy(dstPtr, dstLen, srcPtr, srcLen);

                    //// Release source and dest locks
                    //grakaDevice.ImmediateContext.Unmap(cpuScreenTexture, 0);
                    //bitmap.UnlockBits(mapDest);

                    //gpuScreenResource.Dispose();
                    //sw.Stop();

                    //bitmap.Save($@"G:\DXGI_Test_{k}.jpg", ImageFormat.Jpeg);
                    //var end43534 = 155;
                }
                catch (SharpGenException e) // SharpDXException
                {
                    var desc5 = e.Descriptor;
                    var rc5 = e.ResultCode;

                    if (e.ResultCode.Code != WaitTimeout.Result.Code)
                    {
                        throw;
                    }
                }
            }

            var elapsed = sw.ElapsedMilliseconds;


            //duplicatedOutput.Dispose();
            //cpuScreenTexture.Dispose();
            ////   monitor_op1.Dispose();
            ////   monitor_op5.Dispose();
            //monitor.Dispose();

            // grakaDevice.ImmediateContext.Dispose();
            //grakaDevice.Dispose();
            //adapter.Dispose();
            //factory.Dispose();


            //var tr = DXGIDebug.TryCreate();
            //tr.typeof(T).GetTypeInfo().GUID(new Guid(0xe48ae283, 0xda80, 0x490b, 0x87, 0xe6, 0x43, 0xe9, 0xa9, 0xcf, 0xda, 0x8), 
            // DebugRloFlags.All);


            return null;
        }
    }

}