using System.Security.Cryptography;

using Avalonia;
using Avalonia.Controls;
using Avalonia.LogicalTree;
using Avalonia.Platform;
using Avalonia.Rendering.Composition;
using Avalonia.Threading;

using GSS2.Vulkan;

using Iot.Device.FtCommon;

using LibCameraSharp;

using Microsoft.Extensions.Logging.Abstractions;

using Silk.NET.Core;
using Silk.NET.Vulkan;
using Silk.NET.Vulkan.Extensions.KHR;

namespace GSS2.Test;

interface IImage
{
    public (IPlatformHandle handle, PlatformGraphicsExternalImageProperties properties, Silk.NET.Vulkan.Semaphore semaphore) Export();
}
interface IRenderer
{
    public abstract IImage ImportOrUpdate(int fd, int width, int height);
}

class VkImage
{
    public int Fd { get; set; }
    public int Width { get; set; }
    public int Height { get; set; }
    public ulong MemorySize { get; set; }
    public Silk.NET.Vulkan.Semaphore Semaphore { get; set; }

    public (IPlatformHandle handle, PlatformGraphicsExternalImageProperties properties, Silk.NET.Vulkan.Semaphore semaphore) Export()
    {
        return (
            new PlatformHandle(new IntPtr(Fd), KnownPlatformGraphicsExternalImageHandleTypes.VulkanOpaquePosixFileDescriptor),
            new PlatformGraphicsExternalImageProperties
            {
                Width = Width,
                Height = Height,
                Format = PlatformGraphicsExternalImageFormat.R8G8B8A8UNorm,
                MemorySize = MemorySize
            },
            Semaphore
        );
    }
}
class VkRenderer
{
    readonly VulkanContext context = new VulkanContext("GSS2.Test", "CameraView");

    public IPlatformHandle ExportSemaphore(bool renderFinished)
    {
        int fd = context.ExportSemaphoreFd(renderFinished ? context.RenderFinishedSemaphore : context.ImageAvailableSemaphore);
        return new PlatformHandle(new IntPtr(fd), KnownPlatformGraphicsExternalImageHandleTypes.VulkanOpaquePosixFileDescriptor);
    }

    unsafe public VkImage ImportOrUpdate(int fd, int width, int height)
    {
        try
        {
            var extImageInfo = new ExternalMemoryImageCreateInfo
            {
                SType = StructureType.ExternalMemoryImageCreateInfo,
                HandleTypes = ExternalMemoryHandleTypeFlags.OpaqueFDBit
            };

            var imageInfo = new ImageCreateInfo
            {
                SType = StructureType.ImageCreateInfo,
                PNext = &extImageInfo,
                ImageType = ImageType.Type2D,
                Format = Format.R8G8B8A8Unorm,
                Extent = new Extent3D
                {
                    Width = checked((uint)width),
                    Height = checked((uint)height),
                    Depth = 1
                },
                MipLevels = 1,
                ArrayLayers = 1,
                Samples = SampleCountFlags.Count1Bit,
                Tiling = ImageTiling.Optimal,
                Usage = ImageUsageFlags.TransferDstBit | ImageUsageFlags.SampledBit,
                SharingMode = SharingMode.Exclusive,
                InitialLayout = ImageLayout.Undefined
            };

            context.Api.CreateImage(context.Device, &imageInfo, null, out var image).ThrowOnError();
            context.Api.GetImageMemoryRequirements(context.Device, image, out var memReq);

            var exportAllocInfo = new ExportMemoryAllocateInfo
            {
                SType = StructureType.ExportMemoryAllocateInfo,
                HandleTypes = ExternalMemoryHandleTypeFlags.OpaqueFDBit
            };

            var allocInfo = new MemoryAllocateInfo
            {
                SType = StructureType.MemoryAllocateInfo,
                PNext = &exportAllocInfo,
                AllocationSize = memReq.Size,
                MemoryTypeIndex = checked((uint)FindMemoryType(memReq.MemoryTypeBits, MemoryPropertyFlags.DeviceLocalBit))
            };

            context.Api.AllocateMemory(context.Device, &allocInfo, null, out var memory).ThrowOnError();
            context.Api.BindImageMemory(context.Device, image, memory, 0).ThrowOnError();

            var poolInfo = new CommandPoolCreateInfo
            {
                SType = StructureType.CommandPoolCreateInfo,
                Flags = CommandPoolCreateFlags.ResetCommandBufferBit,
                QueueFamilyIndex = context.QueueFamilyIndex
            };
            context.Api.CreateCommandPool(context.Device, &poolInfo, null, out var commandPool).ThrowOnError();

            var cmdBufferAllocInfo = new CommandBufferAllocateInfo
            {
                SType = StructureType.CommandBufferAllocateInfo,
                CommandPool = commandPool,
                Level = CommandBufferLevel.Primary,
                CommandBufferCount = 1
            };

            context.Api.AllocateCommandBuffers(context.Device, &cmdBufferAllocInfo, out var cmd).ThrowOnError();

            var clearColor = new ClearColorValue((float)Random.Shared.NextDouble(), (float)Random.Shared.NextDouble(), (float)Random.Shared.NextDouble(), (float)Random.Shared.NextDouble());
            var range = new ImageSubresourceRange
            {
                AspectMask = ImageAspectFlags.ColorBit,
                BaseMipLevel = 0,
                LevelCount = 1,
                BaseArrayLayer = 0,
                LayerCount = 1
            };

            var beginInfo = new CommandBufferBeginInfo
            {
                SType = StructureType.CommandBufferBeginInfo,
                Flags = CommandBufferUsageFlags.OneTimeSubmitBit
            };
            context.Api.BeginCommandBuffer(cmd, &beginInfo).ThrowOnError();

            TransitionImageLayout(cmd, image, ImageLayout.Undefined, ImageLayout.TransferDstOptimal);

            context.Api.CmdClearColorImage(cmd, image, ImageLayout.TransferDstOptimal, &clearColor, 1, &range);

            TransitionImageLayout(cmd, image, ImageLayout.TransferDstOptimal, ImageLayout.General);

            context.Api.EndCommandBuffer(cmd).ThrowOnError();

            var renderFinished = context.RenderFinishedSemaphore;

            var submitInfo = new SubmitInfo
            {
                SType = StructureType.SubmitInfo,
                CommandBufferCount = 1,
                PCommandBuffers = &cmd,
                PSignalSemaphores = &renderFinished,
                SignalSemaphoreCount = 1
            };

            context.Api.QueueSubmit(context.Queue, 1, &submitInfo, default).ThrowOnError();

            var getFdInfo = new MemoryGetFdInfoKHR
            {
                SType = StructureType.MemoryGetFDInfoKhr,
                Memory = memory,
                HandleType = ExternalMemoryHandleTypeFlags.OpaqueFDBit
            };
            if (context.Api.TryGetDeviceExtension<KhrExternalMemoryFd>(context.Instance, context.Device, out var khrExternalMemoryFd))
                Console.WriteLine("KhrExternalMemoryFd import success");
            else
                throw new Exception("KhrExternalMemoryFd import error");
            khrExternalMemoryFd.GetMemoryF(context.Device, &getFdInfo, out var fd1).ThrowOnError();
            Console.WriteLine($"Image export success {fd1}");

            return new VkImage()
            {
                Width = width,
                Height = height,
                Fd = fd1,
                MemorySize = memReq.Size
            };
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
            Console.WriteLine(e.StackTrace);
            throw;
        }
    }

    private int FindMemoryType(uint typeFilter, MemoryPropertyFlags properties)
    {
        context!.Api.GetPhysicalDeviceMemoryProperties(context.PhysicalDevice, out var memProps);
        for (int i = 0; i < memProps.MemoryTypeCount; i++)
            if ((typeFilter & (1 << i)) != 0 && (memProps.MemoryTypes[i].PropertyFlags & properties) == properties)
                return i;
        return -1;
    }
    unsafe private void TransitionImageLayout(CommandBuffer cmd, Silk.NET.Vulkan.Image image, ImageLayout oldLayout, ImageLayout newLayout)
    {
        var barrier = new ImageMemoryBarrier
        {
            SType = StructureType.ImageMemoryBarrier,
            OldLayout = oldLayout,
            NewLayout = newLayout,
            SrcQueueFamilyIndex = 0,
            DstQueueFamilyIndex = 0,
            Image = image,
            SubresourceRange = new ImageSubresourceRange
            {
                AspectMask = ImageAspectFlags.ColorBit,
                BaseMipLevel = 0,
                LevelCount = 1,
                BaseArrayLayer = 0,
                LayerCount = 1
            }
        };

        PipelineStageFlags srcStage;
        PipelineStageFlags dstStage;

        if (oldLayout == ImageLayout.Undefined && newLayout == ImageLayout.TransferDstOptimal)
        {
            barrier.SrcAccessMask = 0;
            barrier.DstAccessMask = AccessFlags.TransferWriteBit;

            srcStage = PipelineStageFlags.TopOfPipeBit;
            dstStage = PipelineStageFlags.TransferBit;

        }
        else if (oldLayout == ImageLayout.TransferDstOptimal && newLayout == ImageLayout.ShaderReadOnlyOptimal)
        {

            barrier.SrcAccessMask = AccessFlags.TransferWriteBit;
            barrier.DstAccessMask = AccessFlags.ShaderReadBit;

            srcStage = PipelineStageFlags.TransferBit;
            dstStage = PipelineStageFlags.FragmentShaderBit;

        }
        else
        {
            srcStage = PipelineStageFlags.AllCommandsBit;
            dstStage = PipelineStageFlags.AllCommandsBit;
        }

        context!.Api.CmdPipelineBarrier(cmd, srcStage, dstStage, 0, 0, null, 0, null, 1, &barrier);
    }

}

public partial class CameraView : Control
{
    private bool _initialized = false;
    private Compositor? _compositor;
    private CompositionSurfaceVisual? _visual;
    private ICompositionGpuInterop? _gpuInterop;
    private CompositionDrawingSurface? Surface { get; set; }
    private bool _compositionRequested;
    private VkRenderer? _renerer;
    private VkImage? _latestImage;

    public CameraView()
    { }

    protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
    {
        base.OnAttachedToVisualTree(e);
        Initialize();
    }
    protected override void OnDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e)
    {
        if (_initialized)
            Surface?.Dispose();

        _initialized = false;
        base.OnDetachedFromLogicalTree(e);
    }
    private async void Initialize()
    {
        try
        {
            var selfVisual = ElementComposition.GetElementVisual(this)!;
            _compositor = selfVisual.Compositor;

            Surface = _compositor.CreateDrawingSurface();
            _visual = _compositor.CreateSurfaceVisual();
            _visual.Surface = Surface;
            ElementComposition.SetElementChildVisual(this, _visual);
            _gpuInterop = await _compositor.TryGetCompositionGpuInterop();
            _renerer = new VkRenderer();
            _initialized = true;
        }
        catch (Exception e)
        {
            Console.WriteLine($"Error while initialization: \n{e.Message}\n{e.StackTrace}");
        }
    }

    protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
    {
        if (_visual is not null && change.Property == BoundsProperty)
        {
            _visual.Size = new Vector(Bounds.Width, Bounds.Height);
            Update();
        }
        if (change.Property == DataContextProperty)
        {
            (DataContext as CameraViewModel)?.Update += (_, ea) => Update(ea.FrameBuffer, ea.StreamConfiguration);
        }
        base.OnPropertyChanged(change);
    }

    private void RenderToSurface(VkImage image)
    {
        var (handle, properties, semaphore) = image.Export();

        var imageRenderedSemaphore = _gpuInterop!.ImportSemaphore(_renerer!.ExportSemaphore(false));
        var renderCompletedSemaphore = _gpuInterop!.ImportSemaphore(_renerer!.ExportSemaphore(true));

        var importedImage = _gpuInterop!.ImportImage(handle, properties);

        Dispatcher.UIThread.Invoke(async () =>
        {
            await importedImage.ImportCompleted;
            await Surface!.UpdateWithSemaphoresAsync(importedImage, renderCompletedSemaphore, imageRenderedSemaphore)
                .ContinueWith((t) =>
                {
                    if (t.Exception is not null)
                    {
                        Console.WriteLine($"Error while surface update: \n{t.Exception.Message}\n{t.Exception.StackTrace} ");
                        foreach (var e in t.Exception.InnerExceptions)
                        {
                            Console.WriteLine(e.Message);
                            Console.WriteLine(e.StackTrace);
                        }
                    }
                });
        }
        );
    }
    private void OnComposition()
    {
        _compositionRequested = false;

        var image = _latestImage;
        if (image is null)
            return;

        RenderToSurface(image);
    }
    private void Update(FrameBuffer? frameBuffer = null, StreamConfiguration? streamConfiguration = null)
    {
        if (!_initialized || _compositor is null)
            return;

        if (frameBuffer is not null && streamConfiguration is not null && _renerer is not null)
        {
            var image = _renerer.ImportOrUpdate(frameBuffer.Planes.First().Fd.Get(), checked((int)streamConfiguration.Size.Width), checked((int)streamConfiguration.Size.Height));
            _latestImage = image;
        }

        if (_compositionRequested)
            return;

        _compositionRequested = true;
        _compositor?.RequestCompositionUpdate(OnComposition);
    }
}