using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.IO;
using System.Linq;
using System.Text.Json.Serialization;
using System.Threading;
using System.Threading.Tasks;
using AsyncAwaitBestPractices;
using Avalonia.Media.Imaging;
using Avalonia.Threading;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using NLog;
using Refit;
using SkiaSharp;
using StabilityMatrix.Avalonia.Helpers;
using StabilityMatrix.Avalonia.Models;
using StabilityMatrix.Avalonia.Services;
using StabilityMatrix.Avalonia.ViewModels.Base;
using StabilityMatrix.Avalonia.Views;
using StabilityMatrix.Core.Attributes;
using StabilityMatrix.Core.Extensions;
using StabilityMatrix.Core.Helper;
using StabilityMatrix.Core.Inference;
using StabilityMatrix.Core.Models;
using StabilityMatrix.Core.Models.Api.Comfy;
using StabilityMatrix.Core.Models.Api.Comfy.Nodes;
using StabilityMatrix.Core.Models.Api.Comfy.NodeTypes;
using StabilityMatrix.Core.Models.Api.Comfy.WebSocketData;
using StabilityMatrix.Core.Services;
using InferenceTextToImageView = StabilityMatrix.Avalonia.Views.Inference.InferenceTextToImageView;

#pragma warning disable CS0657 // Not a valid attribute location for this declaration

namespace StabilityMatrix.Avalonia.ViewModels.Inference;

[View(typeof(InferenceTextToImageView), persistent: true)]
public partial class InferenceTextToImageViewModel : InferenceTabViewModelBase
{
    private static readonly Logger Logger = LogManager.GetCurrentClassLogger();

    private readonly INotificationService notificationService;
    private readonly ServiceManager<ViewModelBase> vmFactory;
    private readonly IModelIndexService modelIndexService;

    public IInferenceClientManager ClientManager { get; }

    public ImageGalleryCardViewModel ImageGalleryCardViewModel { get; }
    public PromptCardViewModel PromptCardViewModel { get; }
    public StackCardViewModel StackCardViewModel { get; }

    public UpscalerCardViewModel UpscalerCardViewModel =>
        StackCardViewModel.GetCard<StackExpanderViewModel>().GetCard<UpscalerCardViewModel>();

    public SamplerCardViewModel HiresSamplerCardViewModel =>
        StackCardViewModel.GetCard<StackExpanderViewModel>().GetCard<SamplerCardViewModel>();

    public bool IsHiresFixEnabled => StackCardViewModel.GetCard<StackExpanderViewModel>().IsEnabled;

    public bool IsUpscaleEnabled => StackCardViewModel.GetCard<StackExpanderViewModel>(1).IsEnabled;

    [JsonIgnore]
    public ProgressViewModel OutputProgress { get; } = new();

    [ObservableProperty]
    [property: JsonIgnore]
    private string? outputImageSource;

    public InferenceTextToImageViewModel(
        INotificationService notificationService,
        IInferenceClientManager inferenceClientManager,
        ServiceManager<ViewModelBase> vmFactory,
        IModelIndexService modelIndexService
    )
    {
        this.notificationService = notificationService;
        this.vmFactory = vmFactory;
        this.modelIndexService = modelIndexService;
        ClientManager = inferenceClientManager;

        // Get sub view models from service manager

        var seedCard = vmFactory.Get<SeedCardViewModel>();
        seedCard.GenerateNewSeed();

        ImageGalleryCardViewModel = vmFactory.Get<ImageGalleryCardViewModel>();
        PromptCardViewModel = vmFactory.Get<PromptCardViewModel>();

        StackCardViewModel = vmFactory.Get<StackCardViewModel>();

        StackCardViewModel.AddCards(
            new LoadableViewModelBase[]
            {
                // Model Card
                vmFactory.Get<ModelCardViewModel>(),
                // Sampler
                vmFactory.Get<SamplerCardViewModel>(),
                // Hires Fix
                vmFactory.Get<StackExpanderViewModel>(stackExpander =>
                {
                    stackExpander.Title = "Hires Fix";
                    stackExpander.AddCards(
                        new LoadableViewModelBase[]
                        {
                            // Hires Fix Upscaler
                            vmFactory.Get<UpscalerCardViewModel>(),
                            // Hires Fix Sampler
                            vmFactory.Get<SamplerCardViewModel>(samplerCard =>
                            {
                                samplerCard.IsDimensionsEnabled = false;
                                samplerCard.IsCfgScaleEnabled = false;
                                samplerCard.IsSamplerSelectionEnabled = false;
                                samplerCard.IsDenoiseStrengthEnabled = true;
                            })
                        }
                    );
                }),
                vmFactory.Get<StackExpanderViewModel>(stackExpander =>
                {
                    stackExpander.Title = "Upscale";
                    stackExpander.AddCards(
                        new LoadableViewModelBase[]
                        {
                            // Post processing upscaler
                            vmFactory.Get<UpscalerCardViewModel>(),
                        }
                    );
                }),
                // Seed
                seedCard,
                // Batch Size
                vmFactory.Get<BatchSizeCardViewModel>(),
            }
        );

        // GenerateImageCommand.WithNotificationErrorHandler(notificationService);
    }

    private (NodeDictionary prompt, string[] outputs) BuildPrompt(
        GenerateOverrides? overrides = null
    )
    {
        using var _ = new CodeTimer();

        var samplerCard = StackCardViewModel.GetCard<SamplerCardViewModel>();
        var batchCard = StackCardViewModel.GetCard<BatchSizeCardViewModel>();
        var modelCard = StackCardViewModel.GetCard<ModelCardViewModel>();
        var seedCard = StackCardViewModel.GetCard<SeedCardViewModel>();

        var nodes = new NodeDictionary();
        var builder = new ComfyNodeBuilder(nodes);

        var emptyLatentImage = nodes.AddNamedNode(
            new NamedComfyNode("EmptyLatentImage")
            {
                ClassType = "EmptyLatentImage",
                Inputs = new Dictionary<string, object?>
                {
                    ["batch_size"] = batchCard.BatchSize,
                    ["height"] = samplerCard.Height,
                    ["width"] = samplerCard.Width,
                }
            }
        );

        var checkpointLoader = nodes.AddNamedNode(
            new NamedComfyNode("CheckpointLoader")
            {
                ClassType = "CheckpointLoaderSimple",
                Inputs = new Dictionary<string, object?>
                {
                    ["ckpt_name"] = modelCard.SelectedModelName
                }
            }
        );

        // Global connections for chaining
        var modelSource = checkpointLoader.GetOutput<ModelNodeConnection>(0);
        var clipSource = checkpointLoader.GetOutput<ClipNodeConnection>(1);
        var vaeSource = checkpointLoader.GetOutput<VAENodeConnection>(2);

        // Use custom VAE if enabled
        if (modelCard is { IsVaeSelectionEnabled: true, SelectedVae.IsDefault: false })
        {
            // Add a loader
            var vaeLoader = nodes.AddNamedNode(
                ComfyNodeBuilder.VAELoader("VAELoader", modelCard.SelectedVae.FileName)
            );

            // Set as source
            vaeSource = vaeLoader.Output;
        }

        // See if we need to load loras
        var prompt = PromptCardViewModel.GetPrompt();
        prompt.Process();
        var negativePrompt = PromptCardViewModel.GetNegativePrompt();
        negativePrompt.Process();

        // If need to load loras, add a group
        if (prompt.ExtraNetworks.Count > 0)
        {
            // Convert to local file names
            var loras = prompt.ExtraNetworks.Select(n =>
            {
                var localLoras = modelIndexService.ModelIndex.GetOrAdd(SharedFolderType.Lora);
                var localLora = localLoras.FirstOrDefault(
                    m =>
                        m.FileName == n.Name
                        || Path.GetFileNameWithoutExtension(m.FileName) == n.Name
                );

                if (localLora is null)
                {
                    throw new ApplicationException($"Lora model {n.Name} was not found locally");
                }

                return (localLora.FileName, n.ModelWeight, n.ClipWeight);
            });

            var lorasGroup = builder.Group_LoraLoadMany("Loras", modelSource, clipSource, loras);

            // Set as source
            modelSource = lorasGroup.Output1;
            clipSource = lorasGroup.Output2;
        }

        var positiveClip = nodes.AddNamedNode(
            new NamedComfyNode("PositiveCLIP")
            {
                ClassType = "CLIPTextEncode",
                Inputs = new Dictionary<string, object?>
                {
                    ["clip"] = clipSource,
                    ["text"] = prompt.ProcessedText,
                }
            }
        );

        var negativeClip = nodes.AddNamedNode(
            new NamedComfyNode("NegativeCLIP")
            {
                ClassType = "CLIPTextEncode",
                Inputs = new Dictionary<string, object?>
                {
                    ["clip"] = clipSource,
                    ["text"] = negativePrompt.ProcessedText,
                }
            }
        );

        var sampler = nodes.AddNamedNode(
            ComfyNodeBuilder.KSampler(
                "Sampler",
                modelSource,
                Convert.ToUInt64(seedCard.Seed),
                samplerCard.Steps,
                samplerCard.CfgScale,
                samplerCard.SelectedSampler?.Name
                    ?? throw new InvalidOperationException("Sampler not selected"),
                "normal",
                positiveClip.GetOutput<ConditioningNodeConnection>(0),
                negativeClip.GetOutput<ConditioningNodeConnection>(0),
                emptyLatentImage.GetOutput<LatentNodeConnection>(0),
                samplerCard.DenoiseStrength
            )
        );

        var lastLatent = sampler.Output;
        var lastLatentWidth = samplerCard.Width;
        var lastLatentHeight = samplerCard.Height;

        var vaeDecoder = nodes.AddNamedNode(
            new NamedComfyNode("VAEDecoder")
            {
                ClassType = "VAEDecode",
                Inputs = new Dictionary<string, object?>
                {
                    ["samples"] = lastLatent,
                    ["vae"] = vaeSource
                }
            }
        );

        var saveImage = nodes.AddNamedNode(
            new NamedComfyNode("SaveImage")
            {
                ClassType = "SaveImage",
                Inputs = new Dictionary<string, object?>
                {
                    ["filename_prefix"] = "SM-Inference",
                    ["images"] = vaeDecoder.GetOutput(0)
                }
            }
        );

        // If hi-res fix is enabled, add the LatentUpscale node and another KSampler node
        if (overrides?.IsHiresFixEnabled ?? IsHiresFixEnabled)
        {
            var hiresUpscalerCard = UpscalerCardViewModel;
            var hiresSamplerCard = HiresSamplerCardViewModel;

            // Requested upscale to this size
            var hiresWidth = (int)Math.Floor(lastLatentWidth * hiresUpscalerCard.Scale);
            var hiresHeight = (int)Math.Floor(lastLatentHeight * hiresUpscalerCard.Scale);

            LatentNodeConnection hiresLatent;

            // Select between latent upscale and normal upscale based on the upscale method
            var selectedUpscaler = hiresUpscalerCard.SelectedUpscaler!.Value;

            if (selectedUpscaler.Type == ComfyUpscalerType.None)
            {
                // If no upscaler selected or none, just reroute the latent image
                hiresLatent = sampler.Output;
            }
            else
            {
                // Otherwise upscale the latent image
                hiresLatent = builder
                    .Group_UpscaleToLatent(
                        "HiresFix",
                        lastLatent,
                        vaeSource,
                        selectedUpscaler,
                        hiresWidth,
                        hiresHeight
                    )
                    .Output;
            }

            var hiresSampler = nodes.AddNamedNode(
                ComfyNodeBuilder.KSampler(
                    "HiresSampler",
                    modelSource,
                    Convert.ToUInt64(seedCard.Seed),
                    hiresSamplerCard.Steps,
                    hiresSamplerCard.CfgScale,
                    // Use hires sampler name if not null, otherwise use the normal sampler name
                    hiresSamplerCard.SelectedSampler?.Name
                        ?? samplerCard.SelectedSampler?.Name
                        ?? throw new InvalidOperationException("Sampler not selected"),
                    "normal",
                    positiveClip.GetOutput<ConditioningNodeConnection>(0),
                    negativeClip.GetOutput<ConditioningNodeConnection>(0),
                    hiresLatent,
                    hiresSamplerCard.DenoiseStrength
                )
            );

            // Set as last latent
            lastLatent = hiresSampler.Output;
            lastLatentWidth = hiresWidth;
            lastLatentHeight = hiresHeight;
            // Reroute the VAEDecoder's input to be from the hires sampler
            vaeDecoder.Inputs["samples"] = lastLatent;
        }

        // If upscale is enabled, add another upscale group
        if (IsUpscaleEnabled)
        {
            var postUpscalerCard = StackCardViewModel
                .GetCard<StackExpanderViewModel>(1)
                .GetCard<UpscalerCardViewModel>();

            var upscaleWidth = (int)Math.Floor(lastLatentWidth * postUpscalerCard.Scale);
            var upscaleHeight = (int)Math.Floor(lastLatentHeight * postUpscalerCard.Scale);

            // Build group
            var postUpscaleGroup = builder.Group_UpscaleToImage(
                "PostUpscale",
                lastLatent,
                vaeSource,
                postUpscalerCard.SelectedUpscaler!.Value,
                upscaleWidth,
                upscaleHeight
            );

            // Remove the original vae decoder
            nodes.Remove(vaeDecoder.Name);

            // Set as the input for save image
            saveImage.Inputs["images"] = postUpscaleGroup.Output;
        }

        nodes.NormalizeConnectionTypes();

        return (nodes, new[] { saveImage.Name });
    }

    private void OnProgressUpdateReceived(object? sender, ComfyProgressUpdateEventArgs args)
    {
        Dispatcher.UIThread.Post(() =>
        {
            OutputProgress.Value = args.Value;
            OutputProgress.Maximum = args.Maximum;
            OutputProgress.IsIndeterminate = false;

            OutputProgress.Text =
                $"({args.Value} / {args.Maximum})"
                + (args.RunningNode != null ? $" {args.RunningNode}" : "");
        });
    }

    private void OnPreviewImageReceived(object? sender, ComfyWebSocketImageData args)
    {
        Dispatcher.UIThread.Post(() =>
        {
            using var stream = new MemoryStream(args.ImageBytes);

            var bitmap = new Bitmap(stream);

            var currentImage = ImageGalleryCardViewModel.PreviewImage;

            ImageGalleryCardViewModel.PreviewImage = bitmap;
            ImageGalleryCardViewModel.IsPreviewOverlayEnabled = true;

            currentImage?.Dispose();
        });
    }

    private async Task GenerateImageImpl(
        GenerateOverrides? overrides = null,
        CancellationToken cancellationToken = default
    )
    {
        if (!ClientManager.IsConnected)
        {
            notificationService.Show("Client not connected", "Please connect first");
            return;
        }

        // Validate the prompts
        if (!await PromptCardViewModel.ValidatePrompts())
        {
            return;
        }

        // If enabled, randomize the seed
        var seedCard = StackCardViewModel.GetCard<SeedCardViewModel>();
        if (overrides is not { UseCurrentSeed: true } && seedCard.IsRandomizeEnabled)
        {
            seedCard.GenerateNewSeed();
        }

        var client = ClientManager.Client;

        var (nodes, outputNodeNames) = BuildPrompt(overrides);

        // Connect preview image handler
        client.PreviewImageReceived += OnPreviewImageReceived;

        ComfyTask? promptTask = null;
        try
        {
            // Register to interrupt if user cancels
            cancellationToken.Register(() =>
            {
                Logger.Info("Cancelling prompt");
                client
                    .InterruptPromptAsync(new CancellationTokenSource(5000).Token)
                    .SafeFireAndForget();
            });

            try
            {
                promptTask = await client.QueuePromptAsync(nodes, cancellationToken);
            }
            catch (ApiException e)
            {
                Logger.Warn(e, "Api exception while queuing prompt");
                await DialogHelper.CreateApiExceptionDialog(e, "Api Error").ShowAsync();
                return;
            }

            // Register progress handler
            promptTask.ProgressUpdate += OnProgressUpdateReceived;

            // Wait for prompt to finish
            await promptTask.Task.WaitAsync(cancellationToken);
            Logger.Trace($"Prompt task {promptTask.Id} finished");

            // Get output images
            var imageOutputs = await client.GetImagesForExecutedPromptAsync(
                promptTask.Id,
                cancellationToken
            );

            ImageGalleryCardViewModel.ImageSources.Clear();

            var images = imageOutputs[outputNodeNames[0]];
            if (images is null)
                return;

            List<ImageSource> outputImages;
            // Use local file path if available, otherwise use remote URL
            if (client.OutputImagesDir is { } outputPath)
            {
                outputImages = images
                    .Select(i => new ImageSource(i.ToFilePath(outputPath)))
                    .ToList();
            }
            else
            {
                outputImages = images
                    .Select(i => new ImageSource(i.ToUri(client.BaseAddress)))
                    .ToList();
            }

            // Download all images to make grid, if multiple
            if (outputImages.Count > 1)
            {
                var loadedImages = outputImages
                    .Select(i => SKImage.FromEncodedData(i.LocalFile?.Info.OpenRead()))
                    .ToImmutableArray();

                var grid = ImageProcessor.CreateImageGrid(loadedImages);

                // Save to disk
                var lastName = outputImages.Last().LocalFile?.Info.Name;
                var gridPath = client.OutputImagesDir!.JoinFile($"grid-{lastName}");

                await using (var fileStream = gridPath.Info.OpenWrite())
                {
                    await fileStream.WriteAsync(grid.Encode().ToArray(), cancellationToken);
                }

                // Insert to start of images
                var gridImage = new ImageSource(gridPath);
                // Preload
                await gridImage.GetBitmapAsync();
                ImageGalleryCardViewModel.ImageSources.Add(gridImage);
            }

            // Add rest of images
            foreach (var img in outputImages)
            {
                // Preload
                await img.GetBitmapAsync();
                ImageGalleryCardViewModel.ImageSources.Add(img);
            }
        }
        finally
        {
            // Disconnect progress handler
            OutputProgress.Value = 0;
            OutputProgress.Text = "";
            ImageGalleryCardViewModel.PreviewImage?.Dispose();
            ImageGalleryCardViewModel.PreviewImage = null;
            ImageGalleryCardViewModel.IsPreviewOverlayEnabled = false;

            promptTask?.Dispose();
            client.PreviewImageReceived -= OnPreviewImageReceived;
        }
    }

    [RelayCommand(IncludeCancelCommand = true)]
    private async Task GenerateImage(
        string? options = null,
        CancellationToken cancellationToken = default
    )
    {
        try
        {
            var overrides = new GenerateOverrides
            {
                IsHiresFixEnabled = options?.Contains("hires_fix"),
                UseCurrentSeed = options?.Contains("current_seed")
            };

            await GenerateImageImpl(overrides, cancellationToken);
        }
        catch (OperationCanceledException e)
        {
            Logger.Debug($"[Image Generation Canceled] {e.Message}");
        }
    }

    internal class GenerateOverrides
    {
        public bool? IsHiresFixEnabled { get; set; }
        public bool? UseCurrentSeed { get; set; }
    }
}