using System.Collections.ObjectModel;
using System.Drawing;
using System.IO;
using System.Reflection;
using System.Windows;
using Azaion.Annotator.DTO;
using Azaion.Annotator.Extensions;
using LibVLCSharp.Shared;
using MediatR;
using Microsoft.WindowsAPICodePack.Dialogs;
using Point = System.Windows.Point;
using Size = System.Windows.Size;

namespace Azaion.Annotator;

public partial class MainWindow
{
    private readonly LibVLC _libVLC;
    private readonly MediaPlayer _mediaPlayer;
    private readonly IMediator _mediator;
    private readonly FormState _formState;

    private readonly Config _config;
    private readonly HelpWindow _helpWindow;
    private readonly TimeSpan _annotationTime = TimeSpan.FromSeconds(1);
    
    public ObservableCollection<AnnotationClass> AnnotationClasses { get; set; } = new();
    private bool _suspendLayout;

    public Dictionary<string, List<AnnotationInfo>> Annotations { get; set; } = new();
        
    public MainWindow(LibVLC libVLC, MediaPlayer mediaPlayer,
        IMediator mediator,
        FormState formState,
        Config config,
        HelpWindow helpWindow)
    {
        InitializeComponent();
        _libVLC = libVLC;
        _mediaPlayer = mediaPlayer;
        _mediator = mediator;
        _formState = formState;
        _config = config;
        _helpWindow = helpWindow;
        
        VideoView.Loaded += VideoView_Loaded;
        Closed += OnFormClosed;
    }

    private void VideoView_Loaded(object sender, RoutedEventArgs e)
    {
        Core.Initialize();
        InitControls();

        _suspendLayout = true;
        Left = _config.WindowLocation.X;
        Top = _config.WindowLocation.Y;
        Width = _config.WindowSize.Width;
        Height = _config.WindowSize.Height;
        _suspendLayout = false;

        ReloadFiles();
        if (_config.AnnotationClasses.Count == 0)
            _config.AnnotationClasses.Add(new AnnotationClass(0));

        AnnotationClasses = new ObservableCollection<AnnotationClass>(_config.AnnotationClasses);
        LvClasses.ItemsSource = AnnotationClasses;
        LvClasses.SelectedIndex = 0;

        if (LvFiles.Items.IsEmpty) 
            BlinkHelp(HelpTexts.HelpTextsDict[HelpTextEnum.Initial]);
        
        if (_config.ShowHelpOnStart) 
            _helpWindow.Show();
    }

    public void BlinkHelp(string helpText, int times = 3)
    {
        _ = Task.Run(async () =>
        {
            for (int i = 0; i < times; i++)
            {
                Dispatcher.Invoke(() => StatusHelp.Text = helpText);
                await Task.Delay(200);
                Dispatcher.Invoke(() => StatusHelp.Text = "");
                await Task.Delay(200);
            }
            Dispatcher.Invoke(() => StatusHelp.Text = helpText);
        });
    }

    private void InitControls()
    {
        VideoView.MediaPlayer = _mediaPlayer;

        _mediaPlayer.Playing += (sender, args) =>
        {
            uint vw = 0, vh = 0;
            _mediaPlayer.Size(0, ref vw, ref vh);
            _formState.CurrentVideoSize = new Size(vw, vh);
            _formState.CurrentVideoLength = TimeSpan.FromMilliseconds(_mediaPlayer.Length);
        };

        LvFiles.MouseDoubleClick += async (_, _) => await _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.Play));
        
        LvClasses.SelectionChanged += (_, _) =>
        {
            var selectedClass = (AnnotationClass)LvClasses.SelectedItem;
            Editor.CurrentAnnClass = selectedClass;
            _mediator.Publish(new AnnClassSelectedEvent(selectedClass));
        };

        _mediaPlayer.PositionChanged += (o, args) =>
        {
            Dispatcher.Invoke(() => videoSlider.Value = _mediaPlayer.Position * videoSlider.Maximum);
            Dispatcher.Invoke(() => StatusClock.Text = $"{TimeSpan.FromMilliseconds(_mediaPlayer.Time):mm\\:ss} / {_formState.CurrentVideoLength:mm\\:ss}");
            
            var curTime = _formState.GetTimeName(TimeSpan.FromMilliseconds(_mediaPlayer.Time));
            if (!Annotations.TryGetValue(curTime, out var annotationInfos))
                return;

            var annotations = annotationInfos.Select(info =>
            {
                var annClass = _config.AnnotationClasses[info.ClassNumber];
                var annInfo = info.ToCanvasCoordinates(Editor.RenderSize, _formState.CurrentVideoSize);
                var annotation = Dispatcher.Invoke(() => Editor.CreateAnnotation(annClass, annInfo));
                return annotation;
            }).ToList();
            
            //remove annotations: either in 1 sec, either earlier if there is next annotation in a dictionary 
            var timeStr = curTime.Split("_").LastOrDefault();
            if (!int.TryParse(timeStr, out var time))
                return;
            
            var ts = TimeSpan.FromMilliseconds(time * 100);
            var timeSpanRemove = Enumerable.Range(1, (int)_annotationTime.TotalMilliseconds / 100 - 1)
                .Select(x =>
                {
                    var timeNext = TimeSpan.FromMilliseconds(x * 100);
                    var fName = _formState.GetTimeName(ts.Add(timeNext));
                    return Annotations.ContainsKey(fName) ? timeNext : (TimeSpan?)null;
                }).FirstOrDefault(x => x != null) ?? _annotationTime;
            
            _ = Task.Run(async () =>
            {
                await Task.Delay(timeSpanRemove);
                Dispatcher.Invoke(() => Editor.RemoveAnnotations(annotations));
            });
        
        };
        
        videoSlider.ValueChanged += (value, newValue) => 
            _mediaPlayer.Position = (float)(newValue / videoSlider.Maximum);

        videoSlider.KeyDown += (sender, args) => _mediator.Publish(new KeyEvent(sender, args));

        SizeChanged += (sender, args) =>
        {
            if (!_suspendLayout)
                _config.WindowSize = args.NewSize;
        };
        LocationChanged += (_, _) =>
        {
            if (!_suspendLayout)
                _config.WindowLocation = new Point(Left, Top);
        };

        Editor.FormState = _formState;
        Editor.Mediator = _mediator;
    }
    
    public void LoadExistingAnnotations()
    {
        var dirInfo = new DirectoryInfo(_config.LabelsDirectory);
        if (!dirInfo.Exists)
            return;

        var files = dirInfo.GetFiles($"{_formState.VideoName}_*");
        Annotations = files.ToDictionary(f => Path.GetFileNameWithoutExtension(f.Name), f =>
        {
            var str = File.ReadAllText(f.FullName);
            return str.Split(Environment.NewLine).Select(AnnotationInfo.Parse)
                .Where(x => x != null)
                .ToList();
        })!;
    }

    private void ReloadFiles()
    {
        var dir = new DirectoryInfo(_config.VideosDirectory);
        if (!dir.Exists)
            return;

        var files = dir.GetFiles("mp4", "mov").Select(x =>
        {
            _mediaPlayer.Media = new Media(_libVLC, x.FullName);
            
            return new VideoFileInfo
            {
                Name = x.Name,
                Path = x.FullName,
                Duration = TimeSpan.FromMilliseconds(_mediaPlayer.Media.Duration)
            };
        }).ToList();

        LvFiles.ItemsSource = new ObservableCollection<VideoFileInfo>(files);
        TbFolder.Text = _config.VideosDirectory;

        BlinkHelp(files.Count == 0
            ? HelpTexts.HelpTextsDict[HelpTextEnum.Initial] 
            : HelpTexts.HelpTextsDict[HelpTextEnum.PlayVideo]);
    }

    private void OnFormClosed(object? sender, EventArgs e)
    {
        _mediaPlayer.Stop();
        _mediaPlayer.Dispose();
        _libVLC.Dispose();
        _config.AnnotationClasses = AnnotationClasses.ToList();
        _config.Save();
        Application.Current.Shutdown();
    }

    // private void AddClassBtnClick(object sender, RoutedEventArgs e)
    // {
    //     LvClasses.IsReadOnly = false;
    //     AnnotationClasses.Add(new AnnotationClass(AnnotationClasses.Count));
    //     LvClasses.SelectedIndex = AnnotationClasses.Count - 1;
    // }
    private void OpenFolderItemClick(object sender, RoutedEventArgs e) => OpenFolder();
    private void OpenFolderButtonClick(object sender, RoutedEventArgs e) => OpenFolder();
    private void OpenFolder()
    {
        var dlg = new CommonOpenFileDialog
        {
            Title = "Open Video folder",
            IsFolderPicker = true,
            InitialDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)
        };
        if (dlg.ShowDialog() != CommonFileDialogResult.Ok)
            return;

        if (!string.IsNullOrEmpty(dlg.FileName)) 
            _config.VideosDirectory = dlg.FileName;
        
        ReloadFiles();
    }

    private void PlayClick(object sender, RoutedEventArgs e) => _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.Play));
    private void PauseClick(object sender, RoutedEventArgs e)=> _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.Pause));
    private void StopClick(object sender, RoutedEventArgs e) => _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.Stop));

    private void PreviousFrameClick(object sender, RoutedEventArgs e) => _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.PreviousFrame));
    private void NextFrameClick(object sender, RoutedEventArgs e) =>  _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.NextFrame));

    private void SaveAnnotationsClick(object sender, RoutedEventArgs e) => _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.SaveAnnotations));

    private void RemoveSelectedClick(object sender, RoutedEventArgs e) => _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.RemoveSelectedAnns));
    private void RemoveAllClick(object sender, RoutedEventArgs e) => _mediator.Publish(new PlaybackControlEvent(PlaybackControlEnum.RemoveAllAnns));
    
    private void OpenHelpWindowClick(object sender, RoutedEventArgs e)
    {
        _helpWindow.Show();
        _helpWindow.Activate();
    }
}