using DirectShowLib;
using System;
using System.Windows;
using System.Windows.Input;
using System.Windows.Interop;
using WPFMediaKit.DirectShow.MediaPlayers;

namespace WPFMediaKit.DirectShow.Controls;

/// <summary>
/// The VideoCaptureElement is a WPF control that
/// displays video from a capture device, such as
/// a web cam.
/// </summary>
public class VideoCaptureElement : MediaElementBase
{
    public VideoCaptureElement()
    {
        CommandBindings.Add(new CommandBinding(ShowPropertyPagesCommand, OnShowPropertyPagesCommand));
    }

    #region DesiredPixelWidth

    public static readonly DependencyProperty DesiredPixelWidthProperty =
        DependencyProperty.Register("DesiredPixelWidth", typeof(int), typeof(VideoCaptureElement),
            new FrameworkPropertyMetadata(0));

    public int DesiredPixelWidth
    {
        get { return (int)GetValue(DesiredPixelWidthProperty); }
        set { SetValue(DesiredPixelWidthProperty, value); }
    }

    #endregion DesiredPixelWidth

    #region DesiredPixelHeight

    public static readonly DependencyProperty DesiredPixelHeightProperty =
        DependencyProperty.Register("DesiredPixelHeight", typeof(int), typeof(VideoCaptureElement),
            new FrameworkPropertyMetadata(0));

    public int DesiredPixelHeight
    {
        get { return (int)GetValue(DesiredPixelHeightProperty); }
        set { SetValue(DesiredPixelHeightProperty, value); }
    }

    #endregion DesiredPixelHeight

    #region FPS

    public static readonly DependencyProperty FPSProperty =
        DependencyProperty.Register("FPS", typeof(int), typeof(VideoCaptureElement),
            new FrameworkPropertyMetadata(30));

    public int FPS
    {
        get { return (int)GetValue(FPSProperty); }
        set { SetValue(FPSProperty, value); }
    }

    #endregion FPS

    #region Commands

    public static readonly RoutedCommand ShowPropertyPagesCommand = new RoutedCommand();

    private void OnShowPropertyPagesCommand(object sender, ExecutedRoutedEventArgs e)
    {
        ShowPropertyPage();
    }

    #endregion Commands

    #region VideoCaptureSource

    public static readonly DependencyProperty VideoCaptureSourceProperty =
        DependencyProperty.Register("VideoCaptureSource", typeof(string), typeof(VideoCaptureElement),
            new FrameworkPropertyMetadata("",
                new PropertyChangedCallback(OnVideoCaptureSourceChanged)));

    private bool m_sourceChanged;

    public string VideoCaptureSource
    {
        get { return (string)GetValue(VideoCaptureSourceProperty); }
        set { SetValue(VideoCaptureSourceProperty, value); }
    }

    public static readonly DependencyProperty VideoCaptureDeviceProperty =
        DependencyProperty.Register("VideoCaptureDevice", typeof(DsDevice), typeof(VideoCaptureElement),
            new FrameworkPropertyMetadata(null, new PropertyChangedCallback(OnVideoCaptureSourceChanged)));

    private bool m_DeviceChanged;

    public DsDevice VideoCaptureDevice
    {
        get { return (DsDevice)GetValue(VideoCaptureDeviceProperty); }
        set { SetValue(VideoCaptureDeviceProperty, value); }
    }

    private static void OnVideoCaptureSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((VideoCaptureElement)d).OnVideoCaptureSourceChanged(e);
    }

    protected virtual void OnVideoCaptureSourceChanged(DependencyPropertyChangedEventArgs e)
    {
        if (e.Property == VideoCaptureSourceProperty)
            m_sourceChanged = true;
        else if (e.Property == VideoCaptureDeviceProperty)
            m_DeviceChanged = true;

        if (HasInitialized)
            PlayerVideoCaptureSource();
    }

    private void PlayerVideoCaptureSource()
    {
        if (m_sourceChanged)
        {
            string videoSource = VideoCaptureSource;
            VideoCapturePlayer.Dispatcher.BeginInvoke((Action)delegate
            {
                VideoCapturePlayer.VideoCaptureSource = videoSource;
            });
            m_sourceChanged = false;
        }
        else if (m_DeviceChanged)
        {
            DsDevice device = VideoCaptureDevice;
            VideoCapturePlayer.Dispatcher.BeginInvoke((Action)delegate
            {
                VideoCapturePlayer.VideoCaptureDevice = device;
            });
            m_DeviceChanged = false;
        }

        //Dispatcher.BeginInvoke((Action)delegate
        //{
        if (IsLoaded)
            ExecuteMediaState(LoadedBehavior);
        //else
        //    ExecuteMediaState(UnloadedBehavior);
        //});
    }

    #endregion VideoCaptureSource

    #region EnableSampleGrabbing

    public static readonly DependencyProperty EnableSampleGrabbingProperty =
        DependencyProperty.Register("EnableSampleGrabbing", typeof(bool), typeof(VideoCaptureElement),
            new FrameworkPropertyMetadata((bool)false,
                new PropertyChangedCallback(OnEnableSampleGrabbingChanged)));

    public bool EnableSampleGrabbing
    {
        get { return (bool)GetValue(EnableSampleGrabbingProperty); }
        set { SetValue(EnableSampleGrabbingProperty, value); }
    }

    private static void OnEnableSampleGrabbingChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((VideoCaptureElement)d).OnEnableSampleGrabbingChanged(e);
    }

    protected virtual void OnEnableSampleGrabbingChanged(DependencyPropertyChangedEventArgs e)
    {
        VideoCapturePlayer.EnableSampleGrabbing = (bool)e.NewValue;
    }

    #endregion EnableSampleGrabbing

    #region UseYuv

    public static readonly DependencyProperty UseYuvProperty =
        DependencyProperty.Register("UseYuv", typeof(bool), typeof(VideoCaptureElement),
            new FrameworkPropertyMetadata((bool)false,
                new PropertyChangedCallback(OnUseYuvChanged)));

    public bool UseYuv
    {
        get { return (bool)GetValue(UseYuvProperty); }
        set { SetValue(UseYuvProperty, value); }
    }

    /// <summary>
    /// Handles changes to the UseYuv property.
    /// </summary>
    private static void OnUseYuvChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((VideoCaptureElement)d).OnUseYuvChanged(e);
    }

    /// <summary>
    /// Provides derived classes an opportunity to handle changes to the UseYuv property.
    /// </summary>
    protected virtual void OnUseYuvChanged(DependencyPropertyChangedEventArgs e)
    {
    }

    #endregion UseYuv

    public static readonly DependencyProperty OutputFileNameProperty = DependencyProperty.Register("OutputFileName", typeof(string), typeof(VideoCaptureElement), new FrameworkPropertyMetadata(string.Empty, new PropertyChangedCallback(OnOutputFileNameChanged)));

    protected static void OnOutputFileNameChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((VideoCaptureElement)d).OnOutputFileNameChanged(e);
    }

    protected virtual void OnOutputFileNameChanged(DependencyPropertyChangedEventArgs e)
    {
        this.VideoCapturePlayer.FileName = (string)e.NewValue;
    }

    public string OutputFileName
    {
        get { return (string)GetValue(OutputFileNameProperty); }
        set { SetValue(OutputFileNameProperty, value); }
    }

    public override void EndInit()
    {
        SetParameters();
        PlayerVideoCaptureSource();
        base.EndInit();
    }

    public override void Play()
    {
        SetParameters();
        base.Play();
    }

    public event EventHandler<VideoSampleArgs> NewVideoSample;

    private void InvokeNewVideoSample(VideoSampleArgs e)
    {
        EventHandler<VideoSampleArgs> sample = NewVideoSample;
        if (sample != null) sample(this, e);
    }

    private void PlayerNewVideoSample(object sender, VideoSampleArgs e)
    {
        InvokeNewVideoSample(e);
    }

    protected override void InitializeMediaPlayer()
    {
        base.InitializeMediaPlayer();

        VideoCapturePlayer.NewVideoSample += PlayerNewVideoSample;
    }

    protected VideoCapturePlayer VideoCapturePlayer
    {
        get
        {
            return MediaPlayerBase as VideoCapturePlayer;
        }
    }

    /// <summary>
    /// Sets the parameters to the video capture player
    /// </summary>
    private void SetParameters()
    {
        int height = DesiredPixelHeight;
        int width = DesiredPixelWidth;
        int fps = FPS;
        bool useYuv = UseYuv;
        string filename = OutputFileName;

        VideoCapturePlayer.Dispatcher.BeginInvoke((Action)delegate
        {
            VideoCapturePlayer.UseYuv = useYuv;
            VideoCapturePlayer.FPS = fps;
            VideoCapturePlayer.DesiredWidth = width;
            VideoCapturePlayer.DesiredHeight = height;
            VideoCapturePlayer.FileName = filename;
        });
    }

    public void ShowPropertyPage()
    {
        var window = Window.GetWindow(this);
        var hwnd = IntPtr.Zero;

        if (window != null)
        {
            hwnd = new WindowInteropHelper(window).Handle;
        }

        MediaPlayerBase.Dispatcher.BeginInvoke((Action)(() => VideoCapturePlayer.ShowCapturePropertyPages(hwnd)));
    }

    protected override MediaPlayerBase OnRequestMediaPlayer()
    {
        return new VideoCapturePlayer();
    }
}