using System.Drawing;
using System.IO;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using System.Windows.Interop;
using System.Windows.Media.Animation;
using System.Windows.Media.Imaging;

using wpfScrollEventType = System.Windows.Controls.Primitives.ScrollEventType;

namespace System.Windows.Forms
{
    public static class Helper
    {
        private static int screenDpi;

        private static int GetDpi()
        {
            using (Bitmap bmp = new Bitmap(1, 1))
            using (Graphics g = Graphics.FromImage(bmp))
            {
                return (int)g.DpiX;
            }
        }

        public static int ScreenDpi
        {
            get
            {
                if (screenDpi == 0)
                    screenDpi = GetDpi();
                return screenDpi;
            }
        }

        public static double GetDpiScale(System.Windows.Media.Visual control) =>
            System.Windows.Media.VisualTreeHelper.GetDpi(control).DpiScaleX;

        public static System.Windows.Thickness PaddingToThickness(Padding p) =>
            new System.Windows.Thickness(p.Left, p.Top, p.Right, p.Bottom);

        public static Padding ThicknessToPadding(System.Windows.Thickness t) =>
            new Padding((int)t.Left, (int)t.Top, (int)t.Right, (int)t.Bottom);

        public static Color GetColor(System.Windows.Media.Color color) =>
            Color.FromArgb(color.A, color.R, color.G, color.B);

        public static System.Windows.Media.Color GetColor(Color color) =>
            System.Windows.Media.Color.FromArgb(color.A, color.R, color.G, color.B);

        public static Color GetColor(System.Windows.Media.Brush brush)
        {
            if (brush is System.Windows.Media.SolidColorBrush br)
                return Helper.GetColor(br.Color);
            return System.Drawing.Color.Transparent;
        }

        public static System.Windows.Media.Brush GetBrush(Color color) =>
            new System.Windows.Media.SolidColorBrush(GetColor(color));

        public static Font GetFont(System.Windows.Controls.Control control) =>
            GetFont(GetDpiScale(control), control.FontFamily, control.FontSize, control.FontStyle, control.FontWeight);

        public static Font GetFont(
            double dpiScale,
            System.Windows.Media.FontFamily family, 
            double size, 
            System.Windows.FontStyle style, 
            System.Windows.FontWeight weight, 
            bool underline = false, 
            bool strikeout = false)
        {
            System.Drawing.FontStyle s = System.Drawing.FontStyle.Regular;
            if (style == System.Windows.FontStyles.Italic)
                s |= System.Drawing.FontStyle.Italic;
            if (weight == System.Windows.FontWeights.Bold)
                s |= System.Drawing.FontStyle.Bold;
            if (underline)
                s |= System.Drawing.FontStyle.Underline;
            if (strikeout)
                s |= System.Drawing.FontStyle.Strikeout;
            return new Font(family.Source, (float)(size * dpiScale / ScreenDpi * 72f), s);
        }

        public static void SetFont(System.Windows.Controls.Control control, Font font) => SetFont(control, GetDpiScale(control), font);

        public static void SetFont(System.Windows.Controls.Control control, double dpiScale, Font font)
        {
            if (font != null)
            {
                SetFont(font, dpiScale, out var family, out var size, out var style, out var weight, out _);
                control.FontFamily = family;
                control.FontSize = size;
                control.FontStyle = style;
                control.FontWeight = weight;
            }
        }

        public static void SetFont(Font font,
            double dpiScale,
            out System.Windows.Media.FontFamily family,
            out double size,
            out System.Windows.FontStyle style,
            out System.Windows.FontWeight weight,
            out System.Windows.TextDecorationCollection deco) => SetFont(font.Name, font.Size, font.Style, dpiScale, out family, out size, out style, out weight, out deco);

        public static void SetFont(
            string fontName, 
            float fontSize,
            Drawing.FontStyle fontStyle,
            double dpiScale,
            out System.Windows.Media.FontFamily family, 
            out double size, 
            out System.Windows.FontStyle style, 
            out System.Windows.FontWeight weight, 
            out System.Windows.TextDecorationCollection deco)
        {
            family = new System.Windows.Media.FontFamily(fontName);

            size = fontSize / (dpiScale / ScreenDpi * 72f);  // / 72f * ScreenDpi / dpiScale;
            
            style = System.Windows.FontStyles.Normal;
            if ((fontStyle & System.Drawing.FontStyle.Italic) != 0)
                style = System.Windows.FontStyles.Italic;
            
            weight = System.Windows.FontWeights.Normal;
            if ((fontStyle & System.Drawing.FontStyle.Bold) != 0)
                weight = System.Windows.FontWeights.Bold;
            
            deco = new TextDecorationCollection();
            if ((fontStyle & System.Drawing.FontStyle.Underline) != 0)
                deco.Add(TextDecorations.Underline);
            if ((fontStyle & System.Drawing.FontStyle.Strikeout) != 0)
                deco.Add(TextDecorations.Strikethrough);
        }

        private static System.Windows.Media.PixelFormat GetPixelFormat(System.Drawing.Imaging.PixelFormat format)
        {
            switch (format)
            {
                case Drawing.Imaging.PixelFormat.Indexed:
                    break;
                case Drawing.Imaging.PixelFormat.Gdi:
                    break;
                case Drawing.Imaging.PixelFormat.Alpha:
                    break;
                case Drawing.Imaging.PixelFormat.PAlpha:
                    break;
                case Drawing.Imaging.PixelFormat.Extended:
                    break;
                case Drawing.Imaging.PixelFormat.Canonical:
                    break;
                case Drawing.Imaging.PixelFormat.Undefined:
                    break;
                case Drawing.Imaging.PixelFormat.Format1bppIndexed:
                    return System.Windows.Media.PixelFormats.Indexed1;
                case Drawing.Imaging.PixelFormat.Format4bppIndexed:
                    return System.Windows.Media.PixelFormats.Indexed4;
                case Drawing.Imaging.PixelFormat.Format8bppIndexed:
                    return System.Windows.Media.PixelFormats.Indexed8;
                case Drawing.Imaging.PixelFormat.Format16bppGrayScale:
                    return System.Windows.Media.PixelFormats.Gray16;
                case Drawing.Imaging.PixelFormat.Format16bppRgb555:
                    return System.Windows.Media.PixelFormats.Bgr555;
                case Drawing.Imaging.PixelFormat.Format16bppRgb565:
                    return System.Windows.Media.PixelFormats.Bgr565;
                case Drawing.Imaging.PixelFormat.Format16bppArgb1555:
                    break;
                case Drawing.Imaging.PixelFormat.Format24bppRgb:
                    return System.Windows.Media.PixelFormats.Bgr24;
                case Drawing.Imaging.PixelFormat.Format32bppRgb:
                    return System.Windows.Media.PixelFormats.Bgr32;
                case Drawing.Imaging.PixelFormat.Format32bppArgb:
                    return System.Windows.Media.PixelFormats.Bgra32;
                case Drawing.Imaging.PixelFormat.Format32bppPArgb:
                    return System.Windows.Media.PixelFormats.Pbgra32;
                case Drawing.Imaging.PixelFormat.Format48bppRgb:
                    return System.Windows.Media.PixelFormats.Rgb48;
                case Drawing.Imaging.PixelFormat.Format64bppArgb:
                    return System.Windows.Media.PixelFormats.Rgba64;
                case Drawing.Imaging.PixelFormat.Format64bppPArgb:
                    return System.Windows.Media.PixelFormats.Prgba64;
            }
            throw new Exception("Pixel format is not supported");
        }

        public static BitmapSource GetImage(Image image, float dpiX = 0, float dpiY = 0)
        {
            var bitmap = image as Bitmap;
            if (bitmap == null)
                return null;

            var bitmapData = bitmap.LockBits(
                new Rectangle(0, 0, bitmap.Width, bitmap.Height),
                System.Drawing.Imaging.ImageLockMode.ReadOnly, bitmap.PixelFormat);

            if (dpiX == 0 || dpiY == 0)
            {
                dpiX = bitmap.HorizontalResolution;
                dpiY = bitmap.VerticalResolution;
            }

            var bitmapSource = BitmapSource.Create(
                bitmapData.Width, bitmapData.Height,
                dpiX, dpiY,
                GetPixelFormat(bitmap.PixelFormat), null,
                bitmapData.Scan0, bitmapData.Stride * bitmapData.Height, bitmapData.Stride);

            bitmap.UnlockBits(bitmapData);

            return bitmapSource;
        }

        public static Image GetImage(BitmapSource image)
        {
            if (image == null)
                return null;

            using (var outStream = new MemoryStream())
            {
                var enc = new PngBitmapEncoder();
                enc.Frames.Add(BitmapFrame.Create(image));
                enc.Save(outStream);
                using (var bitmap = new Bitmap(outStream))
                    return CloneBitmap(bitmap);
            }
        }

        public static void DrawControl(System.Windows.Controls.Control control, Bitmap bitmap, int width, int height, double dpi)
        {
            if (control == null)
                return;

            // dv is created using the default dpi; control dpi may vary in multi-monitor setup
            var dv = new System.Windows.Media.DrawingVisual();
            double dvdpi = GetDpiScale(dv) * 96;
            RenderTargetBitmap rtb = new RenderTargetBitmap(width, height, dvdpi, dvdpi, System.Windows.Media.PixelFormats.Pbgra32);
            using (var ctx = dv.RenderOpen())
            {
                var vb = new System.Windows.Media.VisualBrush(control) { Stretch = Media.Stretch.None, AlignmentX = Media.AlignmentX.Left, AlignmentY = Media.AlignmentY.Top };
                double rescale = dpi / dvdpi;
                ctx.PushTransform(new Media.ScaleTransform(rescale, rescale));
                ctx.DrawRectangle(vb, null, new Rect(0, 0, width, height));
            }
            rtb.Render(dv);

            using (var outStream = new MemoryStream())
            {
                var enc = new PngBitmapEncoder();
                enc.Frames.Add(BitmapFrame.Create(rtb));
                enc.Save(outStream);
                using (var bmp = new Bitmap(outStream))
                using (Graphics g = Graphics.FromImage(bitmap))
                {
                    g.Clear(System.Drawing.SystemColors.Control);
                    g.DrawImageUnscaled(bmp, 0, 0);
                }
            }
        }

        private static Bitmap CloneBitmap(Image source)
        {
            if (source == null)
                return null;

            Bitmap image = new Bitmap(source.Width, source.Height);
            image.SetResolution(source.HorizontalResolution, source.VerticalResolution);
            using (Graphics g = Graphics.FromImage(image))
            {
                g.DrawImageUnscaled(source, 0, 0);
            }
            return image;
        }

        public static Media.ImageSource GetIcon(Icon icon)
        {
            if (icon == null)
                return null;
            return Imaging.CreateBitmapSourceFromHIcon(icon.Handle, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
        }

        public static MouseButtons GetMouseButton(System.Windows.Input.MouseButton button)
        {
            return button switch
            {
                Input.MouseButton.Left => MouseButtons.Left,
                Input.MouseButton.Right => MouseButtons.Right,
                Input.MouseButton.Middle => MouseButtons.Middle,
                Input.MouseButton.XButton1 => MouseButtons.XButton1,
                Input.MouseButton.XButton2 => MouseButtons.XButton2,
                _ => MouseButtons.None
            };
        }

        public static MouseEventArgs GetMouseEventArgs(System.Windows.Controls.Control control, System.Windows.Input.MouseEventArgs args)
        {
            var button = MouseButtons.None;
            if (args.LeftButton == Input.MouseButtonState.Pressed)
                button |= MouseButtons.Left;
            if (args.RightButton == Input.MouseButtonState.Pressed)
                button |= MouseButtons.Right;
            if (args.MiddleButton == Input.MouseButtonState.Pressed)
                button |= MouseButtons.Middle;
            if (args.XButton1 == Input.MouseButtonState.Pressed)
                button |= MouseButtons.XButton1;
            if (args.XButton2 == Input.MouseButtonState.Pressed)
                button |= MouseButtons.XButton2;

            var pos = args.GetPosition(control);
            var dpi = GetDpiScale(control);
            if (control.FlowDirection == FlowDirection.RightToLeft)
                pos.X = control.Width - pos.X;
            
            int delta = args is System.Windows.Input.MouseWheelEventArgs wArgs ? wArgs.Delta : 0;
            return new MouseEventArgs(button, 0, (int)(pos.X * dpi), (int)(pos.Y * dpi), delta);
        }

        public static MouseEventArgs GetMouseEventArgs(System.Windows.Controls.Control control, System.Windows.Input.MouseButtonEventArgs args)
        {
            var button = MouseButtons.None;
            if (args.ChangedButton == Input.MouseButton.Left)
                button |= MouseButtons.Left;
            if (args.ChangedButton == Input.MouseButton.Right)
                button |= MouseButtons.Right;
            if (args.ChangedButton == Input.MouseButton.Middle)
                button |= MouseButtons.Middle;
            if (args.ChangedButton == Input.MouseButton.XButton1)
                button |= MouseButtons.XButton1;
            if (args.ChangedButton == Input.MouseButton.XButton2)
                button |= MouseButtons.XButton2;

            var pos = args.GetPosition(control);
            var dpi = GetDpiScale(control);
            if (control.FlowDirection == FlowDirection.RightToLeft)
                pos.X = control.Width - pos.X;

            return new MouseEventArgs(button, 0, (int)(pos.X * dpi), (int)(pos.Y * dpi), 0);
        }

        public static KeyEventArgs GetKeyEventArgs(System.Windows.Input.KeyEventArgs args)
        {
            var wpfKey = args.Key == System.Windows.Input.Key.System ? args.SystemKey : args.Key;
            var winformModifiers = GetKeyModifiers(args.KeyboardDevice.Modifiers);
            var winformKeys = (Keys)System.Windows.Input.KeyInterop.VirtualKeyFromKey(wpfKey);
            return new KeyEventArgs(winformKeys | winformModifiers);
        }

        public static Keys GetKeyModifiers(System.Windows.Input.ModifierKeys modifier)
        {
            var retVal = Keys.None;
            if (modifier.HasFlag(System.Windows.Input.ModifierKeys.Alt))
                retVal |= Keys.Alt;
            if (modifier.HasFlag(System.Windows.Input.ModifierKeys.Control))
                retVal |= Keys.Control;
            if (modifier.HasFlag(System.Windows.Input.ModifierKeys.Shift))
                retVal |= Keys.Shift;
            return retVal;
        }

        public static DragEventArgs GetDragEventArgs(System.Windows.Controls.Control control, System.Windows.DragEventArgs args)
        {
            var pos = args.GetPosition(control);
            var dpi = GetDpiScale(control);
            return new DragEventArgs(new DataObjectImpl(args.Data), (int)args.KeyStates, (int)(pos.X * dpi), (int)(pos.Y * dpi), (DragDropEffects)args.AllowedEffects, (DragDropEffects)args.Effects);
        }

        public static ScrollEventArgs GetScrollEventArgs(System.Windows.Controls.Primitives.ScrollEventArgs args, bool horizontal)
        {
            ScrollEventType t = args.ScrollEventType switch
            {
                wpfScrollEventType.SmallDecrement => ScrollEventType.SmallDecrement,
                wpfScrollEventType.SmallIncrement => ScrollEventType.SmallIncrement,
                wpfScrollEventType.LargeDecrement => ScrollEventType.LargeDecrement,
                wpfScrollEventType.LargeIncrement => ScrollEventType.LargeIncrement,
                wpfScrollEventType.ThumbPosition => ScrollEventType.ThumbPosition,
                wpfScrollEventType.ThumbTrack => ScrollEventType.ThumbTrack,
                wpfScrollEventType.First => ScrollEventType.First,
                wpfScrollEventType.Last => ScrollEventType.Last,
                _ => ScrollEventType.EndScroll
            };
            return new ScrollEventArgs(t, (int)args.NewValue, horizontal ? ScrollOrientation.HorizontalScroll : ScrollOrientation.VerticalScroll);
        }

        public static void GetContentAlignment(ContentAlignment value, out System.Windows.HorizontalAlignment h, out System.Windows.VerticalAlignment v)
        {
            h = System.Windows.HorizontalAlignment.Left;
            v = System.Windows.VerticalAlignment.Top;
            switch (value)
            {
                case ContentAlignment.TopLeft:
                    break;
                case ContentAlignment.TopCenter:
                    h = System.Windows.HorizontalAlignment.Center;
                    break;
                case ContentAlignment.TopRight:
                    h = System.Windows.HorizontalAlignment.Right;
                    break;
                case ContentAlignment.MiddleLeft:
                    v = System.Windows.VerticalAlignment.Center;
                    break;
                case ContentAlignment.MiddleCenter:
                    h = System.Windows.HorizontalAlignment.Center;
                    v = System.Windows.VerticalAlignment.Center;
                    break;
                case ContentAlignment.MiddleRight:
                    h = System.Windows.HorizontalAlignment.Right;
                    v = System.Windows.VerticalAlignment.Center;
                    break;
                case ContentAlignment.BottomLeft:
                    v = System.Windows.VerticalAlignment.Bottom;
                    break;
                case ContentAlignment.BottomCenter:
                    h = System.Windows.HorizontalAlignment.Center;
                    v = System.Windows.VerticalAlignment.Bottom;
                    break;
                case ContentAlignment.BottomRight:
                    h = System.Windows.HorizontalAlignment.Right;
                    v = System.Windows.VerticalAlignment.Bottom;
                    break;
            }
        }

        public static Day GetDay(DayOfWeek day)
        {
            return day switch
            {
                DayOfWeek.Monday => Day.Monday,
                DayOfWeek.Tuesday => Day.Tuesday,
                DayOfWeek.Wednesday => Day.Wednesday,
                DayOfWeek.Thursday => Day.Thursday,
                DayOfWeek.Friday => Day.Friday,
                DayOfWeek.Saturday => Day.Saturday,
                DayOfWeek.Sunday => Day.Sunday,
                _ => Day.Default
            };
        }

        public static DayOfWeek GetDayOfWeek(Day day)
        {
            return day switch
            {
                Day.Monday => DayOfWeek.Monday,
                Day.Tuesday => DayOfWeek.Tuesday,
                Day.Wednesday => DayOfWeek.Wednesday,
                Day.Thursday => DayOfWeek.Thursday,
                Day.Friday => DayOfWeek.Friday,
                Day.Saturday => DayOfWeek.Saturday,
                Day.Sunday => DayOfWeek.Sunday,
                _ => DayOfWeek.Monday
            };
        }

        public static void AnimateOpacity(this UIElement element, double from, double to, int duration)
        {
            DoubleAnimation animation = new DoubleAnimation(from, to, TimeSpan.FromMilliseconds(duration));
            element.BeginAnimation(UIElement.OpacityProperty, animation);
        }
    }
}