using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Media;

namespace DTS.Common.Utils
{
    public class MouseUtilities
    {
        [StructLayout(LayoutKind.Sequential)]
        private struct Win32Point
        {
            public int X;
            public int Y;
        };

        [DllImport("user32.dll")]
        private static extern bool GetCursorPos(ref Win32Point pt);

        [DllImport("user32.dll")]
        private static extern bool GetPhysicalCursorPos(ref Win32Point pt);

        [DllImport("user32.dll")]
        private static extern bool ScreenToClient(IntPtr hwnd, ref Win32Point pt);

        public static Point GetMousePosition(Visual relativeTo)
        {
            var mouse = new Win32Point();
            GetCursorPos(ref mouse);

            var presentationSource =
                (System.Windows.Interop.HwndSource)PresentationSource.FromVisual(relativeTo);

            var factor = 2D - presentationSource.CompositionTarget.TransformToDevice.M22;

            ScreenToClient(presentationSource.Handle, ref mouse);

            var transform = relativeTo.TransformToAncestor(presentationSource.RootVisual);

            var offset = transform.Transform(new Point(0, 0));
            if (factor > 0)
            {
                offset.Y = offset.Y + offset.Y * (presentationSource.CompositionTarget.TransformToDevice.M22 - 1);
            }
            return new Point(mouse.X - offset.X, mouse.Y - offset.Y);
        }


    }
}