using System;
using System.ComponentModel;
using System.Drawing;
using System.IO;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Media.Imaging;

namespace JD.WinFormExtensions
{
    public static class ImageExtensions
    {
        /// <summary>
        /// FxCop requires all Marshalled functions to be in a class called NativeMethods.
        /// </summary>
        internal static class NativeMethods
        {
            [DllImport("gdi32.dll")]
            [return: MarshalAs(UnmanagedType.Bool)]
            internal static extern bool DeleteObject(IntPtr hObject);
        }

        public static Image ToImage(this System.Windows.Media.Imaging.BitmapSource image)
        {
            MemoryStream ms = new MemoryStream();
            var encoder = new System.Windows.Media.Imaging.BmpBitmapEncoder();
            encoder.Frames.Add(System.Windows.Media.Imaging.BitmapFrame.Create(image));
            encoder.Save(ms);
            ms.Flush();
            return Image.FromStream(ms);
        }

        /// <summary>
        /// Converts a <see cref="System.Drawing.Image"/> into a WPF <see cref="BitmapSource"/>.
        /// </summary>
        /// <param name="source">The source image.</param>
        /// <returns>A BitmapSource</returns>
        public static BitmapSource ToBitmapSource(this System.Drawing.Image source)
        {
            System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(source);

            var bitSrc = bitmap.ToBitmapSource();

            bitmap.Dispose();
            bitmap = null;

            return bitSrc;
        }

        /// <summary>
        /// Converts a <see cref="System.Drawing.Bitmap"/> into a WPF <see cref="BitmapSource"/>.
        /// </summary>
        /// <remarks>Uses GDI to do the conversion. Hence the call to the marshalled DeleteObject.
        /// </remarks>
        /// <param name="source">The source bitmap.</param>
        /// <returns>A BitmapSource</returns>
        public static BitmapSource ToBitmapSource(this System.Drawing.Bitmap source)
        {
            BitmapSource bitSrc = null;

            var hBitmap = source.GetHbitmap();

            try
            {
                bitSrc = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
                    hBitmap,
                    IntPtr.Zero,
                    Int32Rect.Empty,
                    BitmapSizeOptions.FromEmptyOptions());
            }
            catch (Win32Exception)
            {
                bitSrc = null;
            }
            finally
            {
                NativeMethods.DeleteObject(hBitmap);
            }

            return bitSrc;
        }
    }
}