using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media.Imaging;
using System.Runtime.InteropServices;
using System.Windows.Media;
using System.Windows;
using DirectShowLib;
using System.Windows.Interop;
using System.IO;

namespace Tango.Video.DirectShow
{
    #region MakeBitmapSource
    public class BitmapHelper
    {
        [DllImport("kernel32.dll", EntryPoint = "RtlMoveMemory")]
        internal static extern void CopyMemory(IntPtr Destination, IntPtr Source, uint Length);

        public static WriteableBitmap FromNativePointer(IntPtr pData, long dataLength, int w, int h, int ch, bool flipImage)
        {
            PixelFormat format = PixelFormats.Default;
            int bitCount = 8;
            if (ch == 1) format = PixelFormats.Gray8; //grey scale image 0-255
            if (ch == 3)
            {
                format = PixelFormats.Bgr24; //RGB
                bitCount = 24;
            }
            if (ch == 4)
            {
                format = PixelFormats.Bgr32; //RGB + alpha
                bitCount = 32;
            }

            WriteableBitmap wbm = new WriteableBitmap(w, h, 96, 96, format, null);

            if (flipImage)
            {
                int stride = ((w * bitCount / 8) + 3) & ~3;
                unsafe
                {
                    var pDest = (byte*)wbm.BackBuffer;
                    var pSrc = (byte*)pData;
                    pSrc += dataLength;

                    for (int i = 0; i < h; i++)
                    {
                        byte* pDstTmp = pDest + i * stride;
                        byte* pSrcTemp = pSrc - (i + 1) * stride;



                        CopyMemory((IntPtr)pDstTmp, (IntPtr)pSrcTemp, (uint)stride);
                    }
                }
            }
            else
            {
                CopyMemory(wbm.BackBuffer, pData, (uint)(w * h * ch));
            }



            wbm.Lock();


            wbm.AddDirtyRect(new Int32Rect(0, 0, wbm.PixelWidth, wbm.PixelHeight));
            wbm.Unlock();

            return wbm;
        }

        public static BitmapSource FromArray(byte[] data, int w, int h, int ch)
        {
            PixelFormat format = PixelFormats.Default;

            if (ch == 1) format = PixelFormats.Gray8; //grey scale image 0-255
            if (ch == 3) format = PixelFormats.Bgr24; //RGB
            if (ch == 4) format = PixelFormats.Bgr32; //RGB + alpha


            WriteableBitmap wbm = new WriteableBitmap(w, h, 96, 96, format, null);
            wbm.WritePixels(new Int32Rect(0, 0, w, h), data, ch * w, 0);

            return wbm;
        }

        public static BitmapSource CreateEmptySource(System.Windows.Size size, System.Windows.Media.Color color)
        {
            int width = (int)size.Width;
            int height = (int)size.Height;
            int stride = width / 8;
            byte[] pixels = new byte[height * stride];
            try
            {
                return BitmapSource.Create(width, height, 96, 96, PixelFormats.Indexed1, new BitmapPalette(new List<System.Windows.Media.Color> { color }), pixels, stride);
            }
            catch
            {
                width = 1920;
                height = 1080;
                stride = width / 8;
                pixels = new byte[height * stride];
                return BitmapSource.Create(width, height, 96, 96, PixelFormats.Indexed1, new BitmapPalette(new List<System.Windows.Media.Color> { color }), pixels, stride);
            }
        }

        public static WriteableBitmap BitmapSourceToWriteableBitmap(BitmapSource source)
        {
            int stride = source.PixelWidth * (source.Format.BitsPerPixel / 8);

            // Create data array to hold source pixel data
            byte[] data = new byte[stride * source.PixelHeight];

            // Copy source image pixels to the data array
            source.CopyPixels(data, stride, 0);

            // Create WriteableBitmap to copy the pixel data to.      
            WriteableBitmap target = new WriteableBitmap(
              source.PixelWidth,
              source.PixelHeight,
              source.DpiX, source.DpiY,
              source.Format, null);

            // Write the pixel data to the WriteableBitmap.
            target.WritePixels(
              new Int32Rect(0, 0, source.PixelWidth, source.PixelHeight),
              data, stride, 0);

            return target;
        }
    }
    #endregion

}