using System.IO;
using System.Windows.Documents;
using System.Windows.Xps.Packaging;
using System.Windows.Media.Imaging;
using System;
using System.Threading;
using System.Drawing;
using System.Threading.Tasks;

namespace Bitmapper
{
    static public class XpsBitmapHelper
    {
        static public bool SaveXpsPageToPng(string xpsFileName)
        {
            bool rv = false;
            var tcs = new TaskCompletionSource<bool>();
            Thread thread = new Thread(() =>
            {
                try
                {
                    tcs.SetResult(SaveXpsPageToBitmap(xpsFileName));
                }
                catch (Exception e)
                {
                    tcs.SetException(e);
                }
            });
            thread.SetApartmentState(ApartmentState.STA);
            thread.Start();
           
            tcs.Task.Wait();
            if (tcs.Task.IsCompleted)
                rv = tcs.Task.Result;
            return rv;
        }
        static bool  SaveXpsPageToBitmap(string para1)
        {
            bool rv = false;
            string xpsFileName = para1 as string;
            XpsDocument xpsDoc = new XpsDocument(xpsFileName, System.IO.FileAccess.Read);
            var t = xpsDoc.FixedDocumentSequenceReader.FixedDocuments[0].FixedPages[0];
            BitmapEncoder encoder = null;

            string ext = ".png";
            var th = xpsDoc.Thumbnail;
            if (false)
            { //th != null ) {
                //ext = System.IO.Path.GetExtension(th.Uri.OriginalString);//  ".jpeg" string
                var x = th.GetStream();
                var bf = BitmapFrame.Create(x);
                encoder = new PngBitmapEncoder();
                encoder.Frames.Add(bf);
                using (FileStream pageOutStream = new FileStream(System.IO.Path.Combine(System.IO.Path.GetDirectoryName(xpsFileName), System.IO.Path.GetFileNameWithoutExtension(xpsFileName)) + ext, FileMode.Create, FileAccess.Write))
                {
                    encoder.Save(pageOutStream);
                    pageOutStream.Close();
                }
            }
            else
            {
                string outfilename = System.IO.Path.Combine(System.IO.Path.GetDirectoryName(xpsFileName), System.IO.Path.GetFileNameWithoutExtension(xpsFileName)) + ext;
                FixedDocumentSequence docSeq = xpsDoc.GetFixedDocumentSequence();
                if (docSeq.DocumentPaginator.PageCount > 0)
                {
                    RenderTargetBitmap renderTarget;
                    using (DocumentPage docPage = docSeq.DocumentPaginator.GetPage(0))
                    {
                        renderTarget =
                            new RenderTargetBitmap((int)docPage.Size.Width,
                                                    (int)docPage.Size.Height,
                                                    96, // WPF (Avalon) units are 96dpi based
                                                    96,
                                                    System.Windows.Media.PixelFormats.Default);

                        renderTarget.Render(docPage.Visual);

                    }
                    System.Drawing.Image bitmap1 = null;
                    encoder = new PngBitmapEncoder();  // Choose type here ie: JpegBitmapEncoder, etc
                    var bm = BitmapFrame.Create(renderTarget);
                    encoder.Frames.Add(BitmapFrame.Create(renderTarget));
                    var h = bm.Height;
                    using (MemoryStream ms = new MemoryStream())
                    {
                        encoder.Save(ms);
                        bitmap1 = System.Drawing.Bitmap.FromStream(ms);
                    }
                    int newHeight = 128;
                    int newWidth = (int)(bitmap1.Width * 128.0 / bitmap1.Height);
                    Bitmap bm2 = new Bitmap(bitmap1, newWidth, newHeight);
                    bm2.Save(outfilename, System.Drawing.Imaging.ImageFormat.Png);
                    rv = true;
                }
                
            }
            return rv;
        }
        public static bool BitmapToThumbnail(string bitmapFileName, out string outfilename)
        {
            outfilename = System.IO.Path.Combine(System.IO.Path.GetDirectoryName(bitmapFileName), System.IO.Path.GetFileNameWithoutExtension(bitmapFileName) + "_th.png");
            bool ok = false;
            Image i = Image.FromFile(bitmapFileName);
            int newHeight = 128;
            int newWidth = (int)(i.Width * 128.0 / i.Height);
            Bitmap bm2 = new Bitmap(i, newWidth, newHeight);
            bm2.Save(outfilename, System.Drawing.Imaging.ImageFormat.Png);
            ok = true;
            return ok;
        }
    }
}