/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

/*
Compile with:

    "...../csc" \
        /lib:"....." \
        /reference:"ReachFramework.dll" \
        /reference:"WindowsBase.dll" \
        /reference:"PresentationCore.dll" \
        /reference:"PresentationFramework.dll" \
        xps_to_png.cs

*/
// logic inspired by this example: https://goo.gl/nCxrjQ
class Program {
    static void convert(string path, string out_path) {
        System.Windows.Xps.Packaging.XpsDocument xpsDoc =
            new System.Windows.Xps.Packaging.XpsDocument(path, System.IO.FileAccess.Read);
        if (xpsDoc == null) {
            throw new System.Exception("XpsDocumentfailed");
        }
        System.Windows.Documents.FixedDocumentSequence docSeq = xpsDoc.GetFixedDocumentSequence();
        if (docSeq == null) {
            throw new System.Exception("GetFixedDocumentSequence failed");
        }
        System.Windows.Documents.DocumentReferenceCollection drc = docSeq.References;
        int index = 0;
        foreach (System.Windows.Documents.DocumentReference dr in drc) {
            System.Windows.Documents.FixedDocument dp = dr.GetDocument(false);
            foreach (System.Windows.Documents.PageContent pc in dp.Pages) {
                System.Windows.Documents.FixedPage fixedPage = pc.GetPageRoot(false);
                double width = fixedPage.Width;
                double height = fixedPage.Height;
                System.Windows.Size sz = new System.Windows.Size(width, height);
                fixedPage.Measure(sz);
                fixedPage.Arrange(new System.Windows.Rect(new System.Windows.Point(), sz));
                fixedPage.UpdateLayout();
                System.Windows.Media.Imaging.BitmapImage bitmap = new System.Windows.Media.Imaging.BitmapImage();
                System.Windows.Media.Imaging.RenderTargetBitmap renderTarget =
                    new System.Windows.Media.Imaging.RenderTargetBitmap((int)width, (int)height, 96, 96,
                                                                        System.Windows.Media.PixelFormats.Default);
                renderTarget.Render(fixedPage);
                System.Windows.Media.Imaging.BitmapEncoder encoder = new System.Windows.Media.Imaging.PngBitmapEncoder();
                encoder.Frames.Add(System.Windows.Media.Imaging.BitmapFrame.Create(renderTarget));
                System.IO.FileStream pageOutStream = new System.IO.FileStream(
                    string.Format("{0}_{1}.png", out_path, index),
                    System.IO.FileMode.Create, System.IO.FileAccess.Write);
                encoder.Save(pageOutStream);
                pageOutStream.Close();
                ++index;
            }
        }
    }
        // Executes convert, catching thrown exceptions, and printing them to stdout, and exiting immediately
    static void try_convert(string path, string out_path) {
        try {
            convert(path, out_path);
        } catch (System.Exception e) {
            System.Console.WriteLine(e);
            System.Environment.Exit(1);
        }
    }
        // For each command line argument, convert xps to sequence of pngs
    static void Main(string[] args) {
        foreach (string arg in args) {
            System.Threading.Thread t = new System.Threading.Thread(() => try_convert(arg, arg));
            t.SetApartmentState(System.Threading.ApartmentState.STA);
            t.Start();
        }
    }
}