//
// This code is part of Document Solutions for PDF demos.
// Copyright (c) MESCIUS inc. All rights reserved.
//
using System;
using System.IO;
using System.Linq;
using System.Drawing;
using System.Collections.Generic;
using GrapeCity.Documents.Pdf;
using GrapeCity.Documents.Svg;
using GrapeCity.Documents.Text;
using GrapeCity.Documents.Drawing;

namespace DsPdfWeb.Demos.Basics
{
    // This sample shows how to save pages of an existing PDF as images.
    // It loads a PDF generated by the SlidePages sample, then saves
    // the whole PDF as a multi-page TIFF. It also saves each of the pages
    // as a separate JPEG image. Finally, the last page of the loaded PDF
    // is saved as SVGZ (compressed SVG).
    // All generated images are attached to the resulting PDF.
    // 
    // Other image formats that are also supported: PNG, BMP, GIF.
    public class SaveAsImage
    {
        public int CreatePDF(Stream stream)
        {
            var doc = new GcPdfDocument();
            var page = doc.NewPage();

            Common.Util.AddNote(
                "We load the PDF generated by the 'Slide Pages' sample, " +
                "and save the whole PDF as a multi-page TIFF. " +
                "We also save each of the pages as a separate JPEG image. " +
                "Finally, the last page is saved as SVGZ (compressed SVG). " +
                "All created images are then attached to this document.",
                page);

            // Keep track of temp files, delete them on exit:
            var tfiles = new List<string>();

            using var fs = File.OpenRead(Path.Combine("Resources", "PDFs", "SlidePages.pdf"));
            var docSrc = new GcPdfDocument();
            docSrc.Load(fs);
            // Save all pages of the loaded PDF as a multi-page TIFF:
            var tf = Path.GetTempFileName();
            docSrc.SaveAsTiff(tf);
            var fspec = FileSpecification.FromEmbeddedFile(EmbeddedFileStream.FromFile(doc, tf));
            fspec.File.FileName = "SlidePages.tiff";
            doc.EmbeddedFiles.Add(fspec.File.FileName, fspec);
            tfiles.Add(tf);

            // Save each page of the loaded PDF as a JPEG:
            foreach (var p in docSrc.Pages)
            {
                tf = Path.GetTempFileName();
                p.SaveAsJpeg(tf);
                fspec = FileSpecification.FromEmbeddedFile(EmbeddedFileStream.FromFile(doc, tf));
                fspec.File.FileName = $"Page_{p.Index}.jpeg";
                doc.EmbeddedFiles.Add(fspec.File.FileName, fspec);
                tfiles.Add(tf);
            }

            // Finally, save the last page of the PDF as SVGZ (compressed SVG):
            var bytes = docSrc.Pages.Last.ToSvgz(new SaveAsImageOptions() { BackColor = Color.Transparent });
            fspec = FileSpecification.FromEmbeddedFile(EmbeddedFileStream.FromBytes(doc, bytes));
            fspec.File.FileName = $"Page_{docSrc.Pages.Last.Index}.svgz";
            doc.EmbeddedFiles.Add(fspec.File.FileName, fspec);

            doc.Save(stream);
            // Clean up:
            tfiles.ForEach(tf_ => File.Delete(tf_));
            // Done:
            return doc.Pages.Count;
        }
    }
}