protected virtual async Task EmbedImagesAsync(IHtmlDocument doc, OpfFile opfFile, Chapter chapter, string outputDir)
{
var tasks = new List<Task>();
var images = new Dictionary<Uri, string>();
foreach (var img in doc.QuerySelectorAll("img"))
{
string src = img.GetAttribute("src");
if (src.StartsWith("//"))
{
src = src.Substring(2);
if (!(src.StartsWith("http://") || src.StartsWith("https://")))
src = "http://" + src;
}
Uri uri;
if (!Uri.TryCreate(src, UriKind.RelativeOrAbsolute, out uri))
continue;
UriBuilder ub = new UriBuilder(uri) { Query = string.Empty };
uri = ub.Uri;
string fileName = $"{Path.GetRandomFileName()}.{Path.GetExtension(uri.ToString())}".ToValidFilePath();
if (string.IsNullOrEmpty(fileName))
return;
string path = Path.Combine(outputDir, fileName);
if (!images.ContainsKey(uri))
images.Add(uri, path);
string filePath = Path.Combine(new DirectoryInfo(outputDir).Name, Path.GetFileName(path)).Replace(@"\", "/");
img.SetAttribute("src", filePath);
}
foreach (var img in images)
{
tasks.Add(Task.Run(async () =>
{
Uri uri = img.Key;
string path = img.Value;
string outputPath = Path.Combine(new DirectoryInfo(outputDir).Name, Path.GetFileName(path)).Replace(@"\", "/");
string src = uri.ToString();
if (uri.IsAbsoluteUri && !uri.IsFile)
{
try
{
using (HttpClient client = new HttpClient())
{
HttpResponseMessage resp = await client.GetAsync(src);
resp.EnsureSuccessStatusCode();
string mediaType = resp.Content.Headers.ContentType.MediaType.ToLower();
if (mediaType != MediaType.JpegType && mediaType != MediaType.PngType)
return;
if (File.Exists(path))
return;
using (FileStream fs = new FileStream(path, FileMode.CreateNew))
await resp.Content.CopyToAsync(fs);
}
}
catch (Exception)
{
return;
}
}
else if (File.Exists(src))
{
File.Copy(src, path);
}
MediaType mType = MediaType.FromExtension(Path.GetExtension(path));
if (mType == null)
return;
opfFile.AddItem(new OpfItem(outputPath, StringUtilities.GenerateRandomString(),
mType), false);
}));
}
await Task.WhenAll(tasks.ToArray());
chapter.Content = doc.QuerySelector("body").ChildNodes.ToHtml(new XmlMarkupFormatter());
}
public async Task GenerateEpubAsync(string epubDest, GenerateOptions options)
{
OpfFile opf = new OpfFile(new OpfMetadata
{
Title = { Text = Title },
Language = { Text = Language },
Description = { Text = Description },
Creator = { Text = Creator },
Publisher = { Text = Publisher }
});
string tmpDir = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
string epub = Path.Combine(tmpDir, "EPUB");
string metaInf = Path.Combine(tmpDir, "META-INF");
Directory.CreateDirectory(tmpDir);
Directory.CreateDirectory(epub);
Directory.CreateDirectory(Path.Combine(epub, "covers"));
Directory.CreateDirectory(Path.Combine(epub, "css"));
Directory.CreateDirectory(Path.Combine(epub, "fonts"));
Directory.CreateDirectory(Path.Combine(epub, "images"));
Directory.CreateDirectory(metaInf);
File.WriteAllText(Path.Combine(tmpDir, "mimetype"), "application/epub+zip");
Container container = new Container();
container.AddRootFile(new RootFile { FullPath = "EPUB/package.opf", MediaType = "application/oebps-package+xml" });
container.Save(Path.Combine(metaInf, "container.xml"));
if (!string.IsNullOrEmpty(CoverImage))
{
string coverExt = Path.GetExtension(CoverImage);
MediaType mType = MediaType.FromExtension(coverExt);
if (mType != MediaType.PngType && mType != MediaType.JpegType)
throw new Exception("Invalid cover image extension!");
string coverImgFile = Path.GetFileName(CoverImage);
string coverImg = Path.Combine("covers", coverImgFile);
Uri coverImgUri;
if (Uri.TryCreate(CoverImage, UriKind.RelativeOrAbsolute, out coverImgUri))
{
if (!coverImgUri.IsFile)
using (WebClient wc = new WebClient())
await wc.DownloadFileTaskAsync(CoverImage, Path.Combine(epub, coverImg));
else if (File.Exists(CoverImage))
File.Copy(CoverImage, Path.Combine(epub, coverImg));
OpfItem coverImageItem = new OpfItem(coverImg.Replace(@"\", "/"), Path.GetFileNameWithoutExtension(coverImg), mType)
{
Linear = false,
Properties = "cover-image"
};
OpfItem coverItem = new OpfItem("cover.xhtml", "cover", MediaType.XHtmlType);
File.WriteAllText(Path.Combine(epub, "cover.xhtml"),
RazorCompiler.Get(Templates[EBookTemplate.Cover], "cover", $"covers/{coverImgFile}"));
opf.AddItem(coverItem);
opf.AddItem(coverImageItem, false);
}
}
TableOfContents toc = new TableOfContents { Title = Title };
OpfItem navItem = new OpfItem("toc.xhtml", "toc", MediaType.XHtmlType) { Properties = "nav" };
opf.AddItem(navItem);
var parser = new HtmlParser();
foreach (Chapter chapter in Chapters)
{
var doc = parser.Parse(chapter.Content);
if (options.EmbedImages)
await EmbedImagesAsync(doc, opf, chapter, Path.Combine(epub, "images"));
else
chapter.Content = doc.QuerySelector("body").ChildNodes.ToHtml(new XmlMarkupFormatter());
string randomFile = Path.GetRandomFileName() + ".xhtml";
OpfItem item = new OpfItem(randomFile, StringUtilities.GenerateRandomString(6), MediaType.XHtmlType);
opf.AddItem(item);
File.WriteAllText(Path.Combine(epub, randomFile),
RazorCompiler.Get(Templates[EBookTemplate.Chapter], "chapter", chapter));
toc.Sections.Add(new Section
{
Name = chapter.Name,
Href = randomFile
});
}
string tocFile = Path.Combine(epub, "toc.xhtml");
File.WriteAllText(tocFile, RazorCompiler.Get(Templates[EBookTemplate.TableOfContents], "toc", toc));
opf.Save(Path.Combine(epub, "package.opf"));
if (File.Exists(epubDest))
File.Delete(epubDest);
using (FileStream fs = new FileStream(epubDest, FileMode.CreateNew))
using (ZipArchive za = new ZipArchive(fs, ZipArchiveMode.Create))
{
za.CreateEntryFromFile(Path.Combine(tmpDir, "mimetype"), "mimetype", CompressionLevel.NoCompression);
Zip(za, epub, "EPUB");
Zip(za, metaInf, "META-INF");
}
Directory.Delete(tmpDir, true);
}
