fasdfsa's picture
init
fab29d7
using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using System.Xml.Linq;
using VersOne.Epub.Environment;
using VersOne.Epub.Options;
using VersOne.Epub.Schema;
using VersOne.Epub.Utils;
namespace VersOne.Epub.Internal
{
internal class PackageReader
{
private readonly EpubReaderOptions epubReaderOptions;
public PackageReader(EpubReaderOptions? epubReaderOptions = null)
{
this.epubReaderOptions = epubReaderOptions ?? new EpubReaderOptions();
}
public async Task<EpubPackage> ReadPackageAsync(IZipFile epubFile, string rootFilePath)
{
IZipFileEntry? rootFileEntry = epubFile.GetEntry(rootFilePath) ?? throw new EpubContainerException("EPUB parsing error: root file not found in the EPUB file.");
XDocument containerDocument;
using (Stream containerStream = rootFileEntry.Open())
{
containerDocument = await XmlUtils.LoadDocumentAsync(containerStream, epubReaderOptions.XmlReaderOptions).ConfigureAwait(false);
}
XNamespace opfNamespace = "http://www.idpf.org/2007/opf";
XElement packageNode = containerDocument.Element(opfNamespace + "package") ??
throw new EpubPackageException("EPUB parsing error: package XML element not found in the package file.");
string? uniqueIdentifier = null;
string? epubVersionString = null;
string? id = null;
EpubTextDirection? textDirection = null;
string? prefix = null;
string? language = null;
foreach (XAttribute packageNodeAttribute in packageNode.Attributes())
{
string attributeValue = packageNodeAttribute.Value;
switch (packageNodeAttribute.GetLowerCaseLocalName())
{
case "unique-identifier":
uniqueIdentifier = attributeValue;
break;
case "version":
epubVersionString = attributeValue;
break;
case "id":
id = attributeValue;
break;
case "dir":
textDirection = EpubTextDirectionParser.Parse(attributeValue);
break;
case "prefix":
prefix = attributeValue;
break;
case "lang":
language = attributeValue;
break;
}
}
if (epubVersionString == null)
{
throw new EpubPackageException("EPUB parsing error: EPUB version is not specified in the package.");
}
EpubVersion epubVersion = epubVersionString switch
{
"2.0" => EpubVersion.EPUB_2,
"3.0" => EpubVersion.EPUB_3,
"3.1" => EpubVersion.EPUB_3_1,
_ => throw new EpubPackageException($"Unsupported EPUB version: \"{epubVersionString}\".")
};
XElement metadataNode = packageNode.Element(opfNamespace + "metadata") ?? throw new EpubPackageException("EPUB parsing error: metadata not found in the package.");
EpubMetadata metadata = MetadataReader.ReadMetadata(metadataNode);
XElement manifestNode = packageNode.Element(opfNamespace + "manifest") ?? throw new EpubPackageException("EPUB parsing error: manifest not found in the package.");
EpubManifest manifest = ReadManifest(manifestNode, epubReaderOptions.PackageReaderOptions);
XElement spineNode = packageNode.Element(opfNamespace + "spine") ?? throw new EpubPackageException("EPUB parsing error: spine not found in the package.");
EpubSpine spine = ReadSpine(spineNode, epubVersion, epubReaderOptions.PackageReaderOptions);
EpubGuide? guide = null;
XElement guideNode = packageNode.Element(opfNamespace + "guide");
if (guideNode != null)
{
guide = ReadGuide(guideNode);
}
List<EpubCollection> collections = ReadCollections(packageNode);
return new(uniqueIdentifier, epubVersion, metadata, manifest, spine, guide, collections, id, textDirection, prefix, language);
}
private static EpubManifest ReadManifest(XElement manifestNode, PackageReaderOptions packageReaderOptions)
{
XAttribute? manifestIdAttribute = manifestNode.Attribute("id");
string? manifestId = manifestIdAttribute?.Value;
List<EpubManifestItem> items = new();
HashSet<string> manifestItemIds = new();
HashSet<string> manifestItemHrefs = new();
foreach (XElement manifestItemNode in manifestNode.Elements())
{
if (manifestItemNode.CompareNameTo("item"))
{
string? manifestItemId = null;
string? href = null;
string? mediaType = null;
string? mediaOverlay = null;
string? requiredNamespace = null;
string? requiredModules = null;
string? fallback = null;
string? fallbackStyle = null;
List<EpubManifestProperty>? properties = null;
foreach (XAttribute manifestItemNodeAttribute in manifestItemNode.Attributes())
{
string attributeValue = manifestItemNodeAttribute.Value;
switch (manifestItemNodeAttribute.GetLowerCaseLocalName())
{
case "id":
manifestItemId = attributeValue;
break;
case "href":
href = Uri.UnescapeDataString(attributeValue);
break;
case "media-type":
mediaType = attributeValue;
break;
case "media-overlay":
mediaOverlay = attributeValue;
break;
case "required-namespace":
requiredNamespace = attributeValue;
break;
case "required-modules":
requiredModules = attributeValue;
break;
case "fallback":
fallback = attributeValue;
break;
case "fallback-style":
fallbackStyle = attributeValue;
break;
case "properties":
properties = EpubManifestPropertyParser.ParsePropertyList(attributeValue);
break;
}
}
if (manifestItemId == null)
{
if (packageReaderOptions != null && packageReaderOptions.SkipInvalidManifestItems)
{
continue;
}
throw new EpubPackageException("Incorrect EPUB manifest: item ID is missing.");
}
if (href == null)
{
if (packageReaderOptions != null && packageReaderOptions.SkipInvalidManifestItems)
{
continue;
}
throw new EpubPackageException("Incorrect EPUB manifest: item href is missing.");
}
if (mediaType == null)
{
if (packageReaderOptions != null && packageReaderOptions.SkipInvalidManifestItems)
{
continue;
}
throw new EpubPackageException("Incorrect EPUB manifest: item media type is missing.");
}
if (manifestItemIds.Contains(manifestItemId))
{
throw new EpubPackageException($"Incorrect EPUB manifest: item with ID = \"{manifestItemId}\" is not unique.");
}
manifestItemIds.Add(manifestItemId);
if (manifestItemHrefs.Contains(href))
{
throw new EpubPackageException($"Incorrect EPUB manifest: item with href = \"{href}\" is not unique.");
}
manifestItemHrefs.Add(href);
items.Add(new EpubManifestItem(manifestItemId, href, mediaType, mediaOverlay, requiredNamespace, requiredModules, fallback, fallbackStyle, properties));
}
}
return new(manifestId, items);
}
private static EpubSpine ReadSpine(XElement spineNode, EpubVersion epubVersion, PackageReaderOptions packageReaderOptions)
{
string? spineId = null;
EpubPageProgressionDirection? pageProgressionDirection = null;
string? toc = null;
List<EpubSpineItemRef> items = new();
foreach (XAttribute spineNodeAttribute in spineNode.Attributes())
{
string attributeValue = spineNodeAttribute.Value;
switch (spineNodeAttribute.GetLowerCaseLocalName())
{
case "id":
spineId = attributeValue;
break;
case "page-progression-direction":
pageProgressionDirection = EpubPageProgressionDirectionParser.Parse(attributeValue);
break;
case "toc":
toc = attributeValue;
break;
}
}
if (epubVersion == EpubVersion.EPUB_2 && String.IsNullOrWhiteSpace(toc) && (packageReaderOptions == null || !packageReaderOptions.IgnoreMissingToc))
{
throw new EpubPackageException("Incorrect EPUB spine: TOC is missing.");
}
foreach (XElement spineItemNode in spineNode.Elements())
{
if (spineItemNode.CompareNameTo("itemref"))
{
string? spineItemRefId = null;
string? idRef = null;
bool isLinear;
List<EpubSpineProperty>? properties = null;
foreach (XAttribute spineItemNodeAttribute in spineItemNode.Attributes())
{
string attributeValue = spineItemNodeAttribute.Value;
switch (spineItemNodeAttribute.GetLowerCaseLocalName())
{
case "id":
spineItemRefId = attributeValue;
break;
case "idref":
idRef = attributeValue;
break;
case "properties":
properties = EpubSpinePropertyParser.ParsePropertyList(attributeValue);
break;
}
}
if (idRef == null)
{
throw new EpubPackageException("Incorrect EPUB spine: item ID ref is missing.");
}
XAttribute linearAttribute = spineItemNode.Attribute("linear");
isLinear = linearAttribute == null || !linearAttribute.CompareValueTo("no");
items.Add(new EpubSpineItemRef(spineItemRefId, idRef, isLinear, properties));
}
}
return new(spineId, pageProgressionDirection, toc, items);
}
private static EpubGuide ReadGuide(XElement guideNode)
{
List<EpubGuideReference> items = new();
foreach (XElement guideReferenceNode in guideNode.Elements())
{
if (guideReferenceNode.CompareNameTo("reference"))
{
string? type = null;
string? title = null;
string? href = null;
foreach (XAttribute guideReferenceNodeAttribute in guideReferenceNode.Attributes())
{
string attributeValue = guideReferenceNodeAttribute.Value;
switch (guideReferenceNodeAttribute.GetLowerCaseLocalName())
{
case "type":
type = attributeValue;
break;
case "title":
title = attributeValue;
break;
case "href":
href = Uri.UnescapeDataString(attributeValue);
break;
}
}
if (type == null)
{
throw new EpubPackageException("Incorrect EPUB guide: item type is missing.");
}
if (href == null)
{
throw new EpubPackageException("Incorrect EPUB guide: item href is missing.");
}
items.Add(new EpubGuideReference(type, title, href));
}
}
return new(items);
}
private static List<EpubCollection> ReadCollections(XElement packageNode)
{
List<EpubCollection> result = new();
foreach (XElement collectionNode in packageNode.Elements(packageNode.Name.Namespace + "collection"))
{
result.Add(ReadCollection(collectionNode));
}
return result;
}
private static EpubCollection ReadCollection(XElement collectionNode)
{
string? role = null;
string? id = null;
EpubTextDirection? textDirection = null;
string? language = null;
foreach (XAttribute collectionNodeAttribute in collectionNode.Attributes())
{
string attributeValue = collectionNodeAttribute.Value;
switch (collectionNodeAttribute.GetLowerCaseLocalName())
{
case "role":
role = attributeValue;
break;
case "id":
id = attributeValue;
break;
case "dir":
textDirection = EpubTextDirectionParser.Parse(attributeValue);
break;
case "lang":
language = attributeValue;
break;
}
}
if (role == null)
{
throw new EpubPackageException("Incorrect EPUB collection: collection role is missing.");
}
EpubMetadata? metadata = null;
List<EpubCollection> nestedCollections = new();
List<EpubMetadataLink> links = new();
foreach (XElement collectionChildNode in collectionNode.Elements())
{
switch (collectionChildNode.GetLowerCaseLocalName())
{
case "metadata":
metadata = MetadataReader.ReadMetadata(collectionChildNode);
break;
case "collection":
EpubCollection nestedCollection = ReadCollection(collectionChildNode);
nestedCollections.Add(nestedCollection);
break;
case "link":
EpubMetadataLink link = MetadataReader.ReadLink(collectionChildNode);
links.Add(link);
break;
}
}
return new(role, metadata, nestedCollections, links, id, textDirection, language);
}
}
}