File indexing completed on 2024-05-12 15:37:04

 /*
     SPDX-FileCopyrightText: 2019 Friedrich W. H. Kossebau <kossebau@kde.org>
 
     SPDX-License-Identifier: LGPL-2.1-or-later
 */
 
 #include "appimageextractor.h"
 
 // KF
 #include <KDesktopFile>
 // Qt
 #include <QTextDocument>
 #include <QDomDocument>
 #include <QTemporaryFile>
 #include <QLocale>
 // libappimage
 #include <appimage/appimage.h>
 
 using namespace KFileMetaData;
 
 
 namespace {
 namespace AttributeNames {
 QString xml_lang() { return QStringLiteral("xml:lang"); }
 }
 }
 
 
 // helper class to extract the interesting data from the appdata file
 // prefers localized strings over unlocalized, using system locale
 class AppDataParser
 {
 public:
     AppDataParser(const char* appImageFilePath, const QString& appdataFilePath);
 
 public:
     QString summary() const        { return !m_localized.summary.isEmpty() ? m_localized.summary : m_unlocalized.summary; }
     QString description() const    { return !m_localized.description.isEmpty() ? m_localized.description : m_unlocalized.description; }
     QString developerName() const  { return !m_localized.developerName.isEmpty() ? m_localized.developerName : m_unlocalized.developerName; }
     QString projectLicense() const { return m_projectLicense; }
 
 private:
     void extractDescription(const QDomElement& e, const QString& localeName);
 
 private:
     struct Data {
         QString summary;
         QString description;
         QString developerName;
     };
     Data m_localized;
     Data m_unlocalized;
     QString m_projectLicense;
 };
 
 
 AppDataParser::AppDataParser(const char* appImageFilePath, const QString& appdataFilePath)
 {
     if (appdataFilePath.isEmpty()) {
         return;
     }
 
     unsigned long size = 0L;
     char* buf = nullptr;
     bool ok = appimage_read_file_into_buffer_following_symlinks(appImageFilePath,
                                                                 qUtf8Printable(appdataFilePath),
                                                                 &buf,
                                                                 &size);
 
     QScopedPointer<char, QScopedPointerPodDeleter> cleanup(buf);
 
     if (!ok) {
         return;
     }
 
     QDomDocument domDocument;
     if (!domDocument.setContent(QByteArray::fromRawData(buf, size))) {
         return;
     }
 
     QDomElement docElem = domDocument.documentElement();
     if (docElem.tagName() != QLatin1String("component")) {
         return;
     }
 
     const auto localeName = QLocale::system().bcp47Name();
 
     QDomElement ec = docElem.firstChildElement();
     while (!ec.isNull()) {
         const auto tagName = ec.tagName();
         const auto hasLangAttribute = ec.hasAttribute(AttributeNames::xml_lang());
         const auto matchingLocale = hasLangAttribute && (ec.attribute(AttributeNames::xml_lang()) == localeName);
         if (matchingLocale || !hasLangAttribute) {
             if (tagName == QLatin1String("summary")) {
                 Data& data = hasLangAttribute ? m_localized : m_unlocalized;
                 data.summary = ec.text();
             } else if (tagName == QLatin1String("description")) {
                 extractDescription(ec, localeName);
             } else if (tagName == QLatin1String("developer_name")) {
                 Data& data = hasLangAttribute ? m_localized : m_unlocalized;
                 data.developerName = ec.text();
             } else if (tagName == QLatin1String("project_license")) {
                 m_projectLicense = ec.text();
             }
         }
         ec = ec.nextSiblingElement();
     }
 }
 
 using DesriptionDomFilter = std::function<bool(const QDomElement& e)>;
 
 void stripDescriptionTextElements(QDomElement& element, const DesriptionDomFilter& stripFilter)
 {
     auto childElement = element.firstChildElement();
     while (!childElement.isNull()) {
         auto nextChildElement = childElement.nextSiblingElement();
 
         const auto tagName = childElement.tagName();
         const bool isElementToFilter = (tagName == QLatin1String("p")) || (tagName == QLatin1String("li"));
         if (isElementToFilter && stripFilter(childElement)) {
             element.removeChild(childElement);
         } else {
             stripDescriptionTextElements(childElement, stripFilter);
         }
 
         childElement = nextChildElement;
     }
 }
 
 void AppDataParser::extractDescription(const QDomElement& e, const QString& localeName)
 {
     // create fake html from it and let QTextDocument transform it to plain text for us
     QDomDocument descriptionDocument;
     auto htmlElement = descriptionDocument.createElement(QStringLiteral("html"));
     descriptionDocument.appendChild(htmlElement);
 
     // first localized...
     auto clonedE = descriptionDocument.importNode(e, true).toElement();
     clonedE.setTagName(QStringLiteral("body"));
     stripDescriptionTextElements(clonedE, [localeName](const QDomElement& e) {
         return !e.hasAttribute(AttributeNames::xml_lang()) ||
             e.attribute(AttributeNames::xml_lang()) != localeName;
     });
     htmlElement.appendChild(clonedE);
 
     QTextDocument textDocument;
     textDocument.setHtml(descriptionDocument.toString(-1));
 
     m_localized.description = textDocument.toPlainText().trimmed();
 
     if (!m_localized.description.isEmpty()) {
         // localized will be preferred, no need to calculate unlocalized one
         return;
     }
 
     // then unlocalized if still needed
     htmlElement.removeChild(clonedE); // reuse descriptionDocument
     clonedE = descriptionDocument.importNode(e, true).toElement();
     clonedE.setTagName(QStringLiteral("body"));
     stripDescriptionTextElements(clonedE, [](const QDomElement& e) {
         return e.hasAttribute(AttributeNames::xml_lang());
     });
     htmlElement.appendChild(clonedE);
 
     textDocument.setHtml(descriptionDocument.toString(-1));
 
     m_unlocalized.description = textDocument.toPlainText().trimmed();
 }
 
 
 // helper class to extract the interesting data from the desktop file
 class DesktopFileParser
 {
 public:
     DesktopFileParser(const char* appImageFilePath, const QString& desktopFilePath);
 
 public:
     QString name;
     QString comment;
 };
 
 
 DesktopFileParser::DesktopFileParser(const char* appImageFilePath, const QString& desktopFilePath)
 {
     if (desktopFilePath.isEmpty()) {
         return;
     }
 
     unsigned long size = 0L;
     char* buf = nullptr;
     bool ok = appimage_read_file_into_buffer_following_symlinks(appImageFilePath,
                                                                 qUtf8Printable(desktopFilePath),
                                                                 &buf,
                                                                 &size);
 
     QScopedPointer<char, QScopedPointerPodDeleter> cleanup(buf);
 
     if (!ok) {
         return;
     }
 
     // create real file, KDesktopFile needs that
     QTemporaryFile tmpDesktopFile;
     tmpDesktopFile.open();
     tmpDesktopFile.write(buf, size);
     tmpDesktopFile.close();
 
     KDesktopFile desktopFile(tmpDesktopFile.fileName());
     name = desktopFile.readName();
     comment = desktopFile.readComment();
 }
 
 
 AppImageExtractor::AppImageExtractor(QObject* parent)
     : ExtractorPlugin(parent)
 {
 }
 
 QStringList AppImageExtractor::mimetypes() const
 {
     return QStringList{
         QStringLiteral("application/x-iso9660-appimage"),
         QStringLiteral("application/vnd.appimage"),
     };
 }
 
 void KFileMetaData::AppImageExtractor::extract(ExtractionResult* result)
 {
     const auto appImageFilePath = result->inputUrl().toUtf8();
     const auto appImageType = appimage_get_type(appImageFilePath.constData(), false);
     // not a valid appimage file?
     if (appImageType <= 0) {
         return;
     }
 
     // find desktop file and appdata file
     // need to scan ourselves, given there are no fixed names in the spec yet defined
     // and we just can try as the other appimage tools to simply use the first file of the type found
     char** filePaths = appimage_list_files(appImageFilePath.constData());
     if (!filePaths) {
         return;
     }
 
     QString desktopFilePath;
     QString appdataFilePath;
     for (int i = 0; filePaths[i] != nullptr; ++i) {
         const auto filePath = QString::fromUtf8(filePaths[i]);
 
         if (filePath.startsWith(QLatin1String("usr/share/metainfo/")) &&
             filePath.endsWith(QLatin1String(".appdata.xml"))) {
             appdataFilePath = filePath;
             if (!desktopFilePath.isEmpty()) {
                 break;
             }
         }
 
         if (filePath.endsWith(QLatin1String(".desktop")) && !filePath.contains(QLatin1Char('/'))) {
             desktopFilePath = filePath;
             if (!appdataFilePath.isEmpty()) {
                 break;
             }
         }
     }
 
     appimage_string_list_free(filePaths);
 
     // extract data from both files...
     const AppDataParser appData(appImageFilePath.constData(), appdataFilePath);
 
     const DesktopFileParser desktopFileData(appImageFilePath.constData(), desktopFilePath);
 
     // ... and insert into the result
     result->add(Property::Title, desktopFileData.name);
 
     if (!desktopFileData.comment.isEmpty()) {
         result->add(Property::Comment, desktopFileData.comment);
     } else if (!appData.summary().isEmpty()) {
         result->add(Property::Comment, appData.summary());
     }
     if (!appData.description().isEmpty()) {
         result->add(Property::Description, appData.description());
     }
     if (!appData.projectLicense().isEmpty()) {
         result->add(Property::License, appData.projectLicense());
     }
     if (!appData.developerName().isEmpty()) {
         result->add(Property::Author, appData.developerName());
     }
 }
 
 #include "moc_appimageextractor.cpp"