File indexing completed on 2024-05-05 05:50:41

 /*
     SPDX-FileCopyrightText: 2016 Ragnar Thomsen <rthomsen6@gmail.com>
 
     SPDX-License-Identifier: BSD-2-Clause
 */
 
 #include "mimetypes.h"
 #include "ark_debug.h"
 
 #include <QFileInfo>
 #include <QMimeDatabase>
 #include <QRegularExpression>
 #include <QStandardPaths>
 
 namespace Kerfuffle
 {
 QMimeType determineMimeType(const QString &filename, MimePreference mp)
 {
     QMimeDatabase db;
 
     QFileInfo fileinfo(filename);
     QString inputFile = filename;
 
     // #328815: since detection-by-content does not work for compressed tar archives (see below why)
     // we cannot rely on it when the archive extension is wrong; we need to validate by hand.
     if (fileinfo.completeSuffix().toLower().remove(QRegularExpression(QStringLiteral("[^a-z\\.]"))).contains(QLatin1String("tar."))) {
         inputFile.chop(fileinfo.completeSuffix().length());
         QString cleanExtension(fileinfo.completeSuffix().toLower());
 
         // tar.bz2 and tar.lz4 need special treatment since they contain numbers.
         bool isBZ2 = false;
         bool isLZ4 = false;
         if (fileinfo.completeSuffix().contains(QLatin1String("bz2"), Qt::CaseInsensitive)) {
             cleanExtension.remove(QStringLiteral("bz2"));
             isBZ2 = true;
         }
         if (fileinfo.completeSuffix().contains(QLatin1String("lz4"), Qt::CaseInsensitive)) {
             cleanExtension.remove(QStringLiteral("lz4"));
             isLZ4 = true;
         }
 
         // We remove non-alpha chars from the filename extension, but not periods.
         // If the filename is e.g. "foo.tar.gz.1", we get the "foo.tar.gz." string,
         // so we need to manually drop the last period character from it.
         cleanExtension.remove(QRegularExpression(QStringLiteral("[^a-z\\.]")));
         if (cleanExtension.endsWith(QLatin1Char('.'))) {
             cleanExtension.chop(1);
         }
 
         // Re-add extension for tar.bz2 and tar.lz4.
         if (isBZ2) {
             cleanExtension.append(QStringLiteral(".bz2"));
         }
         if (isLZ4) {
             cleanExtension.append(QStringLiteral(".lz4"));
         }
 
         inputFile += cleanExtension;
         qCDebug(ARK) << "Validated filename of compressed tar" << filename << "into filename" << inputFile;
     }
 
     QMimeType mimeFromExtension = db.mimeTypeForFile(inputFile, QMimeDatabase::MatchExtension);
     QMimeType mimeFromContent = db.mimeTypeForFile(filename, QMimeDatabase::MatchContent);
 
     // mimeFromContent will be "application/octet-stream" when file is
     // unreadable, so use extension.
     if (!fileinfo.isReadable()) {
         return mimeFromExtension;
     }
 
     // Compressed tar-archives are detected as single compressed files when
     // detecting by content. The following code fixes detection of tar.gz, tar.bz2, tar.xz,
     // tar.lzo, tar.lz, tar.lrz and tar.zst.
     if ((mimeFromExtension.inherits(QStringLiteral("application/x-compressed-tar"))
          && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/gzip")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-bzip-compressed-tar"))
             && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/x-bzip")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-bzip2-compressed-tar"))
             && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/x-bzip2")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-xz-compressed-tar"))
             && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/x-xz")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-tarz")) && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/x-compress")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-tzo")) && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/x-lzop")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-lzip-compressed-tar"))
             && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/x-lzip")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-lrzip-compressed-tar"))
             && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/x-lrzip")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-lz4-compressed-tar"))
             && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/x-lz4")))
         || (mimeFromExtension.inherits(QStringLiteral("application/x-zstd-compressed-tar"))
             && mimeFromContent == db.mimeTypeForName(QStringLiteral("application/zstd")))) {
         return mimeFromExtension;
     }
 
     if (mimeFromExtension != mimeFromContent) {
         if (mimeFromContent.isDefault()) {
             qCWarning(ARK) << "Could not detect mimetype from content."
                            << "Using extension-based mimetype:" << mimeFromExtension.name();
             return mimeFromExtension;
         }
 
         qCDebug(ARK) << "Mimetype for filename extension (" << mimeFromExtension.name() << ") did not match mimetype for content (" << mimeFromContent.name()
                      << "). Using content-based mimetype.";
     }
 
     return mp == PreferExtensionMime ? mimeFromExtension : mimeFromContent;
 }
 
 } // namespace Kerfuffle