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#include "setpathonqtcoreoperation.h"

#include "qtpatch.h"

#include <QtCore/QByteArrayMatcher>
#include <QtCore/QDir>
#include <QtCore/QDebug>

using namespace QInstaller;

namespace {
    QByteArray getOldValue(const QString &binaryPath, const QByteArray &typeValue)
    {
        QFileInfo fileInfo(binaryPath);

        if (!fileInfo.exists()) {
            qDebug() << QString::fromLatin1("qpatch: warning: file '%1' not found.").arg(
                        binaryPath);
            return QByteArray();
        }

        QFile file(binaryPath);
        int readOpenCount = 0;
        while (!file.open(QFile::ReadOnly) && readOpenCount < 20000) {
            ++readOpenCount;
            qApp->processEvents();
        }
        Q_ASSERT(file.isOpen());
        if (!file.isOpen()) {
            qDebug() << QString::fromLatin1("qpatch: warning: file '%1' can not be opened as ReadOnly.").arg(
                        binaryPath);
            qDebug() << file.errorString();
            return QByteArray();
        }

        const QByteArray source = file.readAll();
        file.close();

        int offset = 0;
        QByteArray searchValue = typeValue;
        searchValue.append("=");
        QByteArrayMatcher byteArrayMatcher(searchValue);
        offset = byteArrayMatcher.indexIn(source, offset);
        Q_ASSERT(offset > 0);
        if (offset == -1)
            return QByteArray();

        int stringEndPosition = offset;

        // go to the position where the other data starts
        while (source.at(stringEndPosition++) != '\0') {}

        // between the search string and the first \0 is the QByteArray we are looking for
        return source.mid(offset + searchValue.size(), stringEndPosition - offset);
    }
}

SetPathOnQtCoreOperation::SetPathOnQtCoreOperation()
{
    setName(QLatin1String("SetPathOnQtCore"));
}

void SetPathOnQtCoreOperation::backup()
{
}

bool SetPathOnQtCoreOperation::performOperation()
{
    const QStringList args = arguments();

    if (args.count() != 3) {
        setError(InvalidArguments);
        setErrorString(tr("Invalid arguments in %0: %1 arguments given, %2 expected%3.")
            .arg(name()).arg(arguments().count()).arg(tr("exactly 3"), QLatin1String("")));
        return false;
    }

    const QString qtCoreLibraryDir = args.at(0);
    const QByteArray typeValue(args.at(1).toUtf8());
    const QByteArray newValue = QDir::toNativeSeparators(args.at(2)).toUtf8();

    QStringList possibleTypes;
    possibleTypes << QLatin1String("qt_prfxpath")
                  << QLatin1String("qt_docspath")
                  << QLatin1String("qt_hdrspath")
                  << QLatin1String("qt_libspath")
                  << QLatin1String("qt_binspath")
                  << QLatin1String("qt_plugpath")
                  << QLatin1String("qt_impspath")
                  << QLatin1String("qt_datapath")
                  << QLatin1String("qt_trnspath")
                  << QLatin1String("qt_xmplpath")
                  << QLatin1String("qt_demopath");

    if (!possibleTypes.contains(QString::fromUtf8(typeValue))) {
        setError(InvalidArguments);
        setErrorString(tr("The second type/value needs to be one of: %1").arg(possibleTypes.join(
            QLatin1String(", "))));
        return false;
    }

    if (newValue.size() >= 255) {
        qDebug() << "qpatch: error: newQtDir needs to be less than 255 characters.";
        return false;
    }
    QStringList libraryFiles;
#ifdef Q_OS_WIN
    libraryFiles << QString::fromLatin1("%1/QtCore4.dll").arg(qtCoreLibraryDir);
    libraryFiles << QString::fromLatin1("%1/QtCore4d.dll").arg(qtCoreLibraryDir);
#else
    libraryFiles << qtCoreLibraryDir + QLatin1String("/libQtCore.so");
#endif
    foreach (const QString coreLibrary, libraryFiles) {
        if (QFile::exists(coreLibrary)) {
            QByteArray oldValue(getOldValue(coreLibrary, typeValue));
            Q_ASSERT(!oldValue.isEmpty());
            oldValue = QByteArray("%0=%1").replace("%0", typeValue).replace("%1", oldValue);
            QByteArray adjutedNewValue =
                QByteArray("%0=%1").replace("%0", typeValue).replace("%1", newValue);

            bool isPatched = QtPatch::patchBinaryFile(coreLibrary, oldValue, adjutedNewValue);
            if (!isPatched) {
                qDebug() << "qpatch: warning: could not patch the plugin path in" << coreLibrary;
            }
        }
    }

    return true;
}

bool SetPathOnQtCoreOperation::undoOperation()
{
    return true;
}

bool SetPathOnQtCoreOperation::testOperation()
{
    return true;
}

Operation *SetPathOnQtCoreOperation::clone() const
{
    return new SetPathOnQtCoreOperation();
}