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** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
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** This file is part of Qt Creator.
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** accordance with the commercial license agreement provided with the
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
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#include "patchtool.h"
#include "messagemanager.h"
#include "icore.h"
#include <utils/synchronousprocess.h>
#include <utils/environment.h>

#include <QProcess>
#include <QProcessEnvironment>
#include <QDir>
#include <QApplication>

static const char settingsGroupC[] = "General";
static const char legacySettingsGroupC[] = "VCS";
static const char patchCommandKeyC[] = "PatchCommand";
static const char patchCommandDefaultC[] = "patch";

namespace Core {

static QString readLegacyCommand()
{
    QSettings *s = ICore::settings();

    s->beginGroup(QLatin1String(legacySettingsGroupC));
    const bool legacyExists = s->contains(QLatin1String(patchCommandKeyC));
    const QString legacyCommand = s->value(QLatin1String(patchCommandKeyC), QLatin1String(patchCommandDefaultC)).toString();
    if (legacyExists)
        s->remove(QLatin1String(patchCommandKeyC));
    s->endGroup();

    if (legacyExists && legacyCommand != QLatin1String(patchCommandDefaultC))
        PatchTool::setPatchCommand(legacyCommand);

    return legacyCommand;
}

QString PatchTool::patchCommand()
{
    QSettings *s = ICore::settings();

    const QString defaultCommand = readLegacyCommand(); // replace it with QLatin1String(patchCommandDefaultC) when dropping legacy stuff

    s->beginGroup(QLatin1String(settingsGroupC));
    const QString command = s->value(QLatin1String(patchCommandKeyC), defaultCommand).toString();
    s->endGroup();

    return command;
}

void PatchTool::setPatchCommand(const QString &newCommand)
{
    QSettings *s = ICore::settings();
    s->beginGroup(QLatin1String(settingsGroupC));
    s->setValue(QLatin1String(patchCommandKeyC), newCommand);
    s->endGroup();
}

static bool runPatchHelper(const QByteArray &input, const QString &workingDirectory,
                           int strip, bool reverse, bool withCrlf)
{
    const QString patch = PatchTool::patchCommand();
    if (patch.isEmpty()) {
        MessageManager::write(QApplication::translate("Core::PatchTool", "There is no patch-command configured in the general \"Environment\" settings."));
        return false;
    }

    if (!Utils::FilePath::fromString(patch).exists()
            && !Utils::Environment::systemEnvironment().searchInPath(patch).exists()) {
        MessageManager::write(QApplication::translate("Core::PatchTool", "The patch-command configured in the general \"Environment\" settings does not exist."));
        return false;
    }

    QProcess patchProcess;
    if (!workingDirectory.isEmpty())
        patchProcess.setWorkingDirectory(workingDirectory);
    QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
    Utils::Environment::setupEnglishOutput(&env);
    patchProcess.setProcessEnvironment(env);
    QStringList args;
    // Add argument 'apply' when git is used as patch command since git 2.5/Windows
    // no longer ships patch.exe.
    if (patch.endsWith(QLatin1String("git"), Qt::CaseInsensitive)
        || patch.endsWith(QLatin1String("git.exe"), Qt::CaseInsensitive)) {
        args << QLatin1String("apply");
    }
    if (strip >= 0)
        args << (QLatin1String("-p") + QString::number(strip));
    if (reverse)
        args << QLatin1String("-R");
    if (withCrlf)
        args << QLatin1String("--binary");
    MessageManager::write(QApplication::translate("Core::PatchTool", "Running in %1: %2 %3").
                          arg(QDir::toNativeSeparators(workingDirectory),
                              QDir::toNativeSeparators(patch), args.join(QLatin1Char(' '))));
    patchProcess.start(patch, args);
    if (!patchProcess.waitForStarted()) {
        MessageManager::write(QApplication::translate("Core::PatchTool", "Unable to launch \"%1\": %2").arg(patch, patchProcess.errorString()));
        return false;
    }
    patchProcess.write(input);
    patchProcess.closeWriteChannel();
    QByteArray stdOut;
    QByteArray stdErr;
    if (!Utils::SynchronousProcess::readDataFromProcess(patchProcess, 30, &stdOut, &stdErr, true)) {
        Utils::SynchronousProcess::stopProcess(patchProcess);
        MessageManager::write(QApplication::translate("Core::PatchTool", "A timeout occurred running \"%1\"").arg(patch));
        return false;

    }
    if (!stdOut.isEmpty()) {
        if (stdOut.contains("(different line endings)") && !withCrlf) {
            QByteArray crlfInput = input;
            crlfInput.replace('\n', "\r\n");
            return runPatchHelper(crlfInput, workingDirectory, strip, reverse, true);
        } else {
            MessageManager::write(QString::fromLocal8Bit(stdOut));
        }
    }
    if (!stdErr.isEmpty())
        MessageManager::write(QString::fromLocal8Bit(stdErr));

    if (patchProcess.exitStatus() != QProcess::NormalExit) {
        MessageManager::write(QApplication::translate("Core::PatchTool", "\"%1\" crashed.").arg(patch));
        return false;
    }
    if (patchProcess.exitCode() != 0) {
        MessageManager::write(QApplication::translate("Core::PatchTool", "\"%1\" failed (exit code %2).").arg(patch).arg(patchProcess.exitCode()));
        return false;
    }
    return true;
}

bool PatchTool::runPatch(const QByteArray &input, const QString &workingDirectory,
                         int strip, bool reverse)
{
    return runPatchHelper(input, workingDirectory, strip, reverse, false);
}

} // namespace Core