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** Copyright (C) 2016 Orgad Shaneh <orgads@gmail.com>.
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#include "gitgrep.h"
#include "gitclient.h"
#include "gitconstants.h"
#include "gitplugin.h"

#include <coreplugin/editormanager/editormanager.h>
#include <coreplugin/progressmanager/progressmanager.h>
#include <coreplugin/vcsmanager.h>
#include <texteditor/findinfiles.h>
#include <vcsbase/vcscommand.h>
#include <vcsbase/vcsbaseconstants.h>

#include <utils/algorithm.h>
#include <utils/fancylineedit.h>
#include <utils/filesearch.h>
#include <utils/fileutils.h>
#include <utils/qtcassert.h>
#include <utils/runextensions.h>
#include <utils/synchronousprocess.h>
#include <utils/textfileformat.h>

#include <QCheckBox>
#include <QFuture>
#include <QFutureWatcher>
#include <QHBoxLayout>
#include <QRegularExpressionValidator>
#include <QScopedPointer>
#include <QSettings>
#include <QTextStream>

namespace Git {
namespace Internal {

class GitGrepParameters
{
public:
    QString ref;
    bool recurseSubmodules = false;
    QString id() const { return recurseSubmodules ? ref + ".Rec" : ref; }
};

using namespace Core;
using namespace Utils;
using VcsBase::VcsCommand;

namespace {

const char GitGrepRef[] = "GitGrepRef";

class GitGrepRunner : public QObject
{
    using FutureInterfaceType = QFutureInterface<FileSearchResultList>;

public:
    GitGrepRunner(FutureInterfaceType &fi,
                  const TextEditor::FileFindParameters &parameters) :
        m_fi(fi),
        m_parameters(parameters)
    {
        m_directory = parameters.additionalParameters.toString();
    }

    struct Match
    {
        Match() = default;
        Match(int start, int length) :
            matchStart(start), matchLength(length) {}

        int matchStart = 0;
        int matchLength = 0;
        QStringList regexpCapturedTexts;
    };

    void processLine(const QString &line, FileSearchResultList *resultList) const
    {
        if (line.isEmpty())
            return;
        static const QLatin1String boldRed("\x1b[1;31m");
        static const QLatin1String resetColor("\x1b[m");
        FileSearchResult single;
        const int lineSeparator = line.indexOf(QChar::Null);
        QString filePath = line.left(lineSeparator);
        if (!m_ref.isEmpty() && filePath.startsWith(m_ref))
            filePath.remove(0, m_ref.length());
        single.fileName = m_directory + '/' + filePath;
        const int textSeparator = line.indexOf(QChar::Null, lineSeparator + 1);
        single.lineNumber = line.midRef(lineSeparator + 1, textSeparator - lineSeparator - 1).toInt();
        QString text = line.mid(textSeparator + 1);
        QRegularExpression regexp;
        QVector<Match> matches;
        if (m_parameters.flags & FindRegularExpression) {
            const QRegularExpression::PatternOptions patternOptions =
                    (m_parameters.flags & FindCaseSensitively)
                    ? QRegularExpression::NoPatternOption : QRegularExpression::CaseInsensitiveOption;
            regexp.setPattern(m_parameters.text);
            regexp.setPatternOptions(patternOptions);
        }
        for (;;) {
            const int matchStart = text.indexOf(boldRed);
            if (matchStart == -1)
                break;
            const int matchTextStart = matchStart + boldRed.size();
            const int matchEnd = text.indexOf(resetColor, matchTextStart);
            QTC_ASSERT(matchEnd != -1, break);
            const int matchLength = matchEnd - matchTextStart;
            Match match(matchStart, matchLength);
            const QStringRef matchText = text.midRef(matchTextStart, matchLength);
            if (m_parameters.flags & FindRegularExpression)
                match.regexpCapturedTexts = regexp.match(matchText).capturedTexts();
            matches.append(match);
            text = text.leftRef(matchStart) + matchText + text.midRef(matchEnd + resetColor.size());
        }
        single.matchingLine = text;

        for (const auto &match : qAsConst(matches)) {
            single.matchStart = match.matchStart;
            single.matchLength = match.matchLength;
            single.regexpCapturedTexts = match.regexpCapturedTexts;
            resultList->append(single);
        }
    }

    void read(const QString &text)
    {
        FileSearchResultList resultList;
        QString t = text;
        QTextStream stream(&t);
        while (!stream.atEnd() && !m_fi.isCanceled())
            processLine(stream.readLine(), &resultList);
        if (!resultList.isEmpty())
            m_fi.reportResult(resultList);
    }

    void exec()
    {
        GitClient *client = GitPlugin::client();
        QStringList arguments = {
            "-c", "color.grep.match=bold red",
            "-c", "color.grep=always",
            "grep", "-zn", "--no-full-name"
        };
        if (!(m_parameters.flags & FindCaseSensitively))
            arguments << "-i";
        if (m_parameters.flags & FindWholeWords)
            arguments << "-w";
        if (m_parameters.flags & FindRegularExpression)
            arguments << "-P";
        else
            arguments << "-F";
        arguments << "-e" << m_parameters.text;
        GitGrepParameters params = m_parameters.searchEngineParameters.value<GitGrepParameters>();
        if (params.recurseSubmodules)
            arguments << "--recurse-submodules";
        if (!params.ref.isEmpty()) {
            arguments << params.ref;
            m_ref = params.ref + ':';
        }
        const QStringList filterArgs =
                m_parameters.nameFilters.isEmpty() ? QStringList("*") // needed for exclusion filters
                                                   : m_parameters.nameFilters;
        const QStringList exclusionArgs =
                Utils::transform(m_parameters.exclusionFilters, [](const QString &filter) {
                    return QString(":!" + filter);
                });
        arguments << "--" << filterArgs << exclusionArgs;
        QScopedPointer<VcsCommand> command(client->createCommand(m_directory));
        command->addFlags(VcsCommand::SilentOutput | VcsCommand::SuppressFailMessage);
        command->setProgressiveOutput(true);
        QFutureWatcher<FileSearchResultList> watcher;
        watcher.setFuture(m_fi.future());
        connect(&watcher, &QFutureWatcher<FileSearchResultList>::canceled,
                command.data(), &VcsCommand::cancel);
        connect(command.data(), &VcsCommand::stdOutText, this, &GitGrepRunner::read);
        SynchronousProcessResponse resp = command->runCommand(client->vcsBinary(), arguments, 0);
        switch (resp.result) {
        case SynchronousProcessResponse::TerminatedAbnormally:
        case SynchronousProcessResponse::StartFailed:
        case SynchronousProcessResponse::Hang:
            m_fi.reportCanceled();
            break;
        case SynchronousProcessResponse::Finished:
        case SynchronousProcessResponse::FinishedError:
            // When no results are found, git-grep exits with non-zero status.
            // Do not consider this as an error.
            break;
        }
    }

    static void run(QFutureInterface<FileSearchResultList> &fi,
                    TextEditor::FileFindParameters parameters)
    {
        GitGrepRunner runner(fi, parameters);
        Core::ProgressTimer progress(fi, 5);
        runner.exec();
    }

private:
    FutureInterfaceType m_fi;
    QString m_directory;
    QString m_ref;
    const TextEditor::FileFindParameters &m_parameters;
};

} // namespace

static bool isGitDirectory(const QString &path)
{
    static IVersionControl *gitVc = VcsManager::versionControl(VcsBase::Constants::VCS_ID_GIT);
    QTC_ASSERT(gitVc, return false);
    return gitVc == VcsManager::findVersionControlForDirectory(path, nullptr);
}

GitGrep::GitGrep(QObject *parent)
    : SearchEngine(parent)
{
    m_widget = new QWidget;
    auto layout = new QHBoxLayout(m_widget);
    layout->setMargin(0);
    m_treeLineEdit = new FancyLineEdit;
    m_treeLineEdit->setPlaceholderText(tr("Tree (optional)"));
    m_treeLineEdit->setToolTip(tr("Can be HEAD, tag, local or remote branch, or a commit hash.\n"
                                  "Leave empty to search through the file system."));
    const QRegularExpression refExpression("[\\S]*");
    m_treeLineEdit->setValidator(new QRegularExpressionValidator(refExpression, this));
    layout->addWidget(m_treeLineEdit);
    if (GitPlugin::client()->gitVersion() >= 0x021300) {
        m_recurseSubmodules = new QCheckBox(tr("Recurse submodules"));
        layout->addWidget(m_recurseSubmodules);
    }
    TextEditor::FindInFiles *findInFiles = TextEditor::FindInFiles::instance();
    QTC_ASSERT(findInFiles, return);
    connect(findInFiles, &TextEditor::FindInFiles::pathChanged,
            m_widget, [this](const QString &path) {
        setEnabled(isGitDirectory(path));
    });
    connect(this, &SearchEngine::enabledChanged, m_widget, &QWidget::setEnabled);
    findInFiles->addSearchEngine(this);
}

GitGrep::~GitGrep()
{
    delete m_widget;
}

QString GitGrep::title() const
{
    return tr("Git Grep");
}

QString GitGrep::toolTip() const
{
    const QString ref = m_treeLineEdit->text();
    if (!ref.isEmpty())
        return tr("Ref: %1\n%2").arg(ref);
    return QLatin1String("%1");
}

QWidget *GitGrep::widget() const
{
    return m_widget;
}

QVariant GitGrep::parameters() const
{
    GitGrepParameters params;
    params.ref = m_treeLineEdit->text();
    if (m_recurseSubmodules)
        params.recurseSubmodules = m_recurseSubmodules->isChecked();
    return QVariant::fromValue(params);
}

void GitGrep::readSettings(QSettings *settings)
{
    m_treeLineEdit->setText(settings->value(GitGrepRef).toString());
}

void GitGrep::writeSettings(QSettings *settings) const
{
    settings->setValue(GitGrepRef, m_treeLineEdit->text());
}

QFuture<FileSearchResultList> GitGrep::executeSearch(const TextEditor::FileFindParameters &parameters,
        TextEditor::BaseFileFind * /*baseFileFind*/)
{
    return Utils::runAsync(GitGrepRunner::run, parameters);
}

IEditor *GitGrep::openEditor(const SearchResultItem &item,
                             const TextEditor::FileFindParameters &parameters)
{
    GitGrepParameters params = parameters.searchEngineParameters.value<GitGrepParameters>();
    if (params.ref.isEmpty() || item.path.isEmpty())
        return nullptr;
    const QString path = QDir::fromNativeSeparators(item.path.first());
    QByteArray content;
    const QString topLevel = parameters.additionalParameters.toString();
    const QString relativePath = QDir(topLevel).relativeFilePath(path);
    if (!GitPlugin::client()->synchronousShow(topLevel, params.ref + ":./" + relativePath,
                                              &content, nullptr)) {
        return nullptr;
    }
    if (content.isEmpty())
        return nullptr;
    QByteArray fileContent;
    if (TextFileFormat::readFileUTF8(path, nullptr, &fileContent, nullptr)
            == TextFileFormat::ReadSuccess) {
        if (fileContent == content)
            return nullptr; // open the file for read/write
    }

    const QString documentId = QLatin1String(Git::Constants::GIT_PLUGIN)
            + QLatin1String(".GitShow.") + params.id()
            + QLatin1String(".") + relativePath;
    QString title = tr("Git Show %1:%2").arg(params.ref).arg(relativePath);
    IEditor *editor = EditorManager::openEditorWithContents(Id(), &title, content, documentId,
                                                            EditorManager::DoNotSwitchToDesignMode);
    editor->gotoLine(item.mainRange.begin.line, item.mainRange.begin.column);
    editor->document()->setTemporary(true);
    return editor;
}

} // Internal
} // Git

Q_DECLARE_METATYPE(Git::Internal::GitGrepParameters)