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#include "vcsoutputwindow.h"

#include <coreplugin/editormanager/editormanager.h>

#include <coreplugin/outputwindow.h>
#include <utils/fileutils.h>
#include <utils/qtcprocess.h>
#include <texteditor/behaviorsettings.h>
#include <texteditor/fontsettings.h>
#include <texteditor/texteditorsettings.h>
#include <utils/theme/theme.h>
#include <vcsbase/vcsoutputformatter.h>

#include <QAction>
#include <QContextMenuEvent>
#include <QDir>
#include <QFileInfo>
#include <QMenu>
#include <QPlainTextEdit>
#include <QPoint>
#include <QPointer>
#include <QRegularExpression>
#include <QTextBlock>
#include <QTextBlockUserData>
#include <QTextCharFormat>
#include <QTextCodec>
#include <QTextStream>
#include <QTime>

using namespace Utils;

/*!
    \class VcsBase::VcsBaseOutputWindow

    \brief The VcsBaseOutputWindow class is an output window for Version Control
    System commands and other output (Singleton).

    Installed by the base plugin and accessible for the other plugins
    via static instance()-accessor. Provides slots to append output with
    special formatting.

    It is possible to associate a repository with plain log text, enabling
    an "Open" context menu action over relative file name tokens in the text
    (absolute paths will also work). This can be used for "status" logs,
    showing modified file names, allowing the user to open them.
*/

namespace VcsBase {
namespace Internal {

const char C_VCS_OUTPUT_PANE[] = "Vcs.OutputPane";

const char zoomSettingsKey[] = "Vcs/OutputPane/Zoom";

// Store repository along with text blocks
class RepositoryUserData : public QTextBlockUserData
{
public:
    explicit RepositoryUserData(const QString &repo) : m_repository(repo) {}
    const QString &repository() const { return m_repository; }

private:
    const QString m_repository;
};

// A plain text edit with a special context menu containing "Clear"
// and functions to append specially formatted entries.
class OutputWindowPlainTextEdit : public Core::OutputWindow
{
public:
    explicit OutputWindowPlainTextEdit(QWidget *parent = nullptr);

    void appendLines(const QString &s, const QString &repository = QString());
    void appendLinesWithStyle(const QString &s, VcsOutputWindow::MessageStyle style,
                              const QString &repository = QString());
    VcsOutputLineParser *parser();

protected:
    void contextMenuEvent(QContextMenuEvent *event) override;
    void handleLink(const QPoint &pos) override;

private:
    void setFormat(VcsOutputWindow::MessageStyle style);
    QString identifierUnderCursor(const QPoint &pos, QString *repository = nullptr) const;

    Utils::OutputFormat m_format;
    VcsOutputLineParser *m_parser = nullptr;
};

OutputWindowPlainTextEdit::OutputWindowPlainTextEdit(QWidget *parent) :
    Core::OutputWindow(Core::Context(C_VCS_OUTPUT_PANE), zoomSettingsKey, parent)
{
    setReadOnly(true);
    setUndoRedoEnabled(false);
    setFrameStyle(QFrame::NoFrame);
    outputFormatter()->setBoldFontEnabled(false);
    m_parser = new VcsOutputLineParser;
    setLineParsers({m_parser});
}

// Search back for beginning of word
static inline int firstWordCharacter(const QString &s, int startPos)
{
    for ( ; startPos >= 0 ; startPos--) {
        if (s.at(startPos).isSpace())
            return startPos + 1;
    }
    return 0;
}

QString OutputWindowPlainTextEdit::identifierUnderCursor(const QPoint &widgetPos, QString *repository) const
{
    if (repository)
        repository->clear();
    // Get the blank-delimited word under cursor. Note that
    // using "SelectWordUnderCursor" does not work since it breaks
    // at delimiters like '/'. Get the whole line
    QTextCursor cursor = cursorForPosition(widgetPos);
    const int cursorDocumentPos = cursor.position();
    cursor.select(QTextCursor::BlockUnderCursor);
    if (!cursor.hasSelection())
        return QString();
    QString block = cursor.selectedText();
    // Determine cursor position within line and find blank-delimited word
    const int cursorPos = cursorDocumentPos - cursor.block().position();
    const int blockSize = block.size();
    if (cursorPos < 0 || cursorPos >= blockSize || block.at(cursorPos).isSpace())
        return QString();
    // Retrieve repository if desired
    if (repository)
        if (QTextBlockUserData *data = cursor.block().userData())
            *repository = static_cast<const RepositoryUserData *>(data)->repository();
    // Find first non-space character of word and find first non-space character past
    const int startPos = firstWordCharacter(block, cursorPos);
    int endPos = cursorPos;
    for ( ; endPos < blockSize && !block.at(endPos).isSpace(); endPos++) ;
    return endPos > startPos ? block.mid(startPos, endPos - startPos) : QString();
}

void OutputWindowPlainTextEdit::contextMenuEvent(QContextMenuEvent *event)
{
    const QString href = anchorAt(event->pos());
    QMenu *menu = href.isEmpty() ? createStandardContextMenu(event->pos()) : new QMenu;
    // Add 'open file'
    QString repository;
    const QString token = identifierUnderCursor(event->pos(), &repository);
    if (!repository.isEmpty()) {
        if (VcsOutputLineParser * const p = parser()) {
            if (!href.isEmpty())
                p->fillLinkContextMenu(menu, FilePath::fromString(repository), href);
        }
    }
    QAction *openAction = nullptr;
    if (!token.isEmpty()) {
        // Check for a file, expand via repository if relative
        QFileInfo fi(token);
        if (!repository.isEmpty() && !fi.isFile() && fi.isRelative())
            fi = QFileInfo(repository + '/' + token);
        if (fi.isFile())  {
            menu->addSeparator();
            openAction = menu->addAction(VcsOutputWindow::tr("Open \"%1\"").
                                         arg(QDir::toNativeSeparators(fi.fileName())));
            openAction->setData(fi.absoluteFilePath());
        }
    }
    QAction *clearAction = nullptr;
    if (href.isEmpty()) {
        // Add 'clear'
        menu->addSeparator();
        clearAction = menu->addAction(VcsOutputWindow::tr("Clear"));
    }

    // Run
    QAction *action = menu->exec(event->globalPos());
    if (action) {
        if (action == clearAction) {
            clear();
            return;
        }
        if (action == openAction) {
            const QString fileName = action->data().toString();
            Core::EditorManager::openEditor(fileName);
        }
    }
    delete menu;
}

void OutputWindowPlainTextEdit::handleLink(const QPoint &pos)
{
    const QString href = anchorAt(pos);
    if (href.isEmpty())
        return;
    QString repository;
    identifierUnderCursor(pos, &repository);
    if (repository.isEmpty()) {
        OutputWindow::handleLink(pos);
        return;
    }
    if (outputFormatter()->handleFileLink(href))
        return;
    if (VcsOutputLineParser * const p = parser())
        p->handleVcsLink(FilePath::fromString(repository), href);
}

void OutputWindowPlainTextEdit::appendLines(const QString &s, const QString &repository)
{
    if (s.isEmpty())
        return;

    const int previousLineCount = document()->lineCount();

    outputFormatter()->appendMessage(s, m_format);

    // Scroll down
    moveCursor(QTextCursor::End);
    ensureCursorVisible();
    if (!repository.isEmpty()) {
        // Associate repository with new data.
        QTextBlock block = document()->findBlockByLineNumber(previousLineCount);
        for ( ; block.isValid(); block = block.next())
            block.setUserData(new RepositoryUserData(repository));
    }
}

void OutputWindowPlainTextEdit::appendLinesWithStyle(const QString &s,
                                                     VcsOutputWindow::MessageStyle style,
                                                     const QString &repository)
{
    setFormat(style);

    if (style == VcsOutputWindow::Command) {
        const QString timeStamp = QTime::currentTime().toString("\nHH:mm:ss ");
        appendLines(timeStamp + s, repository);
    } else {
        appendLines(s, repository);
    }
}

VcsOutputLineParser *OutputWindowPlainTextEdit::parser()
{
    return m_parser;
}

void OutputWindowPlainTextEdit::setFormat(VcsOutputWindow::MessageStyle style)
{
    outputFormatter()->setBoldFontEnabled(style == VcsOutputWindow::Command);

    switch (style) {
    case VcsOutputWindow::Warning:
        m_format = LogMessageFormat;
        break;
    case VcsOutputWindow::Error:
        m_format = StdErrFormat;
        break;
    case VcsOutputWindow::Message:
        m_format = StdOutFormat;
        break;
    case VcsOutputWindow::Command:
        m_format = NormalMessageFormat;
        break;
    default:
    case VcsOutputWindow::None:
        m_format = OutputFormat::StdOutFormat;
        break;
    }
}

} // namespace Internal

// ------------------- VcsBaseOutputWindowPrivate
class VcsOutputWindowPrivate
{
public:
    Internal::OutputWindowPlainTextEdit widget;
    QString repository;
    const QRegularExpression passwordRegExp = QRegularExpression("://([^@:]+):([^@]+)@");
};

static VcsOutputWindow *m_instance = nullptr;
static VcsOutputWindowPrivate *d = nullptr;

VcsOutputWindow::VcsOutputWindow()
{
    d = new VcsOutputWindowPrivate;
    Q_ASSERT(d->passwordRegExp.isValid());
    m_instance = this;

    auto updateBehaviorSettings = [] {
        d->widget.setWheelZoomEnabled(
                    TextEditor::TextEditorSettings::behaviorSettings().m_scrollWheelZooming);
    };

    updateBehaviorSettings();
    setupContext(Internal::C_VCS_OUTPUT_PANE, &d->widget);

    connect(this, &IOutputPane::zoomInRequested, &d->widget, &Core::OutputWindow::zoomIn);
    connect(this, &IOutputPane::zoomOutRequested, &d->widget, &Core::OutputWindow::zoomOut);
    connect(this, &IOutputPane::resetZoomRequested, &d->widget, &Core::OutputWindow::resetZoom);
    connect(TextEditor::TextEditorSettings::instance(), &TextEditor::TextEditorSettings::behaviorSettingsChanged,
            this, updateBehaviorSettings);
}

static QString filterPasswordFromUrls(QString input)
{
    return input.replace(d->passwordRegExp, "://\\1:***@");
}

VcsOutputWindow::~VcsOutputWindow()
{
    m_instance = nullptr;
    delete d;
}

QWidget *VcsOutputWindow::outputWidget(QWidget *parent)
{
    if (parent != d->widget.parent())
        d->widget.setParent(parent);
    return &d->widget;
}

QString VcsOutputWindow::displayName() const
{
    return tr("Version Control");
}

int VcsOutputWindow::priorityInStatusBar() const
{
    return -1;
}

void VcsOutputWindow::clearContents()
{
    d->widget.clear();
}

void VcsOutputWindow::setFocus()
{
    d->widget.setFocus();
}

bool VcsOutputWindow::hasFocus() const
{
    return d->widget.hasFocus();
}

bool VcsOutputWindow::canFocus() const
{
    return true;
}

bool VcsOutputWindow::canNavigate() const
{
    return false;
}

bool VcsOutputWindow::canNext() const
{
    return false;
}

bool VcsOutputWindow::canPrevious() const
{
    return false;
}

void VcsOutputWindow::goToNext()
{
}

void VcsOutputWindow::goToPrev()
{
}

void VcsOutputWindow::setText(const QString &text)
{
    d->widget.setPlainText(text);
}

void VcsOutputWindow::setData(const QByteArray &data)
{
    setText(QTextCodec::codecForLocale()->toUnicode(data));
}

void VcsOutputWindow::appendSilently(const QString &text)
{
    append(text, None, true);
}

void VcsOutputWindow::append(const QString &text, MessageStyle style, bool silently)
{
    d->widget.appendLinesWithStyle(text, style, d->repository);

    if (!silently && !d->widget.isVisible())
        m_instance->popup(Core::IOutputPane::NoModeSwitch);
}

void VcsOutputWindow::appendError(const QString &text)
{
    append(text, Error, false);
}

void VcsOutputWindow::appendWarning(const QString &text)
{
    append(text, Warning, false);
}

QString VcsOutputWindow::msgExecutionLogEntry(const FilePath &workingDir, const CommandLine &command)
{
    if (workingDir.isEmpty())
        return tr("Running: %1").arg(command.toUserOutput()) + '\n';
    return tr("Running in %1: %2").arg(workingDir.toUserOutput(), command.toUserOutput()) + '\n';
}

void VcsOutputWindow::appendShellCommandLine(const QString &text)
{
    append(filterPasswordFromUrls(text), Command, true);
}

void VcsOutputWindow::appendCommand(const FilePath &workingDirectory, const CommandLine &command)
{
    appendShellCommandLine(msgExecutionLogEntry(workingDirectory, command));
}

void VcsOutputWindow::appendMessage(const QString &text)
{
    append(text, Message, true);
}

void VcsOutputWindow::destroy()
{
    delete m_instance;
    m_instance = nullptr;
}

VcsOutputWindow *VcsOutputWindow::instance()
{
    if (!m_instance)
        (void) new VcsOutputWindow;
    return m_instance;
}

QString VcsOutputWindow::repository() const
{
    return d->repository;
}

void VcsOutputWindow::setRepository(const QString &r)
{
    d->repository = r;
}

void VcsOutputWindow::clearRepository()
{
    d->repository.clear();
}

} // namespace VcsBase