/***************************************************************************
 *   Copyright (C) 2007-2010 by Peter Penz <peter.penz19@gmail.com>        *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
 ***************************************************************************/

#include "terminalpanel.h"

#include <KIO/DesktopExecParser>
#include <KIO/Job>
#include <KIO/JobUiDelegate>
#include <KJobWidgets>
#include <KLocalizedString>
#include <KMessageWidget>
#include <KParts/ReadOnlyPart>
#include <KPluginFactory>
#include <KPluginLoader>
#include <KService>
#include <KShell>
#include <kde_terminal_interface.h>

#include <QAction>
#include <QDesktopServices>
#include <QDir>
#include <QLabel>
#include <QShowEvent>
#include <QTimer>
#include <QVBoxLayout>

TerminalPanel::TerminalPanel(QWidget* parent) :
    Panel(parent),
    m_clearTerminal(true),
    m_mostLocalUrlJob(nullptr),
    m_layout(nullptr),
    m_terminal(nullptr),
    m_terminalWidget(nullptr),
    m_konsolePartMissingMessage(nullptr),
    m_konsolePart(nullptr),
    m_konsolePartCurrentDirectory(),
    m_sendCdToTerminalHistory()
{
    m_layout = new QVBoxLayout(this);
    m_layout->setContentsMargins(0, 0, 0, 0);
}

TerminalPanel::~TerminalPanel()
{
}

void TerminalPanel::goHome()
{
    sendCdToTerminal(QDir::homePath(), HistoryPolicy::SkipHistory);
}

QString TerminalPanel::currentWorkingDirectory()
{
    if (m_terminal) {
        return m_terminal->currentWorkingDirectory();
    }
    return QString();
}

void TerminalPanel::terminalExited()
{
    m_terminal = nullptr;
    emit hideTerminalPanel();
}

bool TerminalPanel::isHiddenInVisibleWindow() const
{
    return parentWidget()
        && parentWidget()->isHidden()
        && m_terminal
        && !hasProgramRunning();
}

void TerminalPanel::dockVisibilityChanged()
{
    // Only react when the DockWidget itself (not some parent) is hidden. This way we don't
    // respond when e.g. Dolphin is minimized.
    if (isHiddenInVisibleWindow()) {
        // Make sure that the following "cd /" command will not affect the view.
        disconnect(m_konsolePart, SIGNAL(currentDirectoryChanged(QString)),
                   this, SLOT(slotKonsolePartCurrentDirectoryChanged(QString)));

        // Make sure this terminal does not prevent unmounting any removable drives
        changeDir(QUrl::fromLocalFile(QStringLiteral("/")));

        // Because we have disconnected from the part's currentDirectoryChanged()
        // signal, we have to update m_konsolePartCurrentDirectory manually. If this
        // was not done, showing the panel again might not set the part's working
        // directory correctly.
        m_konsolePartCurrentDirectory = '/';
    }
}

QString TerminalPanel::runningProgramName() const
{
    return m_terminal ? m_terminal->foregroundProcessName() : QString();
}

bool TerminalPanel::hasProgramRunning() const
{
    return m_terminal && (m_terminal->foregroundProcessId() != -1);
}

bool TerminalPanel::urlChanged()
{
    if (!url().isValid()) {
        return false;
    }

    const bool sendInput = m_terminal && !hasProgramRunning() && isVisible();
    if (sendInput) {
        changeDir(url());
    }

    return true;
}

void TerminalPanel::showEvent(QShowEvent* event)
{
    if (event->spontaneous()) {
        Panel::showEvent(event);
        return;
    }

    if (!m_terminal) {
        m_clearTerminal = true;
        KPluginFactory* factory = nullptr;
        KService::Ptr service = KService::serviceByDesktopName(QStringLiteral("konsolepart"));
        if (service) {
            factory = KPluginLoader(service->library()).factory();
        }
        m_konsolePart = factory ? (factory->create<KParts::ReadOnlyPart>(this)) : nullptr;
        if (m_konsolePart) {
            connect(m_konsolePart, &KParts::ReadOnlyPart::destroyed, this, &TerminalPanel::terminalExited);
            m_terminalWidget = m_konsolePart->widget();
            m_layout->addWidget(m_terminalWidget);
            if (m_konsolePartMissingMessage) {
                m_layout->removeWidget(m_konsolePartMissingMessage);
            }
            m_terminal = qobject_cast<TerminalInterface*>(m_konsolePart);
        } else if (!m_konsolePartMissingMessage) {
            const auto konsoleInstallUrl = QUrl("appstream://org.kde.konsole.desktop");
            const auto konsoleNotInstalledText = i18n("Terminal cannot be shown because Konsole is not installed. "
                                                      "Please install it and then reopen the panel.");
            m_konsolePartMissingMessage = new KMessageWidget(konsoleNotInstalledText, this);
            m_konsolePartMissingMessage->setCloseButtonVisible(false);
            m_konsolePartMissingMessage->hide();
            if (KIO::DesktopExecParser::hasSchemeHandler(konsoleInstallUrl)) {
                auto installKonsoleAction = new QAction(i18n("Install Konsole"), this);
                connect(installKonsoleAction, &QAction::triggered, [konsoleInstallUrl]() {
                    QDesktopServices::openUrl(konsoleInstallUrl);
                });
                m_konsolePartMissingMessage->addAction(installKonsoleAction);
            }
            m_layout->addWidget(m_konsolePartMissingMessage);
            m_layout->addStretch();
            QTimer::singleShot(0, m_konsolePartMissingMessage, &KMessageWidget::animatedShow);
        } else {
            m_konsolePartMissingMessage->animatedShow();
        }
    }
    if (m_terminal) {
        m_terminal->showShellInDir(url().toLocalFile());
        changeDir(url());
        m_terminalWidget->setFocus();
        connect(m_konsolePart, SIGNAL(currentDirectoryChanged(QString)),
                this, SLOT(slotKonsolePartCurrentDirectoryChanged(QString)));
    }

    Panel::showEvent(event);
}

void TerminalPanel::changeDir(const QUrl& url)
{
    delete m_mostLocalUrlJob;
    m_mostLocalUrlJob = nullptr;

    if (url.isLocalFile()) {
        sendCdToTerminal(url.toLocalFile());
    } else {
        m_mostLocalUrlJob = KIO::mostLocalUrl(url, KIO::HideProgressInfo);
        if (m_mostLocalUrlJob->uiDelegate()) {
            KJobWidgets::setWindow(m_mostLocalUrlJob, this);
        }
        connect(m_mostLocalUrlJob, &KIO::StatJob::result, this, &TerminalPanel::slotMostLocalUrlResult);
    }
}

void TerminalPanel::sendCdToTerminal(const QString& dir, HistoryPolicy addToHistory)
{
    if (dir == m_konsolePartCurrentDirectory) {
        m_clearTerminal = false;
        return;
    }

#ifndef Q_OS_WIN
    if (!m_clearTerminal) {
        // The TerminalV2 interface does not provide a way to delete the
        // current line before sending a new input. This is mandatory,
        // otherwise sending a 'cd x' to a existing 'rm -rf *' might
        // result in data loss. As workaround SIGINT is sent.
        const int processId = m_terminal->terminalProcessId();
        if (processId > 0) {
            kill(processId, SIGINT);
        }
    }
#endif

    m_terminal->sendInput(" cd " + KShell::quoteArg(dir) + '\n');

    // We want to ignore the currentDirectoryChanged(QString) signal, which we will receive after
    // the directory change, because this directory change is not caused by a "cd" command that the
    // user entered in the panel. Therefore, we have to remember 'dir'. Note that it could also be
    // a symbolic link -> remember the 'canonical' path.
    if (addToHistory == HistoryPolicy::AddToHistory)
        m_sendCdToTerminalHistory.enqueue(QDir(dir).canonicalPath());

    if (m_clearTerminal) {
        m_terminal->sendInput(QStringLiteral(" clear\n"));
        m_clearTerminal = false;
    }
}

void TerminalPanel::slotMostLocalUrlResult(KJob* job)
{
    KIO::StatJob* statJob = static_cast<KIO::StatJob *>(job);
    const QUrl url = statJob->mostLocalUrl();
    if (url.isLocalFile()) {
        sendCdToTerminal(url.toLocalFile());
    }

    m_mostLocalUrlJob = nullptr;
}

void TerminalPanel::slotKonsolePartCurrentDirectoryChanged(const QString& dir)
{
    m_konsolePartCurrentDirectory = QDir(dir).canonicalPath();

    // Only emit a changeUrl signal if the directory change was caused by the user inside the
    // terminal, and not by sendCdToTerminal(QString).
    while (!m_sendCdToTerminalHistory.empty()) {
        if (m_konsolePartCurrentDirectory == m_sendCdToTerminalHistory.dequeue()) {
            return;
        }
    }

    const QUrl url(QUrl::fromLocalFile(dir));
    emit changeUrl(url);
}
