/*
    SPDX-FileCopyrightText: 2014 Marco Martin <mart@kde.org>
    SPDX-FileCopyrightText: 2014 Vishesh Handa <me@vhanda.in>
    SPDX-FileCopyrightText: 2019 Cyril Rossi <cyril.rossi@enioka.com>
    SPDX-FileCopyrightText: 2021 Benjamin Port <benjamin.port@enioka.com>
    SPDX-FileCopyrightText: 2022 Dominic Hayes <ferenosdev@outlook.com>
    SPDX-FileCopyrightText: 2023 Ismael Asensio <isma.af@gmail.com>

    SPDX-License-Identifier: LGPL-2.0-only
*/

#include "kcm.h"
#include "../kcms-common_p.h"
#include "config-kcm.h"
#include "config-workspace.h"
#include "krdb.h"

#include <KDialogJobUiDelegate>
#include <KIO/ApplicationLauncherJob>
#include <KIconLoader>
#include <KMessageBox>
#include <KService>

#include <QCollator>
#include <QDBusConnection>
#include <QDBusMessage>
#include <QDebug>
#include <QProcess>
#include <QQuickItem>
#include <QQuickWindow>
#include <QStandardItemModel>
#include <QStandardPaths>
#include <private/qtx11extras_p.h>

#include <KLocalizedString>
#include <KPackage/PackageLoader>

#include <array>

#include <X11/Xlib.h>

#include <QFileInfo>

#ifdef HAVE_XCURSOR
#include "../cursortheme/xcursor/xcursortheme.h"
#include <X11/Xcursor/Xcursor.h>
#endif

#ifdef HAVE_XFIXES
#include <X11/extensions/Xfixes.h>
#endif

using namespace Qt::StringLiterals;

KCMLookandFeel::KCMLookandFeel(QObject *parent, const KPluginMetaData &data)
    : KQuickManagedConfigModule(parent, data)
    , m_lnf(new LookAndFeelManager(this))
    , m_themeContents(LookAndFeelManager::Empty)
    , m_selectedContents(LookAndFeelManager::AppearanceSettings)
{
    constexpr char uri[] = "org.kde.private.kcms.lookandfeel";
    qmlRegisterAnonymousType<LookAndFeelSettings>("", 1);
    qmlRegisterAnonymousType<QStandardItemModel>("", 1);
    qmlRegisterUncreatableType<KCMLookandFeel>(uri, 1, 0, "KCMLookandFeel", u"Can't create KCMLookandFeel"_s);
    qmlRegisterUncreatableType<LookAndFeelManager>(uri, 1, 0, "LookandFeelManager", u"Can't create LookandFeelManager"_s);

    setButtons(Default | Help);

    m_model = new QStandardItemModel(this);
    QHash<int, QByteArray> roles = m_model->roleNames();
    roles[PluginNameRole] = "pluginName";
    roles[DescriptionRole] = "description";
    roles[ScreenshotRole] = "screenshot";
    roles[FullScreenPreviewRole] = "fullScreenPreview";
    roles[ContentsRole] = "contents";
    roles[PackagePathRole] = "packagePath";
    roles[UninstallableRole] = "uninstallable";

    m_model->setItemRoleNames(roles);
    loadModel();

    connect(lookAndFeelSettings(), &LookAndFeelSettings::lookAndFeelPackageChanged, this, [this]() {
        // When the selected LNF package changes, update the available theme contents
        const int index = pluginIndex(lookAndFeelSettings()->lookAndFeelPackage());
        const LookAndFeelManager::Contents packageContents = m_model->index(index, 0).data(ContentsRole).value<LookAndFeelManager::Contents>();
        if (m_themeContents != packageContents) {
            m_themeContents = packageContents;
            Q_EMIT themeContentsChanged();
        }
        // And also reset the user selection to the new available contents
        resetSelectedContents();
    });

    connect(m_lnf, &LookAndFeelManager::refreshServices, this, [](const QStringList &toStop, const QList<KService::Ptr> &toStart) {
        for (const auto &serviceName : toStop) {
            // FIXME: quite ugly way to stop things, and what about non KDE things?
            QProcess::startDetached(QStringLiteral("kquitapp6"), {QStringLiteral("--service"), serviceName});
        }
        for (const auto &service : toStart) {
            auto *job = new KIO::ApplicationLauncherJob(service);
            job->setUiDelegate(new KDialogJobUiDelegate(KJobUiDelegate::AutoHandlingEnabled, nullptr));
            job->start();
        }
    });
    connect(m_lnf, &LookAndFeelManager::styleChanged, this, [] {
        // FIXME: changing style on the fly breaks QQuickWidgets
        notifyKcmChange(GlobalChangeType::StyleChanged);
    });
    connect(m_lnf, &LookAndFeelManager::colorsChanged, this, [] {
        // FIXME: changing style on the fly breaks QQuickWidgets
        notifyKcmChange(GlobalChangeType::PaletteChanged);
    });
    connect(m_lnf, &LookAndFeelManager::iconsChanged, this, [] {
        for (int i = 0; i < KIconLoader::LastGroup; i++) {
            KIconLoader::emitChange(KIconLoader::Group(i));
        }
    });
    connect(m_lnf, &LookAndFeelManager::cursorsChanged, this, &KCMLookandFeel::cursorsChanged);
    connect(m_lnf, &LookAndFeelManager::fontsChanged, this, [] {
        QDBusMessage message = QDBusMessage::createSignal(u"/KDEPlatformTheme"_s, u"org.kde.KDEPlatformTheme"_s, u"refreshFonts"_s);
        QDBusConnection::sessionBus().send(message);
    });
}

KCMLookandFeel::~KCMLookandFeel()
{
}

void KCMLookandFeel::knsEntryChanged(const KNSCore::Entry &entry)
{
    if (!entry.isValid()) {
        return;
    }
    auto removeItemFromModel = [&entry, this]() {
        if (entry.uninstalledFiles().isEmpty()) {
            return;
        }
        const QString guessedPluginId = QFileInfo(entry.uninstalledFiles().constFirst()).fileName();
        const int index = pluginIndex(guessedPluginId);
        if (index != -1) {
            m_model->removeRows(index, 1);
        }
    };
    if (entry.status() == KNSCore::Entry::Deleted) {
        removeItemFromModel();
    } else if (entry.status() == KNSCore::Entry::Installed && !entry.installedFiles().isEmpty()) {
        if (!entry.uninstalledFiles().isEmpty()) {
            removeItemFromModel(); // In case we updated it we don't want to have it in twice
        }
        KPackage::Package pkg = KPackage::PackageLoader::self()->loadPackage(QStringLiteral("Plasma/LookAndFeel"));
        pkg.setPath(entry.installedFiles().constFirst());
        addKPackageToModel(pkg);
    }
}

QStandardItemModel *KCMLookandFeel::lookAndFeelModel() const
{
    return m_model;
}

bool KCMLookandFeel::removeRow(int row, bool removeDependencies)
{
    const QModelIndex index = m_model->index(row, 0);
    if (!m_model->checkIndex(index) || !index.data(UninstallableRole).toBool()) {
        // Invalid request
        return false;
    }

    KPackage::Package package = KPackage::PackageLoader::self()->loadPackage(QStringLiteral("Plasma/LookAndFeel"));
    package.setPath(index.data(PackagePathRole).toString());

    if (!package.isValid()) {
        return false;
    }

    const auto contentsToRemove = removeDependencies ? index.data(ContentsRole).value<LookAndFeelManager::Contents>() : LookAndFeelManager::Empty;
    const bool isRemoved = m_lnf->remove(package, contentsToRemove);

    if (isRemoved) {
        // Remove the theme from the item model
        const bool ret = m_model->removeRow(row);
        Q_ASSERT_X(ret, "removeRow", QStringLiteral("Failed to remove item at row %1").arg(row).toLatin1().constData()); // Shouldn't happen
    }

    return isRemoved;
}

int KCMLookandFeel::pluginIndex(const QString &pluginName) const
{
    const auto results = m_model->match(m_model->index(0, 0), PluginNameRole, pluginName, 1, Qt::MatchExactly);
    if (results.count() == 1) {
        return results.first().row();
    }

    return -1;
}

QList<KPackage::Package> KCMLookandFeel::availablePackages(const QStringList &components)
{
    QList<KPackage::Package> packages;

    const QList<KPluginMetaData> packagesMetaData = KPackage::PackageLoader::self()->listPackages(QStringLiteral("Plasma/LookAndFeel"));

    for (const KPluginMetaData &metadata : packagesMetaData) {
        KPackage::Package pkg = KPackage::PackageLoader::self()->loadPackage(QStringLiteral("Plasma/LookAndFeel"), metadata.pluginId());
        if (components.isEmpty()) {
            packages << pkg;
        } else {
            for (const auto &component : components) {
                if (!pkg.filePath(component.toUtf8()).isEmpty()) {
                    packages << pkg;
                    break;
                }
            }
        }
    }

    return packages;
}

LookAndFeelSettings *KCMLookandFeel::lookAndFeelSettings() const
{
    return m_lnf->settings();
}

void KCMLookandFeel::loadModel()
{
    m_model->clear();

    QList<KPackage::Package> pkgs = availablePackages({u"defaults"_s, u"layouts"_s});

    // Sort case-insensitively
    QCollator collator;
    collator.setCaseSensitivity(Qt::CaseInsensitive);
    std::sort(pkgs.begin(), pkgs.end(), [&collator](const KPackage::Package &a, const KPackage::Package &b) {
        return collator.compare(a.metadata().name(), b.metadata().name()) < 0;
    });

    for (const KPackage::Package &pkg : pkgs) {
        addKPackageToModel(pkg);
    }

    // Model has been cleared so pretend the selected look and fell changed to force view update
    Q_EMIT lookAndFeelSettings()->lookAndFeelPackageChanged();
}

void KCMLookandFeel::addKPackageToModel(const KPackage::Package &pkg)
{
    if (!pkg.metadata().isValid()) {
        return;
    }
    QStandardItem *row = new QStandardItem(pkg.metadata().name());
    row->setData(pkg.metadata().pluginId(), PluginNameRole);
    row->setData(pkg.metadata().description(), DescriptionRole);
    row->setData(QUrl::fromLocalFile(pkg.filePath("preview")), ScreenshotRole);
    row->setData(pkg.filePath("fullscreenpreview"), FullScreenPreviewRole);
    row->setData(QVariant::fromValue(m_lnf->packageContents(pkg)), ContentsRole);

    row->setData(pkg.path(), PackagePathRole);
    const QString writableLocation = QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation);
    row->setData(pkg.path().startsWith(writableLocation), UninstallableRole);

    m_model->appendRow(row);
}

bool KCMLookandFeel::isSaveNeeded() const
{
    return lookAndFeelSettings()->isSaveNeeded();
}

void KCMLookandFeel::load()
{
    KQuickManagedConfigModule::load();

    m_package = KPackage::PackageLoader::self()->loadPackage(QStringLiteral("Plasma/LookAndFeel"), lookAndFeelSettings()->lookAndFeelPackage());
}

void KCMLookandFeel::save()
{
    QString newLnfPackage = lookAndFeelSettings()->lookAndFeelPackage();
    KPackage::Package package = KPackage::PackageLoader::self()->loadPackage(QStringLiteral("Plasma/LookAndFeel"));
    package.setPath(newLnfPackage);

    if (!package.isValid()) {
        return;
    }

    KQuickManagedConfigModule::save();
    m_lnf->save(package, m_package, m_selectedContents);
    m_package.setPath(newLnfPackage);
    runRdb(KRdbExportQtColors | KRdbExportGtkTheme | KRdbExportColors | KRdbExportQtSettings | KRdbExportXftSettings);
}

void KCMLookandFeel::defaults()
{
    KQuickManagedConfigModule::defaults();
    Q_EMIT showConfirmation();
}

LookAndFeelManager::Contents KCMLookandFeel::themeContents() const
{
    return m_themeContents;
}

LookAndFeelManager::Contents KCMLookandFeel::selectedContents() const
{
    return m_selectedContents;
}

void KCMLookandFeel::setSelectedContents(LookAndFeelManager::Contents items)
{
    if (selectedContents() == items) {
        return;
    }

    m_selectedContents = items;
    Q_EMIT selectedContentsChanged();
}

void KCMLookandFeel::resetSelectedContents()
{
    // Reset the user selection to those contents provided by the theme.
    LookAndFeelManager::Contents resetContents = m_themeContents;
    // But do not select layout contents by default if there appaerance settings
    if (m_themeContents & LookAndFeelManager::AppearanceSettings) {
        resetContents &= ~LookAndFeelManager::LayoutSettings;
    }
    setSelectedContents(resetContents);
}

QDir KCMLookandFeel::cursorThemeDir(const QString &theme, const int depth)
{
    // Prevent infinite recursion
    if (depth > 10) {
        return QDir();
    }

    // Search each icon theme directory for 'theme'
    for (const QString &baseDir : cursorSearchPaths()) {
        QDir dir(baseDir);
        if (!dir.exists() || !dir.cd(theme)) {
            continue;
        }

        // If there's a cursors subdir, we'll assume this is a cursor theme
        if (dir.exists(QStringLiteral("cursors"))) {
            return dir;
        }

        // If the theme doesn't have an index.theme file, it can't inherit any themes.
        if (!dir.exists(QStringLiteral("index.theme"))) {
            continue;
        }

        // Open the index.theme file, so we can get the list of inherited themes
        KConfig config(dir.path() + QStringLiteral("/index.theme"), KConfig::NoGlobals);
        KConfigGroup cg(&config, u"Icon Theme"_s);

        // Recurse through the list of inherited themes, to check if one of them
        // is a cursor theme.
        const QStringList inherits = cg.readEntry("Inherits", QStringList());
        for (const QString &inherit : inherits) {
            // Avoid possible DoS
            if (inherit == theme) {
                continue;
            }

            if (cursorThemeDir(inherit, depth + 1).exists()) {
                return dir;
            }
        }
    }

    return QDir();
}

QStringList KCMLookandFeel::cursorSearchPaths()
{
#ifdef HAVE_XCURSOR
#if XCURSOR_LIB_MAJOR == 1 && XCURSOR_LIB_MINOR < 1

    if (!m_cursorSearchPaths.isEmpty())
        return m_cursorSearchPaths;
    // These are the default paths Xcursor will scan for cursor themes
    QString path("~/.icons:/usr/share/icons:/usr/share/pixmaps:/usr/X11R6/lib/X11/icons");

    // If XCURSOR_PATH is set, use that instead of the default path
    char *xcursorPath = std::getenv("XCURSOR_PATH");
    if (xcursorPath)
        path = xcursorPath;
#else
    // Get the search path from Xcursor
    QString path = QString::fromLocal8Bit(XcursorLibraryPath());
#endif

    // Separate the paths
    m_cursorSearchPaths = path.split(QLatin1Char(':'), Qt::SkipEmptyParts);

    // Remove duplicates
    QMutableStringListIterator i(m_cursorSearchPaths);
    while (i.hasNext()) {
        const QString path = i.next();
        QMutableStringListIterator j(i);
        while (j.hasNext())
            if (j.next() == path)
                j.remove();
    }

    // Expand all occurrences of ~/ to the home dir
    m_cursorSearchPaths.replaceInStrings(QRegularExpression(QStringLiteral("^~\\/")), QString(QDir::home().path() + QDir::separator()));
#endif
    return m_cursorSearchPaths;
}

void KCMLookandFeel::cursorsChanged(const QString &themeName)
{
#ifdef HAVE_XCURSOR
    // Require the Xcursor version that shipped with X11R6.9 or greater, since
    // in previous versions the Xfixes code wasn't enabled due to a bug in the
    // build system (freedesktop bug #975).
#if defined(HAVE_XFIXES) && XFIXES_MAJOR >= 2 && XCURSOR_LIB_VERSION >= 10105
    KSharedConfigPtr config = KSharedConfig::openConfig(QStringLiteral("kcminputrc"));
    KConfigGroup cg(config, QStringLiteral("Mouse"));
    const int cursorSize = cg.readEntry("cursorSize", 24);

    QDir themeDir = cursorThemeDir(themeName, 0);
    if (!themeDir.exists()) {
        return;
    }

    XCursorTheme theme(themeDir);

    if (!CursorTheme::haveXfixes()) {
        return;
    }

    // Update the Xcursor X resources
    runRdb(0);

    // Notify all applications that the cursor theme has changed
    notifyKcmChange(GlobalChangeType::CursorChanged);

    // Reload the standard cursors
    QStringList names;

    // Qt cursors
    names << QStringLiteral("left_ptr") << QStringLiteral("up_arrow") << QStringLiteral("cross") << QStringLiteral("wait") << QStringLiteral("left_ptr_watch")
          << QStringLiteral("ibeam") << QStringLiteral("size_ver") << QStringLiteral("size_hor") << QStringLiteral("size_bdiag") << QStringLiteral("size_fdiag")
          << QStringLiteral("size_all") << QStringLiteral("split_v") << QStringLiteral("split_h") << QStringLiteral("pointing_hand")
          << QStringLiteral("openhand") << QStringLiteral("closedhand") << QStringLiteral("forbidden") << QStringLiteral("whats_this") << QStringLiteral("copy")
          << QStringLiteral("move") << QStringLiteral("link");

    // X core cursors
    names << QStringLiteral("X_cursor") << QStringLiteral("right_ptr") << QStringLiteral("hand1") << QStringLiteral("hand2") << QStringLiteral("watch")
          << QStringLiteral("xterm") << QStringLiteral("crosshair") << QStringLiteral("left_ptr_watch") << QStringLiteral("center_ptr")
          << QStringLiteral("sb_h_double_arrow") << QStringLiteral("sb_v_double_arrow") << QStringLiteral("fleur") << QStringLiteral("top_left_corner")
          << QStringLiteral("top_side") << QStringLiteral("top_right_corner") << QStringLiteral("right_side") << QStringLiteral("bottom_right_corner")
          << QStringLiteral("bottom_side") << QStringLiteral("bottom_left_corner") << QStringLiteral("left_side") << QStringLiteral("question_arrow")
          << QStringLiteral("pirate");

    for (const QString &name : std::as_const(names)) {
        XFixesChangeCursorByName(QX11Info::display(), theme.loadCursor(name, cursorSize), QFile::encodeName(name).constData());
    }

#else
    KMessageBox::information(this,
                             i18n("You have to restart the Plasma session for these changes to take effect."),
                             i18n("Cursor Settings Changed"),
                             "CursorSettingsChanged");
#endif
#endif
}
