/*  This file is part of the KDE project
    Copyright (C) 2004 Frans Englich <frans.englich@telia.com>
    Copyright (C) 2003 Matthias Kretz <kretz@kde.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License version 2 as published by the Free Software Foundation.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#include "kcmoduleproxy.h"
#include "kcmoduleproxy_p.h"

#include <QtGui/QApplication>
#include <QtGui/QLayout>
#include <QtDBus/QDBusConnectionInterface>
#include <QtDBus/QDBusInterface>
#include <QtDBus/QDBusReply>

#include <kaboutdata.h>
#include <kcmodule.h>
#include <kcmoduleinfo.h>
#include <kdebug.h>
#include <kdialog.h>
#include <klocale.h>
#include <kservice.h>
#include <kstandarddirs.h>
#include <kuser.h>
#include <kcmoduleloader.h>

#include "kcolorscheme.h"
#include "ksettingswidgetadaptor.h"

/*
 TODO:

 - Two Layout problems in runAsRoot:
    * lblBusy doesn't show
    * d->kcm/d->rootInfo doesn't get it right when the user presses cancel in the kdesudo dialog

 - Resizing horizontally is contrained; minimum size is set somewhere.
   It appears to be somehow derived from the module's size.

 - Prettify: set icon in KCMultiDialog.

*/
/***************************************************************/
KCModule* KCModuleProxy::realModule() const
{
    Q_D(const KCModuleProxy);
    /*
     * Note, don't call any function that calls realModule() since
     * that leads to an infinite loop.
     */

    /* Already loaded */
    if (!d->kcm) {
        QApplication::setOverrideCursor(Qt::WaitCursor);
        const_cast<KCModuleProxyPrivate*>(d)->loadModule();
        QApplication::restoreOverrideCursor();
    }
    return d->kcm;
}

void KCModuleProxyPrivate::loadModule()
{
    if (!topLayout) {
        topLayout = new QVBoxLayout(parent);
        topLayout->setMargin(0);

        QString name = modInfo.library();
        name.replace("-", "_"); //hyphen is not allowed in dbus, only [A-Z][a-z][0-9]_
        dbusPath = QLatin1String("/internal/KSettingsWidget/") + name;
        dbusService = QLatin1String("org.kde.internal.KSettingsWidget_") + name;
    }

    if (QDBusConnection::sessionBus().registerService(dbusService) || bogusOccupier) {
        /* We got the name we requested, because no one was before us,
         * or, it was an random application which had picked that name
         */
        kDebug(711) << "Module not already loaded, loading module " << modInfo.moduleName()
                    << " from library " << modInfo.library();

        kcm = KCModuleLoader::loadModule(modInfo, KCModuleLoader::Inline, parent, args);

        QObject::connect(kcm, SIGNAL(changed(bool)), parent, SLOT(_k_moduleChanged(bool)));
        QObject::connect(kcm, SIGNAL(destroyed()), parent, SLOT(_k_moduleDestroyed()));
        QObject::connect(kcm, SIGNAL(quickHelpChanged()), parent, SIGNAL(quickHelpChanged()));
        parent->setWhatsThis(kcm->quickHelp());

        if (kcm->layout()) {
            kcm->layout()->setMargin(0);
        }
        topLayout->addWidget( kcm );
        if (!modInfo.library().isEmpty()) {
            QDBusConnection::sessionBus().registerObject(
                dbusPath, new KSettingsWidgetAdaptor(parent), QDBusConnection::ExportAllSlots
            );
        }

        if (!rootInfo && /* If it's not already done */
            kcm->useRootOnlyMessage() && /* kcm wants root message */
            !KUser().isSuperUser() ) /* Not necessary if we're root */
        {
#if 0
            rootInfo = new QLabel(parent);
            topLayout->insertWidget(0, rootInfo);

            QPalette palette = rootInfo->palette();
            KStatefulBrush stbrush(KColorScheme::Window, KColorScheme::NeutralBackground);
            qDebug() << stbrush.brush(rootInfo);
            palette.setBrush(QPalette::Window, stbrush.brush(rootInfo));
            rootInfo->setPalette(palette);
            rootInfo->setAutoFillBackground(true);

            const QString message = kcm->rootOnlyMessage();
            if (message.isEmpty() )
                rootInfo->setText(
                    i18n(
                        "<b>Changes in this section require root access.</b><br />"
                        "On applying your changes you will have to supply your root "
                        "password." )
                    );
            } else {
                rootInfo->setText(message);
            }

            rootInfo->setWhatsThis(
                i18n(
                    "This section requires special permissions, probably "
                    "for system-wide changes; therefore, it is "
                    "required that you provide the root password to be "
                    "able to change the module's properties. If "
                    "you cannot provide the password, the changes of the "
                    "module cannot be saved "
                )
            );
#endif
        }
    } else {
        kDebug(711) << "Module already loaded, loading KCMError";

        /* Figure out the name of where the module is already loaded */
        QDBusInterface proxy(dbusService, dbusPath, "org.kde.internal.KSettingsWidget");
        QDBusReply<QString> reply = proxy.call("applicationName");

        if (reply.isValid()) {
            QObject::connect(
                QDBusConnection::sessionBus().interface(), SIGNAL(serviceOwnerChanged(QString,QString,QString)),
                parent, SLOT(_k_ownerChanged(QString,QString,QString))
            );
            kcm = KCModuleLoader::reportError(
                KCModuleLoader::Inline,
                i18nc(
                    "Argument is application name", "This configuration section is "
                    "already opened in %1", reply.value()
                ),
                " ",
                parent
            );
            topLayout->addWidget(kcm);
        } else {
            kDebug(711) << "Calling KCModuleProxy's DBus interface for fetching the name failed.";
            bogusOccupier = true;
            loadModule();
        }
    }
}

void KCModuleProxyPrivate::_k_ownerChanged(const QString &service, const QString &oldOwner, const QString &)
{
    if (service == dbusService && !oldOwner.isEmpty()) {
        // Violence: Get rid of KCMError & CO, so that
        // realModule() attempts to reload the module
        delete kcm;
        kcm = nullptr;
        Q_Q(KCModuleProxy);
        q->realModule();

        Q_ASSERT(kcm);
        kcm->show();
    }
}

void KCModuleProxy::showEvent(QShowEvent *ev)
{
    Q_D(KCModuleProxy);

    (void)realModule();

    /* We have no kcm, if we're in root mode */
    if( d->kcm ) {
        d->kcm->showEvent(ev);
    }

    QWidget::showEvent(ev);

}

KCModuleProxy::~KCModuleProxy()
{
    deleteClient();
    delete d_ptr;
}

void KCModuleProxy::deleteClient()
{
    Q_D(KCModuleProxy);
    delete d->kcm;
    d->kcm = nullptr;

    if (qApp) {
        qApp->syncX();
    }
}

void KCModuleProxyPrivate::_k_moduleChanged(bool c)
{
    if (changed == c) {
        return;
    }

    Q_Q(KCModuleProxy);
    changed = c;
    emit q->changed(c);
    emit q->changed(q);
}

void KCModuleProxyPrivate::_k_moduleDestroyed()
{
    kcm = nullptr;
}

KCModuleProxy::KCModuleProxy(const KService::Ptr &service, QWidget *parent,
                             const QStringList &args)
    : QWidget(parent),
    d_ptr(new KCModuleProxyPrivate(this, KCModuleInfo(service), args))
{
    d_ptr->q_ptr = this;
}

KCModuleProxy::KCModuleProxy(const KCModuleInfo &info, QWidget *parent,
                             const QStringList &args)
    : QWidget(parent),
    d_ptr(new KCModuleProxyPrivate(this, info, args))
{
    d_ptr->q_ptr = this;
}

KCModuleProxy::KCModuleProxy(const QString &serviceName, QWidget *parent,
                             const QStringList &args)
    : QWidget(parent),
    d_ptr(new KCModuleProxyPrivate(this, KCModuleInfo(serviceName), args))
{
    d_ptr->q_ptr = this;
}

void KCModuleProxy::load()
{
    Q_D(KCModuleProxy);
    if (realModule()) {
        d->kcm->load();
        d->_k_moduleChanged(false);
    }
}

void KCModuleProxy::save()
{
    Q_D(KCModuleProxy);
    if (d->changed && realModule()) {
        d->kcm->save();
        d->_k_moduleChanged(false);
    }
}

void KCModuleProxy::defaults()
{
    Q_D(KCModuleProxy);
    if (realModule()) {
        d->kcm->defaults();
    }
}

QString KCModuleProxy::quickHelp() const
{
    return realModule() ? realModule()->quickHelp() : QString();
}

const KAboutData* KCModuleProxy::aboutData() const
{
    return realModule() ? realModule()->aboutData() : nullptr;
}

KCModule::Buttons KCModuleProxy::buttons() const
{
    if (realModule()) {
        return realModule()->buttons();
    }
    return KCModule::Buttons(KCModule::Help | KCModule::Default | KCModule::Apply);
}

QString KCModuleProxy::rootOnlyMessage() const
{
    return realModule() ? realModule()->rootOnlyMessage() : QString();
}

bool KCModuleProxy::useRootOnlyMessage() const
{
    return realModule() ? realModule()->useRootOnlyMessage() : true;
}

KComponentData KCModuleProxy::componentData() const
{
    return realModule() ? realModule()->componentData() : KComponentData();
}

bool KCModuleProxy::changed() const
{
    Q_D(const KCModuleProxy);
    return d->changed;
}

KCModuleInfo KCModuleProxy::moduleInfo() const
{
    Q_D(const KCModuleProxy);
    return d->modInfo;
}

QString KCModuleProxy::dbusService() const
{
    Q_D(const KCModuleProxy);
    return d->dbusService;
}

QString KCModuleProxy::dbusPath() const
{
    Q_D(const KCModuleProxy);
    return d->dbusPath;
}

//X void KCModuleProxy::emitQuickHelpChanged()
//X {
//X     emit quickHelpChanged();
//X }

/***************************************************************/
#include "moc_kcmoduleproxy.cpp"