/****************************************************************************
**
** Copyright (C) 2021 Ilya Fedin <fedin-ilja2010@ya.ru>
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtNetwork module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** accordance with the commercial license agreement provided with the
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** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
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** $QT_END_LICENSE$
**
****************************************************************************/

#include <QtNetwork/private/qnetworkinformation_p.h>

#include <QtCore/qglobal.h>
#include <QtCore/private/qobject_p.h>

#include <gio/gio.h>

QT_BEGIN_NAMESPACE
Q_DECLARE_LOGGING_CATEGORY(lcNetInfoGlib)
Q_LOGGING_CATEGORY(lcNetInfoGlib, "qt.network.info.glib");

namespace {
QNetworkInformation::Reachability reachabilityFromGNetworkConnectivity(GNetworkConnectivity connectivity)
{
    switch (connectivity) {
    case G_NETWORK_CONNECTIVITY_LOCAL:
        return QNetworkInformation::Reachability::Disconnected;
    case G_NETWORK_CONNECTIVITY_LIMITED:
    case G_NETWORK_CONNECTIVITY_PORTAL:
        return QNetworkInformation::Reachability::Site;
    case G_NETWORK_CONNECTIVITY_FULL:
        return QNetworkInformation::Reachability::Online;
    }
    return QNetworkInformation::Reachability::Unknown;
}
}

static QString backendName = QStringLiteral("glib");

class QGlibNetworkInformationBackend : public QNetworkInformationBackend
{
    Q_OBJECT
public:
    QGlibNetworkInformationBackend();
    ~QGlibNetworkInformationBackend();

    QString name() const override { return backendName; }
    QNetworkInformation::Features featuresSupported() const override
    {
        if (!isValid())
            return {};
        return featuresSupportedStatic();
    }

    static QNetworkInformation::Features featuresSupportedStatic()
    {
        using Feature = QNetworkInformation::Feature;
        return QNetworkInformation::Features(Feature::Reachability | Feature::CaptivePortal);
    }

    bool isValid() const;

private:
    Q_DISABLE_COPY_MOVE(QGlibNetworkInformationBackend)

    static void updateInformation(QGlibNetworkInformationBackend *backend);

    GNetworkMonitor *networkMonitor = nullptr;
    gulong handlerId = 0;
};

class QGlibNetworkInformationBackendFactory : public QNetworkInformationBackendFactory
{
    Q_OBJECT
    Q_PLUGIN_METADATA(IID QNetworkInformationBackendFactory_iid)
    Q_INTERFACES(QNetworkInformationBackendFactory)
public:
    QGlibNetworkInformationBackendFactory() = default;
    ~QGlibNetworkInformationBackendFactory() = default;
    QString name() const override { return backendName; }
    QNetworkInformation::Features featuresSupported() const override
    {
        return QGlibNetworkInformationBackend::featuresSupportedStatic();
    }

    QNetworkInformationBackend *create(QNetworkInformation::Features requiredFeatures) const override
    {
        if ((requiredFeatures & featuresSupported()) != requiredFeatures)
            return nullptr;
        auto backend = new QGlibNetworkInformationBackend();
        if (!backend->isValid())
            delete std::exchange(backend, nullptr);
        return backend;
    }
private:
    Q_DISABLE_COPY_MOVE(QGlibNetworkInformationBackendFactory)
};

QGlibNetworkInformationBackend::QGlibNetworkInformationBackend()
: networkMonitor(g_network_monitor_get_default())
{
    updateInformation(this);

    handlerId = g_signal_connect_swapped(networkMonitor, "notify::connectivity",
                                         G_CALLBACK(updateInformation), this);
}

QGlibNetworkInformationBackend::~QGlibNetworkInformationBackend()
{
    g_signal_handler_disconnect(networkMonitor, handlerId);
}

bool QGlibNetworkInformationBackend::isValid() const
{
    return G_OBJECT_TYPE_NAME(networkMonitor) != QLatin1String("GNetworkMonitorBase");
}

void QGlibNetworkInformationBackend::updateInformation(QGlibNetworkInformationBackend *backend)
{
    const auto connectivityState = g_network_monitor_get_connectivity(backend->networkMonitor);
    const bool behindPortal = (connectivityState == G_NETWORK_CONNECTIVITY_PORTAL);
    backend->setReachability(reachabilityFromGNetworkConnectivity(connectivityState));
    backend->setBehindCaptivePortal(behindPortal);
}

QT_END_NAMESPACE

#include "qglibnetworkinformationbackend.moc"