/*  This file is part of the KDE project
    Copyright (C) 2023 Ivailo Monev <xakepa10@gmail.com>

    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 "batterymonitor.h"

#include <QMutex>
#include <QTimer>
#include <QGraphicsLinearLayout>
#include <Solid/Device>
#include <Solid/Battery>
#include <Solid/PowerManagement>
#include <Solid/DeviceNotifier>
#include <Plasma/CheckBox>
#include <Plasma/Separator>
#include <Plasma/IconWidget>
#include <Plasma/ToolTipManager>
#include <KIcon>
#include <KIconLoader>
#include <KDebug>

static const int s_svgiconsize = 256;
static const QString s_suppressreason = QString::fromLatin1("battery monitor");

static QString kChargeStateToString(const Solid::Battery::ChargeState state)
{
    switch (state) {
        case Solid::Battery::UnknownCharge: {
            return i18n("Unknown");
        }
        case Solid::Battery::Charging: {
            return i18n("Charging");
        }
        case Solid::Battery::Discharging: {
            return i18n("Discharging");
        }
        case Solid::Battery::FullyCharged: {
            return i18n("Fully Charged");
        }
    }
    Q_ASSERT(false);
    return QString();
}

static QString kChargePercentToElement(const int percent)
{
    if (percent >= 80) {
        return QString::fromLatin1("Fill100");
    } else if (percent >= 60) {
        return QString::fromLatin1("Fill80");
    } else if (percent >= 40) {
        return QString::fromLatin1("Fill60");
    } else if (percent >= 20) {
        return QString::fromLatin1("Fill40");
    }
    return QString::fromLatin1("Fill20");
}


class BatteryMonitorWidget : public QGraphicsWidget
{
    Q_OBJECT
public:
    BatteryMonitorWidget(BatteryMonitor* batterymonitor);
    ~BatteryMonitorWidget();

    QString activeBattery() const;
    void setActiveBattery(const QString &udi);
    QIcon batteryUnavailableIcon();
    QIcon batteryIcon(const Solid::Battery *batterydevice, const QString &fallback);

public Q_SLOTS:
    void slotUpdateLayout();
    void slotDeviceAdded(const QString &udi);
    void slotDeviceRemoved(const QString &udi);

private Q_SLOTS:
    void slotSuppressSleep(const bool suppress);
    void slotSuppressScreen(const bool suppress);
    void slotUpdateActive();
    void slotUpdateIcon(const int state, const QString &udi);

private:
    QMutex m_mutex;
    BatteryMonitor* m_batterymonitor;
    QGraphicsLinearLayout* m_layout;
    int m_suppresssleepcookie;
    Plasma::CheckBox* m_suppresssleepbox;
    int m_suppressscreencookie;
    Plasma::CheckBox* m_suppressscreenbox;
    Plasma::Separator* m_separator;
    QList<Plasma::IconWidget*> m_iconwidgets;
    QString m_activebattery;
    // references to the devices for the signals
    QList<Solid::Device> m_batterydevices;
};

BatteryMonitorWidget::BatteryMonitorWidget(BatteryMonitor* batterymonitor)
    : QGraphicsWidget(batterymonitor),
    m_batterymonitor(batterymonitor),
    m_layout(nullptr),
    m_suppresssleepcookie(0),
    m_suppresssleepbox(nullptr),
    m_suppressscreencookie(0),
    m_suppressscreenbox(nullptr),
    m_separator(nullptr)
{
    m_layout = new QGraphicsLinearLayout(Qt::Vertical, this);
    m_suppresssleepbox = new Plasma::CheckBox(this);
    m_suppresssleepbox->setText(i18n("Suppress sleep power management"));
    connect(m_suppresssleepbox, SIGNAL(toggled(bool)), this, SLOT(slotSuppressSleep(bool)));
    m_layout->addItem(m_suppresssleepbox);
    m_suppressscreenbox = new Plasma::CheckBox(this);
    m_suppressscreenbox->setText(i18n("Suppress screen power management"));
    connect(m_suppressscreenbox, SIGNAL(toggled(bool)), this, SLOT(slotSuppressScreen(bool)));
    m_layout->addItem(m_suppressscreenbox);
    setLayout(m_layout);

    connect(
        Solid::DeviceNotifier::instance(), SIGNAL(deviceAdded(QString)),
        this, SLOT(slotDeviceAdded(QString))
    );
    connect(
        Solid::DeviceNotifier::instance(), SIGNAL(deviceRemoved(QString)),
        this, SLOT(slotDeviceRemoved(QString))
    );
}

BatteryMonitorWidget::~BatteryMonitorWidget()
{
    // have to stop sleep and screen power management supression at some point
    slotSuppressSleep(false);
    slotSuppressScreen(false);
}

QString BatteryMonitorWidget::activeBattery() const
{
    return m_activebattery;
}

void BatteryMonitorWidget::setActiveBattery(const QString &udi)
{
    m_activebattery = udi;
    const Solid::Device soliddevice(udi);
    const Solid::Battery* batterydevice = soliddevice.as<Solid::Battery>();
    if (batterydevice) {
        m_batterymonitor->setPopupIcon(batteryIcon(batterydevice, soliddevice.icon()));

        QString batterytooltip;
        batterytooltip.append(i18n("Charge percent: %1%<br/>").arg(batterydevice->chargePercent()));
        batterytooltip.append(i18n("Charge state: %1").arg(kChargeStateToString(batterydevice->chargeState())));
        Plasma::ToolTipContent plasmatooltipcontent = Plasma::ToolTipContent(
            soliddevice.description(), batterytooltip,
            batteryIcon(batterydevice, soliddevice.icon())
        );
        Plasma::ToolTipManager::self()->setContent(m_batterymonitor, plasmatooltipcontent);

        if (batterydevice->chargeState() == Solid::Battery::Discharging && batterydevice->chargePercent() < 30) {
            // low battery warning
            m_batterymonitor->setStatus(Plasma::ItemStatus::NeedsAttentionStatus);
        }

        emit m_batterymonitor->configNeedsSaving();
    }
}

QIcon BatteryMonitorWidget::batteryIcon(const Solid::Battery *batterydevice, const QString &fallback)
{
    QIcon result;
    Plasma::Svg plasmasvg(this);
    plasmasvg.setImagePath("icons/battery");
    plasmasvg.setContainsMultipleImages(true);
    if (plasmasvg.isValid()) {
        QPixmap iconpixmap(s_svgiconsize, s_svgiconsize);
        iconpixmap.fill(Qt::transparent);
        QPainter iconpainter(&iconpixmap);
        plasmasvg.paint(&iconpainter, iconpixmap.rect(), "Battery");
        plasmasvg.paint(&iconpainter, iconpixmap.rect(), kChargePercentToElement(batterydevice->chargePercent()));
        if (batterydevice->chargeState() == Solid::Battery::Charging) {
            plasmasvg.paint(&iconpainter, iconpixmap.rect(), "AcAdapter");
        }
        result = QIcon(iconpixmap);
    } else {
        result = KIcon(fallback);
    }
    return result;
}

QIcon BatteryMonitorWidget::batteryUnavailableIcon()
{
    QIcon result;
    Plasma::Svg plasmasvg(this);
    plasmasvg.setImagePath("icons/battery");
    plasmasvg.setContainsMultipleImages(true);
    if (plasmasvg.isValid()) {
        QPixmap iconpixmap(s_svgiconsize, s_svgiconsize);
        iconpixmap.fill(Qt::transparent);
        QPainter iconpainter(&iconpixmap);
        plasmasvg.paint(&iconpainter, iconpixmap.rect(), "Battery");
        plasmasvg.paint(&iconpainter, iconpixmap.rect(), "Unavailable");
        result = QIcon(iconpixmap);
    } else {
        result = KIcon("battery");
    }
    return result;
}

void BatteryMonitorWidget::slotUpdateLayout()
{
    QMutexLocker locker(&m_mutex);
    foreach (Plasma::IconWidget* iconwidget, m_iconwidgets) {
        m_layout->removeItem(iconwidget);
    }
    qDeleteAll(m_iconwidgets);
    m_iconwidgets.clear();
    if (m_separator) {
        m_layout->removeItem(m_separator);
        delete m_separator;
        m_separator = nullptr;
    }

    m_batterydevices = Solid::Device::listFromType(Solid::DeviceInterface::Battery);
    if (m_batterydevices.size() > 0) {
        m_separator = new Plasma::Separator(this);
        m_separator->setOrientation(Qt::Horizontal);
        m_layout->addItem(m_separator);
        m_batterymonitor->setStatus(Plasma::ItemStatus::ActiveStatus);
    } else {
        m_batterymonitor->setStatus(Plasma::ItemStatus::PassiveStatus);
        m_batterymonitor->setPopupIcon(batteryUnavailableIcon());
    }

    const Solid::Device soliddevice(m_activebattery);
    const Solid::Battery* batterydevice = soliddevice.as<Solid::Battery>();
    // if the battery device is not valid then the first battery will be picked instead
    if (!batterydevice) {
        m_activebattery.clear();
    }

    const int paneliconsize = KIconLoader::global()->currentSize(KIconLoader::Panel);
    foreach (const Solid::Device &batterydevice, m_batterydevices) {
        if (m_activebattery.isEmpty()) {
            // pick the first as active
            m_activebattery = batterydevice.udi();
        }

        const Solid::Battery* battery = batterydevice.as<Solid::Battery>();
        Plasma::IconWidget* iconwidget = new Plasma::IconWidget(
            batteryIcon(battery, batterydevice.icon()), batterydevice.description(),
            this
        );
        iconwidget->setOrientation(Qt::Horizontal);
        iconwidget->setPreferredIconSize(QSizeF(paneliconsize, paneliconsize));
        iconwidget->setProperty("_k_udi", batterydevice.udi());
        connect(
            iconwidget, SIGNAL(activated()),
            this, SLOT(slotUpdateActive())
        );
        m_iconwidgets.append(iconwidget);
        m_layout->addItem(iconwidget);
        connect(
            battery, SIGNAL(chargePercentChanged(int,QString)),
            this, SLOT(slotUpdateIcon(int,QString))
        );
        connect(
            battery, SIGNAL(chargeStateChanged(int,QString)),
            this, SLOT(slotUpdateIcon(int,QString))
        );
    }

    if (!m_activebattery.isEmpty()) {
        setActiveBattery(m_activebattery);
    }
}

void BatteryMonitorWidget::slotDeviceAdded(const QString &udi)
{
    // TODO: enable once battery events are not busted
#if 0
    const Solid::Device soliddevice(udi);
    const Solid::Battery* batterydevice = soliddevice.as<Solid::Battery>();
    if (batterydevice) {
        slotUpdateLayout();
    }
#else
    slotUpdateLayout();
#endif
}

void BatteryMonitorWidget::slotDeviceRemoved(const QString &udi)
{
    foreach (const Solid::Device &batterydevice, m_batterydevices) {
        if (batterydevice.udi() == udi) {
            slotUpdateLayout();
            break;
        }
    }
}

void BatteryMonitorWidget::slotSuppressSleep(const bool suppress)
{
    if (suppress) {
        m_suppresssleepcookie = Solid::PowerManagement::beginSuppressingSleep(s_suppressreason);
        if (m_suppresssleepcookie <= 0) {
            kWarning() << "could not suppress sleep";
            m_batterymonitor->showMessage(
                KIcon("dialog-warning"),
                i18n("Could not suppress sleep power management"),
                Plasma::ButtonOk
            );
            m_suppresssleepbox->setChecked(false);
        }
    } else if (m_suppresssleepcookie > 0) {
        const bool suppressresult = Solid::PowerManagement::stopSuppressingSleep(m_suppresssleepcookie);
        if (!suppressresult) {
            kWarning() << "could not stop sleep suppress";
            m_suppresssleepbox->setChecked(true);
        } else {
            m_suppresssleepcookie = 0;
        }
    }
}

void BatteryMonitorWidget::slotSuppressScreen(const bool suppress)
{
    if (suppress) {
        m_suppressscreencookie = Solid::PowerManagement::beginSuppressingScreenPowerManagement(s_suppressreason);
        if (m_suppressscreencookie <= 0) {
            kWarning() << "could not suppress screen";
            m_batterymonitor->showMessage(
                KIcon("dialog-warning"),
                i18n("Could not suppress screen power management"),
                Plasma::ButtonOk
            );
            m_suppressscreenbox->setChecked(false);
        }
    } else if (m_suppressscreencookie > 0) {
        const bool suppressresult = Solid::PowerManagement::stopSuppressingScreenPowerManagement(m_suppressscreencookie);
        if (!suppressresult) {
            kWarning() << "could not stop screen suppress";
            m_suppressscreenbox->setChecked(true);
        } else {
            m_suppressscreencookie = 0;
        }
    }
}

void BatteryMonitorWidget::slotUpdateActive()
{
    Plasma::IconWidget* iconwidget = qobject_cast<Plasma::IconWidget*>(sender());
    const QString iconwidgetudi = iconwidget->property("_k_udi").toString();
    Q_ASSERT(!iconwidgetudi.isEmpty());
    setActiveBattery(iconwidgetudi);
    m_batterymonitor->hidePopup();
}

void BatteryMonitorWidget::slotUpdateIcon(const int state, const QString &udi)
{
    Q_UNUSED(state);
    QMutexLocker locker(&m_mutex);
    foreach (Plasma::IconWidget* iconwidget, m_iconwidgets) {
        const QString iconwidgetudi = iconwidget->property("_k_udi").toString();
        Q_ASSERT(!iconwidgetudi.isEmpty());
        if (iconwidgetudi == udi) {
            const Solid::Device soliddevice(udi);
            const Solid::Battery* batterydevice = soliddevice.as<Solid::Battery>();
            Q_ASSERT(batterydevice);
            iconwidget->setIcon(batteryIcon(batterydevice, soliddevice.icon()));
            if (iconwidgetudi == m_activebattery) {
                setActiveBattery(m_activebattery);
            }
            break;
        }
    }
}


BatteryMonitor::BatteryMonitor(QObject *parent, const QVariantList &args)
    : Plasma::PopupApplet(parent, args),
    m_batterywidget(nullptr)
{
    KGlobal::locale()->insertCatalog("plasma_applet_battery");
    setAspectRatioMode(Plasma::AspectRatioMode::IgnoreAspectRatio);
    m_batterywidget = new BatteryMonitorWidget(this);
    setPopupIcon(m_batterywidget->batteryUnavailableIcon());
}

BatteryMonitor::~BatteryMonitor()
{
    delete m_batterywidget;
}

void BatteryMonitor::init()
{
    configChanged();
    QTimer::singleShot(500, m_batterywidget, SLOT(slotUpdateLayout()));
}

QGraphicsWidget* BatteryMonitor::graphicsWidget()
{
    return m_batterywidget;
}

void BatteryMonitor::configChanged()
{
    KConfigGroup configgroup = config();
    const QString activebattery = configgroup.readEntry("activeBattery", QString());
    if (!activebattery.isEmpty()) {
        m_batterywidget->setActiveBattery(activebattery);
    }
}

void BatteryMonitor::saveState(KConfigGroup &group) const
{
    group.writeEntry("activeBattery", m_batterywidget->activeBattery());
    Plasma::PopupApplet::saveState(group);
}

#include "moc_batterymonitor.cpp"
#include "batterymonitor.moc"