/********************************************************************
 KWin - the KDE window manager
 This file is part of the KDE project.

Copyright (C) 2014 Martin Gräßlin <mgraesslin@kde.org>

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, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#include "connection.h"
#include "context.h"
#include "device.h"
#include "events.h"
#ifndef KWIN_BUILD_TESTING
#include "../screens.h"
#endif
#include "../logind.h"
#include "../udev.h"
#include "libinput_logging.h"

#include <QDBusMessage>
#include <QDBusConnection>
#include <QDBusPendingCall>
#include <QMutexLocker>
#include <QSocketNotifier>
#include <QThread>

#include <libinput.h>
#include <cmath>

namespace KWin
{
namespace LibInput
{

class ConnectionAdaptor : public QObject
{
    Q_OBJECT
    Q_CLASSINFO("D-Bus Interface", "org.kde.KWin.InputDeviceManager")
    Q_PROPERTY(QStringList devicesSysNames READ devicesSysNames CONSTANT)

private:
    Connection *m_con;

public:
    ConnectionAdaptor(Connection *con)
        : m_con(con)
    {
        connect(con, &Connection::deviceAddedSysName, this, &ConnectionAdaptor::deviceAdded, Qt::QueuedConnection);
        connect(con, &Connection::deviceRemovedSysName, this, &ConnectionAdaptor::deviceRemoved, Qt::QueuedConnection);

        QDBusConnection::sessionBus().registerObject(QStringLiteral("/org/kde/KWin/InputDevice"),
                                                     QStringLiteral("org.kde.KWin.InputDeviceManager"),
                                                     this,
                                                     QDBusConnection::ExportAllProperties | QDBusConnection::ExportAllSignals
        );
    }

    ~ConnectionAdaptor() override {
        QDBusConnection::sessionBus().unregisterObject(QStringLiteral("/org/kde/KWin/InputDeviceManager"));
    }

    QStringList devicesSysNames() {
        // TODO: is this allowed? directly calling function of object in another thread!?
        //       otherwise use signal-slot mechanism
        return m_con->devicesSysNames();
    }

Q_SIGNALS:
    void deviceAdded(QString sysName);
    void deviceRemoved(QString sysName);

};

Connection *Connection::s_self = nullptr;
QPointer<QThread> Connection::s_thread;

static ConnectionAdaptor *s_adaptor = nullptr;
static Context *s_context = nullptr;

static quint32 toLibinputLEDS(Xkb::LEDs leds)
{
    quint32 libinputLeds = 0;
    if (leds.testFlag(Xkb::LED::NumLock)) {
        libinputLeds = libinputLeds | LIBINPUT_LED_NUM_LOCK;
    }
    if (leds.testFlag(Xkb::LED::CapsLock)) {
        libinputLeds = libinputLeds | LIBINPUT_LED_CAPS_LOCK;
    }
    if (leds.testFlag(Xkb::LED::ScrollLock)) {
        libinputLeds = libinputLeds | LIBINPUT_LED_SCROLL_LOCK;
    }
    return libinputLeds;
}

Connection::Connection(QObject *parent)
    : Connection(nullptr, parent)
{
    // only here to fix build, using will crash, BUG 343529
}

void Connection::createThread()
{
    if (s_thread) {
        return;
    }
    s_thread = new QThread();
    s_thread->setObjectName(QStringLiteral("libinput-connection"));
    s_thread->start();
}

Connection *Connection::create(QObject *parent)
{
    Q_ASSERT(!s_self);
    static Udev s_udev;
    if (!s_udev.isValid()) {
        qCWarning(KWIN_LIBINPUT) << "Failed to initialize udev";
        return nullptr;
    }
    if (!s_context) {
        s_context = new Context(s_udev);
        if (!s_context->isValid()) {
            qCWarning(KWIN_LIBINPUT) << "Failed to create context from udev";
            delete s_context;
            s_context = nullptr;
            return nullptr;
        }
        if (!s_context->assignSeat(LogindIntegration::self()->seat().toUtf8().constData())) {
            qCWarning(KWIN_LIBINPUT) << "Failed to assign seat" << LogindIntegration::self()->seat();
            delete s_context;
            s_context = nullptr;
            return nullptr;
        }
    }
    Connection::createThread();
    s_self = new Connection(s_context);
    s_self->moveToThread(s_thread);
    QObject::connect(s_thread, &QThread::finished, s_self, &QObject::deleteLater);
    QObject::connect(s_thread, &QThread::finished, s_thread, &QObject::deleteLater);
    QObject::connect(parent, &QObject::destroyed, s_thread, &QThread::quit);
    if (!s_adaptor) {
        s_adaptor = new ConnectionAdaptor(s_self);
    }

    return s_self;
}


Connection::Connection(Context *input, QObject *parent)
    : QObject(parent)
    , m_input(input)
    , m_notifier(nullptr)
    , m_mutex(QMutex::Recursive)
    , m_leds()
{
    Q_ASSERT(m_input);
    // need to connect to KGlobalSettings as the mouse KCM does not emit a dedicated signal
    QDBusConnection::sessionBus().connect(QString(), QStringLiteral("/KGlobalSettings"), QStringLiteral("org.kde.KGlobalSettings"),
                                          QStringLiteral("notifyChange"), this, SLOT(slotKGlobalSettingsNotifyChange(int,int)));
}

Connection::~Connection()
{
    delete s_adaptor;
    s_adaptor = nullptr;
    s_self = nullptr;
    delete s_context;
    s_context = nullptr;
}

void Connection::setup()
{
    QMetaObject::invokeMethod(this, "doSetup", Qt::QueuedConnection);
}

void Connection::doSetup()
{
    connect(s_self, &Connection::deviceAdded, s_self, [](Device* device) {
                emit s_self->deviceAddedSysName(device->sysName());
            });
    connect(s_self, &Connection::deviceRemoved, s_self, [](Device* device) {
                emit s_self->deviceRemovedSysName(device->sysName());
            });

    Q_ASSERT(!m_notifier);
    m_notifier = new QSocketNotifier(m_input->fileDescriptor(), QSocketNotifier::Read, this);
    connect(m_notifier, &QSocketNotifier::activated, this, &Connection::handleEvent);

    LogindIntegration *logind = LogindIntegration::self();
    connect(logind, &LogindIntegration::sessionActiveChanged, this,
        [this](bool active) {
            if (active) {
                if (!m_input->isSuspended()) {
                    return;
                }
                m_input->resume();
                wasSuspended = true;
            } else {
                deactivate();
            }
        }
    );
    handleEvent();
}

void Connection::deactivate()
{
    if (m_input->isSuspended()) {
        return;
    }
    m_keyboardBeforeSuspend = hasKeyboard();
    m_alphaNumericKeyboardBeforeSuspend = hasAlphaNumericKeyboard();
    m_pointerBeforeSuspend = hasPointer();
    m_touchBeforeSuspend = hasTouch();
    m_tabletModeSwitchBeforeSuspend = hasTabletModeSwitch();
    m_input->suspend();
    handleEvent();
}

void Connection::handleEvent()
{
    QMutexLocker locker(&m_mutex);
    const bool wasEmpty = m_eventQueue.isEmpty();
    do {
        m_input->dispatch();
        Event *event = m_input->event();
        if (!event) {
            break;
        }
        m_eventQueue << event;
    } while (true);
    if (wasEmpty && !m_eventQueue.isEmpty()) {
        emit eventsRead();
    }
}

void Connection::processEvents()
{
    QMutexLocker locker(&m_mutex);
    while (!m_eventQueue.isEmpty()) {
        QScopedPointer<Event> event(m_eventQueue.takeFirst());
        switch (event->type()) {
            case LIBINPUT_EVENT_DEVICE_ADDED: {
                auto device = new Device(event->nativeDevice());
                device->moveToThread(s_thread);
                m_devices << device;
                if (device->isKeyboard()) {
                    m_keyboard++;
                    if (device->isAlphaNumericKeyboard()) {
                        m_alphaNumericKeyboard++;
                        if (m_alphaNumericKeyboard == 1) {
                            emit hasAlphaNumericKeyboardChanged(true);
                        }
                    }
                    if (m_keyboard == 1) {
                        emit hasKeyboardChanged(true);
                    }
                }
                if (device->isPointer()) {
                    m_pointer++;
                    if (m_pointer == 1) {
                        emit hasPointerChanged(true);
                    }
                }
                if (device->isTouch()) {
                    m_touch++;
                    if (m_touch == 1) {
                        emit hasTouchChanged(true);
                    }
                }
                if (device->isTabletModeSwitch()) {
                    m_tabletModeSwitch++;
                    if (m_tabletModeSwitch == 1) {
                        emit hasTabletModeSwitchChanged(true);
                    }
                }
                applyDeviceConfig(device);
                applyScreenToDevice(device);

                // enable possible leds
                libinput_device_led_update(device->device(), static_cast<libinput_led>(toLibinputLEDS(m_leds)));

                emit deviceAdded(device);
                break;
            }
            case LIBINPUT_EVENT_DEVICE_REMOVED: {
                auto it = std::find_if(m_devices.begin(), m_devices.end(), [&event] (Device *d) { return event->device() == d; } );
                if (it == m_devices.end()) {
                    // we don't know this device
                    break;
                }
                auto device = *it;
                m_devices.erase(it);
                emit deviceRemoved(device);

                if (device->isKeyboard()) {
                    m_keyboard--;
                    if (device->isAlphaNumericKeyboard()) {
                        m_alphaNumericKeyboard--;
                        if (m_alphaNumericKeyboard == 0) {
                            emit hasAlphaNumericKeyboardChanged(false);
                        }
                    }
                    if (m_keyboard == 0) {
                        emit hasKeyboardChanged(false);
                    }
                }
                if (device->isPointer()) {
                    m_pointer--;
                    if (m_pointer == 0) {
                        emit hasPointerChanged(false);
                    }
                }
                if (device->isTouch()) {
                    m_touch--;
                    if (m_touch == 0) {
                        emit hasTouchChanged(false);
                    }
                }
                if (device->isTabletModeSwitch()) {
                    m_tabletModeSwitch--;
                    if (m_tabletModeSwitch == 0) {
                        emit hasTabletModeSwitchChanged(false);
                    }
                }
                device->deleteLater();
                break;
            }
            case LIBINPUT_EVENT_KEYBOARD_KEY: {
                KeyEvent *ke = static_cast<KeyEvent*>(event.data());
                emit keyChanged(ke->key(), ke->state(), ke->time(), ke->device());
                break;
            }
            case LIBINPUT_EVENT_POINTER_AXIS: {
                PointerEvent *pe = static_cast<PointerEvent*>(event.data());
                const auto axes = pe->axis();
                for (const InputRedirection::PointerAxis &axis : axes) {
                    emit pointerAxisChanged(axis, pe->axisValue(axis), pe->discreteAxisValue(axis),
                        pe->axisSource(), pe->time(), pe->device());
                }
                break;
            }
            case LIBINPUT_EVENT_POINTER_BUTTON: {
                PointerEvent *pe = static_cast<PointerEvent*>(event.data());
                emit pointerButtonChanged(pe->button(), pe->buttonState(), pe->time(), pe->device());
                break;
            }
            case LIBINPUT_EVENT_POINTER_MOTION: {
                PointerEvent *pe = static_cast<PointerEvent*>(event.data());
                auto delta = pe->delta();
                auto deltaNonAccel = pe->deltaUnaccelerated();
                quint32 latestTime = pe->time();
                quint64 latestTimeUsec = pe->timeMicroseconds();
                auto it = m_eventQueue.begin();
                while (it != m_eventQueue.end()) {
                    if ((*it)->type() == LIBINPUT_EVENT_POINTER_MOTION) {
                        QScopedPointer<PointerEvent> p(static_cast<PointerEvent*>(*it));
                        delta += p->delta();
                        deltaNonAccel += p->deltaUnaccelerated();
                        latestTime = p->time();
                        latestTimeUsec = p->timeMicroseconds();
                        it = m_eventQueue.erase(it);
                    } else {
                        break;
                    }
                }
                emit pointerMotion(delta, deltaNonAccel, latestTime, latestTimeUsec, pe->device());
                break;
            }
            case LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE: {
                PointerEvent *pe = static_cast<PointerEvent*>(event.data());
                emit pointerMotionAbsolute(pe->absolutePos(), pe->absolutePos(m_size), pe->time(), pe->device());
                break;
            }
            case LIBINPUT_EVENT_TOUCH_DOWN: {
#ifndef KWIN_BUILD_TESTING
                TouchEvent *te = static_cast<TouchEvent*>(event.data());
                const auto &geo = screens()->geometry(te->device()->screenId());
                emit touchDown(te->id(), geo.topLeft() + te->absolutePos(geo.size()), te->time(), te->device());
                break;
#endif
            }
            case LIBINPUT_EVENT_TOUCH_UP: {
                TouchEvent *te = static_cast<TouchEvent*>(event.data());
                emit touchUp(te->id(), te->time(), te->device());
                break;
            }
            case LIBINPUT_EVENT_TOUCH_MOTION: {
#ifndef KWIN_BUILD_TESTING
                TouchEvent *te = static_cast<TouchEvent*>(event.data());
                const auto &geo = screens()->geometry(te->device()->screenId());
                emit touchMotion(te->id(), geo.topLeft() + te->absolutePos(geo.size()), te->time(), te->device());
                break;
#endif
            }
            case LIBINPUT_EVENT_TOUCH_CANCEL: {
                emit touchCanceled(event->device());
                break;
            }
            case LIBINPUT_EVENT_TOUCH_FRAME: {
                emit touchFrame(event->device());
                break;
            }
            case LIBINPUT_EVENT_GESTURE_PINCH_BEGIN: {
                PinchGestureEvent *pe = static_cast<PinchGestureEvent*>(event.data());
                emit pinchGestureBegin(pe->fingerCount(), pe->time(), pe->device());
                break;
            }
            case LIBINPUT_EVENT_GESTURE_PINCH_UPDATE: {
                PinchGestureEvent *pe = static_cast<PinchGestureEvent*>(event.data());
                emit pinchGestureUpdate(pe->scale(), pe->angleDelta(), pe->delta(), pe->time(), pe->device());
                break;
            }
            case LIBINPUT_EVENT_GESTURE_PINCH_END: {
                PinchGestureEvent *pe = static_cast<PinchGestureEvent*>(event.data());
                if (pe->isCancelled()) {
                    emit pinchGestureCancelled(pe->time(), pe->device());
                } else {
                    emit pinchGestureEnd(pe->time(), pe->device());
                }
                break;
            }
            case LIBINPUT_EVENT_GESTURE_SWIPE_BEGIN: {
                SwipeGestureEvent *se = static_cast<SwipeGestureEvent*>(event.data());
                emit swipeGestureBegin(se->fingerCount(), se->time(), se->device());
                break;
            }
            case LIBINPUT_EVENT_GESTURE_SWIPE_UPDATE: {
                SwipeGestureEvent *se = static_cast<SwipeGestureEvent*>(event.data());
                emit swipeGestureUpdate(se->delta(), se->time(), se->device());
                break;
            }
            case LIBINPUT_EVENT_GESTURE_SWIPE_END: {
                SwipeGestureEvent *se = static_cast<SwipeGestureEvent*>(event.data());
                if (se->isCancelled()) {
                    emit swipeGestureCancelled(se->time(), se->device());
                } else {
                    emit swipeGestureEnd(se->time(), se->device());
                }
                break;
            }
            case LIBINPUT_EVENT_SWITCH_TOGGLE: {
                SwitchEvent *se = static_cast<SwitchEvent*>(event.data());
                switch (se->state()) {
                case SwitchEvent::State::Off:
                    emit switchToggledOff(se->time(), se->timeMicroseconds(), se->device());
                    break;
                case SwitchEvent::State::On:
                    emit switchToggledOn(se->time(), se->timeMicroseconds(), se->device());
                    break;
                default:
                    Q_UNREACHABLE();
                }
                break;
            }
            default:
                // nothing
                break;
        }
    }
    if (wasSuspended) {
        if (m_keyboardBeforeSuspend && !m_keyboard) {
            emit hasKeyboardChanged(false);
        }
        if (m_alphaNumericKeyboardBeforeSuspend && !m_alphaNumericKeyboard) {
            emit hasAlphaNumericKeyboardChanged(false);
        }
        if (m_pointerBeforeSuspend && !m_pointer) {
            emit hasPointerChanged(false);
        }
        if (m_touchBeforeSuspend && !m_touch) {
            emit hasTouchChanged(false);
        }
        if (m_tabletModeSwitchBeforeSuspend && !m_tabletModeSwitch) {
            emit hasTabletModeSwitchChanged(false);
        }
        wasSuspended = false;
    }
}

void Connection::setScreenSize(const QSize &size)
{
    m_size = size;
}

void Connection::updateScreens()
{
    QMutexLocker locker(&m_mutex);
    for (auto device: qAsConst(m_devices)) {
        applyScreenToDevice(device);
    }
}


void Connection::applyScreenToDevice(Device *device)
{
#ifndef KWIN_BUILD_TESTING
    QMutexLocker locker(&m_mutex);
    if (!device->isTouch()) {
        return;
    }
    int id = -1;
    // let's try to find a screen for it
    if (screens()->count() == 1) {
        id = 0;
    }
    if (id == -1 && !device->outputName().isEmpty()) {
        // we have an output name, try to find a screen with matching name
        for (int i = 0; i < screens()->count(); i++) {
            if (screens()->name(i) == device->outputName()) {
                id = i;
                break;
            }
        }
    }
    if (id == -1) {
        // do we have an internal screen?
        int internalId = -1;
        for (int i = 0; i < screens()->count(); i++) {
            if (screens()->isInternal(i)) {
                internalId = i;
                break;
            }
        }
        auto testScreenMatches = [device] (int id) {
            const auto &size = device->size();
            const auto &screenSize = screens()->physicalSize(id);
            return std::round(size.width()) == std::round(screenSize.width())
                && std::round(size.height()) == std::round(screenSize.height());
        };
        if (internalId != -1 && testScreenMatches(internalId)) {
            id = internalId;
        }
        // let's compare all screens for size
        for (int i = 0; i < screens()->count(); i++) {
            if (testScreenMatches(i)) {
                id = i;
                break;
            }
        }
        if (id == -1) {
            // still not found
            if (internalId != -1) {
                // we have an internal id, so let's use that
                id = internalId;
            } else {
                // just take first screen, we have no clue
                id = 0;
            }
        }
    }
    device->setScreenId(id);
    device->setOrientation(screens()->orientation(id));
#else
    Q_UNUSED(device)
#endif
}

bool Connection::isSuspended() const
{
    if (!s_context) {
        return false;
    }
    return s_context->isSuspended();
}

void Connection::applyDeviceConfig(Device *device)
{
    // pass configuration to Device
    device->setConfig(m_config->group("Libinput").group(QString::number(device->vendor())).group(QString::number(device->product())).group(device->name()));
    device->loadConfiguration();
}

void Connection::slotKGlobalSettingsNotifyChange(int type, int arg)
{
    if (type == 3 /**SettingsChanged**/ && arg == 0 /** SETTINGS_MOUSE */) {
        m_config->reparseConfiguration();
        for (auto it = m_devices.constBegin(), end = m_devices.constEnd(); it != end; ++it) {
            if ((*it)->isPointer()) {
                applyDeviceConfig(*it);
            }
        }
    }
}

void Connection::toggleTouchpads()
{
    bool changed = false;
    m_touchpadsEnabled = !m_touchpadsEnabled;
    for (auto it = m_devices.constBegin(); it != m_devices.constEnd(); ++it) {
        auto device = *it;
        if (!device->isTouchpad()) {
            continue;
        }
        const bool old = device->isEnabled();
        device->setEnabled(m_touchpadsEnabled);
        if (old != device->isEnabled()) {
            changed = true;
        }
    }
    if (changed) {
        // send OSD message
        QDBusMessage msg = QDBusMessage::createMethodCall(
            QStringLiteral("org.kde.plasmashell"),
            QStringLiteral("/org/kde/osdService"),
            QStringLiteral("org.kde.osdService"),
            QStringLiteral("touchpadEnabledChanged")
        );
        msg.setArguments({m_touchpadsEnabled});
        QDBusConnection::sessionBus().asyncCall(msg);
    }
}

void Connection::enableTouchpads()
{
    if (m_touchpadsEnabled) {
        return;
    }
    toggleTouchpads();
}

void Connection::disableTouchpads()
{
    if (!m_touchpadsEnabled) {
        return;
    }
    toggleTouchpads();
}

void Connection::updateLEDs(Xkb::LEDs leds)
{
    if (m_leds == leds) {
        return;
    }
    m_leds = leds;
    // update on devices
    const libinput_led l = static_cast<libinput_led>(toLibinputLEDS(leds));
    for (auto it = m_devices.constBegin(), end = m_devices.constEnd(); it != end; ++it) {
        libinput_device_led_update((*it)->device(), l);
    }
}

QStringList Connection::devicesSysNames() const {
    QStringList sl;
    foreach (Device *d, m_devices) {
        sl.append(d->sysName());
    }
    return sl;
}

}
}

#include "connection.moc"
