/*
 * Copyright (C) 2013 Alexander Mezin <mezin.alexander@gmail.com>
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <cstring>
#include <cmath>

#include <QtAlgorithms>
#include <QScopedPointer>

#include <KLocalizedString>
#include <QDebug>

//Includes are ordered this way because of #defines in Xorg's headers
#include "xrecordkeyboardmonitor.h" // krazy:exclude=includes
#include "xlibbackend.h" // krazy:exclude=includes
#include "xlibnotifications.h" // krazy:exclude=includes

#include <X11/Xlib-xcb.h>
#include <X11/Xatom.h>
#include <X11/extensions/XInput.h>
#include <X11/extensions/XInput2.h>

#include <synaptics-properties.h>
#include <xserver-properties.h>

#include "synclientproperties.h"

static void XDeleter(void *p)
{
    if (p) {
        XFree(p);
    }
}

static void XIDeviceInfoDeleter(XIDeviceInfo *p)
{
    if (p) {
        XIFreeDeviceInfo(p);
    }
}

void XlibBackend::XDisplayCleanup::cleanup(Display *p)
{
    if (p) {
        XCloseDisplay(p);
    }
}

struct PropertyInfo
{
    Atom type;
    int format;
    QSharedPointer<unsigned char> data;
    unsigned long nitems;

    float *f;
    int *i;
    char *b;

    Display *display;
    int device;
    Atom prop;

    PropertyInfo() :
        type(0), format(0), nitems(0), f(0), i(0), b(0),
        display(0), device(0), prop(0)
    {
    }

    PropertyInfo(Display *display, int device, Atom prop, Atom floatType)
        : type(0), format(0), nitems(0), f(0), i(0), b(0),
          display(display), device(device), prop(prop)
    {
        unsigned char *dataPtr = 0;
        unsigned long bytes_after;
        XIGetProperty(display, device, prop, 0, 1000, False,
                      AnyPropertyType, &type, &format, &nitems,
                      &bytes_after, &dataPtr);
        data = QSharedPointer<unsigned char>(dataPtr, XDeleter);

        if (format == CHAR_BIT && type == XA_INTEGER) {
            b = reinterpret_cast<char *>(dataPtr);
        }
        if (format == sizeof(int) * CHAR_BIT &&
                (type == XA_INTEGER || type == XA_CARDINAL))
        {
            i = reinterpret_cast<int *>(dataPtr);
        }
        if (format == sizeof(float) * CHAR_BIT &&
                floatType && type == floatType)
        {
            f = reinterpret_cast<float *>(dataPtr);
        }
    }

    QVariant value(unsigned offset) const
    {
        QVariant v;
        if (offset >= nitems) {
            return v;
        }

        if (b) {
            v = QVariant(static_cast<int>(b[offset]));
        }
        if (i) {
            v = QVariant(i[offset]);
        }
        if (f) {
            v = QVariant(f[offset]);
        }

        return v;
    }

    void set()
    {
        XIChangeProperty(display, device, prop, type, format,
                         XIPropModeReplace, data.data(), nitems);
    }
};

class XlibSynapticsBackend : public XlibBackend
{
public:
    XlibSynapticsBackend(QObject *parent = 0);
};

class XlibLibinputBackend : public XlibBackend
{
public:
    XlibLibinputBackend(QObject *parent = 0);
};

XlibSynapticsBackend::XlibSynapticsBackend(QObject *parent) :
    XlibBackend(parent)
{
    m_capsAtom.intern(m_connection, SYNAPTICS_PROP_CAPABILITIES);
    if (!m_capsAtom.atom()) {
        m_errorString = i18nc("Synaptics touchpad driver","Synaptics backend not found");
        return;
    }

    m_device = findTouchpad(m_capsAtom);
    if (m_device == XIAllDevices) {
        m_errorString = i18n("No touchpad found");
        return;
    }

    m_touchpadOffAtom.intern(m_connection, SYNAPTICS_PROP_OFF);
    XcbAtom resolutionAtom(m_connection, SYNAPTICS_PROP_RESOLUTION);
    XcbAtom edgesAtom(m_connection, SYNAPTICS_PROP_EDGES);

    if (!loadSupportedProperties(synapticsProperties)) {
        m_errorString = i18n("Cannot read any of touchpad's properties");
        return;
    }

    m_toRadians.append("CircScrollDelta");

    PropertyInfo edges(m_display.data(), m_device, edgesAtom, 0);
    if (edges.i && edges.nitems == 4) {
        int w = qAbs(edges.i[1] - edges.i[0]);
        int h = qAbs(edges.i[3] - edges.i[2]);
        m_resX = w / 90;
        m_resY = h / 50;
        qDebug() << "Width: " << w << " height: " << h;
        qDebug() << "Approx. resX: " << m_resX << " resY: " << m_resY;
    }

    PropertyInfo resolution(m_display.data(), m_device, resolutionAtom, 0);
    if (resolution.i && resolution.nitems == 2 &&
        resolution.i[0] > 1 && resolution.i[1] > 1)
    {
        m_resY = qMin(static_cast<unsigned long>(resolution.i[0]),
                static_cast<unsigned long>(INT_MAX));
        m_resX = qMin(static_cast<unsigned long>(resolution.i[1]),
                static_cast<unsigned long>(INT_MAX));
        qDebug() << "Touchpad resolution: x: " << m_resX << " y: " << m_resY;
    }

    m_scaleByResX.append("HorizScrollDelta");
    m_scaleByResY.append("VertScrollDelta");
    m_scaleByResX.append("MaxTapMove");
    m_scaleByResY.append("MaxTapMove");

    m_resX = qMax(10, m_resX);
    m_resY = qMax(10, m_resY);
    qDebug() << "Final resolution x:" << m_resX << " y:" << m_resY;
    m_negate["HorizScrollDelta"] = "InvertHorizScroll";
    m_negate["VertScrollDelta"] = "InvertVertScroll";
    m_supported.append(m_negate.values());
    m_supported.append("Coasting");

    PropertyInfo caps(m_display.data(), m_device, m_capsAtom.atom(), 0);
    if (!caps.b) {
        m_errorString = i18n("Cannot read touchpad's capabilities");
        return;
    }

    enum TouchpadCapabilitiy
    {
        TouchpadHasLeftButton,
        TouchpadHasMiddleButton,
        TouchpadHasRightButton,
        TouchpadTwoFingerDetect,
        TouchpadThreeFingerDetect,
        TouchpadPressureDetect,
        TouchpadPalmDetect,
        TouchpadCapsCount
    };

    QVector<bool> cap(TouchpadCapsCount, false);
    qCopy(caps.b, caps.b + qMin(cap.size(), static_cast<int>(caps.nitems)),
          cap.begin());

    if (!cap[TouchpadTwoFingerDetect]) {
        m_supported.removeAll("HorizTwoFingerScroll");
        m_supported.removeAll("VertTwoFingerScroll");
        m_supported.removeAll("TwoFingerTapButton");
    }

    if (!cap[TouchpadThreeFingerDetect]) {
        m_supported.removeAll("ThreeFingerTapButton");
    }

    if (!cap[TouchpadPressureDetect]) {
        m_supported.removeAll("FingerHigh");
        m_supported.removeAll("FingerLow");

        m_supported.removeAll("PalmMinZ");
        m_supported.removeAll("PressureMotionMinZ");
        m_supported.removeAll("PressureMotionMinFactor");
        m_supported.removeAll("PressureMotionMaxZ");
        m_supported.removeAll("PressureMotionMaxFactor");
        m_supported.removeAll("EmulateTwoFingerMinZ");
    }

    if (!cap[TouchpadPalmDetect]) {
        m_supported.removeAll("PalmDetect");
        m_supported.removeAll("PalmMinWidth");
        m_supported.removeAll("PalmMinZ");
        m_supported.removeAll("EmulateTwoFingerMinW");
    }

    for (QMap<QString, QString>::Iterator i = m_negate.begin();
         i != m_negate.end(); ++i)
    {
        if (!m_supported.contains(i.key())) {
            m_supported.removeAll(i.value());
        }
    }

    m_identifierAtom.intern(m_connection, SYNAPTICS_PROP_CAPABILITIES);
    m_paramList = synapticsProperties;
}

XlibLibinputBackend::XlibLibinputBackend(QObject *parent) :
    XlibBackend(parent)
{
    XcbAtom identifier(m_connection,
                       "libinput Tapping Enabled",
                       true);

    if (!identifier.atom()) {
        m_errorString = i18nc("Libinput touchpad driver","Libinput backend not found");
        return;
    }

    m_device = findTouchpad(identifier);
    if (m_device == XIAllDevices) {
        m_errorString = i18n("No touchpad found");
        return;
    }

    m_identifierAtom.intern(m_connection,
                            "libinput Send Events Modes Available");

    if (!loadSupportedProperties(libinputProperties)) {
        m_errorString = i18n("Cannot read any of touchpad's properties");
        return;
    }

    /* FIXME: has a different format than Synaptics Off but we don't expose
       the toggle so this is just to stop it from crashing when we check
       m_touchpadOffAtom  */
    m_touchpadOffAtom.intern(m_connection,
                             "libinput Send Events Mode enabled");


    XcbAtom scroll_methods(m_connection,
                           "libinput Scroll Methods Available",
                           true);
    if (scroll_methods.atom() != 0) {
        PropertyInfo methods(m_display.data(),
                             m_device,
                             scroll_methods.atom(),
                             0);
        if (!methods.value(0).toInt())
            m_supported.removeAll("VertTwoFingerScroll");
        else if (!methods.value(1).toInt())
            m_supported.removeAll("VertEdgeScroll");
    }

    m_paramList = libinputProperties;
}

XlibBackend* XlibBackend::initialize(QObject *parent)
{
    XlibBackend* backend = nullptr;
    QScopedPointer<Display, XDisplayCleanup> display(XOpenDisplay(0));
    xcb_connection_t *connection = XGetXCBConnection(display.data());
    XcbAtom synaptics_prop_capablities, libinput_prop_tapping;

    backend = new XlibLibinputBackend(parent);
    if (! backend->errorString().isNull()) {
        delete backend;
        backend = new XlibSynapticsBackend(parent);
    }
    return backend;
}

XlibBackend::~XlibBackend()
{
}

XlibBackend::XlibBackend(QObject *parent) :
    TouchpadBackend(parent),
    m_display(XOpenDisplay(0)), m_connection(0),
    m_resX(1), m_resY(1)
{
    if (m_display) {
        m_connection = XGetXCBConnection(m_display.data());
    }

    if (!m_connection) {
        m_errorString = i18n("Cannot connect to X server");
        return;
    }

    m_floatType.intern(m_connection, "FLOAT");
    m_mouseAtom.intern(m_connection, XI_MOUSE);
    m_keyboardAtom.intern(m_connection, XI_KEYBOARD);
    m_enabledAtom.intern(m_connection, XI_PROP_ENABLED);
}

int XlibBackend::findTouchpad(XcbAtom &identifier)
{
    int nDevices = 0;
    QSharedPointer<XIDeviceInfo> deviceInfo(
                XIQueryDevice(m_display.data(), XIAllDevices, &nDevices),
                XIDeviceInfoDeleter);

    for (XIDeviceInfo *info = deviceInfo.data();
         info < deviceInfo.data() + nDevices; info++)
    {
        int nProperties = 0;
        QSharedPointer<Atom> properties(
                    XIListProperties(m_display.data(), info->deviceid,
                                     &nProperties), XDeleter);

        if (std::count(properties.data(), properties.data() + nProperties,
                       identifier.atom()))
        {
            return info->deviceid;
        }
    }

    return XIAllDevices;
}

const Parameter * XlibBackend::findParameter(const QString &name)
{
    for (const Parameter *par = m_paramList; par->name; par++) {
        if (name == par->name) {
            return par;
        }
    }
    return 0;
}

bool XlibBackend::loadSupportedProperties(const Parameter *props)
{
    for (const Parameter *param = props; param->name; param++) {
        QLatin1String name(param->prop_name);

        if (!m_atoms.contains(name)) {
            m_atoms.insert(name, QSharedPointer<XcbAtom>(
                               new XcbAtom(m_connection, param->prop_name)));
        }
    }

    for (const Parameter *p = props; p->name; p++) {
        if (getParameter(p).isValid()) {
            m_supported.append(p->name);
        }
    }

    return !m_supported.isEmpty();
}

double XlibBackend::getPropertyScale(const QString &name) const
{
    if (m_scaleByResX.contains(name) && m_scaleByResY.contains(name)) {
        return std::sqrt(static_cast<double>(m_resX) * m_resX
                         + static_cast<double>(m_resY) * m_resY);
    } else if (m_scaleByResX.contains(name)) {
        return m_resX;
    } else if (m_scaleByResY.contains(name)) {
        return m_resY;
    } else if (m_toRadians.contains(name)) {
        return M_PI_4 / 45.0;
    }
    return 1.0;
}

static QVariant negateVariant(const QVariant &value)
{
    if (value.type() == QVariant::Double) {
        return QVariant(-value.toDouble());
    } else if (value.type() == QVariant::Int) {
        return QVariant(-value.toInt());
    }
    return value;
}

bool XlibBackend::applyConfig(const QVariantHash &p)
{
    if (m_supported.isEmpty()) {
        return false;
    }

    m_props.clear();

    bool error = false;
    Q_FOREACH(const QString &name, m_supported) {
        QVariantHash::ConstIterator i = p.find(name);
        if (i == p.end()) {
            continue;
        }
        const Parameter *par = findParameter(name);
        if (par) {
            QVariant value(i.value());

            double k = getPropertyScale(name);
            if (k != 1.0) {
                bool ok = false;
                value = QVariant(value.toDouble(&ok) * k);
                if (!ok) {
                    error = true;
                    continue;
                }
            }

            if (m_negate.contains(name)) {
                QVariantHash::ConstIterator i = p.find(m_negate[name]);
                if (i != p.end() && i.value().toBool()) {
                    value = negateVariant(value);
                }
            }

            if (name == "CoastingSpeed") {
                QVariantHash::ConstIterator coastingEnabled = p.find("Coasting");
                if (coastingEnabled != p.end() &&
                        !coastingEnabled.value().toBool())
                {
                    value = QVariant(0);
                }
            }

            if (!setParameter(par, value)) {
                error = true;
            }
        }
    }

    flush();

    if (error) {
        m_errorString = i18n("Cannot apply touchpad configuration");
    }
    return !error;
}

void XlibBackend::flush()
{
    Q_FOREACH(const QLatin1String &name, m_changed) {
        m_props[name].set();
    }
    m_changed.clear();

    XFlush(m_display.data());
}

bool XlibBackend::getConfig(QVariantHash &p)
{
    if (m_supported.isEmpty()) {
        return false;
    }

    m_props.clear();

    bool error = false;
    Q_FOREACH(const QString &name, m_supported) {
        const Parameter *par = findParameter(name);
        if (!par) {
            continue;
        }

        QVariant value(getParameter(par));
        if (!value.isValid()) {
            error = true;
            continue;
        }

        double k = getPropertyScale(name);
        if (k != 1.0) {
            bool ok = false;
            value = QVariant(value.toDouble(&ok) / k);
            if (!ok) {
                error = true;
                continue;
            }
        }

        if (m_negate.contains(name)) {
            bool negative = value.toDouble() < 0.0;
            p[m_negate[name]] = QVariant(negative);
            if (negative) {
                value = negateVariant(value);
            }
        }

        if (name == "CoastingSpeed") {
            bool coasting = value.toDouble() != 0.0;
            p["Coasting"] = QVariant(coasting);
            if (!coasting) {
                continue;
            }
        }

        p[name] = value;
    }

    if (error) {
        m_errorString = i18n("Cannot read touchpad configuration");
    }
    return !error;
}

QVariant XlibBackend::getParameter(const Parameter *par)
{
    PropertyInfo *p = getDevProperty(QLatin1String(par->prop_name));
    if (!p || par->prop_offset >= p->nitems) {
        return QVariant();
    }

    return p->value(par->prop_offset);
}

PropertyInfo *XlibBackend::getDevProperty(const QLatin1String &propName)
{
    if (m_props.contains(propName)) {
        return &m_props[propName];
    }

    if (!m_atoms.contains(propName) || !m_atoms[propName]) {
        return 0;
    }

    xcb_atom_t prop = m_atoms[propName]->atom();
    if (!prop) {
        return 0;
    }

    PropertyInfo p(m_display.data(), m_device, prop, m_floatType.atom());
    if (!p.b && !p.f && !p.i) {
        return 0;
    }
    return &m_props.insert(propName, p).value();
}

bool XlibBackend::setParameter(const Parameter *par, const QVariant &value)
{
    QLatin1String propName(par->prop_name);
    PropertyInfo *p = getDevProperty(propName);
    if (!p || par->prop_offset >= p->nitems) {
        return false;
    }

    QVariant converted(value);
    QVariant::Type convType = QVariant::Int;
    if (p->f) {
        convType = QVariant::Double;
    } else if (value.type() == QVariant::Double) {
        converted = QVariant(qRound(static_cast<qreal>(value.toDouble())));
    }

    if (!converted.convert(convType)) {
        return false;
    }

    if (converted == p->value(par->prop_offset)) {
        return true;
    }

    if (p->b) {
        p->b[par->prop_offset] = static_cast<char>(converted.toInt());
    } else if (p->i) {
        p->i[par->prop_offset] = converted.toInt();
    } else if (p->f) {
        p->f[par->prop_offset] = converted.toDouble();
    }

    m_changed.insert(propName);
    return true;
}

void XlibBackend::setTouchpadEnabled(bool enable)
{
    PropertyInfo enabled(m_display.data(), m_device, m_enabledAtom.atom(), 0);
    if (enabled.b && *(enabled.b) != enable) {
        *(enabled.b) = enable;
        enabled.set();
    }

    flush();
}

void XlibBackend::setTouchpadOff(TouchpadBackend::TouchpadOffState state)
{
    int touchpadOff = 0;
    switch (state) {
    case TouchpadEnabled:
        touchpadOff = 0;
        break;
    case TouchpadFullyDisabled:
        touchpadOff = 1;
        break;
    case TouchpadTapAndScrollDisabled:
        touchpadOff = 2;
        break;
    default:
        qCritical() << "Unknown TouchpadOffState" << state;
        return;
    }

    PropertyInfo off(m_display.data(), m_device, m_touchpadOffAtom.atom(), 0);
    if (off.b && *(off.b) != touchpadOff) {
        *(off.b) = touchpadOff;
        off.set();
    }

    flush();
}

bool XlibBackend::isTouchpadEnabled()
{
    PropertyInfo enabled(m_display.data(), m_device, m_enabledAtom.atom(), 0);
    return enabled.value(0).toBool();
}

TouchpadBackend::TouchpadOffState XlibBackend::getTouchpadOff()
{
    PropertyInfo off(m_display.data(), m_device, m_touchpadOffAtom.atom(), 0);
    switch (off.value(0).toInt()) {
    case 0:
        return TouchpadEnabled;
    case 1:
        return TouchpadFullyDisabled;
    case 2:
        return TouchpadTapAndScrollDisabled;
    default:
        qCritical() << "Unknown TouchpadOff value" << off.value(0).toInt();
        return TouchpadFullyDisabled;
    }
}

void XlibBackend::touchpadDetached()
{
    qWarning() << "Touchpad detached";
    m_device = XIAllDevices;
}

void XlibBackend::devicePlugged(int device)
{
    if (m_device == XIAllDevices) {
        m_device = findTouchpad(m_identifierAtom);
        if (m_device != XIAllDevices) {
            qWarning() << "Touchpad reset";
            m_notifications.reset();
            watchForEvents(m_keyboard);
            Q_EMIT touchpadReset();
        }
    }
    if (device != m_device) {
        Q_EMIT mousesChanged();
    }
}

void XlibBackend::propertyChanged(xcb_atom_t prop)
{
    if (prop == m_touchpadOffAtom.atom() ||
            prop == m_enabledAtom.atom())
    {
        Q_EMIT touchpadStateChanged();
    }
}

struct DeviceListDeleter
{
    static void cleanup(XDeviceInfo *p)
    {
        if (p) {
            XFreeDeviceList(p);
        }
    }
};

QStringList XlibBackend::listMouses(const QStringList &blacklist)
{
    int nDevices = 0;
    QScopedPointer<XDeviceInfo, DeviceListDeleter>
            info(XListInputDevices(m_display.data(), &nDevices));
    QStringList list;
    for (XDeviceInfo *i = info.data(); i != info.data() + nDevices; i++) {
        if (i->id == static_cast<XID>(m_device)) {
            continue;
        }
        if (i->use != IsXExtensionPointer && i->use != IsXPointer) {
            continue;
        }
        //type = KEYBOARD && use = Pointer means usb receiver for both keyboard
        //and mouse
        if (i->type != m_mouseAtom.atom() && i->type != m_keyboardAtom.atom()) {
            continue;
        }
        QString name(i->name);
        if (blacklist.contains(name, Qt::CaseInsensitive)) {
            continue;
        }
        PropertyInfo enabled(m_display.data(), i->id, m_enabledAtom.atom(), 0);
        if (enabled.value(0) == false) {
            continue;
        }
        list.append(name);
    }

    return list;
}

void XlibBackend::watchForEvents(bool keyboard)
{
    if (!m_notifications) {
        m_notifications.reset(new XlibNotifications(m_display.data(), m_device));
        connect(m_notifications.data(), SIGNAL(devicePlugged(int)),
                SLOT(devicePlugged(int)));
        connect(m_notifications.data(), SIGNAL(touchpadDetached()),
                SLOT(touchpadDetached()));
        connect(m_notifications.data(), SIGNAL(propertyChanged(xcb_atom_t)),
                SLOT(propertyChanged(xcb_atom_t)));
    }

    if (keyboard == !m_keyboard.isNull()) {
        return;
    }

    if (!keyboard) {
        m_keyboard.reset();
        return;
    }

    m_keyboard.reset(new XRecordKeyboardMonitor(m_display.data()));
    connect(m_keyboard.data(), SIGNAL(keyboardActivityStarted()),
            SIGNAL(keyboardActivityStarted()));
    connect(m_keyboard.data(), SIGNAL(keyboardActivityFinished()),
            SIGNAL(keyboardActivityFinished()));
}