/*
 * 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 "libinputtouchpad.h"
#include "synapticstouchpad.h"
#include "propertyinfo.h"

#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>

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

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

XlibBackend* XlibBackend::initialize(QObject *parent)
{
    XlibBackend* backend = new XlibBackend(parent);
    if (!backend->m_display) {
        delete backend;
        return nullptr;
    }
    return backend;
}

XlibBackend::~XlibBackend()
{
}

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

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

    m_mouseAtom.intern(m_connection, XI_MOUSE);
    m_keyboardAtom.intern(m_connection, XI_KEYBOARD);
    m_touchpadAtom.intern(m_connection, XI_TOUCHPAD);
    m_enabledAtom.intern(m_connection, XI_PROP_ENABLED);

    m_synapticsIdentifierAtom.intern(m_connection, SYNAPTICS_PROP_CAPABILITIES);
    m_libinputIdentifierAtom.intern(m_connection, "libinput Send Events Modes Available");

    m_device.reset(findTouchpad());
    if (!m_device) {
        m_errorString = i18n("No touchpad found");
    }
}

XlibTouchpad* XlibBackend::findTouchpad()
{
    int nDevices = 0;
    QScopedPointer<XDeviceInfo, DeviceListDeleter>
            deviceInfo(XListInputDevices(m_display.data(), &nDevices));

    for (XDeviceInfo *info = deviceInfo.data();
         info < deviceInfo.data() + nDevices; info++)
    {
        // Make sure device is touchpad
        if (info->type != m_touchpadAtom.atom()) {
            continue;
        }
        int nProperties = 0;
        QSharedPointer<Atom> properties(
                    XIListProperties(m_display.data(), info->id,
                                     &nProperties), XDeleter);

        Atom *atom = properties.data(), *atomEnd = properties.data() + nProperties;
        for (; atom != atomEnd; atom++) {
            if (*atom == m_libinputIdentifierAtom.atom()) {
                return new LibinputTouchpad(m_display.data(), info->id);
            } else if (*atom == m_synapticsIdentifierAtom.atom()) {
                return new SynapticsTouchpad(m_display.data(), info->id);
            }
        }
    }

    return nullptr;
}

bool XlibBackend::applyConfig(const QVariantHash &p)
{
    if (!m_device) {
        return false;
    }

    bool success = m_device->applyConfig(p);
    if (!success) {
        m_errorString = i18n("Cannot apply touchpad configuration");
    }

    return success;
}

bool XlibBackend::getConfig(QVariantHash &p)
{
    if (!m_device) {
        return false;
    }

    bool success = m_device->getConfig(p);
    if (!success) {
        m_errorString = i18n("Cannot read touchpad configuration");
    }
    return success;
}

void XlibBackend::setTouchpadEnabled(bool enable)
{
    if (!m_device) {
        return;
    }

    m_device->setEnabled(enable);

    // FIXME? This should not be needed, m_notifications should trigger
    // a propertyChanged signal when we enable/disable the touchpad,
    // that will emit touchpadStateChanged, but for some reason
    // XlibNotifications is not getting the property change events
    // so we just emit touchpadStateChanged from here as a workaround
    Q_EMIT touchpadStateChanged();
}

void XlibBackend::setTouchpadOff(TouchpadBackend::TouchpadOffState state)
{
    if (!m_device) {
        return;
    }

    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;
    }

    m_device->setTouchpadOff(touchpadOff);
}

bool XlibBackend::isTouchpadAvailable()
{
    return m_device;
}

bool XlibBackend::isTouchpadEnabled()
{
    if (!m_device) {
        return false;
    }

    return m_device->enabled();
}

TouchpadBackend::TouchpadOffState XlibBackend::getTouchpadOff()
{
    if (!m_device) {
        return TouchpadFullyDisabled;
    }
    int value = m_device->touchpadOff();
    switch (value) {
    case 0:
        return TouchpadEnabled;
    case 1:
        return TouchpadFullyDisabled;
    case 2:
        return TouchpadTapAndScrollDisabled;
    default:
        qCritical() << "Unknown TouchpadOff value" << value;
        return TouchpadFullyDisabled;
    }
}

void XlibBackend::touchpadDetached()
{
    qWarning() << "Touchpad detached";
    m_device.reset();
    Q_EMIT touchpadReset();
}

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

void XlibBackend::propertyChanged(xcb_atom_t prop)
{
    if ((m_device && prop == m_device->touchpadOffAtom().atom()) ||
            prop == m_enabledAtom.atom())
    {
        Q_EMIT touchpadStateChanged();
    }
}

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 (m_device && i->id == static_cast<XID>(m_device->deviceId())) {
            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 ? m_device->deviceId() : XIAllDevices));
        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()));
}
