/****************************************************************************
**
** Copyright (C) 2017 Denis Shienkov <denis.shienkov@gmail.com>
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtSerialBus module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL3$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://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.LGPLv3 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.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 later as published by the Free
** Software Foundation and appearing in the file LICENSE.GPL included in
** the packaging of this file. Please review the following information to
** ensure the GNU General Public License version 2.0 requirements will be
** met: http://www.gnu.org/licenses/gpl-2.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "peakcanbackend.h"
#include "peakcanbackend_p.h"
#include "peakcan_symbols_p.h"

#include <QtSerialBus/qcanbusdevice.h>

#include <QtCore/qtimer.h>
#include <QtCore/qcoreevent.h>
#include <QtCore/qloggingcategory.h>

#include <algorithm>

#ifdef Q_OS_WIN32
#   include <QtCore/qwineventnotifier.h>
#else
#   include <QtCore/qsocketnotifier.h>
#endif

QT_BEGIN_NAMESPACE

Q_DECLARE_LOGGING_CATEGORY(QT_CANBUS_PLUGINS_PEAKCAN)

#ifndef LINK_LIBPCANBASIC
Q_GLOBAL_STATIC(QLibrary, pcanLibrary)
#endif

bool PeakCanBackend::canCreate(QString *errorReason)
{
#ifdef LINK_LIBPCANBASIC
    return true;
#else
    static bool symbolsResolved = resolveSymbols(pcanLibrary());
    if (Q_UNLIKELY(!symbolsResolved)) {
        *errorReason = pcanLibrary()->errorString();
        return false;
    }
    return true;
#endif
}

struct PcanChannel{
    char        name[6];
    TPCANHandle index;
};
static const PcanChannel pcanChannels[] = {
    { "usb0",  PCAN_USBBUS1  },
    { "usb1",  PCAN_USBBUS2  },
    { "usb2",  PCAN_USBBUS3  },
    { "usb3",  PCAN_USBBUS4  },
    { "usb4",  PCAN_USBBUS5  },
    { "usb5",  PCAN_USBBUS6  },
    { "usb6",  PCAN_USBBUS7  },
    { "usb7",  PCAN_USBBUS8  },
    { "usb8",  PCAN_USBBUS9  },
    { "usb9",  PCAN_USBBUS10 },
    { "usb10", PCAN_USBBUS11 },
    { "usb11", PCAN_USBBUS12 },
    { "usb12", PCAN_USBBUS13 },
    { "usb13", PCAN_USBBUS14 },
    { "usb14", PCAN_USBBUS15 },
    { "usb15", PCAN_USBBUS16 },
    { "pci0",  PCAN_PCIBUS1  },
    { "pci1",  PCAN_PCIBUS2  },
    { "pci2",  PCAN_PCIBUS3  },
    { "pci3",  PCAN_PCIBUS4  },
    { "pci4",  PCAN_PCIBUS5  },
    { "pci5",  PCAN_PCIBUS6  },
    { "pci6",  PCAN_PCIBUS7  },
    { "pci7",  PCAN_PCIBUS8  },
    { "pci8",  PCAN_PCIBUS9  },
    { "pci9",  PCAN_PCIBUS10 },
    { "pci10", PCAN_PCIBUS11 },
    { "pci11", PCAN_PCIBUS12 },
    { "pci12", PCAN_PCIBUS13 },
    { "pci13", PCAN_PCIBUS14 },
    { "pci14", PCAN_PCIBUS15 },
    { "pci15", PCAN_PCIBUS16 },
    { "none",  PCAN_NONEBUS  }
};

QList<QCanBusDeviceInfo> PeakCanBackend::interfaces()
{
    QList<QCanBusDeviceInfo> result;

    for (int i = 0; pcanChannels[i].index != PCAN_NONEBUS; ++i) {
        uint value = 0;
        const TPCANHandle index = pcanChannels[i].index;
        const TPCANStatus stat = ::CAN_GetValue(index, PCAN_CHANNEL_CONDITION,
                                                &value, sizeof(value));
        if ((stat == PCAN_ERROR_OK) && (value & PCAN_CHANNEL_AVAILABLE)) {
            const TPCANStatus fdStat = ::CAN_GetValue(index, PCAN_CHANNEL_FEATURES,
                                                      &value, sizeof(value));
            const bool isFd = (fdStat == PCAN_ERROR_OK) && (value & FEATURE_FD_CAPABLE);

            char description[256] = {0};
            const TPCANStatus descStat = ::CAN_GetValue(index, PCAN_HARDWARE_NAME,
                                                        description, sizeof(description));
            if (descStat != PCAN_ERROR_OK)
                description[0] = 0;

            int channel = 0;
            const TPCANStatus chnStat = ::CAN_GetValue(index, PCAN_CONTROLLER_NUMBER,
                                                       &channel, sizeof(channel));
            if (chnStat != PCAN_ERROR_OK)
                channel = 0;

            result.append(std::move(createDeviceInfo(QLatin1String(pcanChannels[i].name),
                                                     QString(), QLatin1String(description),
                                                     channel, false, isFd)));
        }
    }

    return result;
}

#if defined(Q_OS_WIN32)
class ReadNotifier : public QWinEventNotifier
{
    // no Q_OBJECT macro!
public:
    explicit ReadNotifier(PeakCanBackendPrivate *d, QObject *parent)
        : QWinEventNotifier(parent)
        , dptr(d)
    {
        setHandle(dptr->readHandle);
    }

protected:
    bool event(QEvent *e) override
    {
        if (e->type() == QEvent::WinEventAct) {
            dptr->startRead();
            return true;
        }
        return QWinEventNotifier::event(e);
    }

private:
    PeakCanBackendPrivate * const dptr;
};
#else
class ReadNotifier : public QSocketNotifier
{
    // no Q_OBJECT macro!
public:
    explicit ReadNotifier(PeakCanBackendPrivate *d, QObject *parent)
        : QSocketNotifier(d->readHandle, QSocketNotifier::Read, parent)
        , dptr(d)
    {
    }

protected:
    bool event(QEvent *e) override
    {
        if (e->type() == QEvent::SockAct) {
            dptr->startRead();
            return true;
        }
        return QSocketNotifier::event(e);
    }

private:
    PeakCanBackendPrivate * const dptr;
};
#endif

class WriteNotifier : public QTimer
{
    // no Q_OBJECT macro!
public:
    WriteNotifier(PeakCanBackendPrivate *d, QObject *parent)
        : QTimer(parent)
        , dptr(d)
    {
    }

protected:
    void timerEvent(QTimerEvent *e) override
    {
        if (e->timerId() == timerId()) {
            dptr->startWrite();
            return;
        }
        QTimer::timerEvent(e);
    }

private:
    PeakCanBackendPrivate * const dptr;
};

PeakCanBackendPrivate::PeakCanBackendPrivate(PeakCanBackend *q)
    : q_ptr(q)
{
}

struct BitrateItem
{
    int bitrate;
    TPCANBaudrate code;
};

struct BitrateLessFunctor
{
    bool operator()( const BitrateItem &item1, const BitrateItem &item2) const
    {
        return item1.bitrate < item2.bitrate;
    }
};

static TPCANBaudrate bitrateCodeFromBitrate(int bitrate)
{
    static const BitrateItem bitratetable[] = {
        { 5000, PCAN_BAUD_5K },
        { 10000, PCAN_BAUD_10K },
        { 20000, PCAN_BAUD_20K },
        { 33000, PCAN_BAUD_33K },
        { 47000, PCAN_BAUD_47K },
        { 50000, PCAN_BAUD_50K },
        { 83000, PCAN_BAUD_83K },
        { 95000, PCAN_BAUD_95K },
        { 100000, PCAN_BAUD_100K },
        { 125000, PCAN_BAUD_125K },
        { 250000, PCAN_BAUD_250K },
        { 500000, PCAN_BAUD_500K },
        { 800000, PCAN_BAUD_800K },
        { 1000000, PCAN_BAUD_1M }
    };

    static const BitrateItem *endtable = bitratetable + (sizeof(bitratetable) / sizeof(*bitratetable));

    const BitrateItem item = { bitrate , 0 };
    const BitrateItem *where = std::lower_bound(bitratetable, endtable, item, BitrateLessFunctor());
    return where != endtable ? where->code : PCAN_BAUD_INVALID;
}

static QByteArray nominalBitrateString(int nominalBitrate)
{
    switch (nominalBitrate) {
    case 125000:
        return "f_clock=80000000, nom_brp=40, nom_tseg1=12, nom_tseg2=3, nom_sjw=1";
    case 250000:
        return "f_clock=80000000, nom_brp=20, nom_tseg1=12, nom_tseg2=3, nom_sjw=1";
    case 500000:
        return "f_clock=80000000, nom_brp=10, nom_tseg1=12, nom_tseg2=3, nom_sjw=1";
    case 1000000:
        return "f_clock=80000000, nom_brp=10, nom_tseg1=5,  nom_tseg2=2, nom_sjw=1";
    default:
        return QByteArray();
    }
}

static QByteArray dataBitrateString(int dataBitrate)
{
    switch (dataBitrate) {
    case 2000000:
        return ", data_brp=4, data_tseg1=7, data_tseg2=2, data_sjw=1";
    case 4000000:
        return ", data_brp=2, data_tseg1=7, data_tseg2=2, data_sjw=1";
    case 8000000:
        return ", data_brp=1, data_tseg1=7, data_tseg2=2, data_sjw=1";
    case 10000000:
        return ", data_brp=1, data_tseg1=5, data_tseg2=2, data_sjw=1";
    default:
        return QByteArray();
    }
}

static QByteArray bitrateStringFromBitrate(int nominalBitrate, int dataBitrate)
{
    QByteArray result = nominalBitrateString(nominalBitrate);

    if (result.isEmpty())
        return QByteArray();

    result += dataBitrateString(dataBitrate);

    return result;
}

bool PeakCanBackendPrivate::open()
{
    Q_Q(PeakCanBackend);

    const int nominalBitrate = q->configurationParameter(QCanBusDevice::BitRateKey).toInt();
    TPCANStatus st = PCAN_ERROR_OK;

    if (isFlexibleDatarateEnabled) {
        const int dataBitrate = q->configurationParameter(QCanBusDevice::DataBitRateKey).toInt();
        const QByteArray bitrateStr = bitrateStringFromBitrate(nominalBitrate, dataBitrate);
        st = ::CAN_InitializeFD(channelIndex, const_cast<char *>(bitrateStr.data()));
    } else {
        const TPCANBaudrate bitrateCode = bitrateCodeFromBitrate(nominalBitrate);
        st = ::CAN_Initialize(channelIndex, bitrateCode, 0, 0, 0);
    }

    if (Q_UNLIKELY(st != PCAN_ERROR_OK)) {
        q->setError(systemErrorString(st), QCanBusDevice::ConnectionError);
        return false;
    }

#if defined(Q_OS_WIN32)
    if (readHandle == INVALID_HANDLE_VALUE) {
        readHandle = ::CreateEvent(nullptr, FALSE, FALSE, nullptr);
        if (!readHandle) {
            q->setError(qt_error_string(::GetLastError()), QCanBusDevice::ConnectionError);
            return false;
        }
    }

    const TPCANStatus err = ::CAN_SetValue(channelIndex, PCAN_RECEIVE_EVENT, &readHandle, sizeof(readHandle));
    if (Q_UNLIKELY(err != PCAN_ERROR_OK)) {
        q->setError(systemErrorString(err), QCanBusDevice::ConnectionError);
        return false;
    }

#else
    const TPCANStatus err = ::CAN_GetValue(channelIndex, PCAN_RECEIVE_EVENT, &readHandle, sizeof(readHandle));
    if (Q_UNLIKELY(err != PCAN_ERROR_OK)) {
        q->setError(systemErrorString(err), QCanBusDevice::ConnectionError);
        return false;
    }
#endif

    writeNotifier = new WriteNotifier(this, q);
    writeNotifier->setInterval(0);

    readNotifier = new ReadNotifier(this, q);
    readNotifier->setEnabled(true);

    isOpen = true;
    return true;
}

void PeakCanBackendPrivate::close()
{
    Q_Q(PeakCanBackend);

    delete readNotifier;
    readNotifier = nullptr;

    delete writeNotifier;
    writeNotifier = nullptr;

    quint32 value = 0;
    const TPCANStatus err = ::CAN_SetValue(channelIndex, PCAN_RECEIVE_EVENT, &value, sizeof(value));
    if (Q_UNLIKELY(err != PCAN_ERROR_OK))
        q->setError(systemErrorString(err), QCanBusDevice::ConnectionError);

    const TPCANStatus st = ::CAN_Uninitialize(channelIndex);
    if (Q_UNLIKELY(st != PCAN_ERROR_OK))
        q->setError(systemErrorString(st), QCanBusDevice::ConnectionError);

#if defined(Q_OS_WIN32)
    if (readHandle && (readHandle != INVALID_HANDLE_VALUE)) {
        if (Q_UNLIKELY(!::CloseHandle(readHandle)))
            q->setError(qt_error_string(::GetLastError()), QCanBusDevice::ConnectionError);
        readHandle = INVALID_HANDLE_VALUE;
    }
#else
    readHandle = -1;
#endif

    isOpen = false;
}

bool PeakCanBackendPrivate::setConfigurationParameter(int key, const QVariant &value)
{
    Q_Q(PeakCanBackend);

    switch (key) {
    case QCanBusDevice::BitRateKey:
        return verifyBitRate(value.toInt());
    case QCanBusDevice::CanFdKey:
        isFlexibleDatarateEnabled = value.toBool();
        return true;
    case QCanBusDevice::DataBitRateKey: {
        const int dataBitrate = value.toInt();
        if (Q_UNLIKELY(dataBitrateString(dataBitrate).isEmpty())) {
            q->setError(PeakCanBackend::tr("Unsupported data bitrate value: %1.").arg(dataBitrate),
                        QCanBusDevice::ConfigurationError);
            return false;
        }
        return true;
    }
    default:
        q->setError(PeakCanBackend::tr("Unsupported configuration key: %1").arg(key),
                    QCanBusDevice::ConfigurationError);
        return false;
    }
}

void PeakCanBackendPrivate::setupChannel(const QByteArray &interfaceName)
{
    const PcanChannel *chn = pcanChannels;
    while (chn->index != PCAN_NONEBUS && chn->name != interfaceName)
        ++chn;
    channelIndex = chn->index;
}

// Calls only when the device is closed
void PeakCanBackendPrivate::setupDefaultConfigurations()
{
    Q_Q(PeakCanBackend);

    q->setConfigurationParameter(QCanBusDevice::BitRateKey, 500000);
}

QString PeakCanBackendPrivate::systemErrorString(TPCANStatus errorCode)
{
    QByteArray buffer(256, 0);
    if (Q_UNLIKELY(::CAN_GetErrorText(errorCode, 0, buffer.data()) != PCAN_ERROR_OK))
        return PeakCanBackend::tr("Unable to retrieve an error string");
    return QString::fromLatin1(buffer);
}

enum CanFrameDlc {
    Dlc00 =  0,
    Dlc01 =  1,
    Dlc02 =  2,
    Dlc03 =  3,
    Dlc04 =  4,
    Dlc05 =  5,
    Dlc06 =  6,
    Dlc07 =  7,
    Dlc08 =  8,
    Dlc12 =  9,
    Dlc16 = 10,
    Dlc20 = 11,
    Dlc24 = 12,
    Dlc32 = 13,
    Dlc48 = 14,
    Dlc64 = 15
};

static CanFrameDlc sizeToDlc(int size)
{
    switch (size) {
    case 12:
        return Dlc12;
    case 16:
        return Dlc16;
    case 20:
        return Dlc20;
    case 24:
        return Dlc24;
    case 32:
        return Dlc32;
    case 48:
        return Dlc48;
    case 64:
        return Dlc64;
    default:
        if (size >= 0 && size <= 8)
            return static_cast<CanFrameDlc>(size);

        return Dlc00;
    }
}

static int dlcToSize(CanFrameDlc dlc)
{
    switch (dlc) {
    case Dlc00:
    case Dlc01:
    case Dlc02:
    case Dlc03:
    case Dlc04:
    case Dlc05:
    case Dlc06:
    case Dlc07:
    case Dlc08:
        return static_cast<int>(dlc);
    case Dlc12:
        return 12;
    case Dlc16:
        return 16;
    case Dlc20:
        return 20;
    case Dlc24:
        return 24;
    case Dlc32:
        return 32;
    case Dlc48:
        return 48;
    case Dlc64:
        return 64;
    }
    return 0;
}

void PeakCanBackendPrivate::startWrite()
{
    Q_Q(PeakCanBackend);

    if (!q->hasOutgoingFrames()) {
        writeNotifier->stop();
        return;
    }

    const QCanBusFrame frame = q->dequeueOutgoingFrame();
    const QByteArray payload = frame.payload();
    TPCANStatus st = PCAN_ERROR_OK;

    if (isFlexibleDatarateEnabled) {
        const int size = payload.size();
        TPCANMsgFD message;
        ::memset(&message, 0, sizeof(message));
        message.ID = frame.frameId();
        message.DLC = sizeToDlc(size);
        message.MSGTYPE = frame.hasExtendedFrameFormat() ? PCAN_MESSAGE_EXTENDED
                                                         : PCAN_MESSAGE_STANDARD;

        if (frame.hasFlexibleDataRateFormat())
            message.MSGTYPE |= PCAN_MESSAGE_FD;
        if (frame.hasBitrateSwitch())
            message.MSGTYPE |= PCAN_MESSAGE_BRS;

        if (frame.frameType() == QCanBusFrame::RemoteRequestFrame)
            message.MSGTYPE |= PCAN_MESSAGE_RTR; // we do not care about the payload
        else
            ::memcpy(message.DATA, payload.constData(), sizeof(message.DATA));
        st = ::CAN_WriteFD(channelIndex, &message);
    } else if (frame.hasFlexibleDataRateFormat()) {
        q->setError(PeakCanBackend::tr("Cannot send CAN FD frame format as CAN FD is not enabled."),
                    QCanBusDevice::WriteError);
    } else {
        TPCANMsg message;
        ::memset(&message, 0, sizeof(message));

        message.ID = frame.frameId();
        message.LEN = static_cast<quint8>(payload.size());
        message.MSGTYPE = frame.hasExtendedFrameFormat() ? PCAN_MESSAGE_EXTENDED
                                                         : PCAN_MESSAGE_STANDARD;

        if (frame.frameType() == QCanBusFrame::RemoteRequestFrame)
            message.MSGTYPE |= PCAN_MESSAGE_RTR; // we do not care about the payload
        else
            ::memcpy(message.DATA, payload.constData(), sizeof(message.DATA));
        st = ::CAN_Write(channelIndex, &message);
    }

    if (Q_UNLIKELY(st != PCAN_ERROR_OK))
        q->setError(systemErrorString(st), QCanBusDevice::WriteError);
    else
        emit q->framesWritten(qint64(1));

    if (q->hasOutgoingFrames() && !writeNotifier->isActive())
        writeNotifier->start();
}

void PeakCanBackendPrivate::startRead()
{
    Q_Q(PeakCanBackend);

    QVector<QCanBusFrame> newFrames;

    for (;;) {
        if (isFlexibleDatarateEnabled) {
            TPCANMsgFD message;
            ::memset(&message, 0, sizeof(message));
            TPCANTimestampFD timestamp;
            ::memset(&timestamp, 0, sizeof(timestamp));

            const TPCANStatus st = ::CAN_ReadFD(channelIndex, &message, &timestamp);
            if (st != PCAN_ERROR_OK) {
                if (Q_UNLIKELY(st != PCAN_ERROR_QRCVEMPTY))
                    q->setError(systemErrorString(st), QCanBusDevice::ReadError);
                break;
            }

            // Filter out PCAN status frames, to avoid turning them
            // into QCanBusFrame::DataFrames with random canId
            if (Q_UNLIKELY(message.MSGTYPE & PCAN_MESSAGE_STATUS))
                continue;

            const int size = dlcToSize(static_cast<CanFrameDlc>(message.DLC));
            QCanBusFrame frame(message.ID,
                               QByteArray(reinterpret_cast<const char *>(message.DATA), size));
            frame.setTimeStamp(QCanBusFrame::TimeStamp::fromMicroSeconds(static_cast<qint64>(timestamp)));
            frame.setExtendedFrameFormat(message.MSGTYPE & PCAN_MESSAGE_EXTENDED);
            frame.setFrameType((message.MSGTYPE & PCAN_MESSAGE_RTR)
                               ? QCanBusFrame::RemoteRequestFrame : QCanBusFrame::DataFrame);
            frame.setFlexibleDataRateFormat(message.MSGTYPE & PCAN_MESSAGE_FD);
            frame.setBitrateSwitch(message.MSGTYPE & PCAN_MESSAGE_BRS);
            frame.setErrorStateIndicator(message.MSGTYPE & PCAN_MESSAGE_ESI);

            newFrames.append(std::move(frame));
        } else {
            TPCANMsg message;
            ::memset(&message, 0, sizeof(message));
            TPCANTimestamp timestamp;
            ::memset(&timestamp, 0, sizeof(timestamp));

            const TPCANStatus st = ::CAN_Read(channelIndex, &message, &timestamp);
            if (st != PCAN_ERROR_OK) {
                if (Q_UNLIKELY(st != PCAN_ERROR_QRCVEMPTY))
                    q->setError(systemErrorString(st), QCanBusDevice::ReadError);
                break;
            }

            // Filter out PCAN status frames, to avoid turning them
            // into QCanBusFrame::DataFrames with random canId
            if (Q_UNLIKELY(message.MSGTYPE & PCAN_MESSAGE_STATUS))
                continue;

            const int size = static_cast<int>(message.LEN);
            QCanBusFrame frame(message.ID,
                               QByteArray(reinterpret_cast<const char *>(message.DATA), size));
            const quint64 millis = timestamp.millis + Q_UINT64_C(0xFFFFFFFF) * timestamp.millis_overflow;
            const quint64 micros = Q_UINT64_C(1000) * millis + timestamp.micros;
            frame.setTimeStamp(QCanBusFrame::TimeStamp::fromMicroSeconds(static_cast<qint64>(micros)));
            frame.setExtendedFrameFormat(message.MSGTYPE & PCAN_MESSAGE_EXTENDED);
            frame.setFrameType((message.MSGTYPE & PCAN_MESSAGE_RTR)
                               ? QCanBusFrame::RemoteRequestFrame : QCanBusFrame::DataFrame);

            newFrames.append(std::move(frame));
        }
    }

    q->enqueueReceivedFrames(newFrames);
}

bool PeakCanBackendPrivate::verifyBitRate(int bitrate)
{
    Q_Q(PeakCanBackend);

    if (Q_UNLIKELY(isOpen)) {
        q->setError(PeakCanBackend::tr("Cannot change bitrate for already opened device."),
                    QCanBusDevice::ConfigurationError);
        return false;
    }

    bool isValidBitrate = false;
    if (q->configurationParameter(QCanBusDevice::CanFdKey).toBool())
        isValidBitrate = !nominalBitrateString(bitrate).isEmpty();
    else
        isValidBitrate = bitrateCodeFromBitrate(bitrate) != PCAN_BAUD_INVALID;

    if (Q_UNLIKELY(!isValidBitrate)) {
        q->setError(PeakCanBackend::tr("Unsupported bitrate value: %1.").arg(bitrate),
                    QCanBusDevice::ConfigurationError);
    }

    return isValidBitrate;
}

PeakCanBackend::PeakCanBackend(const QString &name, QObject *parent)
    : QCanBusDevice(parent)
    , d_ptr(new PeakCanBackendPrivate(this))
{
    Q_D(PeakCanBackend);

    d->setupChannel(name.toLatin1());
    d->setupDefaultConfigurations();
}

PeakCanBackend::~PeakCanBackend()
{
    Q_D(PeakCanBackend);

    if (d->isOpen)
        close();

    delete d_ptr;
}

bool PeakCanBackend::open()
{
    Q_D(PeakCanBackend);

    if (!d->isOpen) {
        if (Q_UNLIKELY(!d->open()))
            return false;

        // apply all stored configurations except bitrate, because
        // the bitrate can not be applied after opening of device
        const auto keys = configurationKeys();
        for (int key : keys) {
            if (key == QCanBusDevice::BitRateKey)
                continue;
            const QVariant param = configurationParameter(key);
            const bool success = d->setConfigurationParameter(key, param);
            if (Q_UNLIKELY(!success)) {
                qCWarning(QT_CANBUS_PLUGINS_PEAKCAN, "Cannot apply parameter: %d with value: %ls.",
                          key, qUtf16Printable(param.toString()));
            }
        }
    }

    setState(QCanBusDevice::ConnectedState);
    return true;
}

void PeakCanBackend::close()
{
    Q_D(PeakCanBackend);

    d->close();

    setState(QCanBusDevice::UnconnectedState);
}

void PeakCanBackend::setConfigurationParameter(int key, const QVariant &value)
{
    Q_D(PeakCanBackend);

    if (d->setConfigurationParameter(key, value))
        QCanBusDevice::setConfigurationParameter(key, value);
}

bool PeakCanBackend::writeFrame(const QCanBusFrame &newData)
{
    Q_D(PeakCanBackend);

    if (Q_UNLIKELY(state() != QCanBusDevice::ConnectedState))
        return false;

    if (Q_UNLIKELY(!newData.isValid())) {
        setError(tr("Cannot write invalid QCanBusFrame"), QCanBusDevice::WriteError);
        return false;
    }

    if (Q_UNLIKELY(newData.frameType() != QCanBusFrame::DataFrame
                   && newData.frameType() != QCanBusFrame::RemoteRequestFrame)) {
        setError(tr("Unable to write a frame with unacceptable type"),
                 QCanBusDevice::WriteError);
        return false;
    }

    enqueueOutgoingFrame(newData);

    if (!d->writeNotifier->isActive())
        d->writeNotifier->start();

    return true;
}

// TODO: Implement me
QString PeakCanBackend::interpretErrorFrame(const QCanBusFrame &errorFrame)
{
    Q_UNUSED(errorFrame);

    return QString();
}

QT_END_NAMESPACE