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** Copyright (C) 2018 The Qt Company Ltd.
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** This file is part of the QtKnx module.
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#include "qknxnetipframe.h"

QT_BEGIN_NAMESPACE

class QKnxNetIpFramePrivate : public QSharedData
{
public:
    QKnxNetIpFrameHeader m_header;
    QKnxNetIpConnectionHeader m_connectionHeader;
    QKnxByteArray m_data;
};


/*!
    \class QKnxNetIpFrame

    \inmodule QtKnx
    \ingroup qtknx-netip

    \brief The QKnxNetIpFrame class represents the base for all KNXnet/IP
    related communication.

    The communication between KNXnet/IP devices is based on KNXnet/IP frames.
    A KNXnet/IP frame is a data packet sent over the non-KNX network protocol
    that consists of a header, comparable to the IP header of an Internet
    protocol data packet, and optional data of variable length. The type of the
    KNXnet/IP frame is described by a KNXnet/IP service type identifier in the
    header.

    \sa {Qt KNXnet/IP Connection Classes}
*/

/*!
    Constructs an empty invalid KNXnet/IP frame object.
*/
QKnxNetIpFrame::QKnxNetIpFrame()
    : d_ptr(new QKnxNetIpFramePrivate)
{}

/*!
    Destroys the KNXnet/IP frame object and releases all allocated resources.
*/
QKnxNetIpFrame::~QKnxNetIpFrame() = default;

/*!
    Creates a new KNXnet/IP frame with the given service type \a type and data
    set to \a data.
*/
QKnxNetIpFrame::QKnxNetIpFrame(QKnxNetIp::ServiceType type, const QKnxByteArray &data)
    : QKnxNetIpFrame(type, {}, data)
{}

/*!
    Creates a new KNXnet/IP frame with the given service type \a type,
    connection header set to \a connectionHeader, and data set to \a data.
*/
QKnxNetIpFrame::QKnxNetIpFrame(QKnxNetIp::ServiceType type,
        const QKnxNetIpConnectionHeader &connectionHeader, const QKnxByteArray &data)
    : d_ptr(new QKnxNetIpFramePrivate)
{
    d_ptr->m_connectionHeader = connectionHeader;
    d_ptr->m_data = data;
    d_ptr->m_header = { type, quint16(connectionHeader.size() + data.size()) };
}

/*!
    Creates a new KNXnet/IP frame with the given frame header \a header,
    connection header set to \a connectionHeader, and data set to \a data.
*/
QKnxNetIpFrame::QKnxNetIpFrame(const QKnxNetIpFrameHeader &header,
        const QKnxNetIpConnectionHeader &connectionHeader, const QKnxByteArray &data)
    : d_ptr(new QKnxNetIpFramePrivate)
{
    d_ptr->m_header = header;
    d_ptr->m_connectionHeader = connectionHeader;
    d_ptr->m_data = data;
}

/*!
    Returns \c true if this is a default constructed frame, otherwise returns
    \c false. A frame is considered null if it contains no initialized values.
*/
bool QKnxNetIpFrame::isNull() const
{
    return d_ptr->m_header.isNull() && d_ptr->m_connectionHeader.isNull() && d_ptr->m_data.isNull();
}

/*!
    Returns \c true if the frame contains initialized values and is in itself
    valid, otherwise returns \c false. A valid KNXnet/IP frame consists of
    at least a valid header and a size in bytes corresponding to the KNXnet/IP
    frame header \l QKnxNetIpFrameHeader::totalSize.
*/
bool QKnxNetIpFrame::isValid() const
{
    if (isNull())
        return false;

    const auto &connectionHeader = d_ptr->m_connectionHeader;
    auto connHeaderValid = connectionHeader.isNull();
    switch (serviceType()) {
        case QKnxNetIp::ServiceType::TunnelingRequest:
        case QKnxNetIp::ServiceType::TunnelingAcknowledge:
        case QKnxNetIp::ServiceType::TunnelingFeatureGet:
        case QKnxNetIp::ServiceType::TunnelingFeatureSet:
        case QKnxNetIp::ServiceType::TunnelingFeatureInfo:
        case QKnxNetIp::ServiceType::TunnelingFeatureResponse:
        case QKnxNetIp::ServiceType::DeviceConfigurationRequest:
        case QKnxNetIp::ServiceType::DeviceConfigurationAcknowledge:
            connHeaderValid = connectionHeader.isValid();
            break;
        default:
            break;
    }

    const auto &header = d_ptr->m_header;
    auto size = header.size() + connectionHeader.size() + d_ptr->m_data.size();

    return header.isValid() && connHeaderValid && header.totalSize() == size
        && header.dataSize() == (d_ptr->m_data.size() + connectionHeader.size());
}

/*!
    Returns the size in bytes of the KNXnet/IP frame. The size includes the
    size of the KNXnet/IP frame header, the optional connection header, and
    the frame's data part.
*/
quint16 QKnxNetIpFrame::size() const
{
    return d_ptr->m_header.totalSize();
}

/*!
    Returns the size of the KNXnet/IP frame data. The data size excludes the
    size of the KNXnet/IP frame header and the optional connection header.
*/
quint16 QKnxNetIpFrame::dataSize() const
{
    return d_ptr->m_header.dataSize() - d_ptr->m_connectionHeader.size();
}

/*!
    Returns the KNXnet/IP frame header.
*/
QKnxNetIpFrameHeader QKnxNetIpFrame::header() const
{
    return d_ptr->m_header;
}

/*!
    Sets the KNXnet/IP frame header to \a header.
*/
void QKnxNetIpFrame::setHeader(const QKnxNetIpFrameHeader &header)
{
    d_ptr->m_header = header;
}

/*!
    Returns the KNXnet/IP frame protocol version.
*/
quint8 QKnxNetIpFrame::protocolVersion() const
{
    return d_ptr->m_header.protocolVersion();
}

/*!
    Returns the KNXnet/IP frame's service type or QKnxNetIp::Unknown for
    a default generated frame.
*/
QKnxNetIp::ServiceType QKnxNetIpFrame::serviceType() const
{
    return d_ptr->m_header.serviceType();
}

/*!
    Sets the KNXnet/IP frame's service type to \a type.
*/
void QKnxNetIpFrame::setServiceType(QKnxNetIp::ServiceType type)
{
    d_ptr->m_header.setServiceType(type);
}

/*!
    Returns the KNXnet/IP frame's connection header.
*/
QKnxNetIpConnectionHeader QKnxNetIpFrame::connectionHeader() const
{
    return d_ptr->m_connectionHeader;
}

/*!
    Sets the KNXnet/IP frame's connection header to \a header and updates
    the total size accordingly.
*/
void QKnxNetIpFrame::setConnectionHeader(const QKnxNetIpConnectionHeader &header)
{
    quint16 dataSize = d_ptr->m_header.dataSize() - d_ptr->m_connectionHeader.size();
    d_ptr->m_connectionHeader = header;
    d_ptr->m_header.setDataSize(dataSize + header.size());
}

/*!
    Returns the KNXnet/IP frame's channel ID if a connection header is set.

    \note By default the function returns null.
*/
quint8 QKnxNetIpFrame::channelId() const
{
    return d_ptr->m_connectionHeader.channelId();
}

/*!
    Returns the KNXnet/IP frame's sequence number if a connection header is set.

    \note By default the function returns null.
*/
quint8 QKnxNetIpFrame::sequenceNumber() const
{
    return d_ptr->m_connectionHeader.sequenceNumber();
}

/*!
    Returns the service type specific value of the KNXnet/IP frame if a
    connection header is set.

    \note By default the function returns null.
*/
quint8 QKnxNetIpFrame::serviceTypeSpecificValue() const
{
    return d_ptr->m_connectionHeader.serviceTypeSpecificValue();
}

/*!
    Returns a byte array with connection type specific header items of the
    KNXnet/IP frame if a connection header is set.

    \note The returned array can be empty.
*/
QKnxByteArray QKnxNetIpFrame::connectionTypeSpecificHeaderItems() const
{
    return d_ptr->m_connectionHeader.connectionTypeSpecificHeaderItems();
}

/*!
    Returns the data part of the KNXnet/IP frame.

    \note If a connection header is set, it is not considered part of the
    returned data.
*/
QKnxByteArray QKnxNetIpFrame::data() const
{
    return d_ptr->m_data;
}

/*!
    Returns the data part of the KNXnet/IP frame as constant reference.

    \note If a connection header is set, it is not considered part of the
    returned data.
*/
const QKnxByteArray &QKnxNetIpFrame::constData() const
{
    return d_ptr->m_data;
}

/*!
    Sets the data part of the KNXnet/IP frame to \a data and updates the
    total size accordingly.

    \note The data part passed may not contain the connection header.
*/
void QKnxNetIpFrame::setData(const QKnxByteArray &data)
{
    auto dataSize = d_ptr->m_header.dataSize() - d_ptr->m_data.size();
    d_ptr->m_data = data;
    d_ptr->m_header.setDataSize(dataSize + data.size());
}

/*!
    Returns an array of bytes that represent the KNXnet/IP frame.
*/
QKnxByteArray QKnxNetIpFrame::bytes() const
{
    return d_ptr->m_header.bytes() + d_ptr->m_connectionHeader.bytes() + d_ptr->m_data;
}

/*!
    Constructs the KNXnet/IP frame from the byte array \a bytes starting
    at position \a index inside the array.
*/
QKnxNetIpFrame QKnxNetIpFrame::fromBytes(const QKnxByteArray &bytes, quint16 index)
{
    auto header = QKnxNetIpFrameHeader::fromBytes(bytes, index);
    if (!header.isValid())
        return {};
    index += header.size();

    QKnxNetIpConnectionHeader connHeader;
    switch (header.serviceType()) {
        case QKnxNetIp::ServiceType::TunnelingRequest:
        case QKnxNetIp::ServiceType::TunnelingAcknowledge:
        case QKnxNetIp::ServiceType::TunnelingFeatureGet:
        case QKnxNetIp::ServiceType::TunnelingFeatureSet:
        case QKnxNetIp::ServiceType::TunnelingFeatureInfo:
        case QKnxNetIp::ServiceType::TunnelingFeatureResponse:
        case QKnxNetIp::ServiceType::DeviceConfigurationRequest:
        case QKnxNetIp::ServiceType::DeviceConfigurationAcknowledge: {
            connHeader = QKnxNetIpConnectionHeader::fromBytes(bytes, index);
            if (!connHeader.isValid())
                return {};
            index += connHeader.size();
        }   break;
        default:
            break;
    }

    const auto dataSize = header.totalSize() - index;
    if ((bytes.size() - index) < dataSize)
        return {};
    return { header, connHeader, bytes.mid(index, dataSize) };
}

/*!
    Constructs a copy of \a other.
*/
QKnxNetIpFrame::QKnxNetIpFrame(const QKnxNetIpFrame &other)
    : d_ptr(other.d_ptr)
{}

/*!
    Assigns the specified \a other to this object.
*/
QKnxNetIpFrame &QKnxNetIpFrame::operator=(const QKnxNetIpFrame &other)
{
    d_ptr = other.d_ptr;
    return *this;
}

/*!
    Move-constructs an object instance, making it point to the same object that
    \a other was pointing to.
*/
QKnxNetIpFrame::QKnxNetIpFrame(QKnxNetIpFrame &&other) Q_DECL_NOTHROW
    : d_ptr(other.d_ptr)
{
    other.d_ptr = Q_NULLPTR;
}

/*!
    Move-assigns \a other to this object instance.
*/
QKnxNetIpFrame &QKnxNetIpFrame::operator=(QKnxNetIpFrame &&other) Q_DECL_NOTHROW
{
    swap(other);
    return *this;
}

/*!
    Swaps \a other with this object. This operation is very fast and never fails.
*/
void QKnxNetIpFrame::swap(QKnxNetIpFrame &other) Q_DECL_NOTHROW
{
    d_ptr.swap(other.d_ptr);
}

/*!
    Returns \c true if this object and the given \a other are equal; otherwise
    returns \c false.
*/
bool QKnxNetIpFrame::operator==(const QKnxNetIpFrame &other) const
{
    return d_ptr == other.d_ptr || [&]() -> bool {
        return d_ptr->m_header == other.d_ptr->m_header
            && d_ptr->m_connectionHeader == other.d_ptr->m_connectionHeader
            && d_ptr->m_data == other.d_ptr->m_data;
    }();
}

/*!
    Returns \c true if this object and the given \a other are not equal;
    otherwise returns \c false.
*/
bool QKnxNetIpFrame::operator!=(const QKnxNetIpFrame &other) const
{
    return !operator==(other);
}

/*!
    \internal
*/
QKnxNetIpFrame::QKnxNetIpFrame(QKnxNetIpFramePrivate &dd)
    : d_ptr(new QKnxNetIpFramePrivate(dd))
{}

/*!
    \relates QKnxNetIpFrame

    Writes the KNXnet/IP \a frame to the \a debug stream.
*/
QDebug operator<<(QDebug debug, const QKnxNetIpFrame &frame)
{
    QDebugStateSaver _(debug);
    return debug.nospace().noquote() << "0x" << frame.bytes().toHex();
}

QT_END_NAMESPACE