#include "ptsocket.h"


PTSocket::PTSocket(QObject* p) : QTcpSocket(p)
{
    setSocketOption(QAbstractSocket::LowDelayOption, 1);
    m_packetSize = 0;
    setTimeout(5000);
    setPingInterval(1000 * 7);
    m_state = Disconnected;
    m_isServerSide = false;
    connect(&m_timeoutTimer, SIGNAL(timeout()), this, SLOT(m_timedout()));
    connect(&m_pingTimer, SIGNAL(timeout()), this, SLOT(m_ping()));
    connect(this, SIGNAL(stateChanged(QAbstractSocket::SocketState)), this, SLOT(m_stateChanged(QAbstractSocket::SocketState)));
    connect(this, SIGNAL(error(QAbstractSocket::SocketError)), this, SLOT(m_socketError(QAbstractSocket::SocketError)));
    connect(this, SIGNAL(readyRead()), this, SLOT(m_readyRead()));
}

int PTSocket::getTimeout() const
{
    return m_timeout;
}

int PTSocket::getPingInterval() const
{
    return m_pingInterval;
}

bool PTSocket::isServerSide() const
{
    return m_isServerSide;
}

QByteArray PTSocket::handshakeData()
{
    return "LibPTSocketv1";
}

void PTSocket::setTimeout(int t)
{
    m_timeout = t;
    if(m_timeoutTimer.isActive())
        m_timeoutTimer.start(m_timeout);
    else
        m_timeoutTimer.setInterval(m_timeout);
}

void PTSocket::setPingInterval(int p)
{
    m_pingInterval = p;
    if(m_pingTimer.isActive())
        m_pingTimer.start(m_pingInterval);
    else
        m_pingTimer.setInterval(m_pingInterval);
}

void PTSocket::setIsServerSide(bool s)
{
    m_isServerSide = s;
}

void PTSocket::send(int pktType, QByteArray data)
{
    send(false, pktType, data);
}

void PTSocket::send(bool sys, int pktType, QByteArray data)
{
    if(data.isEmpty())
        data = "\0";
    data.prepend(intToByteArray(pktType));
    data.prepend((char)sys);
    data.prepend(intToByteArray(data.size()));
    write(data);
}

void PTSocket::m_ping()
{
    m_pingTimer.stop();
    if(m_timeoutTimer.isActive())
        return;
    send(true, PingRequest);
    m_timeoutTimer.start();
}

void PTSocket::m_readyRead()
{
    m_timeoutTimer.stop();
    m_pingTimer.start();
    if(m_state == Handshaked)
    {
        if(m_packetSize == 0)
        {
            if((unsigned)bytesAvailable() >= sizeof(int))
                m_packetSize = byteArrayToInt(read(sizeof(int)));
            else if(bytesAvailable() != 0)
                m_timeoutTimer.start();
        }
        if(m_packetSize != 0)
        {
            if((unsigned)bytesAvailable() >= m_packetSize)
            {
                bool sys = (bool)read(1).at(0);
                QByteArray p = read(sizeof(int));
                int pktType = byteArrayToInt(p);
                QByteArray data = read(m_packetSize - 1 - p.size());
                if(sys)
                {
                    if(pktType == PingRequest)
                        send(true, PingAnswer);
                    //else if(pktType == PingAnswer)
                }
                else
                    emit packetReceived(pktType, data);
                m_packetSize = 0;
                m_readyRead();
            }
            else
                m_timeoutTimer.start();
        }
    }
    else
    {
        QByteArray handshake = handshakeData();
        if(bytesAvailable() >= handshake.size())
        {
            QByteArray data = read(handshake.size());
            if(data == handshake)
            {
                setState(Handshaked);
                m_readyRead();
            }
            else
                m_handshakeError();
        }
        else
            m_timeoutTimer.start();
    }
}

void PTSocket::m_timedout()
{
    if(m_state == Disconnected)
        return;
    if(m_state == HostLookUp)
        setError("Unable to find the host " + peerName() + " in the time (" + QString::number(m_timeout) + " ms)");
    else if(m_state == Connecting)
        setError("The " + QString(isServerSide()? "client " + peerAddress().toString() : "server " + peerName())  + " didn't answer to the connection request in the time (" + QString::number(m_timeout) + " ms)");
    else if(m_state == Connected)
        setError("The " + QString(isServerSide()? "client " + peerAddress().toString() : "server " + peerName()) + " didn't answer to the handshake in the time (" + QString::number(m_timeout) + " ms)");
    else if(m_state == Handshaked)
        setError("The " + QString(isServerSide()? "client " + peerAddress().toString() : "server " + peerName()) + " timed out (" + QString::number(m_timeout) + " ms)");
    else if(m_state == Disconnecting)
        abort();
}

void PTSocket::m_handshakeError()
{
    setError("The " + QString(isServerSide()? "client " + peerAddress().toString() : "server " + peerName()) + " didn't answer to the handshake correclty");
}

void PTSocket::m_stateChanged(QAbstractSocket::SocketState s)
{
    if(s == QAbstractSocket::HostLookupState)
        setState(HostLookUp);
    else if(s == QAbstractSocket::ConnectingState)
        setState(Connecting);
    else if(s == QAbstractSocket::ConnectedState)
    {
        m_packetSize = 0;
        setState(Connected);
        write(handshakeData());
    }
    else if(s == QAbstractSocket::ClosingState)
        setState(Disconnecting);
    m_timeoutTimer.start();
    if(s == QAbstractSocket::UnconnectedState)
    {
        m_timeoutTimer.stop();
        setState(Disconnected);
    }
}

void PTSocket::m_socketError(QAbstractSocket::SocketError)
{
    setState(Error);
}

void PTSocket::setState(PTSocket::State s)
{
    if(s == m_state)
        return;
    if(s == Error)
        abort();
    if(s == Handshaked)
        m_pingTimer.start();
    else
        m_pingTimer.stop();
    if(m_state == Error && (s != HostLookUp && s != Connecting))
        return;
    m_state = s;
    emit stateChanged(m_state);
}

void PTSocket::setError(QString e)
{
    if(m_state == Error)
        return;
    setErrorString(e);
    setState(Error);
}

QByteArray PTSocket::intToByteArray(int a)
{
    QByteArray data;
    for(unsigned char i = 0; i < sizeof(a); ++i)
        data.append((char)(a >> 8 * i));
    return data;
}

int PTSocket::byteArrayToInt(QByteArray d)
{
    int a = 0;
    for(unsigned char i = 0; i < d.size(); ++i)
        a |= (unsigned int)((unsigned char)d.at(i) << i * 8);
    return a;
}