BackendSSH.cpp

// Author: Kang Lin <kl222@126.com>

#include "BackendSSH.h"
#include <QLoggingCategory>
#include <QCoreApplication>

static Q_LOGGING_CATEGORY(log, "Plugin.SSH.Backend")

#define TERMWIDGET_EVENT_TYPE (QEvent::User + 1976)

class QEventTerminal: public QEvent
{
public:
    explicit QEventTerminal(char* data, int len) : QEvent((QEvent::Type)TERMWIDGET_EVENT_TYPE)
        , m_Data(data, len)
    {
    }

    QByteArray m_Data;
};

CBackendSSH::CBackendSSH(COperateSSH *pOperate)
    : CBackend(pOperate)
    , m_pOperate(pOperate)
    , m_pPara(nullptr)
    , m_pChannelSSH(nullptr)
    , m_pTerminal(nullptr)
{
    qDebug(log) << Q_FUNC_INFO;
    m_pPara = qobject_cast<CParameterTerminalSSH*>(pOperate->GetParameter());
    m_pTerminal = qobject_cast<QTermWidget*>(m_pOperate->GetViewer());
}

CBackendSSH::~CBackendSSH()
{
    qDebug(log) << Q_FUNC_INFO;
}

CBackendSSH::OnInitReturnValue CBackendSSH::OnInit()
{
    bool check = false;
    if(!m_pTerminal)
    {
        Q_ASSERT(m_pTerminal);
        return OnInitReturnValue::Fail;
    }

    m_pChannelSSH = new CChannelSSHTerminal(this, &m_pPara->m_SSH);
    if(!m_pChannelSSH) {
        qCritical(log) << "new CChannelSSH fail";
        return OnInitReturnValue::Fail;
    }

    check = connect(m_pChannelSSH, &CChannelSSHTerminal::sigConnected,
                    this, [&](){
                        if(!m_pPara->GetCommands().isEmpty()) {
                            foreach (auto c, m_pPara->GetCommands()) {
                                emit m_pTerminal->sendData(c.toStdString().c_str(), c.length());
                                emit m_pTerminal->sendData("\r", 1);
                            }
                        }
                        emit sigRunning();
                    });
    Q_ASSERT(check);
    check = connect(m_pChannelSSH, &CChannelSSHTerminal::readyRead,
                    this, [&](){
        char* buf = nullptr;
        qint64 nLen = 0;
        qint64 nRet = 0;
        if(m_pChannelSSH) {
            nLen = m_pChannelSSH->bytesAvailable();
            if(nLen <= 0) {
                qDebug(log) << "No data";
                return;
            }
            buf = new char[nLen];
            nRet = m_pChannelSSH->read(buf, nLen);
        }
        if(m_pTerminal && nRet > 0) {
            QByteArray data(buf, nRet);
            if(m_pOperate) {
                emit m_pOperate->sigReceiveData(data);
                if(m_pOperate->GetStats())
                    m_pOperate->GetStats()->AddReceives(nRet);
            }
        } else
            qCritical(log) << "The m_pTerminal is nullptr or nRet <= 0";
        //qDebug(log) << "Write data to QTermWidget: " << nRet << nLen;
        if(buf)
            delete []buf;
    });
    Q_ASSERT(check);
    check = connect(m_pTerminal, &QTermWidget::sendData,
                    this, [&](const char* data, int len){
        QEventTerminal* d = new QEventTerminal((char*)data, len);
        QCoreApplication::postEvent(this, d);
        if(m_pOperate && m_pOperate->GetStats())
            m_pOperate->GetStats()->AddSends(len);
        m_pChannelSSH->WakeUp();
    }, Qt::DirectConnection);
    Q_ASSERT(check);

    m_pChannelSSH->SetSize(m_pTerminal->screenLinesCount(),
                           m_pTerminal->screenColumnsCount());

    if(!m_pChannelSSH->open(QIODevice::ReadWrite)) {
        qCritical(log) << "Open ssh channel fail";
        return OnInitReturnValue::Fail;
    }

    m_pTerminal->startTerminalTeletype();

    return OnInitReturnValue::UseOnProcess;
}

int CBackendSSH::OnProcess()
{
    int nRet = 0;
    if(m_pChannelSSH)
        nRet = m_pChannelSSH->OnProcess(DEFAULT_TIMEOUT);
    return nRet;
}

int CBackendSSH::OnClean()
{
    int nRet = 0;

    if(m_pChannelSSH) {
        m_pChannelSSH->close();
        m_pChannelSSH->deleteLater();
        m_pChannelSSH = nullptr;
    }
    return nRet;
}

bool CBackendSSH::event(QEvent *event)
{
    switch (event->type()) {
    case TERMWIDGET_EVENT_TYPE:
    {
        QEventTerminal *d = (QEventTerminal*)event;
        if(m_pChannelSSH && d->m_Data.length() > 0) {
            qint64 nRet = m_pChannelSSH->write(d->m_Data.data(), d->m_Data.length());
            Q_UNUSED(nRet);
            //qDebug(log) << "Write data to ssh channel:" << nRet << d->m_Data.length();
        } else {
            //qDebug(log) << "m_pChannelSSH && len <= 0";
        }
        break;
    }
    default:
        return QObject::event(event);
    }
    
    event->accept();
    return true;
}

int CBackendSSH::WakeUp()
{
    if(m_pChannelSSH)
        m_pChannelSSH->WakeUp();
    return 0;
}