/**
  * @RDE_HEADER@
  * Display Panel Simulator TCP Server; observes the given port and emits the incoming messages
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by Florian Schult, SLSE, 2016-03-18
  */
//===Include specifications==================================================
#include "displayPanelSimulatorTcpServer.h"
#include <QtNetwork/QTcpServer>
#include <QtNetwork/QTcpSocket>

#include <NGLLogger/NGLLoggerBootstrap.h>

//===DisplayPanelSimulatorTcpServer==========================================

//---Constructors/Destructors------------------------------------------------

/**
 * Constructor.
 */
DisplayPanelSimulatorTcpServer::DisplayPanelSimulatorTcpServer(QObject *parent)
  : QObject(parent)
  , mp_server(new QTcpServer(this))
  , mp_socket(nullptr)
  , m_port(0)
  , m_logger(NGL::NGLLoggerBootstrap::getNGLRootLogger().getNGLLogger("DispSim.DisplayPanelSimulatorWidget"))
{
}

/**
 * Destructor.
 */
DisplayPanelSimulatorTcpServer::~DisplayPanelSimulatorTcpServer()
{
  delete mp_server;
}

//---Private slots-----------------------------------------------------------

/**
 * Handles the 'newConnection' signal of the TCP server.
 */
void DisplayPanelSimulatorTcpServer::handleServerNewConnection()
{
  mp_socket = mp_server->nextPendingConnection();
  connect(mp_socket, &QTcpSocket::readyRead,
          this, &DisplayPanelSimulatorTcpServer::handleSocketReadyRead);
  emit debugMessage(m_port, QStringLiteral("Socket connected!"), MSGLVL_DEBUG);
}

/**
 * Handles the 'readyRead' signal of the TCP socket.
 */
void DisplayPanelSimulatorTcpServer::handleSocketReadyRead()
{
  evaluateData(mp_socket->readAll());
}

//---Private methods---------------------------------------------------------

/**
 * Evaluates the received data from the TCP socket.
 */
void DisplayPanelSimulatorTcpServer::evaluateData(const QByteArray &data)
{
  QByteArray page;
  QString message;
  bool    ackRequested = false;
  bool    dataOk       = false;

  if (data.isEmpty())
    return;

  char cs = data.at(data.size() - 1);
  char csCalc = calculateChecksum(data);
  if (data.size() >= 5)
    ackRequested = data[4] & 0x08;
  if (data.size() < 10)
  {
    message = tr("Message to small!");

    ERROR_LOG(m_logger) << "Error in message data evaluation";
  }
  else if (data[0] != 0)
  {
    message = tr("No SYNC in Message!");

    ERROR_LOG(m_logger) << "Error in message data evaluation";
  }
  else if (cs != csCalc)
  {
    const QByteArray ba = "Wrong Checksum: 0x" + QByteArray::number(cs, 16) + " <-> 0x" + QByteArray::number(csCalc, 16);
    qDebug() << ba.data();
    message = QString::fromLatin1(ba);

    ERROR_LOG(m_logger) << "Error in message data evaluation";
  }
  else
  {
    page    = data.mid(5, 3);
    const QByteArray ba = data.mid(11, (data.size() - 13));
    message = QString::fromUtf8(ba.data(), ba.size());
    emit plainMessage(message);
    emit debugMessage(m_port, tr("New message received: %1").arg(message), MSGLVL_INFO);

    INFO_LOG(m_logger) << "New message received";

    dataOk  = true;
  }
  if (!dataOk/* || page == "001"*/)
  {
    emit debugMessage(m_port, message, MSGLVL_ERROR);

    ERROR_LOG(m_logger) << "Error in message data evaluation";

  }
  if (ackRequested)
  {
    if (dataOk)
    {
      mp_socket->write("\x06"); // ACK
    }
    else
    {
      mp_socket->write("\x15"); // NAK
    }
  }
}

/**
 * Calculates the checksum of the received data from the TCP socket.
 */
char DisplayPanelSimulatorTcpServer::calculateChecksum(const QByteArray &data)
{
  char checksum = 0;
  for (const auto c : data)
    checksum ^= c;

  return checksum;
}

//---Public methods----------------------------------------------------------

/**
 * Starts the TCP server.
 */
void DisplayPanelSimulatorTcpServer::start(int port)
{
  m_port = port;
  connect(mp_server, &QTcpServer::newConnection,
          this, &DisplayPanelSimulatorTcpServer::handleServerNewConnection);
  emit debugMessage(m_port, tr("Waiting for connection"), MSGLVL_DEBUG);

  if (!mp_server->listen(QHostAddress::Any, port))
  {
    emit debugMessage(m_port, tr("Opening socket failed! May be in use!"), MSGLVL_ERROR);

    ERROR_LOG(m_logger) << "Opening socket failed; Port: " << port;
  }
}

//===========================================================================