/**
 * @file   MockServer.cpp
 * @brief  Mock XPL2 server — listens on all three protocol ports.
 */
#include "MockServer.h"

#include <QTcpSocket>

MockServer::MockServer (QObject *parent) : QObject (parent)
{
  setupPort (m_command, "Command", 9110);
  setupPort (m_imaging, "Imaging", 9111);
  setupPort (m_status, "Status", 9112);

  connect (&m_pingTimer, &QTimer::timeout, this, &MockServer::sendKaPing);
  m_pingTimer.start (1000);
}

void
MockServer::setupPort (Port &port, const char *name, quint16 number)
{
  port.name = name;
  port.number = number;

  connect (&port.server, &QTcpServer::newConnection, this,
           &MockServer::onNewConnection);

  if (!port.server.listen (QHostAddress::Any, number))
    qCritical ("Failed to listen on %s port %d: %s", name, number,
               qPrintable (port.server.errorString ()));
  else
    qInfo ("Listening on %s port %d", name, number);
}

const char *
MockServer::portName (quint16 localPort) const
{
  if (localPort == m_command.number)
    return m_command.name;
  if (localPort == m_imaging.number)
    return m_imaging.name;
  if (localPort == m_status.number)
    return m_status.name;
  return "Unknown";
}

void
MockServer::onNewConnection ()
{
  auto *server = qobject_cast<QTcpServer *> (sender ());
  while (auto *sock = server->nextPendingConnection ())
    {
      quint16 lp = sock->localPort ();
      qInfo ("[%s:%d] client connected", portName (lp), lp);
      m_clients.append (sock);
      connect (sock, &QTcpSocket::readyRead, this,
               &MockServer::onClientMessageReady);
      connect (sock, &QTcpSocket::disconnected, this,
               &MockServer::onClientDisconnected);
    }
}

void
MockServer::onClientMessageReady ()
{
  auto *sock = qobject_cast<QTcpSocket *> (sender ());
  while (sock->canReadLine ())
    {
      QByteArray line = sock->readLine ();
      handleCommand (sock, line);
    }
}

void
MockServer::onClientDisconnected ()
{
  auto *sock = qobject_cast<QTcpSocket *> (sender ());
  quint16 lp = sock->localPort ();
  qInfo ("[%s:%d] client disconnected", portName (lp), lp);
  m_clients.removeOne (sock);
  sock->deleteLater ();
}

void
MockServer::sendKaPing ()
{
  for (auto *client : m_clients)
    {
      if (client->state () == QAbstractSocket::ConnectedState)
        client->write ("KA_PING\n");
    }
}

void
MockServer::handleCommand (QTcpSocket *client, const QByteArray &line)
{
  QByteArray trimmed = line.trimmed ();
  if (trimmed.isEmpty ())
    return;

  quint16 lp = client->localPort ();

  /* Split on first comma to get command token. */
  int comma = trimmed.indexOf (',');
  QByteArray cmd = (comma >= 0) ? trimmed.left (comma) : trimmed;

  if (cmd == "KA_PING")
    {
      qDebug ("[%s:%d] KA_PING ACK received", portName (lp), lp);
      return;
    }

  if (cmd == "GS_JC_VERSION")
    {
      qInfo ("[%s:%d] -> GS_JC_VERSION reply", portName (lp), lp);
      client->write ("GS_JC_VERSION,1,\"1.05\",\"2.00\",15\n");
      return;
    }

  qWarning ("[%s:%d] Unknown command: %s", portName (lp), lp,
            trimmed.constData ());
}