/**
 * @file   EchoServer.cpp
 * @brief  Mock XPL2 server for a single port.
 */
#include "EchoServer.h"

#include <QTcpSocket>

EchoServer::EchoServer (quint16 port, const char *name, QObject *parent)
    : QTcpServer (parent), m_name (name), m_port (port)
{
  connect (this, &QTcpServer::newConnection, this,
           &EchoServer::onNewConnection);

  connect (&m_pingTimer, &QTimer::timeout, this, &EchoServer::sendKaPing);

  if (!listen (QHostAddress::Any, port))
    qCritical ("Failed to listen on %s port %d: %s", m_name, m_port,
               qPrintable (errorString ()));
  else
    {
      qInfo ("Listening on %s port %d", m_name, m_port);
      m_pingTimer.start (1000);
    }
}

void
EchoServer::onNewConnection ()
{
  while (auto *sock = nextPendingConnection ())
    {
      qInfo ("[%s:%d] client connected", m_name, m_port);
      m_clients.append (sock);
      connect (sock, &QTcpSocket::readyRead, this,
               &EchoServer::onClientMessageReady);
      connect (sock, &QTcpSocket::disconnected, this,
               &EchoServer::onClientDisconnected);
    }
}

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

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

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

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

  /* 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", m_name, m_port);
      return;
    }

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

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