/**
  * Websocket interface to the training area proxy
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by Christian Ehrlicher, SLSE, 2017-01-11
  */

#include "web_socket_handler.h"

#include "main_handler.h"
#include "ngs_handler.h"
#include "ppm_handler.h"
#include <Common/settings.h>

#include <QJsonDocument>
#include <QWebSocket>

namespace HighLevelArchitecture
{

WebSocketHandler::WebSocketHandler(int exerciseId, MainHandler *mainHandler, QObject *parent)
  : QObject(parent)
  , m_webSocketServer(new QWebSocketServer(QStringLiteral("WLS"), QWebSocketServer::NonSecureMode, this))
  , m_mainHandler(mainHandler)
  , m_exerciseId(exerciseId)
  , m_logger(getLogger("WebSocketHandler"))
{}

WebSocketHandler::~WebSocketHandler()
{
  for (const auto &s : qAsConst(m_webSockets))
    s->disconnect(this);
}

bool WebSocketHandler::init(quint16 listenPort)
{
  if (!m_webSocketServer->listen(QHostAddress::Any, listenPort))
  {
    WARNING_LOG(m_logger) << "Can not listen on port " << listenPort << " - aborting";
    return false;
  }
  connect(m_webSocketServer, &QWebSocketServer::newConnection,
          this, &WebSocketHandler::onNewConnection);

  return true;
}

bool WebSocketHandler::sendTelegramInternal(const TrainingAreaBase::TetraIcd::TrainingAreaTelegram *data,
                                            const QString &type, int exerciseId)
{
  QJsonObject obj;
  obj[QStringLiteral("data")] = data->toJson();
  obj[QStringLiteral("type")] = type;
  obj[QStringLiteral("typeId")] = data->id();
//  if (data->id() != TrainingAreaBase::TetraIcd::TelegramId::BESTAETIGUNG)
//    obj[QStringLiteral("counter")] = m_sendCounter++;
  const QString jsonStr = QString::fromUtf8(QJsonDocument(obj).toJson(QJsonDocument::Compact));
  DEBUG_LOG(m_logger) << "jsonStr: " << jsonStr;

  bool bOk = false;
  for (const auto &wsw : qAsConst(m_webSockets))
  {
    if (wsw->sendTextMessage(jsonStr, exerciseId))
      bOk = true;
  }
  return bOk;
}

void WebSocketHandler::sendHlaConnectionState()
{
  // send wls connection state (to all web sockets, should not hurt much)
  TrainingAreaBase::TetraIcd::ProxyConnectionState connState;
  connState.connectedToSystem = m_mainHandler->isConnectedToHla();
  sendTelegram(&connState, m_exerciseId);
  DEBUG_LOG(m_logger) << "sendHlaConnectionState, isConnected: " << connState.connectedToSystem;
}

void WebSocketHandler::sendParticipantConnectionStates()
{
  DEBUG_LOG(m_logger) << "sendParticipantConnectionStates";
  TrainingAreaBase::TetraIcd::WlsParticipantsConnectionState partConnState;
  partConnState.equipmentNumber = -1;
  partConnState.dataCommunicationPossible = false;
  sendTelegram(&partConnState, m_exerciseId);

  if (!m_mainHandler->isConnectedToHla())
  {
    INFO_LOG(m_logger) << "We are (not) yet connected to HLA - don't send participant connection states";
    return;
  }
  const auto externalEquipmentNumbers = m_mainHandler->ngsHandler()->ppmHandler()->externalEquipmentNumbers();

  for (int equipNo : externalEquipmentNumbers)
  {
    partConnState.equipmentNumber = equipNo;
    partConnState.dataCommunicationPossible = true;
    sendTelegram(&partConnState, m_exerciseId);
  }
}

void WebSocketHandler::onExternalEquipmentNumberAdded(int equipNo)
{
  sendDataCommunicationState(equipNo, true);
}

void WebSocketHandler::onExternalEquipmentNumberRemoved(int equipNo)
{
  sendDataCommunicationState(equipNo, false);
}

void WebSocketHandler::sendDataCommunicationState(int equipNo, bool bIsAvailable)
{
  TrainingAreaBase::TetraIcd::WlsParticipantsConnectionState tele;
  tele.equipmentNumber = equipNo;
  tele.dataCommunicationPossible = bIsAvailable;
  sendTelegram(&tele, m_exerciseId);
}

void WebSocketHandler::onNewConnection()
{
  QWebSocket *ws = m_webSocketServer->nextPendingConnection();
  if (!ws)
    return;
  DEBUG_LOG(m_logger) << "New websocket connection from " << ws->peerAddress().toString() << ":" << ws->peerPort();
  auto wsw = std::make_shared<WebSocketWrapper>(ws);

  connect(wsw.get(), &WebSocketWrapper::textMessageReceived,
          this, &WebSocketHandler::onTextMessageReceived);
  connect(ws, &QWebSocket::disconnected,
          this, &WebSocketHandler::onWebSocketDisconnected);

  m_webSockets += wsw;
}

void WebSocketHandler::onTextMessageReceived(const QByteArray &baJson)
{
  using namespace TrainingAreaBase::TetraIcd;

  TRACE_LOG(m_logger) << "WebSocketHandler::onTextMessageReceived: " << baJson;
  WebSocketWrapper *wsw = qobject_cast<WebSocketWrapper *>(sender());
  if (!wsw)
  {
    ERROR_LOG(m_logger) << "Internal error - sender is no WebSocketWrapper";
    return;
  }

  if (baJson.isEmpty())
    return;
  const QJsonObject obj = QJsonDocument::fromJson(baJson).object();
//  const QJsonValue sendCounter = obj.value(QStringLiteral("counter"));
//  if (!sendCounter.isUndefined())
//  {
//    if (!sendCounter.isDouble())
//      return false;
//    recvCounter = sendCounter.toInt(-1);
//    DEBUG_LOG(m_logger) << "Incoming telegram with Id " << obj.value(QStringLiteral("type")).toString();
//    if (recvCounter < 0)
//      return false;
//  }
  const QJsonValue typeId = obj.value(QStringLiteral("typeId"));
  if (!typeId.isDouble())
  {
    ERROR_LOG(m_logger) << "Can not read type id: " << baJson;
    return;
  }
  const QJsonObject data = obj.value(QStringLiteral("data")).toObject();
  try
  {
    switch (typeId.toInt())
    {
    case Constraints<ExerciseStateData>::id(): // 2008
      wsw->setExerciseId(ExerciseStateData::fromJson(data).exerciseId);
      if (m_exerciseId == wsw->exerciseId())
      {
        sendParticipantConnectionStates();
        sendHlaConnectionState();
      }
      break;
    case Constraints<ExerciseEquipmentAssignmentComplete>::id(): // 2012
      // not interesed in atm but here to not create a warning in the logfile
      break;
    case Constraints<Init>::id(): // 1
      emit initRequest(Init::fromJson(data));
      break;
    case Constraints<DemandBite>::id(): // 4
      emit biteRequest(DemandBite::fromJson(data));
      break;
    case Constraints<DemandVulnerabilityStateChange>::id(): // 54
      emit vulnerabilityStateRequest(DemandVulnerabilityStateChange::fromJson(data));
      break;
    default:
      WARNING_LOG(m_logger) << "Handler for telegram Id " << typeId.toInt()
                            << " not yet implemented (" << baJson << ")";
      return;
    }
  }
  catch (const std::exception &e)
  {
    WARNING_LOG(m_logger) << "Could not parse json: " << e.what() << " (" << baJson << ")";
    return;
  }
}


void WebSocketHandler::onWebSocketDisconnected()
{
  QWebSocket *ws = qobject_cast<QWebSocket *>(sender());
  if (!ws)
    return;
  for (auto it = m_webSockets.begin(); it != m_webSockets.end(); ++it)
  {
    auto wsw = *it;
    if (wsw->webSocket() == ws)
    {
      m_webSockets.erase(it);
      break;
    }
  }
}

//
// WebSocketWrapper
//
WebSocketWrapper::WebSocketWrapper(QWebSocket *ws)
  : m_webSocket(ws)
  , m_exerciseId(-1)
{
  connect(m_webSocket, &QWebSocket::textMessageReceived,
          this, &WebSocketWrapper::onTextMessageReceived);
}

WebSocketWrapper::~WebSocketWrapper()
{
  if (m_webSocket)
  {
    m_webSocket->disconnect(this);
    m_webSocket->close();
  }
  delete m_webSocket;
}

bool WebSocketWrapper::sendTextMessage(const QString &msg, int exerciseId)
{
  if (m_exerciseId != exerciseId && exerciseId != 0 && m_exerciseId != -1)
    return false;
  m_webSocket->sendTextMessage(msg);
  return true;
}

void WebSocketWrapper::setExerciseId(int exerciseId)
{
  m_exerciseId = exerciseId;
}

void WebSocketWrapper::onTextMessageReceived(const QString &data)
{
  emit textMessageReceived(data.toUtf8());
}

} // namespace HighLevelArchitecture