#include "net_session.h"

#include <QUuid>

#include "players_model.h"

#include "rooms_model.h"

NetSession::NetSession(QObject *parent)

    : QObject(parent),

      m_playersModel(new PlayersListModel()),

      m_roomsModel(new RoomsListModel()),

      m_sessionState(NotConnected) {}

NetSession::~NetSession() { close(); }

QUrl NetSession::url() const { return m_url; }

QAbstractSocket::SocketState NetSession::state() const {

  if (m_socket)

    return m_socket->state();

  else

    return QAbstractSocket::UnconnectedState;

}

void NetSession::open() {

  m_socket.reset(new QTcpSocket());

  connect(m_socket.data(), &QAbstractSocket::stateChanged, this,

          &NetSession::stateChanged);

  connect(m_socket.data(), &QTcpSocket::readyRead, this,

          &NetSession::onReadyRead);

  m_socket->connectToHost(m_url.host(),

                          static_cast<quint16>(m_url.port(46631)));

}

QString NetSession::nickname() const { return m_nickname; }

NetSession::SessionState NetSession::sessionState() const {

  return m_sessionState;

}

QString NetSession::room() const { return m_room; }

QString NetSession::passwordHash() const { return m_passwordHash; }

void NetSession::setUrl(const QUrl &url) {

  if (m_url == url) return;

  m_url = url;

  emit urlChanged(m_url);

}

void NetSession::setNickname(const QString &nickname) {

  if (m_nickname == nickname) return;

  m_nickname = nickname;

  emit nicknameChanged(m_nickname);

}

void NetSession::setPasswordHash(const QString &passwordHash) {

  if (m_passwordHash == passwordHash) return;

  m_passwordHash = passwordHash;

  emit passwordHashChanged(m_passwordHash);

  if (m_sessionState == Authentication) sendPassword();

}

void NetSession::setRoom(const QString &room) {

  if (m_room == room) return;

  m_room = room;

  emit roomChanged(m_room);

}

void NetSession::close() {

  if (!m_socket.isNull()) {

    m_socket->disconnectFromHost();

    m_socket.clear();

    setSessionState(NotConnected);

    setRoom({});

  }

}

void NetSession::onReadyRead() {

  while (m_socket->canReadLine()) {

    auto line = QString::fromUtf8(m_socket->readLine().simplified());

    if (line.isEmpty()) {

      parseNetMessage(m_buffer);

      m_buffer.clear();

    } else {

      m_buffer.append(line);

    }

  }

}

void NetSession::parseNetMessage(const QStringList &message) {

  if (message.isEmpty()) {

    qWarning() << "Empty net message received";

    return;

  }

  qDebug() << "[SERVER]" << message;

  using Handler = std::function<void(NetSession *, const QStringList &)>;

  static QMap<QString, Handler> commandsMap{

      {"ADD_TEAM", &NetSession::handleAddTeam},

      {"ASKPASSWORD", &NetSession::handleAskPassword},

      {"BANLIST", &NetSession::handleBanList},

      {"BYE", &NetSession::handleBye},

      {"CFG", &NetSession::handleCfg},

      {"CHAT", &NetSession::handleChat},

      {"CLIENT_FLAGS", &NetSession::handleClientFlags},

      {"CONNECTED", &NetSession::handleConnected},

      {"EM", &NetSession::handleEm},

      {"ERROR", &NetSession::handleError},

      {"HH_NUM", &NetSession::handleHhNum},

      {"INFO", &NetSession::handleInfo},

      {"JOINED", &NetSession::handleJoined},

      {"JOINING", &NetSession::handleJoining},

      {"KICKED", &NetSession::handleKicked},

      {"LEFT", &NetSession::handleLeft},

      {"LOBBY:JOINED", &NetSession::handleLobbyJoined},

      {"LOBBY:LEFT", &NetSession::handleLobbyLeft},

      {"NICK", &NetSession::handleNick},

      {"NOTICE", &NetSession::handleNotice},

      {"PING", &NetSession::handlePing},

      {"PONG", &NetSession::handlePong},

      {"PROTO", &NetSession::handleProto},

      {"REDIRECT", &NetSession::handleRedirect},

      {"REMOVE_TEAM", &NetSession::handleRemoveTeam},

      {"REPLAY_START", &NetSession::handleReplayStart},

      {"ROOMABANDONED", &NetSession::handleRoomAbandoned},

      {"ROOM", &NetSession::handleRoom},

      {"ROOMS", &NetSession::handleRooms},

      {"ROUND_FINISHED", &NetSession::handleRoundFinished},

      {"RUN_GAME", &NetSession::handleRunGame},

      {"SERVER_AUTH", &NetSession::handleServerAuth},

      {"SERVER_MESSAGE", &NetSession::handleServerMessage},

      {"SERVER_VARS", &NetSession::handleServerVars},

      {"TEAM_ACCEPTED", &NetSession::handleTeamAccepted},

      {"TEAM_COLOR", &NetSession::handleTeamColor},

      {"WARNING", &NetSession::handleWarning},

  };

  auto handler =

      commandsMap.value(message[0], &NetSession::handleUnknownCommand);

  handler(this, message.mid(1));

}

void NetSession::handleConnected(const QStringList &parameters) {

  if (parameters.length() < 2 || parameters[1].toInt() < cMinServerVersion) {

    send("QUIT", "Server too old");

    emit error(tr("Server too old"));

    close();

  } else {

    setSessionState(Login);

    send("NICK", m_nickname);

    send("PROTO", QString::number(cProtocolVersion));

  }

}

void NetSession::handlePing(const QStringList &parameters) {

  send("PONG", parameters);

}

void NetSession::handleBye(const QStringList &parameters) { close(); }

void NetSession::handleUnknownCommand(const QStringList &parameters) {

  Q_UNUSED(parameters);

  qWarning() << "Command is not recognized";

}

void NetSession::handleAddTeam(const QStringList &parameters) {}

void NetSession::handleAskPassword(const QStringList &parameters) {

  if (parameters.length() != 1 || parameters[0].length() < 16) {

    qWarning("Bad ASKPASSWORD message");

    return;

  }

  setSessionState(Authentication);

  m_serverSalt = parameters[0];

  m_clientSalt = QUuid::createUuid().toString();

  if (m_passwordHash.isEmpty()) {

    emit passwordAsked();

  } else {

    sendPassword();

  }

}

void NetSession::handleBanList(const QStringList &parameters) {}

void NetSession::handleCfg(const QStringList &parameters) {}

void NetSession::handleChat(const QStringList &parameters) {}

void NetSession::handleClientFlags(const QStringList &parameters) {}

void NetSession::handleEm(const QStringList &parameters) {}

void NetSession::handleError(const QStringList &parameters) {}

void NetSession::handleHhNum(const QStringList &parameters) {}

void NetSession::handleInfo(const QStringList &parameters) {}

void NetSession::handleJoined(const QStringList &parameters) {}

void NetSession::handleJoining(const QStringList &parameters) {}

void NetSession::handleKicked(const QStringList &parameters) {}

void NetSession::handleLeft(const QStringList &parameters) {}

void NetSession::handleLobbyJoined(const QStringList &parameters) {

  for (auto player : parameters) {

    if (player == m_nickname) {

      // check if server is authenticated or no authentication was performed at

      // all

      if (!m_serverAuthHash.isEmpty()) {

        emit error(tr("Server authentication error"));

        close();

      }

      setSessionState(Lobby);

    }

    m_playersModel->addPlayer(player, false);

  }

}

void NetSession::handleLobbyLeft(const QStringList &parameters) {

  if (parameters.length() == 1) {

    m_playersModel->removePlayer(parameters[0]);

  } else if (parameters.length() == 2) {

    m_playersModel->removePlayer(parameters[0], parameters[1]);

  } else {

    qWarning("Malformed LOBBY:LEFT message");

  }

}

void NetSession::handleNick(const QStringList &parameters) {

  if (parameters.length()) setNickname(parameters[0]);

}

void NetSession::handleNotice(const QStringList &parameters) {}

void NetSession::handlePong(const QStringList &parameters) {

  Q_UNUSED(parameters)

}

void NetSession::handleProto(const QStringList &parameters) {}

void NetSession::handleRedirect(const QStringList &parameters) {}

void NetSession::handleRemoveTeam(const QStringList &parameters) {}

void NetSession::handleReplayStart(const QStringList &parameters) {}

void NetSession::handleRoomAbandoned(const QStringList &parameters) {}

void NetSession::handleRoom(const QStringList &parameters) {

  if (parameters.size() == 10 && parameters[0] == "ADD") {

    m_roomsModel->addRoom(parameters.mid(1));

  } else if (parameters.length() == 11 && parameters[0] == "UPD") {

    m_roomsModel->updateRoom(parameters[1], parameters.mid(2));

    // keep track of room name so correct name is displayed

    if (m_room == parameters[1]) {

      setRoom(parameters[2]);

    }

  } else if (parameters.size() == 2 && parameters[0] == "DEL") {

    m_roomsModel->removeRoom(parameters[1]);

  }

}

void NetSession::handleRooms(const QStringList &parameters) {

  if (parameters.size() % 9) {

    qWarning("Net: Malformed ROOMS message");

    return;

  }

  m_roomsModel->setRoomsList(parameters);

}

void NetSession::handleRoundFinished(const QStringList &parameters) {}

void NetSession::handleRunGame(const QStringList &parameters) {}

void NetSession::handleServerAuth(const QStringList &parameters) {}

void NetSession::handleServerMessage(const QStringList &parameters) {}

void NetSession::handleServerVars(const QStringList &parameters) {}

void NetSession::handleTeamAccepted(const QStringList &parameters) {}

void NetSession::handleTeamColor(const QStringList &parameters) {}

void NetSession::handleWarning(const QStringList &parameters) {}

void NetSession::send(const QString &message) { send(QStringList(message)); }

void NetSession::send(const QString &message, const QString &param) {

  send(QStringList{message, param});

}

void NetSession::send(const QString &message, const QStringList &parameters) {

  send(QStringList(message) + parameters);

}

void NetSession::send(const QStringList &message) {

  Q_ASSERT(!m_socket.isNull());

  qDebug() << "[CLIENT]" << message;

  m_socket->write(message.join('\n').toUtf8() + "\n\n");

}

void NetSession::sendPassword() {

  /* When we got password hash, and server asked us for a password, perform

   * mutual authentication: at this point we have salt chosen by server. Client

   * sends client salt and hash of secret (password hash) salted with client

   * salt, server salt, and static salt (predefined string + protocol number).

   * Server should respond with hash of the same set in different order.

   */

  if (m_passwordHash.isEmpty() || m_serverSalt.isEmpty()) return;

  QString hash =

      QCryptographicHash::hash(m_clientSalt.toLatin1()

                                   .append(m_serverSalt.toLatin1())

                                   .append(m_passwordHash)

                                   .append(QByteArray::number(cProtocolVersion))

                                   .append("!hedgewars"),

                               QCryptographicHash::Sha1)

          .toHex();

  m_serverHash =

      QCryptographicHash::hash(m_serverSalt.toLatin1()

                                   .append(m_clientSalt.toLatin1())

                                   .append(m_passwordHash)

                                   .append(QByteArray::number(cProtocolVersion))

                                   .append("!hedgewars"),

                               QCryptographicHash::Sha1)

          .toHex();

  send("PASSWORD", QStringList{hash, m_clientSalt});

}

void NetSession::setSessionState(NetSession::SessionState sessionState) {

  if (m_sessionState == sessionState) return;

  m_sessionState = sessionState;

  emit sessionStateChanged(sessionState);

}