#include "server.h"
#include "util.h"
#include "pacman.pb.h"
#include "block.h"
#include "anyoption.h"
#include <QtNetwork/QTcpServer>
#include <QtNetwork/QTcpSocket>
#include <QTextStream>

Server::Server(QWidget *parent)
  : SceneHolder(parent), m_bindaddress(QHostAddress::Any),
  m_port(Constants::Networking::port), m_numbots(0)
{
  /* determine max players by using order array */
  for(m_maxplayers = 0; Color::order[m_maxplayers] != Color::none; ++m_maxplayers);
}

bool Server::run()
{
  qDebug() << "[Server] Running server...";
  qDebug() << "[Server] Max players:" << m_maxplayers;
  qDebug() << "[Server] Number of bots:" << m_numbots;
  if (!waitForClientConnections())
    return false;

  qDebug() << "[Server] Creating map...";
  Transmission::map_t map =  Util::createDemoMap();
  Util::placeActors(map, m_maxplayers, Color::order);
  Util::makePoints(map);
  updateMap(map);
  sendUpdate(map);
  Util::deleteMap(map);
  map = NULL;

  QTimer *timer = new QTimer(this);
  connect(timer, SIGNAL(timeout()), this, SLOT(tick()));
  timer->start(Constants::tick);
  return true;
}

void Server::tick()
{
  qDebug() << "[Tick] Doing server update";
  Transmission::map_t map = calculateUpdates();
  updateMap(map);
  sendUpdate(map);
  Util::deleteMap(map);
}

Transmission::map_t Server::calculateUpdates()
{
  Transmission::map_t map = Util::createEmptyMap();

  //TODO: ai
  //m_actorMovements[Color::blue] = Actor::Movement((qrand() % 4) + 1);
  //m_actorMovements[Color::green] = Actor::Movement((qrand() % 4) + 1);

  QMutableMapIterator<Color::Color, Actor::Movement> i(m_actorMovements);
  while (i.hasNext())
  {
    i.next();
    int turn = 0;

invalid_direction:
    ++turn;
    Actor *actor = m_actors.value(i.key());
    QPoint mapPosition = CoordToMapPosition(actor->pos().toPoint());
    qDebug() << "[Calc] Actor wants to move: color=" << i.key()
        << "pos=" << mapPosition << "direction=" << i.value();

    QPoint newMapPosition = mapPosition;
    switch (i.value())
    {
    case Actor::Up:
      newMapPosition += QPoint(0, -1);
      break;
    case Actor::Down:
      newMapPosition += QPoint(0, 1);
      break;
    case Actor::Left:
      newMapPosition += QPoint(-1, 0);
      break;
    case Actor::Right:
      newMapPosition += QPoint(1, 0);
      break;
    case Actor::None:
      break;
    default:
      Q_ASSERT(false);
    }

    if (newMapPosition.x() < 0)
      newMapPosition.setX(0);
    if (newMapPosition.x() >= visualMap.size())
      newMapPosition.setX(visualMap.size() - 1);
    if (newMapPosition.y() < 0)
      newMapPosition.setY(0);
    if (newMapPosition.y() >= visualMap[newMapPosition.x()].size())
      newMapPosition.setY(visualMap[newMapPosition.x()].size() - 1);

    // <t3h g4m3 10gic>
    // TODO: support actors eating each other
    // TODO: old item - REMOVE THAT?
    GameEntity *oldItem = visualMap[mapPosition.x()][mapPosition.y()];

    /* check if there's an item at new location of actor */
    GameEntity *item = visualMap[newMapPosition.x()][newMapPosition.y()];
    if (item != NULL && oldItem != item)
    {
      qDebug() << "[Calc] Found item at new actor location";
      if (!item->checkEnter(actor))
      {
        /* movement invalid. e.g. move against wall */
        newMapPosition = mapPosition;
        qDebug() << "[Calc] Item blocks actor";
      }
      else
      {
        /* apply actions of entering this field */
        bool survive = item->enter(actor);
        if (!survive)
        {
          map[newMapPosition.x()][newMapPosition.y()] = Transmission::empty | actor->color();
        }
      }
    }
    // </t3h g4m2 10gic>

    /* movement didn't work - e.g. was blocked */
    if (mapPosition == newMapPosition)
    {
      /* */
      if (turn == 1 && i.value() != actor->direction())
      {
        /* set direction back to last known direction and try again */
        qDebug() << "[Calc] Movement was blocked. Trying last known actor direction";
        m_actorMovements[i.key()] = actor->direction();
        goto invalid_direction;
      }
      else
      {
        /* second turn didn't work too -> stop movement */
        m_actorMovements[i.key()] = Actor::None;
        qDebug() << "[Calc] No good direction known. Movement stopped";
      }
    }

    map[newMapPosition.x()][newMapPosition.y()] |= Transmission::pacman |
        i.key() | Util::actorMovementToTransmission(i.value());

    /* DEBUG: uncomments to disable auto-movement */
    //m_actorMovements[i.key()] = Actor::None;

    if (i.value() == Actor::None)
    {
      /* set actor to non-moving */
      m_actorMovements[i.key()] = Actor::None;
      i.remove();
    }
  }
  return map;
}

bool Server::waitForClientConnections()
{
  // server must stay alive as long as sockets (qt parent mem mechanism)
  QTcpServer *tcpSrv = new QTcpServer(this);
  tcpSrv->listen(m_bindaddress, m_port);
  if (!tcpSrv->isListening())
  {
    qCritical() << "Error while creating socket:" << qPrintable(tcpSrv->errorString());
    return false;
  }
  qDebug() << "[Server] Listening on:"
      << qPrintable(QString("%1:%2").arg(tcpSrv->serverAddress().toString())
      .arg(tcpSrv->serverPort()));

  qDebug() << "[Server] Waiting for clients";
  ProtoBuf::Init packet;
  for (unsigned int i = 0; i < m_maxplayers; ++i)
  {
    bool connectionAvailable = tcpSrv->waitForNewConnection(-1);
    Q_ASSERT(connectionAvailable);
    Q_UNUSED(connectionAvailable);
    QTcpSocket *socket =  tcpSrv->nextPendingConnection();
    connect(socket, SIGNAL(readyRead()), this, SLOT(keyPressUpdate()));

    /* assign color */
    Color::Color color = Color::order[i];
    m_clientConnections[color] = socket;
    /* notify player of color */
    packet.set_color(color);
    packet.set_maxplayers(m_maxplayers);
    Util::sendPacket(packet, socket);

    qDebug() << "[Connect] New Player: color=" << color;
  }

  qDebug() << "[Server] All Clients connected";
  return true;
}

void Server::sendUpdate(Transmission::map_t map)
{
  m_updatepacket.Clear();

  for (unsigned int x = 0; x < Constants::map_size.width; ++x)
  {
    for (unsigned int y = 0; y < Constants::map_size.height; ++y)
      m_updatepacket.add_field(map[x][y]);
  }

  for(unsigned i = 0; i < m_maxplayers; ++i)
  {
    m_updatepacket.add_round_points(m_actors.value(Color::order[i])->getRoundPoints());
    m_updatepacket.add_game_points(m_actors.value(Color::order[i])->getGamePoints());
  }

  QSharedPointer<QByteArray> data = Util::createPacket(m_updatepacket);
  foreach(QTcpSocket *socket, m_clientConnections)
  {
    if (!Util::sendPacket(data.data(), socket))
    {
      qDebug() << "[sendUpdate] Error while sending data to client, exiting...";
      qApp->quit();
    }
  }
}

void Server::keyPressUpdate()
{
  ProtoBuf::KeyPressUpdate packet;
  QMapIterator<Color::Color, QTcpSocket *> i(m_clientConnections);
  while (i.hasNext())
  {
    i.next();
    Color::Color color = i.key();
    QTcpSocket *socket = i.value();
    QDataStream in(i.value());
    while (socket->bytesAvailable() > (qint64)sizeof(qint64))
    {
      QSharedPointer<QByteArray> data = Util::receivePacket(socket);
      bool worked = packet.ParseFromArray(data->data(), data->size());
      Q_ASSERT(worked);
      Q_UNUSED(worked);
      Transmission::field_t direction = packet.newkey();
      qDebug() << "[KeyPress] actor=" << color << "direction=" << direction;
      m_actorMovements[color] = Util::transmissionMovementToActor(direction);
    }
  }
}

bool Server::parseCommandline()
{
  AnyOption opt;
  opt.setVerbose();

  /* usage strings must remain valid until parsing is done */
  QString exec = QFileInfo(qApp->applicationFilePath()).fileName();
  QByteArray usage;
  QTextStream out(&usage, QIODevice::ReadWrite | QIODevice::Text);
  out << "Usage: " << exec << " [OPTION]" << endl
      << "Usage: " << exec << " -h" << endl
      << endl;
  out << "  -b, --bind <bind_address>" << endl
      << "  Specifies the ip address on which the server listens for connections" << endl
      << "  Default: " << m_bindaddress.toString() << endl
      << endl;
  opt.setOption("bind", 'b');
  out << "  -p, --port <port>" << endl
      << "  Specifies the port on which the server listens for connections" << endl
      << "  Default: " << m_port << endl
      << endl;
  opt.setOption("port", 'p');
  out << "  -m, --maxplayers [1.." << m_maxplayers << "]" << endl
      << "  Specifies the maximum number of players/pacmans" << endl
      << "  Default: " << m_maxplayers << endl
      << endl;
  opt.setOption("maxplayers", 'm');
  out << "  --bots [0..maxplayers-1]" << endl
      << "  Specifies the number of AI pacmans/bots" << endl
      << "  Default: " << m_numbots << endl
      << endl;
  opt.setOption("bots");
  out << "  -h, --help" << endl
      << "  Prints this help message" << endl;
  opt.setFlag("help", 'h');
  out.flush();
  opt.addUsage(usage.constData());
  opt.processCommandArgs(qApp->argc(), qApp->argv());

  if (opt.getFlag("help") || opt.getFlag('h'))
  {
    opt.printUsage();
    return false;
  }

  if (opt.getValue("port") != NULL)
  {
    bool ok;
    m_port = QString(opt.getValue("port")).toUInt(&ok);
    if (!ok || m_port < 1 || m_port > 65535)
    {
      qCritical() << "Invalid port-option:" << opt.getValue("port") << endl
          << "Port must be between 1 and 65535";
      return false;
    }
  }

  if (opt.getValue("bind") != NULL)
  {
    m_bindaddress = opt.getValue("bind");
    if (m_bindaddress.isNull())
    {
      qCritical() << "Invalid bind-option:" << opt.getValue("bind") << endl
          << "Bind address must be an ip address";
      return false;
    }
  }

  if (opt.getValue("maxplayers") != NULL)
  {
    bool ok;
    unsigned int maxplayers = QString(opt.getValue("maxplayers")).toUInt(&ok);
    if (!ok || maxplayers < 1 || maxplayers > m_maxplayers)
    {
      qCritical() << "Invalid maxplayers-option:" << opt.getValue("maxplayers") << endl
          << "Maxplayers must be between 1 and" << m_maxplayers;
      return false;
    }
    m_maxplayers = maxplayers;
  }

  if (opt.getValue("bots") != NULL)
  {
    bool ok;
    unsigned int numbots = QString(opt.getValue("bots")).toUInt(&ok);
    if (!ok || numbots >= m_maxplayers)
    {
      qCritical() << "Invalid numbots-options:" << opt.getValue("bots") << endl
          << "AI pacmans/bots must be between 0 and" << m_maxplayers - 1;
      return false;
    }
    m_numbots = numbots;
  }

  return true;
}

bool Constants::server = true;

int main(int argc, char ** argv)
{
  /* Verify that the version of the library that we linked against is
   * compatible with the version of the headers we compiled against.
   */
  GOOGLE_PROTOBUF_VERIFY_VERSION;

  QApplication app(argc, argv, false);
  app.setApplicationName("Pacman Server");
  app.setWindowIcon(QIcon(":/appicon"));

  qsrand(QTime(0, 0, 0).secsTo(QTime::currentTime()));

  int ret = 0;
  Server server;
  if (!ret && !server.parseCommandline())
    ret = 1;
  if (!ret && !server.run())
    ret = 1;
  if (!ret)
    ret = app.exec();

  /* Delete all global objects allocated by libprotobuf */
  google::protobuf::ShutdownProtobufLibrary();

  return ret;
}