#include "server.h"
#include "util.h"
#include "pacman.pb.h"
#include "block.h"
#include "anyoption.h"
#include "bonuspoint.h"
#include "point.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),
  m_rounds(3), m_curRound(0), m_roundFinished(false)
{
  /* determine max players by using order array */
  for(m_maxplayers = 0; Color::order[m_maxplayers] != Color::none; ++m_maxplayers);
}

bool Server::run()
{
  /* create eating order list first - this can also be created dynamically per round (theoretically) */
  for(unsigned i = 0; i < m_maxplayers; ++i)
    m_eatingorder.append(Color::order[i]);
  m_eatingorder.append(Color::order[0]);

  m_tickTimer = new QTimer(this);
  m_tickTimer->setInterval(Constants::tick);
  connect(m_tickTimer, SIGNAL(timeout()), this, SLOT(tick()));

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

  connect(this, SIGNAL(allPointsRemoved()), this, SLOT(setRoundFinished()));
  initRoundMap();
  return true;
}

void Server::tick()
{
  //qDebug() << "[Tick] Doing server update";
  if (m_roundFinished)
  {
    // TODO: call this when a pacman get's eaten
    /* first finish previous round */
    foreach(Actor *actor, m_actors)
      actor->finishRound();

    ++m_curRound;
    if(m_curRound < m_rounds)
      initRoundMap();
    else
    {
      /* end of game */
      qDebug() << "All round finished. Exiting...";
      m_tickTimer->stop();
      qApp->quit();
    }
  }
  else
  {
    /* let the bots move */
    foreach (Color::Color color, m_bots)
      botCalculate(m_actors[color]);

    /* move on the virtual map */
    Transmission::map_t map = calculateUpdates();
    updateMap(map);

    /* add a random bonus point */
    QPoint pos = addRandomPoint(map, Transmission::bonuspoint);
    if (!pos.isNull())
      updateMap(map, pos.x(), pos.y());

    /* add/remove random colorized block */
    if (this->property("coloredblocks").toBool())
      colorizeBlocks(map);

    sendUpdate(map);
    Util::deleteMap(map);
  }
}

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

  QMutableMapIterator<Color::Color, Actor::Movement> i(m_actorMovements);
  while (i.hasNext())
  {
    i.next();
    Actor *actor = m_actors.value(i.key());
    QPoint mapPosition = CoordToMapPosition(actor->pos().toPoint());
    Actor::Movement direction = i.value();
    int turn = 0;

invalid_direction:
    ++turn;
    qDebug() << "[Calc] Actor wants to move: color=" << i.key()
        << "pos=" << mapPosition << "direction=" << direction;

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

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

    /* DEBUG: uncomments to disable auto-movement */
    //direction = Actor::None;

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

QPoint Server::addRandomPoint(Transmission::map_t map, Transmission::field_t type)
{
  int chance = Constants::Game::bouns_point_chance
               - Constants::Game::bouns_point_chance_playerfactor * (m_maxplayers - 1);
  int rand = (int) (chance * (qrand() / (RAND_MAX + 1.0)));
  if (rand != 0)
    return QPoint();

  /* get list of valid positions */
  QList<QPoint> validpos;
  for (unsigned int x = 0; x < Constants::map_size.width; ++x)
  {
    for (unsigned int y = 0; y < Constants::map_size.height; ++y)
    {
      if (visualMap[x][y] == NULL)
        validpos.append(QPoint(x, y));
    }
  }

  /* remove actors positions from list
   * performance would be better if actors would be listed in visualMap too
   * but this isn't possible that easily. see comment in updateMap(map)
   */
  foreach (Actor *actor, m_actors)
  {
    QPoint actorpos = CoordToMapPosition(actor->pos().toPoint());
    validpos.removeAll(actorpos);
  }

  if (validpos.empty())
    return QPoint();

  rand = (int) (validpos.size() * (qrand() / (RAND_MAX + 1.0)));
  QPoint pos = validpos.at(rand);
  map[pos.x()][pos.y()] = type;
  return pos;
}

void Server::colorizeBlocks(Transmission::map_t map)
{
  /* decrement tickcount of colored blocks */
  if (!m_coloredBlocks.empty())
  {
    QMutableMapIterator<QPoint, unsigned int> i(m_coloredBlocks);
    while(i.hasNext())
    {
      i.next();
      unsigned val = i.value();
      if (val > 0)
        i.setValue(--val);
      else
      {
        /* check for actor collision */
        bool skip = false;
        foreach (Actor *actor, m_actors)
        {
          if (CoordToMapPosition(actor->pos().toPoint()) == i.key())
            skip = true;
          if (skip)
            break;
        }
        if (skip)
          continue;

        QPoint block = i.key();
        map[block.x()][block.y()] |= Transmission::block | Color::none;
        updateMap(map, block.x(), block.y());
        m_blocks.append(block);
        i.remove();
      }
    }
  }

  /* colorize a random block */
  int rand = (int) (Constants::Game::colorize_block_chance * (qrand() / (RAND_MAX + 1.0)));
  if (rand == 0)
  {
    rand = (int) (m_blocks.size() * (qrand() / (RAND_MAX + 1.0)));
    QPoint block = m_blocks.at(rand);
    m_blocks.removeAt(rand);

    unsigned int min = Constants::Game::colorize_block_tickcount_min;
    unsigned int max = Constants::Game::colorize_block_tickcount_max;
    int tickcount = min + (int) ((max - min + 1) * (qrand() / (RAND_MAX + 1.0)));
    m_coloredBlocks.insert(block, tickcount);

    unsigned int color = (int) (m_maxplayers * (qrand() / (RAND_MAX + 1.0)));
    map[block.x()][block.y()] |= Transmission::block | Color::order[color];
    updateMap(map, block.x(), block.y());
  }
}

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;
  packet.set_maxplayers(m_maxplayers);
  for (unsigned int i = 0; i < (m_maxplayers - m_numbots); ++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 and notify client */
    Color::Color color = Color::order[i];
    m_clientConnections[color] = socket;
    packet.set_color(color);
    Util::sendPacket(packet, socket);
    qDebug() << "[Connect] New Player: color=" << color;
  }

  for (unsigned int i = (m_maxplayers - m_numbots); i < m_maxplayers; ++i)
  {
    m_bots.append(Color::order[i]);
    m_actorMovements[Color::order[i]] = Actor::None;
  }

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

void Server::sendUpdate(Transmission::map_t map, bool firstPacket)
{
  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());
  }

  /* we send the eating_order inside the first packet */
  if (firstPacket)
  {
    foreach(Color::Color color, m_eatingorder)
      m_updatepacket.add_eating_order(color);
  }

  QSharedPointer<QByteArray> data = Util::createPacket(m_updatepacket);
  QMutableMapIterator<Color::Color, QTcpSocket *> i(m_clientConnections);
  while(i.hasNext())
  {
    i.next();
    QTcpSocket *socket = i.value();

    if (!Util::sendPacket(data.data(), socket))
    {
      qDebug() << "[sendUpdate] Error while sending data to client. Disconnecting...";
      socket->close();
      qDebug() << "[sendUpdate] Actor" << i.key() << "is now a bot";
      m_bots.append(i.key());
      ++m_numbots;
      i.remove();
    }
  }

  if (m_maxplayers == m_numbots)
  {
    qDebug() << "[sendUpdate] No more real players left. Exiting...";
    qApp->quit();
  }
}

void Server::botCalculate(Actor *actor)
{
  QPoint actorpos = CoordToMapPosition(actor->pos().toPoint());

  /* first make list of possible directions based on current actor position */
  QHash<Actor::Movement, unsigned int> directions;
  if (actorpos.x() > 0)
    directions.insert(Actor::Left, 0);
  if (actorpos.x() < visualMap.size() - 1)
    directions.insert(Actor::Right, 0);
  if (actorpos.y() > 0)
    directions.insert(Actor::Up, 0);
  if (actorpos.y() < visualMap[actorpos.x()].size() - 1)
    directions.insert(Actor::Down, 0);

  /* check neighbours for blocks first */
  QMutableHashIterator<Actor::Movement, unsigned int> i(directions);
  while(i.hasNext())
  {
    i.next();
    QPoint newpos = actorpos + Actor::movementToPoint(i.key());
    if (newpos.x() < 0 || newpos.x() >= visualMap.size())
      continue;
    if (newpos.y() < 0 || newpos.y() >= visualMap[newpos.x()].size())
      continue;
    GameEntity *item = visualMap[newpos.x()][newpos.y()];

    /* check if neighbour is a block */
    Block *block = qgraphicsitem_cast<Block *>(item);
    if (block != NULL && block->color() != actor->color())
      i.remove();
  }

  /* we're enclosed by blocks */
  if (directions.empty())
    return;

  /* determine if other actors are in range to be afraid/to hunt */
  int mindistance = Constants::AI::player_minimum_distance;
  QList<QPoint> pos_afraid;
  QList<QPoint> pos_hunt;
  foreach (Actor *other, m_actors)
  {
    if (actor == other)
      continue;

    QList<QPoint> *ptr = NULL;
    if (other->canEat(actor, m_eatingorder))
      ptr = &pos_afraid;
    else if (actor->canEat(other, m_eatingorder))
      ptr = &pos_hunt;
    if (ptr == NULL)
      continue;

    QPoint otherpos = CoordToMapPosition(other->pos().toPoint());
    QPoint distance = actorpos - otherpos;
    if (distance.manhattanLength() < mindistance)
      ptr->append(otherpos);
  }

  /* check new directions and change direction-weight */
  i = directions;
  while(i.hasNext())
  {
    i.next();
    QPoint newpos = actorpos + Actor::movementToPoint(i.key());

    /* check for new positions in afraid list */
    foreach(QPoint otherpos, pos_afraid)
    {
      int olddistance = (actorpos - otherpos).manhattanLength();
      int newdistance = (newpos - otherpos).manhattanLength();
      if (newdistance >= olddistance)
        i.setValue(i.value() + Constants::AI::weight_afraid);

      /* check for blocks of own color: other pacman can't follow their */
      GameEntity *item = visualMap[newpos.x()][newpos.y()];
      Block *block = qgraphicsitem_cast<Block *>(item);
      if (block != NULL && block->color() == actor->color())
        i.setValue(i.value() + Constants::AI::weight_colorblock);
    }

    /* check for new positions in hunt list */
    foreach(QPoint otherpos, pos_hunt)
    {
      int olddistance = (actorpos - otherpos).manhattanLength();
      int newdistance = (newpos - otherpos).manhattanLength();
      if (newdistance <= olddistance)
        i.setValue(i.value() + Constants::AI::weight_hunt);
    }

    /* check for bonuspoint */
    GameEntity *item = visualMap[newpos.x()][newpos.y()];
    BonusPoint *bpoint = qgraphicsitem_cast<BonusPoint *>(item);
    if (bpoint != NULL)
      i.setValue(i.value() + Constants::AI::weight_bonus_point);

    /* check for normal point */
    Point *point = qgraphicsitem_cast<Point *>(item);
    if (point != NULL)
      i.setValue(i.value() + Constants::AI::weight_point);
  }

  /* sort directions */
  QList<unsigned int> weightlist = directions.values();
  qSort(weightlist.begin(), weightlist.end(), qGreater<unsigned int>());

  /* remove directions with lesser weight */
  unsigned int max = weightlist.at(0);
  i = directions;
  while(i.hasNext())
  {
    i.next();
    if (i.value() < max)
      i.remove();
  }

  QList<Actor::Movement> list = directions.keys();

  /* default is no direction change */
  if (list.contains(actor->direction()))
    return;

  /* random direction */
  int rand = (int) (list.size() * (qrand() / (RAND_MAX + 1.0)));
  m_actorMovements[actor->color()] = list.at(rand);
}

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);
    }
  }
}

void Server::setRoundFinished(bool value)
{
  m_roundFinished = value;
}

void Server::initRoundMap()
{
  qDebug() << "[initRoundMap] New round starts...";
  m_tickTimer->stop();

  /* create new map */
  Transmission::map_t map =  Util::createDemoMap();
  Util::placeActors(map, m_maxplayers, Color::order);
  Util::fillPoints(map);

  /* save positions of blocks for later usage */
  m_blocks.clear();
  for (unsigned int x = 0; x < Constants::map_size.width; ++x)
  {
    for (unsigned int y = 0; y < Constants::map_size.height; ++y)
    {
      Transmission::field_t &cur = map[x][y];
      if (cur & Transmission::block)
        m_blocks.append(QPoint(x, y));
    }
  }

  updateMap(map);
  sendUpdate(map, true);
  Util::deleteMap(map);
  map = NULL;

  m_roundFinished = false;
  m_actorMovements.clear();
  m_tickTimer->start();
}

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 << "  --nocolorblocks" << endl
      << "  Disable random colorized blocks" << endl
      << endl;
  opt.setOption("rounds", 'r');
  out << "  -r, --rounds [1..n]" << endl
      << "  Number of rounds to play" << endl
      << "  Default: " << m_rounds << endl
      << endl;
  opt.setFlag("nocolorblocks");
  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 (m_maxplayers == 2)
    {
      qCritical() << "2 player game is not supported (who wins if a player gets eaten?)";
      return false;
    }
  }

  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;
  }

  if (opt.getValue("rounds") != NULL)
  {
    bool ok;
    unsigned int rounds = QString(opt.getValue("rounds")).toUInt(&ok);
    if (!ok || rounds == 0)
    {
      qCritical() << "Invalid number of rounds: " << opt.getValue("rounds") << endl;
      return false;
    }
    m_rounds = rounds;
  }

  this->setProperty("coloredblocks", !opt.getFlag("nocolorblocks"));

  return true;
}

bool operator<(const QPoint& lhs, const QPoint& rhs)
{
  if (lhs.x() < rhs.x())
    return true;
  else if (lhs.x() == rhs.x())
    return lhs.y() < rhs.y();
  else
    return false;
}

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;
}