#include "sceneholder.h"
#include "constants.h"
#include "gameentity.h"
#include "block.h"
#include "actor.h"
#include "bonuspoint.h"
#include "point.h"
#include "util.h"

SceneHolder::SceneHolder(QObject *parent)
  : QGraphicsScene(parent), m_color(Color::none), m_pointsLeft(0)
{
  setSceneRect(0, 0, Constants::map_size_pixel.width, Constants::map_size_pixel.height);
  setBackgroundBrush(Qt::black);

  visualMap.resize(Constants::map_size.width);
  for (int i = 0; i < visualMap.size(); ++i)
    visualMap[i].resize(Constants::map_size.height);
}

void SceneHolder::reset()
{
  processDelayedItems();

  /* remove actors from scene so they don't get deleted during clear */
  foreach(Actor *actor, m_actors)
  {
    actor->resetAnimation();
    removeItem(actor);
  }

  /* clear our stuff */
  clear();
  m_pointsLeft = 0;
  for (int i = 0; i < visualMap.size(); ++i)
  {
    visualMap[i].clear();
    visualMap[i].resize(Constants::map_size.height);
  }

  /* add actors again */
  foreach(Actor *actor, m_actors)
    addItem(actor);
}

void SceneHolder::processDelayedItems()
{
  /* remove items that got marked for removal from scene */
  foreach(GameEntity *item, m_oldItems)
  {
    removeItem(item);
    delete item;
  }
  m_oldItems.clear();

  /* process death */
  foreach(const Color::Color color, m_death.keys())
  {
    Q_ASSERT(m_death[color] != NULL);
    m_death[color]->onDie(m_actors[color]);
  }
  m_death.clear();
}

void SceneHolder::updateMap(const Transmission::map_t& map)
{
  processDelayedItems();

  /* process update */
  for (unsigned int x = 0; x < Constants::map_size.width; ++x)
  {
    for (unsigned int y = 0; y < Constants::map_size.height; ++y)
    {
      const Transmission::field_t &cur = map[x][y];
      if (cur == Transmission::none)
        continue;
      updateMap(map, x, y);
    }
  }

  if (m_pointsLeft == 0)
    emit allPointsRemoved();
}

void SceneHolder::updateMap(const Transmission::map_t& map, const unsigned int x, unsigned int y)
{
  const Transmission::field_t &cur = map[x][y];
  if (cur == Transmission::none)
    return;

  Color::Color color = static_cast<Color::Color>(cur & Transmission::color_mask);
  GameEntity* item = NULL;

  if (cur & Transmission::empty)
  {
    GameEntity *oldItem = visualMap[x][y];
    /* special handling for purging field */
    if (oldItem != NULL)
    {
      /* remove item from visualmap and register item for removal in next update */
      visualMap[x][y] = NULL;
      m_oldItems.append(oldItem);

      /* an item must be removed by an actor */
      Actor *actor = m_actors[color];
      if (actor == NULL)
        Q_ASSERT(false);
      oldItem->onDie(actor);
    }
  }

  if (cur == Transmission::none)
  {
    /* no update */
  }
  else
  {
    if (cur & Transmission::block)
    {
      unsigned int neighbours = Block::None;
      /* check for old block first */
      if (visualMap[x][y] != NULL)
      {
        Block *oldItem = qgraphicsitem_cast<Block *>(visualMap[x][y]);
        if (oldItem != NULL)
          neighbours = oldItem->neighbours();
      }
      /* check left side */
      if (x > 0 && map[x - 1][y] & Transmission::block)
        neighbours |= Block::Left;
      /* check right side */
      if (x < Constants::map_size.width && map[x + 1][y] & Transmission::block)
        neighbours |= Block::Right;
      /* check upside */
      if (y > 0 && map[x][y - 1] & Transmission::block)
        neighbours |= Block::Up;
      /* check down side */
      if (y < Constants::map_size.height && map[x][y + 1] & Transmission::block)
        neighbours |= Block::Down;
      item = new Block(color, neighbours);
    }

    if (cur & Transmission::bonuspoint)
      item = new BonusPoint();

    if (cur & Transmission::point)
    {
      item = new Point();
      connect(item, SIGNAL(destroyed()), this, SLOT(decrementPoints()));
      ++m_pointsLeft;
    }

    if (cur & Transmission::pacman)
    {
      /* WARNING: do NOT add actor to visualMap as visualMap-items may
       * get deleted during update and actors are referenced in_mactors too
       * if you REALLY need that you need to changed updateMap so that all actors
       * will be moved before any new items get allocated (totally untested)
       */
      Actor *actor = m_actors.value(color, NULL);
      if (actor == NULL)
      {
        actor = new Actor(color, (color == m_color));
        m_actors[color] = actor;
        addItem(actor);
        actor->setPos(mapPositionToCoord(x, y));
      }
      else
      {
        Actor::Movement direction = Util::transmissionMovementToActor(
            cur & Transmission::direction_mask);
        /* direction Actor::None is used on round change (i.e. new actor positions)
         * it is animation-safe to use it for this direction only
         */
        if (direction == Actor::None)
          actor->setPos(mapPositionToCoord(x, y));
        actor->move(direction);
        /* that's kind a hack but working right now
         * I think that will fall on our's hat sooner or later
         */
        if (!(cur & Transmission::empty))
          actor->stopEating();
        qDebug() << "[SceneUpdate] actor moves: color=" << color
            << "direction=" << direction << "newpos=" << QPoint(x, y);
      }


      if (cur & Transmission::death)
        m_death[color] = visualMap[x][y];
    }

    if (cur & Transmission::empty)
    {
      /* already handled */
    }
  }

  /* add new created item to scene
   * remove old item on that location if there's one
   */
  if (item != NULL)
  {
    GameEntity *oldItem = visualMap[x][y];
    if (oldItem != NULL)
    {
      removeItem(oldItem);
      delete oldItem;
    }

    addItem(item);
    item->setPos(mapPositionToCoord(x, y));
    visualMap[x][y] = item;
  }
}

void SceneHolder::setColor(Color::Color color)
{
  m_color = color;
}

Color::Color SceneHolder::color()
{
  return m_color;
}

unsigned int SceneHolder::pointsLeft()
{
  return m_pointsLeft;
}

void SceneHolder::decrementPoints()
{
  --m_pointsLeft;
}

void SceneHolder::setEatingOrder(QList<Color::Color> &order)
{
  m_eatingorder = order;
}

QList<Color::Color> &SceneHolder::eatingOrder()
{
  return m_eatingorder;
}

QPoint SceneHolder::mapPositionToCoord(unsigned int x, unsigned int y)
{
  return QPoint(x * Constants::field_size.width, y * Constants::field_size.height);
}

QPoint SceneHolder::mapPositionToCoord(QPoint point)
{
  return mapPositionToCoord(point.x(), point.y());
}

QPoint SceneHolder::CoordToMapPosition(unsigned int x, unsigned int y)
{
  return QPoint(x / Constants::field_size.width, y / Constants::field_size.height);
}

QPoint SceneHolder::CoordToMapPosition(QPoint point)
{
  return CoordToMapPosition(point.x(), point.y());
}