/****************************************************************************

 Copyright (C) 2002-2008 Gilles Debunne. All rights reserved.

 This file is part of the QGLViewer library version 2.3.1.

 http://www.libqglviewer.com - contact@libqglviewer.com

 This file may be used under the terms of the GNU General Public License 
 versions 2.0 or 3.0 as published by the Free Software Foundation and
 appearing in the LICENSE file included in the packaging of this file.
 In addition, as a special exception, Gilles Debunne gives you certain 
 additional rights, described in the file GPL_EXCEPTION in this package.

 libQGLViewer uses dual licensing. Commercial/proprietary software must
 purchase a libQGLViewer Commercial License.

 This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

*****************************************************************************/

#include "game.h"
#include <fstream>
#include <algorithm>

using namespace std;
using namespace dvonn;

Color
dvonn::colorOf(Player p)
{
  return static_cast<Color>(p+1);
}
Player
dvonn::player(Color c)/* throw (range_error)*/
{
  if (c==Red) throw range_error("No Red Player");
  return static_cast<Player>(c-1);
}
QString
dvonn::nameOf(const Player p)
{
  return p==WhitePlayer?"White":"Black";
}
//************************************************************
// Implementation of Game
//************************************************************
Game::Game()
  : fileName_("savedGame.ago")
{
  reinit();
}
void
Game::reinit()
{
  phase_ = RedPlacementPhase;
  player_ = WhitePlayer;
  board_.reinit();
  ghosts_.clear();
  score_[WhitePlayer] = -1;
  score_[BlackPlayer] = -1;
  time_ = 0;
  historyStates_.clear();
  historyPlayers_.clear();
  historyPhases_.clear();
  historyStates_.push_back(board_.state());
  historyPlayers_.push_back(theOnePlaying());
  historyPhases_.push_back(phase());
}
bool
Game::isOver() const
{
  return phase_ == GameOverPhase;
}
int
Game::score(Player p) const
{
  return score_[p];
}
Game::~Game()
{
}
const Board&
Game::board() const
{
  return board_;
}
Player
Game::theOnePlaying() const
{
  return player_;
}
Phase
Game::phase() const
{
  return phase_;
}
bool
Game::isLegalPlacement(const Placement p) const
{
  return
    board_.getUnplacedPiece(p.color) &&
    !board_.stackAt(p.dst)->hasPieces();
}
bool
Game::isLegalMove(const Move m) const
{
  if (Board::isValid(m.src) && Board::isValid(m.dst))
  {
    Board::ConstStackHandle srcH = board_.stackAt(m.src);
    Board::ConstStackHandle dstH = board_.stackAt(m.dst);
    // Test the src is free
    return
      srcH->onTop()->color() == colorOf(theOnePlaying()) &&
      board_.isFree(srcH) &&
      srcH->hasPieces() &&
      dstH->hasPieces() &&
      Board::areAligned(m.src,m.dst) &&
      Board::distance(m.src,m.dst) == srcH->height();
  }
  return false;
}
bool
Game::doPlacement(Placement p)
{
  if ((phase_==RedPlacementPhase && p.color == Red) ||
      (phase_ == PiecePlacementPhase && p.color == colorOf(theOnePlaying())))
  {
    if (isLegalPlacement(p))
    {
      board_.place(board_.getUnplacedPiece(p.color),p.dst);

      if (phase_==RedPlacementPhase && board_.nbUnplacedPieces(Red) == 0)
      {
	phase_ = PiecePlacementPhase;
      }
      else if (board_.nbUnplacedPieces(White) == 0 &&
	       board_.nbUnplacedPieces(Black) == 0)
      {
	phase_ = MovePhase;
      }
      switchPlayers(player_);
      updateHistory();
      return true;
    }
  }
  return false;
}
bool
Game::doMove(const Move m)
{
  switch (phase_)
  {
  case RedPlacementPhase:
  case PiecePlacementPhase:
    return false;
  case MovePhase:
    if (!isLegalMove(m)) return false;
    ghosts_[m] = board_.move(m.src,m.dst,true);
    switchPlayers(player_);
    updateHistory();
    break;
  case GameOverPhase:
    (void) board_.move(m.src,m.dst,false);
    break;
  }
  return true;
}
const
Board::Ghosts*
Game::killedBy(const Move m) const
{
  map<Move,Board::Ghosts>::const_iterator fter = ghosts_.find(m);
  return (fter == ghosts_.end())?NULL:&(fter->second);
}
deque<Board::ConstStackHandle>
Game::possibleDestinations(const Board::ConstStackHandle& ha) const
{
  deque<Board::ConstStackHandle> r;
  if (ha->hasPieces())
  {
    unsigned int h = ha->height();
    Board::Coord s = ha.stackCoord();
    Board::Coord d[6] = {
      Board::Coord(s.x()-h,s.y()),
      Board::Coord(s.x()+h,s.y()),
      Board::Coord(s.x()  ,s.y()-h),
      Board::Coord(s.x()  ,s.y()+h),
      Board::Coord(s.x()-h,s.y()-h),
      Board::Coord(s.x()+h,s.y()+h)
    };
    for (unsigned int i=0;i<6;++i)
    {
      if (Board::isValid(d[i]) &&
	  board_.stackAt(d[i])->hasPieces())
      {
	r.push_back(board_.stackAt(d[i]));
      }
    }
  }
 return r;
}
void
Game::switchPlayers(Player p)
{
  Player n = (p==WhitePlayer)?BlackPlayer:WhitePlayer;
  if (phase_ != MovePhase)
  {
    player_ = n;
    return;
  }
  Move m;
  if (getRandomMove(n,m))
  {
    player_ = n;
    return;
  }
  if (getRandomMove(p,m))
  {
    player_ = p;
    return;
  }
  phase_ = GameOverPhase;
  // Run thru all the stacks and cumulate heights
  score_[WhitePlayer] = 0;
  score_[BlackPlayer] = 0;
  for (Board::ConstStackIterator
	 iter = board_.stacks_begin(),
	 istop= board_.stacks_end();
       iter != istop;++iter)
  {
    if (iter->hasPieces())
    {
      if (iter->onTop()->color() != Red)
      {
	score_[player(iter->onTop()->color())] += iter->height();
      }
    }
  }
}
void
Game::randomlyFinishPlacement()
{
  deque<Color> s(board_.nbUnplacedPieces(Red),Red);
  deque<Color> w(board_.nbUnplacedPieces(White),White);
  deque<Color> b(board_.nbUnplacedPieces(Black),Black);
  s.insert(s.end(),w.begin(),w.end());
  s.insert(s.end(),b.begin(),b.end());

  random_shuffle(s.begin(),s.end());
  deque<Color>::const_iterator pter = s.begin();
  for (Board::ConstStackIterator
	 iter = board_.stacks_begin(),
	 istop= board_.stacks_end();
       iter != istop;++iter)
  {
    if (!(*iter).hasPieces())
    {
      board_.place(board_.getUnplacedPiece(*pter++),iter.stackCoord());
    }
  }
  phase_ = MovePhase;
  player_ = WhitePlayer;
  updateHistory();
}
bool
Game::getRandomMove(Player p,Game::Move& m) const
{
  deque<Move> moves;
  // Traverse all the cases...
  for (Board::ConstStackIterator
	 iter = board_.stacks_begin(),
	 istop= board_.stacks_end();
       iter != istop;++iter)
  {
    // ... to find a free non empty stack controlled by the player
    if (iter->hasPieces() &&
	iter->onTop()->color() == colorOf(p) &&
	board_.isFree(iter))
    {
      const deque<Board::ConstStackHandle> poss = possibleDestinations(iter);
      for (deque<Board::ConstStackHandle>::const_iterator
	     jter = poss.begin();jter!=poss.end();++jter)
      {
	moves.push_back(Move(iter.stackCoord(),jter->stackCoord()));
      }
    }
  }
  if (!moves.empty())
  {
    random_shuffle(moves.begin(),moves.end());
    m = moves.front();
    return true;
  }
  return false;
}
QString
Game::fileName() const
{
  return fileName_;
}
bool
Game::load(const QString& fileName)
{
  fileName_ = fileName;
#if QT_VERSION < 0x040000
  ifstream f(fileName_.latin1());
#else
    ifstream f(fileName_.toLatin1().constData());
#endif
  if (!f.good()) return false;
  // TODO: load here
  f.close();

  return true;
}
bool
Game::save()
{
#if QT_VERSION < 0x040000
  std::ofstream f(fileName_.latin1());
#else
  std::ofstream f(fileName_.toLatin1().constData());
#endif
  if (!f.good()) return false;
  f.close();
  return true;
}
bool
Game::saveAs(const QString& fileName)
{
  fileName_ = fileName;
  return save();
}
void
Game::updateHistory()
{
  ++time_;
  if (time_>=historyStates_.size()) // cannot be more than size() actually
  {
    historyStates_.push_back(board_.state());
    historyPlayers_.push_back(theOnePlaying());
    historyPhases_.push_back(phase());
  }
  else
  {
    historyStates_[time_] = board_.state();
    historyPlayers_[time_] = theOnePlaying();
    historyPhases_[time_] = phase();
  }
  knownTime_ = 0;
}
bool
Game::canUndo() const
{
  return time_>0;
}
bool
Game::canRedo() const
{
  return time_<knownTime_;
}
void
Game::undo()
{
  if (canUndo())
  {
    if (knownTime_ == 0) knownTime_ = time_;
    --time_;
    board_.restore(historyStates_[time_]);
    player_ = historyPlayers_[time_];
    phase_ = historyPhases_[time_];
  }
}
void
Game::redo()
{
  if (canRedo())
  {
    ++time_;
    board_.restore(historyStates_[time_]);
    player_ = historyPlayers_[time_];
    phase_ = historyPhases_[time_];
  }
}
//************************************************************
// Implementation of Game::Placement
//************************************************************
Game::Placement::Placement(Color c,Board::Coord d)
  : color(c),
    dst(d)
{
}
//************************************************************
// Implementation of Game::Move
//************************************************************
Game::Move::Move(Board::Coord s,Board::Coord d)
  : src(s),
    dst(d)
{
}
bool
Game::Move::operator<(const Move other) const
{
  return src < other.src || (src == other.src && dst < other.dst);
}
ostream&
operator<<(ostream& s,const Game::Placement p)
{
  return s<<nameOf(p.color)<<" ->"<<p.dst;
}
ostream&
operator<<(ostream& s,const Game::Move m)
{
  return s<<m.src<<"->"<<m.dst;
}