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

 Copyright (C) 2002-2014 Gilles Debunne. All rights reserved.

 This file is part of the QGLViewer library version 2.8.0.

 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 "board.h"
#include <qmessagebox.h>

bool Board::canBeSelected(int i) {
  QPoint p = pointFromInt(i);
  return (isValid(p) && (stateOf(p) == Board::blueColor(bluePlays())) &&
          (pieceCanMove(p)));
}

bool Board::isValid(const QPoint &p) const {
  return ((p.x() >= 0) && (p.y() >= 0) && (p.x() < sizeX_) &&
          (p.y() < sizeY_) && (stateOf(p) != HOLE));
}

void Board::play(const Move &m) {
  if (!m.isValid(this)) {
    QMessageBox::critical(NULL, "Invalid move", "Invalid move");
    return;
  }

  if (!m.isClose())
    setStateOf(m.start(), Board::EMPTY);

  setStateOf(m.end(), Board::blueColor(bluePlays()));

  for (int i = -1; i <= 1; ++i)
    for (int j = -1; j <= 1; ++j) {
      const QPoint p(m.end().x() + i, m.end().y() + j);
      if (isValid(p) && stateOf(p) == Board::blueColor(!bluePlays()))
        setStateOf(p, Board::blueColor(bluePlays()));
    }

  undo_.addState(stateString());
  bluePlays_ = !bluePlays_;
}

bool Board::gameIsOver() const {
  bool thereAreRed = false;
  bool thereAreBlue = false;
  bool thereAreEmpty = false;
  bool moveIsPossible = false;

  for (int i = 0; i < sizeX_; ++i)
    for (int j = 0; j < sizeY_; ++j) {
      const QPoint p(i, j);
      Board::State state = stateOf(p);
      if (state == EMPTY)
        thereAreEmpty = true;
      if (state == RED)
        thereAreRed = true;
      if (state == BLUE)
        thereAreBlue = true;
      if (state == Board::blueColor(bluePlays()) && (pieceCanMove(p)))
        moveIsPossible = true;
    }

  return !thereAreRed || !thereAreBlue || !thereAreEmpty || !moveIsPossible;
}

#if QT_VERSION < 0x040000
QValueVector<Move> Board::possibleMoves(bool bluePlays) const {
  QValueVector<Move> res;
#else
QVector<Move> Board::possibleMoves(bool bluePlays) const {
  QVector<Move> res;
#endif
  for (int i = 0; i < sizeX_; ++i)
    for (int j = 0; j < sizeY_; ++j) {
      const QPoint s(i, j);
      if (stateOf(s) == Board::blueColor(bluePlays)) {
        for (int ii = -2; ii <= 2; ++ii)
          for (int jj = -2; jj <= 2; ++jj) {
            const QPoint e(s.x() + ii, s.y() + jj);
            if (isValid(e) && stateOf(e) == Board::EMPTY)
              res.append(Move(s, e));
          }
      }
    }
  return res;
}

bool Board::pieceCanMove(const QPoint &p) const {
  for (int i = -2; i <= 2; ++i)
    for (int j = -2; j <= 2; ++j) {
      const QPoint q(p.x() + i, p.y() + j);
      if (isValid(q) && stateOf(q) == Board::EMPTY)
        return true;
    }
  return false;
}

void Board::setStateOf(const QPoint &p, State s) {
  if (stateOf(p) == RED)
    nbRed_--;
  if (stateOf(p) == BLUE)
    nbBlue_--;

  board_[p.x()][p.y()] = s;

  if (stateOf(p) == RED)
    nbRed_++;
  if (stateOf(p) == BLUE)
    nbBlue_++;
}

QString Board::stateString() const {
  QString res;

  for (int i = 0; i < sizeX_; ++i)
    for (int j = 0; j < sizeY_; ++j)
      switch (board_[i][j]) {
      case Board::EMPTY:
        res.append('.');
        break;
      case Board::RED:
        res.append('R');
        break;
      case Board::BLUE:
        res.append('B');
        break;
      case Board::HOLE:
        res.append('X');
        break;
      }
  return res;
}

std::ostream &operator<<(std::ostream &out, const Board &b) {
  out << b.sizeX_ << " " << b.sizeY_ << std::endl;

  QString s = b.stateString();

  for (int i = 0; i < b.sizeX_; ++i)
#if QT_VERSION < 0x040000
    out << s.mid(i * b.sizeY_, b.sizeY_).latin1() << std::endl;
#else
    out << s.mid(i * b.sizeY_, b.sizeY_).toLatin1().constData() << std::endl;
#endif

  out << b.undo_;

  return out;
}

void Board::initFromStateString(const QString &s) {
  nbBlue_ = nbRed_ = 0;

  for (int i = 0; i < sizeX_; ++i)
    for (int j = 0; j < sizeY_; ++j)
#if QT_VERSION < 0x040000
      switch (s[i * sizeY_ + j].latin1())
#else
      switch (s[i * sizeY_ + j].toLatin1())
#endif
      {
      case '.':
        board_[i][j] = Board::EMPTY;
        break;
      case 'R':
        board_[i][j] = Board::RED;
        nbRed_++;
        break;
      case 'B':
        board_[i][j] = Board::BLUE;
        nbBlue_++;
        break;
      case 'X':
        board_[i][j] = Board::HOLE;
        break;
      }
}

std::istream &operator>>(std::istream &in, Board &b) {
  int sx, sy;
  in >> sx >> sy;
  b.resize(sx, sy);

  char c;
  QString s;
  for (int i = 0; i < sx; ++i)
    for (int j = 0; j < sy; ++j) {
      in >> c;
      s.append(c);
    }

  b.initFromStateString(s);

  in >> b.undo_;

  if (b.undo_.isEmpty())
    b.undo_.addState(s);

  b.bluePlays_ = (b.undo_.nbMoves() % 2 == 1);

  return in;
}

void Board::resize(int sizeX, int sizeY) {
  if (board_) {
    for (int i = 0; i < sizeX_; ++i)
      delete[] board_[i];
    delete[] board_;
  }

  sizeX_ = sizeX;
  sizeY_ = sizeY;

  board_ = new int *[sizeX_];
  for (int i = 0; i < sizeX_; ++i)
    board_[i] = new int[sizeY_];
}

bool Board::undo() {
  QString state = undo_.undoState();
  if (state.isEmpty())
    return false;
  else
    initFromStateString(state);
  bluePlays_ = !bluePlays_;
  return true;
}

bool Board::redo() {
  QString state = undo_.redoState();
  if (state.isEmpty())
    return false;
  else
    initFromStateString(state);
  bluePlays_ = !bluePlays_;
  return true;
}

Move Board::bestMoveNumberOfNewPieces() const {
  Move res;
  int bestValue = 0;
#if QT_VERSION < 0x040000
  QValueVector<Move> moves = possibleMoves(bluePlays());
#else
  QVector<Move> moves = possibleMoves(bluePlays());
#endif
  for (int i = 0; i < int(moves.size()); ++i) {
    int value = moves[i].numberOfNewPieces(*this);
    if (value > bestValue) {
      bestValue = value;
      res = moves[i];
    }
  }
  return res;
}

QString Board::statusMessage() const {
  const QString score = "Blue : " + QString::number(nbBlue_) +
                        " - Red : " + QString::number(nbRed_);

  if (gameIsOver())
    if (nbBlue_ == nbRed_)
      return "Deuce !\n" + score;
    else
      return QString("The ") + ((nbBlue_ > nbRed_) ? "Blue" : "Red") +
             " won !\n" + score;
  else
    return score + " - " + (bluePlays_ ? "Blue" : "Red") + " plays";
}
