/**
* This method finds the ordering of all the line segments that are removable from the current
* board state in the current turn for each player.
*
* @param pieceMap
* @param currentPlayerColor
* @return An example output could be: {set: ["white", "segment from a to b"] ["white", "segment
* from b to c"] ["black", "segment from x to y"] ["black", "segment from z to a"; after that
* "white", "segment from a to b"] ["black", "segment from d to f"] }
*/
private Set<List<Pair<PieceColor, Line.Segment>>> getRemovableLineOrderingsSetFromGipfBoard(
Map<Position, Piece> pieceMap, PieceColor currentPlayerColor) {
Set<List<Pair<PieceColor, Line.Segment>>> removableLineSetOrderingsFromGipfboard =
new HashSet<>();
PieceColor opponentColor = currentPlayerColor == WHITE ? BLACK : WHITE;
Set<Line.Segment> removableLineSegmentsCurrentPlayer =
getRemovableLineSegments(pieceMap, currentPlayerColor);
// This loop checks for all line segments that can be removed by the current player.
for (Line.Segment lineSegment : removableLineSegmentsCurrentPlayer) {
// Create a copy of the piecemap where the removed segment is removed
HashMap<Position, Piece> segmentRemovedPieceMap = new HashMap<>(pieceMap);
segmentRemovedPieceMap
.keySet()
.removeAll(lineSegment.getOccupiedPositions(segmentRemovedPieceMap));
List<Pair<PieceColor, Line.Segment>> removableLineSegmentOrdering =
Collections.singletonList(new Pair<>(currentPlayerColor, lineSegment));
// - I have to use removableLineSegmentList because the removableLineSegmentOrdering is
// already in use.
// - If the current player can remove at least 1 more segment, the board state that results
// will be checked
// after that for more subsequent segments that can be removed
Set<List<Pair<PieceColor, Line.Segment>>> removableLineSetOrderingsCurrentPlayer =
getRemovableLineOrderingsSetFromGipfBoard(segmentRemovedPieceMap, currentPlayerColor);
if (removableLineSetOrderingsCurrentPlayer.size() > 0) {
for (List<Pair<PieceColor, Line.Segment>> removableLineSegmentList :
removableLineSetOrderingsCurrentPlayer) {
List<Pair<PieceColor, Line.Segment>> ordering =
new ArrayList<>(removableLineSegmentOrdering);
ordering.addAll(removableLineSegmentList);
removableLineSetOrderingsFromGipfboard.add(ordering);
}
} else {
removableLineSetOrderingsFromGipfboard.add(removableLineSegmentOrdering);
}
// Now check for the line segments removable by the opponent
// Because if this code is ran, the current player can remove line segments. If this is the
// case, the current player
// must remove line segments before the opponent gets its turn.
for (Line.Segment lineSegmenRemovableByOpponent :
getRemovableLineSegments(segmentRemovedPieceMap, opponentColor)) {
// See for the comments in the similar lines above
HashMap<Position, Piece> opponentSegmentRemovedPieceMap =
new HashMap<>(segmentRemovedPieceMap);
opponentSegmentRemovedPieceMap
.keySet()
.removeAll(
lineSegmenRemovableByOpponent.getOccupiedPositions(opponentSegmentRemovedPieceMap));
List<Pair<PieceColor, Line.Segment>> opponentRemovableLineSegmentOrdering =
Collections.singletonList(new Pair<>(opponentColor, lineSegmenRemovableByOpponent));
Set<List<Pair<PieceColor, Line.Segment>>> removableLineSetOrderingsOpponent =
getRemovableLineOrderingsSetFromGipfBoard(
opponentSegmentRemovedPieceMap, opponentColor);
if (removableLineSetOrderingsOpponent.size() > 0) {
for (List<Pair<PieceColor, Line.Segment>> removableLineSegmentOpponentList :
removableLineSetOrderingsOpponent) {
List<Pair<PieceColor, Line.Segment>> ordering =
new ArrayList<>(opponentRemovableLineSegmentOrdering);
ordering.addAll(removableLineSegmentOpponentList);
removableLineSetOrderingsFromGipfboard.add(ordering);
}
} else {
removableLineSetOrderingsFromGipfboard.add(opponentRemovableLineSegmentOrdering);
}
}
}
if (removableLineSegmentsCurrentPlayer.size() == 0) {
// The current player can't remove any line segments, so the opponent can try to remove line
// segments
for (Line.Segment lineSegment : getRemovableLineSegments(pieceMap, opponentColor)) {
// See for the comments the similar lines above
HashMap<Position, Piece> segmentRemovedPieceMap = new HashMap<>(pieceMap);
segmentRemovedPieceMap
.keySet()
.removeAll(lineSegment.getOccupiedPositions(segmentRemovedPieceMap));
List<Pair<PieceColor, Line.Segment>> removableLineSegmentOrdering =
Collections.singletonList(new Pair<>(opponentColor, lineSegment));
Set<List<Pair<PieceColor, Line.Segment>>> removableLineSetOrderingsOpponent =
getRemovableLineOrderingsSetFromGipfBoard(segmentRemovedPieceMap, opponentColor);
if (removableLineSetOrderingsOpponent.size() > 0) {
for (List<Pair<PieceColor, Line.Segment>> removableLineSegmentList :
removableLineSetOrderingsOpponent) {
List<Pair<PieceColor, Line.Segment>> ordering =
new ArrayList<>(removableLineSegmentOrdering);
ordering.addAll(removableLineSegmentList);
removableLineSetOrderingsFromGipfboard.add(ordering);
}
} else {
removableLineSetOrderingsFromGipfboard.add(removableLineSegmentOrdering);
}
}
}
return removableLineSetOrderingsFromGipfboard;
}
public Set<Move> getAllowedMoves() {
// If there is already a winn
if (gipfBoardState.players.winner() != null) {
return Collections.emptySet();
}
// Create a set of incomplete moves containing the starting positions and directions for the
// current piece
Set<Move> potentialMoves = getPotentialStartMoves(getCurrentPiece());
// If the current piece is a GIPF piece, the player is also allowed to place normal pieces.
if (getCurrentPiece().getPieceType() == GIPF)
potentialMoves.addAll(
getPotentialStartMoves(Piece.of(NORMAL, getCurrentPiece().getPieceColor())));
// These moves are marked as complete so a temporary game won't ask for user input.
potentialMoves.stream().forEach(m -> m.isCompleteMove = true);
Set<Move> potentialMovesIncludingLineSegmentRemoval = new HashSet<>();
for (Move potentialMove : potentialMoves) {
try {
Map<Position, Piece> temporaryPieceMap = new HashMap<>(getGipfBoardState().getPieceMap());
temporaryPieceMap.put(potentialMove.startPos, potentialMove.addedPiece);
movePiecesTowards(
temporaryPieceMap, potentialMove.getStartingPosition(), potentialMove.getDirection());
Set<List<Pair<PieceColor, Line.Segment>>> RLineOrderingsSet =
getRemovableLineOrderingsSetFromGipfBoard(
temporaryPieceMap, getCurrentPiece().getPieceColor());
if (RLineOrderingsSet.size() > 0) {
for (List<Pair<PieceColor, Line.Segment>> RLineOrdering : RLineOrderingsSet) {
Set<Position> piecesToWhite = new HashSet<>();
Set<Position> piecesToBlack = new HashSet<>();
Set<Position> piecesRemoved = new HashSet<>();
for (Pair<PieceColor, Line.Segment> RLine : RLineOrdering) {
Line.Segment removedSegment = RLine.getValue();
// The color of the player who removed the line
PieceColor colorRemoved = RLine.getKey();
// Determine per segment to whom the pieces are given. Pieces can only be given to the
// player
// who removed the line, or deleted from the game.
Set<Position> occupiedPositions =
removedSegment.getOccupiedPositions(temporaryPieceMap);
Set<Position> piecesFromSegmentBackToReserve =
occupiedPositions
.stream()
.filter(
position ->
temporaryPieceMap.get(position).getPieceColor() == colorRemoved)
.collect(toSet());
Set<Position> piecesFromSegmentRemoved =
occupiedPositions
.stream()
.filter(position -> !piecesFromSegmentBackToReserve.contains(position))
.collect(toSet());
if (colorRemoved == WHITE) piecesToWhite.addAll(piecesFromSegmentBackToReserve);
if (colorRemoved == BLACK) piecesToBlack.addAll(piecesFromSegmentBackToReserve);
piecesRemoved.addAll(piecesFromSegmentRemoved);
}
// And finally add the move
// the constructor will define this as a complete move, because all the parameters have
// a value.
potentialMovesIncludingLineSegmentRemoval.add(
new Move(
potentialMove.addedPiece,
potentialMove.startPos,
potentialMove.direction,
piecesToWhite,
piecesToBlack,
piecesRemoved));
}
} else {
// If no line segments can be removed, just add the original move
potentialMovesIncludingLineSegmentRemoval.add(potentialMove);
}
} catch (InvalidMoveException e) {
// We don't consider this move if it is invalid
}
}
return potentialMovesIncludingLineSegmentRemoval;
}