def simulate_move(board, move):
if move == chess.Move.null():
return None
# if its a legal move, don't change it at all (generate_pseudo_legal_moves does not include pseudo legal castles)
if move in board.generate_pseudo_legal_moves() or is_psuedo_legal_castle(board, move):
return move
if is_illegal_castle(board, move):
return None
# if the piece is a sliding piece, slide it as far as it can go
piece = board.piece_at(move.from_square)
if piece.piece_type in [chess.PAWN, chess.ROOK, chess.BISHOP, chess.QUEEN]:
move = slide_move(board, move)
return move if move in board.generate_pseudo_legal_moves() else None
def get_moves(board: chess.Board) -> List[chess.Move]:
""" Accounts for the ability to castle through check. """
return list(set(board.pseudo_legal_moves) | set(move for move in util.moves_without_opponent_pieces(board) if util.is_psuedo_legal_castle(board, move)))
def choose_move(self, move_actions: List[chess.Move], seconds_left: float) -> Optional[chess.Move]:
if seconds_left <= 20:
return None
# skip analyzing if in replay and colors don't match
if REPLAY and self.turn_number % 2 != REPLAYCOLOR:
return
table = {}
start = time.time()
# Ability to pass
moves = list(set(move for board in self.states for move in get_moves(board))) + [None]
# Refresh engine
self.engine = chess.engine.SimpleEngine.popen_uci(os.environ[STOCKFISH_ENV_VAR])
# If only one board just let stockfish play it
if len(self.states) == 1:
board = self.states[0]
# overwrite stockfish only if we are able to take the king this move
# OR in checkmate but are able to castle out
for move in get_moves(board):
# assert board.turn == self.color
if move.to_square == board.king(self.opponent_color):
return move
elif board.is_checkmate() and util.is_psuedo_legal_castle(board, move):
return move
# weird UCI exception stuff on valid board
try:
board.clear_stack()
r = self.engine.play(board, chess.engine.Limit(time=(MIN_TIME + MAX_TIME)/2))
best, score = r.move, r.info.get("score", "unknown")
# default to move analysis
except Exception as e:
logger.error("Caught Stockfish error as " + str(self.color) + " (move may not be accurate)")
logger.error("Error: " + str(e))
while(1):
pass
limit = find_time(len(moves))
table = {move: (evaluate(board, move, self.color) if evaluate(board, move, self.color) is not None else self.stkfsh_eval(board, move, limit))
for move in moves}
best = max(table, key=lambda move: table[move])
score = table[best]
else:
states = self.remove_boards()
node_count = len(moves)*len(states)
logger.info(f"Number of nodes to analyze: {node_count}")
limit = find_time(node_count)
for move in moves:
for state in states:
state.turn = self.color
# move is invalid and equivalent to a pass
new_move = result(state, move)
points = evaluate(state, new_move, self.color)
if points is None:
points = self.stkfsh_eval(state, new_move, limit)
# assuming probability is constant, may change later
table[move] = table.get(move, 0) + points/len(states)
if len(table) == 0: return
best = max(table, key=lambda move: table[move])
score = table[best]
logger.info(f"{best} {score if isinstance(score, str) else round(score, 2)}")
logger.info(f"Time left before starting calculations for current move: {time_str(seconds_left)}")
logger.info(f"Time left now: {time_str(seconds_left - time.time() + start)}")
logger.debug(f"{ {str(k): round(v, 2) for k, v in table.items()} }")
return best
