/
cook.py
793 lines (717 loc) · 31.2 KB
/
cook.py
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import logging
from typing import List, Optional, Union
import chess
from chess import square_rank, square_file, Board, SquareSet, Piece, PieceType, square_distance
from chess import KING, QUEEN, ROOK, BISHOP, KNIGHT, PAWN
from chess import WHITE, BLACK
from chess.pgn import ChildNode
from model import Puzzle, TagKind
import util
from util import material_diff
logger = logging.getLogger(__name__)
logging.basicConfig(format='%(asctime)s %(levelname)-4s %(message)s', datefmt='%m/%d %H:%M')
logger.setLevel(logging.INFO)
def log(puzzle: Puzzle) -> None:
logger.info("https://lichess.org/training/{}".format(puzzle.id))
def cook(puzzle: Puzzle) -> List[TagKind]:
tags : List[TagKind] = []
mate_tag = mate_in(puzzle)
if mate_tag:
tags.append(mate_tag)
tags.append("mate")
if smothered_mate(puzzle):
tags.append("smotheredMate")
elif back_rank_mate(puzzle):
tags.append("backRankMate")
elif anastasia_mate(puzzle):
tags.append("anastasiaMate")
elif hook_mate(puzzle):
tags.append("hookMate")
elif arabian_mate(puzzle):
tags.append("arabianMate")
else:
found = boden_or_double_bishop_mate(puzzle)
if found:
tags.append(found)
elif dovetail_mate(puzzle):
tags.append("dovetailMate")
elif puzzle.cp > 600:
tags.append("crushing")
elif puzzle.cp > 200:
tags.append("advantage")
else:
tags.append("equality")
if attraction(puzzle):
tags.append("attraction")
if deflection(puzzle):
tags.append("deflection")
elif overloading(puzzle):
tags.append("overloading")
if advanced_pawn(puzzle):
tags.append("advancedPawn")
if double_check(puzzle):
tags.append("doubleCheck")
if quiet_move(puzzle):
tags.append("quietMove")
if defensive_move(puzzle) or check_escape(puzzle):
tags.append("defensiveMove")
if sacrifice(puzzle):
tags.append("sacrifice")
if x_ray(puzzle):
tags.append("xRayAttack")
if fork(puzzle):
tags.append("fork")
if hanging_piece(puzzle):
tags.append("hangingPiece")
if trapped_piece(puzzle):
tags.append("trappedPiece")
if discovered_attack(puzzle):
tags.append("discoveredAttack")
if exposed_king(puzzle):
tags.append("exposedKing")
if skewer(puzzle):
tags.append("skewer")
if self_interference(puzzle) or interference(puzzle):
tags.append("interference")
if intermezzo(puzzle):
tags.append("intermezzo")
if pin_prevents_attack(puzzle) or pin_prevents_escape(puzzle):
tags.append("pin")
if attacking_f2_f7(puzzle):
tags.append("attackingF2F7")
if clearance(puzzle):
tags.append("clearance")
if en_passant(puzzle):
tags.append("enPassant")
if castling(puzzle):
tags.append("castling")
if promotion(puzzle):
tags.append("promotion")
if under_promotion(puzzle):
tags.append("underPromotion")
if capturing_defender(puzzle):
tags.append("capturingDefender")
if piece_endgame(puzzle, PAWN):
tags.append("pawnEndgame")
elif piece_endgame(puzzle, QUEEN):
tags.append("queenEndgame")
elif piece_endgame(puzzle, ROOK):
tags.append("rookEndgame")
elif piece_endgame(puzzle, BISHOP):
tags.append("bishopEndgame")
elif piece_endgame(puzzle, KNIGHT):
tags.append("knightEndgame")
elif queen_rook_endgame(puzzle):
tags.append("queenRookEndgame")
if "backRankMate" not in tags and "fork" not in tags:
if kingside_attack(puzzle):
tags.append("kingsideAttack")
elif queenside_attack(puzzle):
tags.append("queensideAttack")
if len(puzzle.mainline) == 2:
tags.append("oneMove")
elif len(puzzle.mainline) == 4:
tags.append("short")
elif len(puzzle.mainline) >= 8:
tags.append("veryLong")
else:
tags.append("long")
return tags
def advanced_pawn(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
if util.is_very_advanced_pawn_move(node):
return True
return False
def double_check(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
if len(node.board().checkers()) > 1:
return True
return False
def sacrifice(puzzle: Puzzle) -> bool:
# down in material compared to initial position, after moving
diffs = [material_diff(n.board(), puzzle.pov) for n in puzzle.mainline]
initial = diffs[0]
for d in diffs[1::2][1:]:
if d - initial <= -2:
return not any(n.move.promotion for n in puzzle.mainline[::2][1:])
return False
def x_ray(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2][1:]:
if not util.is_capture(node):
continue
prev_op_node = node.parent
assert isinstance(prev_op_node, ChildNode)
if prev_op_node.move.to_square != node.move.to_square or util.moved_piece_type(prev_op_node) == KING:
continue
prev_pl_node = prev_op_node.parent
assert isinstance(prev_pl_node, ChildNode)
if prev_pl_node.move.to_square != prev_op_node.move.to_square:
continue
if prev_op_node.move.from_square in SquareSet.between(node.move.from_square, node.move.to_square):
return True
return False
def fork(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2][:-1]:
if util.moved_piece_type(node) is not KING:
board = node.board()
if util.is_in_bad_spot(board, node.move.to_square):
continue
nb = 0
for (piece, square) in util.attacked_opponent_squares(board, node.move.to_square, puzzle.pov):
if piece.piece_type == PAWN:
continue
if (
util.king_values[piece.piece_type] > util.king_values[util.moved_piece_type(node)] or (
util.is_hanging(board, piece, square) and
square not in board.attackers(not puzzle.pov, node.move.to_square)
)
):
nb += 1
if nb > 1:
return True
return False
def hanging_piece(puzzle: Puzzle) -> bool:
to = puzzle.mainline[1].move.to_square
captured = puzzle.mainline[0].board().piece_at(to)
if puzzle.mainline[0].board().is_check() and (not captured or captured.piece_type == PAWN):
return False
if captured and captured.piece_type != PAWN:
if util.is_hanging(puzzle.mainline[0].board(), captured, to):
op_move = puzzle.mainline[0].move
op_capture = puzzle.game.board().piece_at(op_move.to_square)
if op_capture and util.values[op_capture.piece_type] >= util.values[captured.piece_type] and op_move.to_square == to:
return False
if len(puzzle.mainline) < 4:
return True
if material_diff(puzzle.mainline[3].board(), puzzle.pov) >= material_diff(puzzle.mainline[1].board(), puzzle.pov):
return True
return False
def trapped_piece(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2][1:]:
square = node.move.to_square
captured = node.parent.board().piece_at(square)
if captured and captured.piece_type != PAWN:
prev = node.parent
assert isinstance(prev, ChildNode)
if prev.move.to_square == square:
square = prev.move.from_square
if util.is_trapped(prev.parent.board(), square):
return True
return False
def overloading(puzzle: Puzzle) -> bool:
return False
def discovered_attack(puzzle: Puzzle) -> bool:
if discovered_check(puzzle):
return True
for node in puzzle.mainline[1::2][1:]:
if util.is_capture(node):
between = SquareSet.between(node.move.from_square, node.move.to_square)
assert isinstance(node.parent, ChildNode)
if node.parent.move.to_square == node.move.to_square:
return False
prev = node.parent.parent
assert isinstance(prev, ChildNode)
if (prev.move.from_square in between and
node.move.to_square != prev.move.to_square and
node.move.from_square != prev.move.to_square and
not util.is_castling(prev)
):
return True
return False
def discovered_check(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
board = node.board()
checkers = board.checkers()
if checkers and not node.move.to_square in checkers:
return True
return False
def quiet_move(puzzle: Puzzle) -> bool:
for node in puzzle.mainline:
if (
# on player move, not the last move of the puzzle
node.turn() != puzzle.pov and not node.is_end() and
# no check given or escaped
not node.board().is_check() and not node.parent.board().is_check() and
# no capture made or threatened
not util.is_capture(node) and not util.attacked_opponent_pieces(node.board(), node.move.to_square, puzzle.pov) and
# no advanced pawn push
not util.is_advanced_pawn_move(node) and
util.moved_piece_type(node) != KING
):
return True
return False
def defensive_move(puzzle: Puzzle) -> bool:
# like quiet_move, but on last move
# at least 3 legal moves
if puzzle.mainline[-2].board().legal_moves.count() < 3:
return False
node = puzzle.mainline[-1]
# no check given, no piece taken
if node.board().is_check() or util.is_capture(node):
return False
# no piece attacked
if util.attacked_opponent_pieces(node.board(), node.move.to_square, puzzle.pov):
return False
# no advanced pawn push
return not util.is_advanced_pawn_move(node)
def check_escape(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
if node.board().is_check() or util.is_capture(node):
return False
if node.parent.board().legal_moves.count() < 3:
return False
if node.parent.board().is_check():
return True
return False
def attraction(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1:]:
if node.turn() == puzzle.pov:
continue
# 1. player moves to a square
first_move_to = node.move.to_square
opponent_reply = util.next_node(node)
# 2. opponent captures on that square
if opponent_reply and opponent_reply.move.to_square == first_move_to:
attracted_piece = util.moved_piece_type(opponent_reply)
if attracted_piece in [KING, QUEEN, ROOK]:
attracted_to_square = opponent_reply.move.to_square
next_node = util.next_node(opponent_reply)
if next_node:
attackers = next_node.board().attackers(puzzle.pov, attracted_to_square)
# 3. player attacks that square
if next_node.move.to_square in attackers:
# 4. player checks on that square
if attracted_piece == KING:
return True
n3 = util.next_next_node(next_node)
# 4. or player later captures on that square
if n3 and n3.move.to_square == attracted_to_square:
return True
return False
def deflection(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2][1:]:
captured_piece = node.parent.board().piece_at(node.move.to_square)
if captured_piece or node.move.promotion:
capturing_piece = util.moved_piece_type(node)
if captured_piece and util.king_values[captured_piece.piece_type] > util.king_values[capturing_piece]:
continue
square = node.move.to_square
prev_op_move = node.parent.move
assert(prev_op_move)
grandpa = node.parent.parent
assert isinstance(grandpa, ChildNode)
prev_player_move = grandpa.move
prev_player_capture = grandpa.parent.board().piece_at(prev_player_move.to_square)
if (
(not prev_player_capture or util.values[prev_player_capture.piece_type] < util.moved_piece_type(grandpa)) and
square != prev_op_move.to_square and square != prev_player_move.to_square and
(prev_op_move.to_square == prev_player_move.to_square or grandpa.board().is_check()) and
(
square in grandpa.board().attacks(prev_op_move.from_square) or
node.move.promotion and
square_file(node.move.to_square) == square_file(prev_op_move.from_square) and
node.move.from_square in grandpa.board().attacks(prev_op_move.from_square)
) and
(not square in node.parent.board().attacks(prev_op_move.to_square))
):
return True
return False
def exposed_king(puzzle: Puzzle) -> bool:
if puzzle.pov:
pov = puzzle.pov
board = puzzle.mainline[0].board()
else:
pov = not puzzle.pov
board = puzzle.mainline[0].board().mirror()
king = board.king(not pov)
assert king is not None
if chess.square_rank(king) < 5:
return False
squares = SquareSet.from_square(king - 8)
if chess.square_file(king) > 0:
squares.add(king - 1)
squares.add(king - 9)
if chess.square_file(king) < 7:
squares.add(king + 1)
squares.add(king - 7)
for square in squares:
if board.piece_at(square) == Piece(PAWN, not pov):
return False
for node in puzzle.mainline[1::2][1:-1]:
if node.board().is_check():
return True
return False
def skewer(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2][1:]:
prev = node.parent
assert isinstance(prev, ChildNode)
capture = prev.board().piece_at(node.move.to_square)
if capture and util.moved_piece_type(node) in util.ray_piece_types and not node.board().is_checkmate():
between = SquareSet.between(node.move.from_square, node.move.to_square)
op_move = prev.move
assert op_move
if (op_move.to_square == node.move.to_square or not op_move.from_square in between):
continue
if (
util.king_values[util.moved_piece_type(prev)] > util.king_values[capture.piece_type] and
util.is_in_bad_spot(prev.board(), node.move.to_square)
):
return True
return False
def self_interference(puzzle: Puzzle) -> bool:
# intereference by opponent piece
for node in puzzle.mainline[1::2][1:]:
prev_board = node.parent.board()
square = node.move.to_square
capture = prev_board.piece_at(square)
if capture and util.is_hanging(prev_board, capture, square):
grandpa = node.parent.parent
assert grandpa
init_board = grandpa.board()
defenders = init_board.attackers(capture.color, square)
defender = defenders.pop() if defenders else None
defender_piece = init_board.piece_at(defender) if defender else None
if defender and defender_piece and defender_piece.piece_type in util.ray_piece_types:
if node.parent.move and node.parent.move.to_square in SquareSet.between(square, defender):
return True
return False
def interference(puzzle: Puzzle) -> bool:
# intereference by player piece
for node in puzzle.mainline[1::2][1:]:
prev_board = node.parent.board()
square = node.move.to_square
capture = prev_board.piece_at(square)
assert node.parent.move
if capture and square != node.parent.move.to_square and util.is_hanging(prev_board, capture, square):
assert node.parent
assert node.parent.parent
assert node.parent.parent.parent
init_board = node.parent.parent.parent.board()
defenders = init_board.attackers(capture.color, square)
defender = defenders.pop() if defenders else None
defender_piece = init_board.piece_at(defender) if defender else None
if defender and defender_piece and defender_piece.piece_type in util.ray_piece_types:
interfering = node.parent.parent
if interfering.move and interfering.move.to_square in SquareSet.between(square, defender):
return True
return False
def intermezzo(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2][1:]:
if util.is_capture(node):
capture_move = node.move
capture_square = node.move.to_square
op_node = node.parent
assert isinstance(op_node, ChildNode)
prev_pov_node = node.parent.parent
assert isinstance(prev_pov_node, ChildNode)
if not op_node.move.from_square in prev_pov_node.board().attackers(not puzzle.pov, capture_square):
if prev_pov_node.move.to_square != capture_square:
prev_op_node = prev_pov_node.parent
assert isinstance(prev_op_node, ChildNode)
return (
prev_op_node.move.to_square == capture_square and
util.is_capture(prev_op_node) and
capture_move in prev_op_node.board().legal_moves
)
return False
# the pinned piece can't attack a player piece
def pin_prevents_attack(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
board = node.board()
for square, piece in board.piece_map().items():
if piece.color == puzzle.pov:
continue
pin_dir = board.pin(piece.color, square)
if pin_dir == chess.BB_ALL:
continue
for attack in board.attacks(square):
attacked = board.piece_at(attack)
if attacked and attacked.color == puzzle.pov and not attack in pin_dir and (
util.values[attacked.piece_type] > util.values[piece.piece_type] or
util.is_hanging(board, attacked, attack)
):
return True
return False
# the pinned piece can't escape the attack
def pin_prevents_escape(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
board = node.board()
for pinned_square, pinned_piece in board.piece_map().items():
if pinned_piece.color == puzzle.pov:
continue
pin_dir = board.pin(pinned_piece.color, pinned_square)
if pin_dir == chess.BB_ALL:
continue
for attacker_square in board.attackers(puzzle.pov, pinned_square):
if attacker_square in pin_dir:
attacker = board.piece_at(attacker_square)
assert(attacker)
if util.values[pinned_piece.piece_type] > util.values[attacker.piece_type]:
return True
if (util.is_hanging(board, pinned_piece, pinned_square) and
pinned_square not in board.attackers(not puzzle.pov, attacker_square) and
[m for m in board.pseudo_legal_moves if m.from_square == pinned_square and m.to_square not in pin_dir]
):
return True
return False
def attacking_f2_f7(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
square = node.move.to_square
if node.parent.board().piece_at(node.move.to_square) and square in [chess.F2, chess.F7]:
king = node.board().piece_at(chess.E8 if square == chess.F7 else chess.E1)
return king is not None and king.piece_type == KING and king.color != puzzle.pov
return False
def kingside_attack(puzzle: Puzzle) -> bool:
return side_attack(puzzle, 7, [6, 7], 20)
def queenside_attack(puzzle: Puzzle) -> bool:
return side_attack(puzzle, 0, [0, 1, 2], 18)
def side_attack(puzzle: Puzzle, corner_file: int, king_files: List[int], nb_pieces: int) -> bool:
back_rank = 7 if puzzle.pov else 0
init_board = puzzle.mainline[0].board()
king_square = init_board.king(not puzzle.pov)
if (
not king_square or
square_rank(king_square) != back_rank or
square_file(king_square) not in king_files or
len(init_board.piece_map()) < nb_pieces or # no endgames
not any(node.board().is_check() for node in puzzle.mainline[1::2])
):
return False
score = 0
corner = chess.square(corner_file, back_rank)
for node in puzzle.mainline[1::2]:
corner_dist = square_distance(corner, node.move.to_square)
if node.board().is_check():
score += 1
if util.is_capture(node) and corner_dist <= 3:
score += 1
elif corner_dist >= 5:
score -= 1
return score >= 2
def clearance(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2][1:]:
board = node.board()
if not node.parent.board().piece_at(node.move.to_square):
piece = board.piece_at(node.move.to_square)
if piece and piece.piece_type in util.ray_piece_types:
prev = node.parent.parent
assert prev
prev_move = prev.move
assert prev_move
assert isinstance(node.parent, ChildNode)
if (not prev_move.promotion and
prev_move.to_square != node.move.from_square and
prev_move.to_square != node.move.to_square and
not node.parent.board().is_check() and
(not board.is_check() or util.moved_piece_type(node.parent) != KING)):
if (prev_move.from_square == node.move.to_square or
prev_move.from_square in SquareSet.between(node.move.from_square, node.move.to_square)):
if prev.parent and not prev.parent.board().piece_at(prev_move.to_square) or util.is_in_bad_spot(prev.board(), prev_move.to_square):
return True
return False
def en_passant(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
if (util.moved_piece_type(node) == PAWN and
square_file(node.move.from_square) != square_file(node.move.to_square) and
not node.parent.board().piece_at(node.move.to_square)
):
return True
return False
def castling(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
if util.is_castling(node):
return True
return False
def promotion(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
if node.move.promotion:
return True
return False
def under_promotion(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2]:
if node.board().is_checkmate():
return True if node.move.promotion == KNIGHT else False
elif node.move.promotion and node.move.promotion != QUEEN:
return True
return False
def capturing_defender(puzzle: Puzzle) -> bool:
for node in puzzle.mainline[1::2][1:]:
board = node.board()
capture = node.parent.board().piece_at(node.move.to_square)
assert isinstance(node.parent, ChildNode)
if board.is_checkmate() or (
capture and
util.moved_piece_type(node) != KING and
util.values[capture.piece_type] <= util.values[util.moved_piece_type(node)] and
util.is_hanging(node.parent.board(), capture, node.move.to_square) and
node.parent.move.to_square != node.move.to_square
):
prev = node.parent.parent
assert isinstance(prev, ChildNode)
if not prev.board().is_check() and prev.move.to_square != node.move.from_square:
assert prev.parent
init_board = prev.parent.board()
defender_square = prev.move.to_square
defender = init_board.piece_at(defender_square)
if (defender and
defender_square in init_board.attackers(defender.color, node.move.to_square) and
not init_board.is_check()):
return True
return False
def back_rank_mate(puzzle: Puzzle) -> bool:
node = puzzle.game.end()
board = node.board()
king = board.king(not puzzle.pov)
assert king is not None
assert isinstance(node, ChildNode)
back_rank = 7 if puzzle.pov else 0
if board.is_checkmate() and square_rank(king) == back_rank:
squares = SquareSet.from_square(king + (-8 if puzzle.pov else 8))
if puzzle.pov:
if chess.square_file(king) < 7:
squares.add(king - 7)
if chess.square_file(king) > 0:
squares.add(king - 9)
else:
if chess.square_file(king) < 7:
squares.add(king + 9)
if chess.square_file(king) > 0:
squares.add(king + 7)
for square in squares:
piece = board.piece_at(square)
if piece is None or piece.color == puzzle.pov or board.attackers(puzzle.pov, square):
return False
return any(square_rank(checker) == back_rank for checker in board.checkers())
return False
def anastasia_mate(puzzle: Puzzle) -> bool:
node = puzzle.game.end()
board = node.board()
king = board.king(not puzzle.pov)
assert king is not None
assert isinstance(node, ChildNode)
if square_file(king) in [0, 7] and square_rank(king) not in [0, 7]:
if square_file(node.move.to_square) == square_file(king) and util.moved_piece_type(node) in [QUEEN, ROOK]:
if square_file(king) != 0:
board.apply_transform(chess.flip_horizontal)
king = board.king(not puzzle.pov)
assert king is not None
blocker = board.piece_at(king + 1)
if blocker is not None and blocker.color != puzzle.pov:
knight = board.piece_at(king + 3)
if knight is not None and knight.color == puzzle.pov and knight.piece_type == KNIGHT:
return True
return False
def hook_mate(puzzle: Puzzle) -> bool:
node = puzzle.game.end()
board = node.board()
king = board.king(not puzzle.pov)
assert king is not None
assert isinstance(node, ChildNode)
if util.moved_piece_type(node) == ROOK and square_distance(node.move.to_square, king) == 1:
for rook_defender_square in board.attackers(puzzle.pov, node.move.to_square):
defender = board.piece_at(rook_defender_square)
if defender and defender.piece_type == KNIGHT and square_distance(rook_defender_square, king) == 1:
for knight_defender_square in board.attackers(puzzle.pov, rook_defender_square):
pawn = board.piece_at(knight_defender_square)
if pawn and pawn.piece_type == PAWN:
return True
return False
def arabian_mate(puzzle: Puzzle) -> bool:
node = puzzle.game.end()
board = node.board()
king = board.king(not puzzle.pov)
assert king is not None
assert isinstance(node, ChildNode)
if square_file(king) in [0, 7] and square_rank(king) in [0, 7] and util.moved_piece_type(node) == ROOK and square_distance(node.move.to_square, king) == 1:
for knight_square in board.attackers(puzzle.pov, node.move.to_square):
knight = board.piece_at(knight_square)
if knight and knight.piece_type == KNIGHT and (
abs(square_rank(knight_square) - square_rank(king)) == 2 and
abs(square_file(knight_square) - square_file(king)) == 2
):
return True
return False
def boden_or_double_bishop_mate(puzzle: Puzzle) -> Optional[TagKind]:
node = puzzle.game.end()
board = node.board()
king = board.king(not puzzle.pov)
assert king is not None
assert isinstance(node, ChildNode)
bishop_squares = list(board.pieces(BISHOP, puzzle.pov))
if len(bishop_squares) < 2:
return None
for square in [s for s in SquareSet(chess.BB_ALL) if square_distance(s, king) < 2]:
if not all([p.piece_type == BISHOP for p in util.attacker_pieces(board, puzzle.pov, square)]):
return None
if (square_file(bishop_squares[0]) < square_file(king)) == (square_file(bishop_squares[1]) > square_file(king)):
return "bodenMate"
else:
return "doubleBishopMate"
def dovetail_mate(puzzle: Puzzle) -> bool:
node = puzzle.game.end()
board = node.board()
king = board.king(not puzzle.pov)
assert king is not None
assert isinstance(node, ChildNode)
if square_file(king) in [0, 7] or square_rank(king) in [0, 7]:
return False
queen_square = node.move.to_square
if (util.moved_piece_type(node) != QUEEN or
square_file(queen_square) == square_file(king) or
square_rank(queen_square) == square_rank(king) or
square_distance(queen_square, king) > 1):
return False
for square in [s for s in SquareSet(chess.BB_ALL) if square_distance(s, king) == 1]:
if square == queen_square:
continue
attackers = list(board.attackers(puzzle.pov, square))
if attackers == [queen_square]:
if board.piece_at(square):
return False
elif attackers:
return False
return True
def piece_endgame(puzzle: Puzzle, piece_type: PieceType) -> bool:
for board in [puzzle.mainline[i].board() for i in [0, 1]]:
if not board.pieces(piece_type, WHITE) and not board.pieces(piece_type, BLACK):
return False
for piece in board.piece_map().values():
if not piece.piece_type in [KING, PAWN, piece_type]:
return False
return True
def queen_rook_endgame(puzzle: Puzzle) -> bool:
def test(board: Board) -> bool:
pieces = board.piece_map().values()
return (
len([p for p in pieces if p.piece_type == QUEEN]) == 1 and
any(p.piece_type == ROOK for p in pieces) and
all(p.piece_type in [QUEEN, ROOK, PAWN, KING] for p in pieces)
)
return all(test(puzzle.mainline[i].board()) for i in [0, 1])
def smothered_mate(puzzle: Puzzle) -> bool:
board = puzzle.game.end().board()
king_square = board.king(not puzzle.pov)
assert king_square is not None
for checker_square in board.checkers():
piece = board.piece_at(checker_square)
assert piece
if piece.piece_type == KNIGHT:
for escape_square in [s for s in chess.SQUARES if square_distance(s, king_square) == 1]:
blocker = board.piece_at(escape_square)
if not blocker or blocker.color == puzzle.pov:
return False
return True
return False
def mate_in(puzzle: Puzzle) -> Optional[TagKind]:
if not puzzle.game.end().board().is_checkmate():
return None
moves_to_mate = len(puzzle.mainline) // 2
if moves_to_mate == 1:
return "mateIn1"
elif moves_to_mate == 2:
return "mateIn2"
elif moves_to_mate == 3:
return "mateIn3"
elif moves_to_mate == 4:
return "mateIn4"
return "mateIn5"