def _check_en_passant(self):
if not self._session.last_move:
raise UserActionError('Invalid en passant attack.')
last_move = self._session.last_move
if not isinstance(self.piece, Pawn) or not isinstance(last_move.piece, Pawn):
raise UserActionError('Invalid en passant attack.')
if not self._between(
self.dst.y_label,
last_move.src.y_label,
last_move.dst.y_label):
raise UserActionError('Invalid en passant attack.')
self._en_passant_attack_dst = last_move.dst
def _check_dst_field(self, route):
dst_piece = self._session.board[self.dst]
if route.attack_required:
assert isinstance(self.piece, Pawn)
if not dst_piece:
self._check_en_passant()
elif self.piece.is_white == dst_piece.is_white:
raise UserActionError('This move has to be an attack.')
if route.attack_forbidden:
if dst_piece:
raise UserActionError('This move can\'t be an attack.')
if dst_piece and self.piece.is_white == dst_piece.is_white:
raise UserActionError('You tried to attack your\'s piece.')
def _parse_loc_label(self, loc_label):
try:
x_label, y_label = loc_label
x = self._parse_x_label(x_label)
y = self._parse_y_label(y_label)
except (ValueError, KeyError):
raise UserActionError(
'{!r} is not a valid location label.'.format(loc_label))
return x_label, y_label, x, y
def _set_queen(self, dst):
if self._queen_resolver.is_usable_field(dst):
self._queen_resolver.reserve_field(dst, self._queen)
self.board[dst] = self._queen
self._queen_count += 1
if self._queen_count == self.max_queen_count:
return True
else:
raise UserActionError('You cannot place a queen here!')
return False
def execute(self):
try:
if not self.can_be_done():
raise UserActionError
self._move_the_rook()
except UserActionError:
raise UserActionError(self.move_error_msg)
with critical_part():
# *no* exception should occur here because
# self._move_the_rook() mutated the session
self._move_the_king()
self._disable_future_castlings()
def _check_src_dst_are_distinct(self):
if self.get_vector() == (0, 0):
raise UserActionError('You tried to move to the same location.')
def _check_if_player_owns_src_piece(self):
if self.piece.is_white != self._session.is_white_turn:
raise UserActionError('You tried to move not your piece.')
def _check_src_not_empty(self):
if self.piece is None:
raise UserActionError('Source location does not contain any figure.')
def _check_path(self, route):
for loc in route.path:
if self._session.board[loc] is not None:
raise UserActionError('Other piece on move path.')