X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=Board.pm;h=d6a0f5524869360b4f171f226aa17086fb34c8da;hp=6af89f39819d16e520d4ff753f0b3db161b901e2;hb=aab426550a1da4daea35eb0b0691fe8bd7907348;hpb=762b4cb898d3300233b773eff370a1562a445efe

diff --git a/Board.pm b/Board.pm
index 6af89f3..d6a0f55 100644
--- a/Board.pm
+++ b/Board.pm
@@ -103,20 +103,19 @@ sub make_move {
 			# en passant?
 			if ($board->[$to_row][$to_col] eq '-') {
 				if ($piece eq 'p') {
-					$nb->[$to_row + 1][$to_col] = '-';
-				} else {
 					$nb->[$to_row - 1][$to_col] = '-';
-				}
-			}
-		} else {
-			if ($promo ne '') {
-				if ($piece eq 'p') {
-					$piece = $promo;
 				} else {
-					$piece = uc($promo);
+					$nb->[$to_row + 1][$to_col] = '-';
 				}
 			}
 		}
+		if (defined($promo) && $promo ne '') {
+			if ($piece eq 'p') {
+				$piece = lc($promo);
+			} else {
+				$piece = uc($promo);
+			}
+		}
 	}
 
 	# update the board
@@ -131,12 +130,86 @@ sub _pos_to_square {
 	return sprintf("%c%d", ord('a') + $col, 8 - $row);
 }
 
+sub _col_letter_to_num {
+        return ord(shift) - ord('a');
+}
+
+sub _row_letter_to_num {
+        return 7 - (ord(shift) - ord('1'));
+}
+
+sub _square_to_pos {
+	my ($square) = @_;
+	$square =~ /^([a-h])([1-8])$/ or die "Invalid square $square";	
+	return (_row_letter_to_num($2), _col_letter_to_num($1));
+}
+
 sub _move_to_uci_notation {
 	my ($from_row, $from_col, $to_row, $to_col, $promo) = @_;
 	$promo //= "";
 	return _pos_to_square($from_row, $from_col) . _pos_to_square($to_row, $to_col) . $promo;
 }
 
+sub parse_pretty_move {
+	my ($board, $move, $toplay) = @_;
+
+	# Strip check or mate
+	$move =~ s/[+#]$//;
+
+	if ($move eq '0-0' or $move eq 'O-O') {
+		if ($toplay eq 'W') {
+			return (_square_to_pos('e1'), _square_to_pos('g1'));
+		} else {
+			return (_square_to_pos('e8'), _square_to_pos('g8'));
+		}
+	} elsif ($move eq '0-0-0' or $move eq 'O-O-O') {
+		if ($toplay eq 'W') {
+			return (_square_to_pos('e1'), _square_to_pos('c1'));
+		} else {
+			return (_square_to_pos('e8'), _square_to_pos('c8'));
+		}
+	}
+
+	# Parse promo
+	my $promo;
+	if ($move =~ s/=([QRNB])$//) {
+		$promo = $1;
+	}
+
+	$move =~ /^([KQRBN])?([a-h])?([1-8])?x?([a-h][1-8])$/ or die "Invalid move $move";
+	my $piece = $1 // 'P';
+	my $from_col = defined($2) ? _col_letter_to_num($2) : undef;
+	my $from_row = defined($3) ? _row_letter_to_num($3) : undef;
+	my ($to_row, $to_col) = _square_to_pos($4);
+	
+	# Find all possible from-squares that could have been meant.
+	my @squares = ();
+	if ($toplay eq 'B') {
+		$piece = lc($piece);
+	}
+	for my $row (0..7) {
+		next if (defined($from_row) && $from_row != $row);
+		for my $col (0..7) {
+			next if (defined($from_col) && $from_col != $col);
+			next if ($board->[$row][$col] ne $piece);
+			next if (!$board->can_reach($piece, $row, $col, $to_row, $to_col));
+
+			# See if doing this move would put us in check
+			# (yes, there are clients that expect us to do this).
+			my $check = $board->make_move($row, $col, $to_row, $to_col, $promo)->in_check();
+			next if ($check eq 'both' ||
+			         ($toplay eq 'W' && $check eq 'white') ||
+			         ($toplay eq 'B' && $check eq 'black'));
+
+			push @squares, [ $row, $col ];
+		}
+	}
+	if (scalar @squares != 1) {
+		die "Ambigious or impossible move $move";
+	}
+	return (@{$squares[0]}, $to_row, $to_col, $promo);
+}
+
 sub fen {
 	my ($board) = @_;
 	my @rows = ();
@@ -224,7 +297,6 @@ sub can_reach {
 		        can_reach($board, 'B', $from_row, $from_col, $to_row, $to_col));
 	}
 
-	# TODO: en passant
 	if ($piece eq 'p') {
 		# black pawn
 		if ($to_col == $from_col && $to_row == $from_row + 1) {
@@ -235,7 +307,12 @@ sub can_reach {
 			return ($dest_piece eq '-' && $middle_piece eq '-');
 		}
 		if (abs($to_col - $from_col) == 1 && $to_row == $from_row + 1) {
-			return ($dest_piece ne '-');
+			if ($dest_piece eq '-') {
+				# En passant. TODO: check that the last move was indeed an EP move
+				return ($to_row == 5 && $board->[4][$to_col] eq 'P');
+			} else {
+				return 1;
+			}
 		}
 		return 0;
 	}
@@ -249,7 +326,12 @@ sub can_reach {
 			return ($dest_piece eq '-' && $middle_piece eq '-');
 		}
 		if (abs($to_col - $from_col) == 1 && $to_row == $from_row - 1) {
-			return ($dest_piece ne '-');
+			if ($dest_piece eq '-') {
+				# En passant. TODO: check that the last move was indeed an EP move
+				return ($to_row == 2 && $board->[3][$to_col] eq 'p');
+			} else {
+				return 1;
+			}
 		}
 		return 0;
 	}