X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=remoteglot.pl;h=371c837e3b760192a76c555bc4bed278c8cfe6a0;hp=e032a254bacfe872a80375c6cbd546b509824b0b;hb=04b8054fd4578a7df332271d314833342d5e7d28;hpb=a01798debae3ac16607e44f4a8fc32668bf21147

diff --git a/remoteglot.pl b/remoteglot.pl
index e032a25..371c837 100755
--- a/remoteglot.pl
+++ b/remoteglot.pl
@@ -14,6 +14,7 @@ use FileHandle;
 use IPC::Open2;
 use Time::HiRes;
 use JSON::XS;
+require 'Position.pm';
 use strict;
 use warnings;
 
@@ -21,12 +22,9 @@ use warnings;
 my $server = "freechess.org";
 my $target = "GMCarlsen";
 my $engine_cmdline = "'./Deep Rybka 4 SSE42 x64'";
-my $engine2_cmdline = "./stockfish_13111119_x64_modern_sse42";
-my $telltarget = undef;   # undef to be silent
-my @tell_intervals = (5, 20, 60, 120, 240, 480, 960);  # after each move
+my $engine2_cmdline = "./stockfish_13111119_x64_modern_sse42";  # undef for none
 my $uci_assume_full_compliance = 0;                    # dangerous :-)
 my $update_max_interval = 1.0;
-my $second_engine_start_depth = 8;
 my @masters = (
 	'Sesse',
 	'Sessse',
@@ -57,9 +55,8 @@ select(STDOUT);
 # open the chess engine
 my $engine = open_engine($engine_cmdline, 'E1');
 my $engine2 = open_engine($engine2_cmdline, 'E2');
-my ($last_move, $last_tell);
+my $last_move;
 my $last_text = '';
-my $last_told_text = '';
 my ($pos_waiting, $pos_calculating, $pos_calculating_second_engine);
 
 uciprint($engine, "setoption name UCI_AnalyseMode value true");
@@ -69,13 +66,15 @@ uciprint($engine, "setoption name Hash value 1024");
 # uciprint($engine, "setoption name MultiPV value 2");
 uciprint($engine, "ucinewgame");
 
-uciprint($engine2, "setoption name UCI_AnalyseMode value true");
-# uciprint($engine2, "setoption name NalimovPath value /srv/tablebase");
-uciprint($engine2, "setoption name NalimovUsage value Rarely");
-uciprint($engine2, "setoption name Hash value 1024");
-uciprint($engine2, "setoption name Threads value 8");
-uciprint($engine2, "setoption name MultiPV value 500");
-uciprint($engine2, "ucinewgame");
+if (defined($engine2)) {
+	uciprint($engine2, "setoption name UCI_AnalyseMode value true");
+	# uciprint($engine2, "setoption name NalimovPath value /srv/tablebase");
+	uciprint($engine2, "setoption name NalimovUsage value Rarely");
+	uciprint($engine2, "setoption name Hash value 1024");
+	uciprint($engine2, "setoption name Threads value 8");
+	uciprint($engine2, "setoption name MultiPV value 500");
+	uciprint($engine2, "ucinewgame");
+}
 
 print "Chess engine ready.\n";
 
@@ -99,7 +98,9 @@ while (1) {
 	my $rin = '';
 	my $rout;
 	vec($rin, fileno($engine->{'read'}), 1) = 1;
-	vec($rin, fileno($engine2->{'read'}), 1) = 1;
+	if (defined($engine2)) {
+		vec($rin, fileno($engine2->{'read'}), 1) = 1;
+	}
 	vec($rin, fileno($t), 1) = 1;
 
 	my ($nfound, $timeleft) = select($rout=$rin, undef, undef, 5.0);
@@ -112,15 +113,15 @@ while (1) {
 		chomp $line;
 		$line =~ tr/\r//d;
 		if ($line =~ /^<12> /) {
-			my $pos = style12_to_pos($line);
+			my $pos = Position->new($line);
 			
 			# if this is already in the queue, ignore it
-			next if (defined($pos_waiting) && $pos->{'fen'} eq $pos_waiting->{'fen'});
+			next if (defined($pos_waiting) && $pos->fen() eq $pos_waiting->fen());
 
 			# if we're already chewing on this and there's nothing else in the queue,
 			# also ignore it
 			next if (!defined($pos_waiting) && defined($pos_calculating) &&
-			         $pos->{'fen'} eq $pos_calculating->{'fen'});
+			         $pos->fen() eq $pos_calculating->fen());
 
 			# if we're already thinking on something, stop and wait for the engine
 			# to approve
@@ -131,7 +132,7 @@ while (1) {
 				if ($uci_assume_full_compliance) {
 					$pos_waiting = $pos;
 				} else {
-					uciprint($engine, "position fen " . $pos->{'fen'});
+					uciprint($engine, "position fen " . $pos->fen());
 					uciprint($engine, "go infinite");
 					$pos_calculating = $pos;
 				}
@@ -139,21 +140,23 @@ while (1) {
 				# it's wrong just to give the FEN (the move history is useful,
 				# and per the UCI spec, we should really have sent "ucinewgame"),
 				# but it's easier
-				uciprint($engine, "position fen " . $pos->{'fen'});
+				uciprint($engine, "position fen " . $pos->fen());
 				uciprint($engine, "go infinite");
 				$pos_calculating = $pos;
 			}
 
-			if (defined($pos_calculating_second_engine)) {
-				uciprint($engine2, "stop");
-			} else {
-				uciprint($engine2, "position fen " . $pos->{'fen'});
-				uciprint($engine2, "go infinite");
-				$pos_calculating_second_engine = $pos;
+			if (defined($engine2)) {
+				if (defined($pos_calculating_second_engine)) {
+					uciprint($engine2, "stop");
+				} else {
+					uciprint($engine2, "position fen " . $pos->fen());
+					uciprint($engine2, "go infinite");
+					$pos_calculating_second_engine = $pos;
+				}
+				$engine2->{'info'} = {};
 			}
 
 			$engine->{'info'} = {};
-			$engine2->{'info'} = {};
 			$last_move = time;
 
 			# 
@@ -195,7 +198,7 @@ while (1) {
 
 		output();
 	}
-	if ($nfound > 0 && vec($rout, fileno($engine2->{'read'}), 1) == 1) {
+	if (defined($engine2) && $nfound > 0 && vec($rout, fileno($engine2->{'read'}), 1) == 1) {
 		my @lines = read_lines($engine2);
 		for my $line (@lines) {
 			next if $line =~ /(upper|lower)bound/;
@@ -232,7 +235,7 @@ sub handle_uci {
 		if ($primary) {
 			return if (!$uci_assume_full_compliance);
 			if (defined($pos_waiting)) {
-				uciprint($engine, "position fen " . $pos_waiting->{'fen'});
+				uciprint($engine, "position fen " . $pos_waiting->fen());
 				uciprint($engine, "go infinite");
 
 				$pos_calculating = $pos_waiting;
@@ -241,7 +244,7 @@ sub handle_uci {
 		} else {
 			$engine2->{'info'} = {};
 			my $pos = $pos_waiting // $pos_calculating;
-			uciprint($engine2, "position fen " . $pos->{'fen'});
+			uciprint($engine2, "position fen " . $pos->fen());
 			uciprint($engine2, "go infinite");
 			$pos_calculating_second_engine = $pos;
 		}
@@ -331,189 +334,6 @@ sub parse_ids {
 	}
 }
 
-sub style12_to_pos {
-	my $str = shift;
-	my %pos = ();
-	my (@x) = split / /, $str;
-	
-	$pos{'board'} = [ @x[1..8] ];
-	$pos{'toplay'} = $x[9];
-	$pos{'ep_file_num'} = $x[10];
-	$pos{'white_castle_k'} = $x[11];
-	$pos{'white_castle_q'} = $x[12];
-	$pos{'black_castle_k'} = $x[13];
-	$pos{'black_castle_q'} = $x[14];
-	$pos{'time_to_100move_rule'} = $x[15];
-	$pos{'move_num'} = $x[26];
-	if ($x[27] =~ /([a-h][1-8])-([a-h][1-8])/) {
-		$pos{'last_move_uci'} = $1 . $2;
-	} else {
-		$pos{'last_move_uci'} = undef;
-	}
-	$pos{'last_move'} = $x[29];
-	$pos{'fen'} = make_fen(\%pos);
-
-	return \%pos;
-}
-
-sub make_fen {
-	my $pos = shift;
-
-	# the board itself
-	my (@board) = @{$pos->{'board'}};
-	for my $rank (0..7) {
-		$board[$rank] =~ s/(-+)/length($1)/ge;
-	}
-	my $fen = join('/', @board);
-
-	# white/black to move
-	$fen .= " ";
-	$fen .= lc($pos->{'toplay'});
-
-	# castling
-	my $castling = "";
-	$castling .= "K" if ($pos->{'white_castle_k'} == 1);
-	$castling .= "Q" if ($pos->{'white_castle_q'} == 1);
-	$castling .= "k" if ($pos->{'black_castle_k'} == 1);
-	$castling .= "q" if ($pos->{'black_castle_q'} == 1);
-	$castling = "-" if ($castling eq "");
-	# $castling = "-"; # chess960
-	$fen .= " ";
-	$fen .= $castling;
-
-	# en passant
-	my $ep = "-";
-	if ($pos->{'ep_file_num'} != -1) {
-		my $col = $pos->{'ep_file_num'};
-		my $nep = (qw(a b c d e f g h))[$col];
-
-		if ($pos->{'toplay'} eq 'B') {
-			$nep .= "3";
-		} else {
-			$nep .= "6";
-		}
-
-		#
-		# Showing the en passant square when actually no capture can be made
-		# seems to confuse at least Rybka. Thus, check if there's actually
-		# a pawn of the opposite side that can do the en passant move, and if
-		# not, just lie -- it doesn't matter anyway. I'm unsure what's the
-		# "right" thing as per the standard, though.
-		#
-		if ($pos->{'toplay'} eq 'B') {
-			$ep = $nep if ($col > 0 && substr($pos->{'board'}[4], $col-1, 1) eq 'p');
-			$ep = $nep if ($col < 7 && substr($pos->{'board'}[4], $col+1, 1) eq 'p');
-		} else {
-			$ep = $nep if ($col > 0 && substr($pos->{'board'}[3], $col-1, 1) eq 'P');
-			$ep = $nep if ($col < 7 && substr($pos->{'board'}[3], $col+1, 1) eq 'P');
-		}
-	}
-	$fen .= " ";
-	$fen .= $ep;
-
-	# half-move clock
-	$fen .= " ";
-	$fen .= $pos->{'time_to_100move_rule'};
-
-	# full-move clock
-	$fen .= " ";
-	$fen .= $pos->{'move_num'};
-
-	return $fen;
-}
-
-sub make_move {
-	my ($board, $from_row, $from_col, $to_row, $to_col, $promo) = @_;
-	my $move = move_to_uci_notation($from_row, $from_col, $to_row, $to_col, $promo);
-	my $piece = substr($board->[$from_row], $from_col, 1);
-	my @nb = @$board;
-
-	if ($piece eq '-') {
-		die "Invalid move $move";
-	}
-
-	# white short castling
-	if ($move eq 'e1g1' && $piece eq 'K') {
-		# king
-		substr($nb[7], 4, 1, '-');
-		substr($nb[7], 6, 1, $piece);
-		
-		# rook
-		substr($nb[7], 7, 1, '-');
-		substr($nb[7], 5, 1, 'R');
-				
-		return \@nb;
-	}
-
-	# white long castling
-	if ($move eq 'e1c1' && $piece eq 'K') {
-		# king
-		substr($nb[7], 4, 1, '-');
-		substr($nb[7], 2, 1, $piece);
-		
-		# rook
-		substr($nb[7], 0, 1, '-');
-		substr($nb[7], 3, 1, 'R');
-				
-		return \@nb;
-	}
-
-	# black short castling
-	if ($move eq 'e8g8' && $piece eq 'k') {
-		# king
-		substr($nb[0], 4, 1, '-');
-		substr($nb[0], 6, 1, $piece);
-		
-		# rook
-		substr($nb[0], 7, 1, '-');
-		substr($nb[0], 5, 1, 'r');
-				
-		return \@nb;
-	}
-
-	# black long castling
-	if ($move eq 'e8c8' && $piece eq 'k') {
-		# king
-		substr($nb[0], 4, 1, '-');
-		substr($nb[0], 2, 1, $piece);
-		
-		# rook
-		substr($nb[0], 0, 1, '-');
-		substr($nb[0], 3, 1, 'r');
-				
-		return \@nb;
-	}
-
-	# check if the from-piece is a pawn
-	if (lc($piece) eq 'p') {
-		# attack?
-		if ($from_col != $to_col) {
-			# en passant?
-			if (substr($board->[$to_row], $to_col, 1) eq '-') {
-				if ($piece eq 'p') {
-					substr($nb[$to_row + 1], $to_col, 1, '-');
-				} else {
-					substr($nb[$to_row - 1], $to_col, 1, '-');
-				}
-			}
-		} else {
-			if ($promo ne '') {
-				if ($piece eq 'p') {
-					$piece = $promo;
-				} else {
-					$piece = uc($promo);
-				}
-			}
-		}
-	}
-
-	# update the board
-	substr($nb[$from_row], $from_col, 1, '-');
-	substr($nb[$to_row], $to_col, 1, $piece);
-
-	return \@nb;
-}
-
 sub prettyprint_pv {
 	my ($board, @pvs) = @_;
 
@@ -528,8 +348,8 @@ sub prettyprint_pv {
 	my $to_row   = row_letter_to_num(substr($pv, 3, 1));
 	my $promo    = substr($pv, 4, 1);
 
-	my $nb = make_move($board, $from_row, $from_col, $to_row, $to_col, $promo);
-	my $piece = substr($board->[$from_row], $from_col, 1);
+	my $nb = $board->make_move($from_row, $from_col, $to_row, $to_col, $promo);
+	my $piece = $board->[$from_row][$from_col];
 
 	if ($piece eq '-') {
 		die "Invalid move $pv";
@@ -584,23 +404,23 @@ sub prettyprint_pv {
 		my $num_total = 0;
 		for my $col (0..7) {
 			for my $row (0..7) {
-				next unless (substr($board->[$row], $col, 1) eq $piece);
-				++$num_total if (can_reach($board, $piece, $row, $col, $to_row, $to_col));
+				next unless ($board->[$row][$col] eq $piece);
+				++$num_total if ($board->can_reach($piece, $row, $col, $to_row, $to_col));
 			}
 		}
 
 		# see how many of these pieces from the given row could go here
 		my $num_row = 0;
 		for my $col (0..7) {
-			next unless (substr($board->[$from_row], $col, 1) eq $piece);
-			++$num_row if (can_reach($board, $piece, $from_row, $col, $to_row, $to_col));
+			next unless ($board->[$from_row][$col] eq $piece);
+			++$num_row if ($board->can_reach($piece, $from_row, $col, $to_row, $to_col));
 		}
 		
 		# and same for columns
 		my $num_col = 0;
 		for my $row (0..7) {
-			next unless (substr($board->[$row], $from_col, 1) eq $piece);
-			++$num_col if (can_reach($board, $piece, $row, $from_col, $to_row, $to_col));
+			next unless ($board->[$row][$from_col] eq $piece);
+			++$num_col if ($board->can_reach($piece, $row, $from_col, $to_row, $to_col));
 		}
 		
 		# see if we need to disambiguate
@@ -615,16 +435,16 @@ sub prettyprint_pv {
 		}
 
 		# attack?
-		if (substr($board->[$to_row], $to_col, 1) ne '-') {
+		if ($board->[$to_row][$to_col] ne '-') {
 			$pretty .= 'x';
 		}
 
 		$pretty .= substr($pv, 2, 2);
 	}
 
-	if (in_mate($nb)) {
+	if ($nb->in_mate()) {
 		$pretty .= '#';
-	} elsif (in_check($nb) ne 'none') {
+	} elsif ($nb->in_check() ne 'none') {
 		$pretty .= '+';
 	}
 	return ($pretty, prettyprint_pv($nb, @pvs));
@@ -751,37 +571,39 @@ sub output_screen {
 		}
 		if (exists($info->{'tbhits'}) && $info->{'tbhits'} > 0) {
 			if ($info->{'tbhits'} == 1) {
-				$text .= ", one Nalimov hit";
+				$text .= ", one Syzygy hit";
 			} else {
-				$text .= sprintf ", %u Nalimov hits", $info->{'tbhits'};
+				$text .= sprintf ", %u Syzygy hits", $info->{'tbhits'};
 			}
 		}
 		$text .= "\n\n";
 	}
 
-	#$text .= book_info($pos_calculating->{'fen'}, $pos_calculating->{'board'}, $pos_calculating->{'toplay'});
+	#$text .= book_info($pos_calculating->fen(), $pos_calculating->{'board'}, $pos_calculating->{'toplay'});
 
 	my @refutation_lines = ();
-	for (my $mpv = 1; $mpv < 500; ++$mpv) {
-		my $info = $engine2->{'info'};
-		last if (!exists($info->{'pv' . $mpv}));
-		eval {
-			my $pv = $info->{'pv' . $mpv};
-
-			my $pretty_move = join('', prettyprint_pv($pos_calculating_second_engine->{'board'}, $pv->[0]));
-			my @pretty_pv = prettyprint_pv($pos_calculating_second_engine->{'board'}, @$pv);
-			if (scalar @pretty_pv > 5) {
-				@pretty_pv = @pretty_pv[0..4];
-				push @pretty_pv, "...";
-			}
-			my $key = $pretty_move;
-			my $line = sprintf("  %-6s %6s %3s  %s",
-				$pretty_move,
-				short_score($info, $pos_calculating_second_engine, $mpv, 0),
-				"d" . $info->{'depth' . $mpv},
-				join(', ', @pretty_pv));
-			push @refutation_lines, [ $key, $line ];
-		};
+	if (defined($engine2)) {
+		for (my $mpv = 1; $mpv < 500; ++$mpv) {
+			my $info = $engine2->{'info'};
+			last if (!exists($info->{'pv' . $mpv}));
+			eval {
+				my $pv = $info->{'pv' . $mpv};
+
+				my $pretty_move = join('', prettyprint_pv($pos_calculating_second_engine->{'board'}, $pv->[0]));
+				my @pretty_pv = prettyprint_pv($pos_calculating_second_engine->{'board'}, @$pv);
+				if (scalar @pretty_pv > 5) {
+					@pretty_pv = @pretty_pv[0..4];
+					push @pretty_pv, "...";
+				}
+				my $key = $pretty_move;
+				my $line = sprintf("  %-6s %6s %3s  %s",
+					$pretty_move,
+					short_score($info, $pos_calculating_second_engine, $mpv, 0),
+					"d" . $info->{'depth' . $mpv},
+					join(', ', @pretty_pv));
+				push @refutation_lines, [ $key, $line ];
+			};
+		}
 	}
 
 	if ($#refutation_lines >= 0) {
@@ -797,71 +619,13 @@ sub output_screen {
 		print $text;
 		$last_text = $text;
 	}
-
-	# Now construct the tell text, if any
-	return if (!defined($telltarget));
-
-	my $tell_text = '';
-
-	if (exists($id->{'name'})) {
-		$tell_text .= "Analysis by $id->{'name'} -- see http://analysis.sesse.net/ for more information\n";
-	} else {
-		$tell_text .= "Computer analysis -- http://analysis.sesse.net/ for more information\n";
-	}
-
-	if (exists($info->{'pv1'}) && exists($info->{'pv2'})) {
-		# multi-PV
-		my $mpv = 1;
-		while (exists($info->{'pv' . $mpv})) {
-			$tell_text .= sprintf "  PV%2u", $mpv;
-			my $score = short_score($info, $pos_calculating, $mpv);
-			$tell_text .= "  ($score)" if (defined($score));
-
-			if (exists($info->{'depth' . $mpv})) {
-				$tell_text .= sprintf " (%2u ply)", $info->{'depth' . $mpv};
-			}
-
-			$tell_text .= ": ";
-			$tell_text .= join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}}));
-			$tell_text .= "\n";
-			++$mpv;
-		}
-	} else {
-		# single-PV
-		my $score = long_score($info, $pos_calculating, '');
-		$tell_text .= "  $score\n" if defined($score);
-		$tell_text .= "  PV: " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}}));
-		if (exists($info->{'depth'})) {
-			$tell_text .= sprintf " (depth %u ply)", $info->{'depth'};
-		}
-		$tell_text .=  "\n";
-	}
-
-	# see if a new tell is called for -- it is if the delay has expired _and_
-	# this is not simply a repetition of the last one
-	if ($last_told_text ne $tell_text) {
-		my $now = time;
-		for my $iv (@tell_intervals) {
-			last if ($now - $last_move < $iv);
-			next if ($last_tell - $last_move >= $iv);
-
-			for my $line (split /\n/, $tell_text) {
-				$t->print("tell $telltarget [$target] $line");
-			}
-
-			$last_told_text = $text;
-			$last_tell = $now;
-
-			last;
-		}
-	}
 }
 
 sub output_json {
 	my $info = $engine->{'info'};
 
 	my $json = {};
-	$json->{'position'} = $pos_calculating;
+	$json->{'position'} = $pos_calculating->to_json_hash();
 	$json->{'id'} = $engine->{'id'};
 	$json->{'score'} = long_score($info, $pos_calculating, '');
 
@@ -877,231 +641,36 @@ sub output_json {
 
 	my %refutation_lines = ();
 	my @refutation_lines = ();
-	for (my $mpv = 1; $mpv < 500; ++$mpv) {
-		my $info = $engine2->{'info'};
-		my $pretty_move = "";
-		my @pretty_pv = ();
-		last if (!exists($info->{'pv' . $mpv}));
-
-		eval {
-			my $pv = $info->{'pv' . $mpv};
-			my $pretty_move = join('', prettyprint_pv($pos_calculating->{'board'}, $pv->[0]));
-			my @pretty_pv = prettyprint_pv($pos_calculating->{'board'}, @$pv);
-			$refutation_lines{$pv->[0]} = {
-				sort_key => $pretty_move,
-				depth => $info->{'depth' . $mpv},
-				score_sort_key => score_sort_key($info, $pos_calculating, $mpv, 0),
-				pretty_score => short_score($info, $pos_calculating, $mpv, 0),
-				pretty_move => $pretty_move,
-				pv_pretty => \@pretty_pv,
+	if (defined($engine2)) {
+		for (my $mpv = 1; $mpv < 500; ++$mpv) {
+			my $info = $engine2->{'info'};
+			my $pretty_move = "";
+			my @pretty_pv = ();
+			last if (!exists($info->{'pv' . $mpv}));
+
+			eval {
+				my $pv = $info->{'pv' . $mpv};
+				my $pretty_move = join('', prettyprint_pv($pos_calculating->{'board'}, $pv->[0]));
+				my @pretty_pv = prettyprint_pv($pos_calculating->{'board'}, @$pv);
+				$refutation_lines{$pv->[0]} = {
+					sort_key => $pretty_move,
+					depth => $info->{'depth' . $mpv},
+					score_sort_key => score_sort_key($info, $pos_calculating, $mpv, 0),
+					pretty_score => short_score($info, $pos_calculating, $mpv, 0),
+					pretty_move => $pretty_move,
+					pv_pretty => \@pretty_pv,
+				};
+				$refutation_lines{$pv->[0]}->{'pv_uci'} = $pv;
 			};
-			$refutation_lines{$pv->[0]}->{'pv_uci'} = $pv;
-		};
+		}
 	}
 	$json->{'refutation_lines'} = \%refutation_lines;
 
-	open my $fh, ">analysis.json.tmp"
+	open my $fh, ">/srv/analysis.sesse.net/www/analysis.json.tmp"
 		or return;
 	print $fh JSON::XS::encode_json($json);
 	close $fh;
-	rename("analysis.json.tmp", "analysis.json");	
-}
-
-sub find_kings {
-	my $board = shift;
-	my ($wkr, $wkc, $bkr, $bkc);
-
-	for my $row (0..7) {
-		for my $col (0..7) {
-			my $piece = substr($board->[$row], $col, 1);
-			if ($piece eq 'K') {
-				($wkr, $wkc) = ($row, $col);
-			} elsif ($piece eq 'k') {
-				($bkr, $bkc) = ($row, $col);
-			}
-		}
-	}
-
-	return ($wkr, $wkc, $bkr, $bkc);
-}
-
-sub in_mate {
-	my $board = shift;
-	my $check = in_check($board);
-	return 0 if ($check eq 'none');
-
-	# try all possible moves for the side in check
-	for my $row (0..7) {
-		for my $col (0..7) {
-			my $piece = substr($board->[$row], $col, 1);
-			next if ($piece eq '-');
-
-			if ($check eq 'white') {
-				next if ($piece eq lc($piece));
-			} else {
-				next if ($piece eq uc($piece));
-			}
-
-			for my $dest_row (0..7) {
-				for my $dest_col (0..7) {
-					next if ($row == $dest_row && $col == $dest_col);
-					next unless (can_reach($board, $piece, $row, $col, $dest_row, $dest_col));
-
-					my @nb = @$board;
-					substr($nb[$row], $col, 1, '-');
-					substr($nb[$dest_row], $dest_col, 1, $piece);
-
-					my $new_check = in_check(\@nb);
-					return 0 if ($new_check ne $check && $new_check ne 'both');
-				}
-			}
-		}
-	}
-
-	# nothing to do; mate
-	return 1;
-}
-
-sub in_check {
-	my $board = shift;
-	my ($black_check, $white_check) = (0, 0);
-
-	my ($wkr, $wkc, $bkr, $bkc) = find_kings($board);
-
-	# check all pieces for the possibility of threatening the two kings
-	for my $row (0..7) {
-		for my $col (0..7) {
-			my $piece = substr($board->[$row], $col, 1);
-			next if ($piece eq '-');
-		
-			if (uc($piece) eq $piece) {
-				# white piece
-				$black_check = 1 if (can_reach($board, $piece, $row, $col, $bkr, $bkc));
-			} else {
-				# black piece
-				$white_check = 1 if (can_reach($board, $piece, $row, $col, $wkr, $wkc));
-			}
-		}
-	}
-
-	if ($black_check && $white_check) {
-		return 'both';
-	} elsif ($black_check) {
-		return 'black';
-	} elsif ($white_check) {
-		return 'white';
-	} else {
-		return 'none';
-	}
-}
-
-sub can_reach {
-	my ($board, $piece, $from_row, $from_col, $to_row, $to_col) = @_;
-	
-	# can't eat your own piece
-	my $dest_piece = substr($board->[$to_row], $to_col, 1);
-	if ($dest_piece ne '-') {
-		return 0 if (($piece eq lc($piece)) == ($dest_piece eq lc($dest_piece)));
-	}
-
-	if (lc($piece) eq 'k') {
-		return (abs($from_row - $to_row) <= 1 && abs($from_col - $to_col) <= 1);
-	}
-	if (lc($piece) eq 'r') {
-		return 0 unless ($from_row == $to_row || $from_col == $to_col);
-
-		# check that there's a clear passage
-		if ($from_row == $to_row) {
-			if ($from_col > $to_col) {
-				($to_col, $from_col) = ($from_col, $to_col);
-			}
-
-			for my $c (($from_col+1)..($to_col-1)) {
-				my $middle_piece = substr($board->[$to_row], $c, 1);
-				return 0 if ($middle_piece ne '-');	
-			}
-
-			return 1;
-		} else {
-			if ($from_row > $to_row) {
-				($to_row, $from_row) = ($from_row, $to_row);
-			}
-
-			for my $r (($from_row+1)..($to_row-1)) {
-				my $middle_piece = substr($board->[$r], $to_col, 1);
-				return 0 if ($middle_piece ne '-');	
-			}
-
-			return 1;
-		}
-	}
-	if (lc($piece) eq 'b') {
-		return 0 unless (abs($from_row - $to_row) == abs($from_col - $to_col));
-
-		my $dr = ($to_row - $from_row) / abs($to_row - $from_row);
-		my $dc = ($to_col - $from_col) / abs($to_col - $from_col);
-
-		my $r = $from_row + $dr;
-		my $c = $from_col + $dc;
-
-		while ($r != $to_row) {
-			my $middle_piece = substr($board->[$r], $c, 1);
-			return 0 if ($middle_piece ne '-');
-			
-			$r += $dr;
-			$c += $dc;
-		}
-
-		return 1;
-	}
-	if (lc($piece) eq 'n') {
-		my $diff_r = abs($from_row - $to_row);
-		my $diff_c = abs($from_col - $to_col);
-		return 1 if ($diff_r == 2 && $diff_c == 1);
-		return 1 if ($diff_r == 1 && $diff_c == 2);
-		return 0;
-	}
-	if ($piece eq 'q') {
-		return (can_reach($board, 'r', $from_row, $from_col, $to_row, $to_col) ||
-		        can_reach($board, 'b', $from_row, $from_col, $to_row, $to_col));
-	}
-	if ($piece eq 'Q') {
-		return (can_reach($board, 'R', $from_row, $from_col, $to_row, $to_col) ||
-		        can_reach($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 == $from_row + 1) {
-			return ($dest_piece eq '-');
-		}
-		if ($to_col == $from_col && $from_row == 1 && $to_row == 3) {
-			my $middle_piece = substr($board->[2], $to_col, 1);
-			return ($dest_piece eq '-' && $middle_piece eq '-');
-		}
-		if (abs($to_col - $from_col) == 1 && $to_row == $from_row + 1) {
-			return ($dest_piece ne '-');
-		}
-		return 0;
-	}
-	if ($piece eq 'P') {
-		# white pawn
-		if ($to_col == $from_col && $to_row == $from_row - 1) {
-			return ($dest_piece eq '-');
-		}
-		if ($to_col == $from_col && $from_row == 6 && $to_row == 4) {
-			my $middle_piece = substr($board->[5], $to_col, 1);
-			return ($dest_piece eq '-' && $middle_piece eq '-');
-		}
-		if (abs($to_col - $from_col) == 1 && $to_row == $from_row - 1) {
-			return ($dest_piece ne '-');
-		}
-		return 0;
-	}
-	
-	# unknown piece
-	return 0;
+	rename("/srv/analysis.sesse.net/www/analysis.json.tmp", "/srv/analysis.sesse.net/www/analysis.json");
 }
 
 sub uciprint {
@@ -1145,9 +714,9 @@ sub score_sort_key {
 
 	if (defined($info->{'score_mate' . $mpv})) {
 		if ($invert) {
-			return -(99999 - $info->{'score_mate' . $mpv});
-		} else {
 			return 99999 - $info->{'score_mate' . $mpv};
+		} else {
+			return -(99999 - $info->{'score_mate' . $mpv});
 		}
 	} else {
 		if (exists($info->{'score_cp' . $mpv})) {
@@ -1178,6 +747,9 @@ sub long_score {
 	} else {
 		if (exists($info->{'score_cp' . $mpv})) {
 			my $score = $info->{'score_cp' . $mpv} * 0.01;
+			if ($score == 0) {
+				return "Score:  0.00";
+			}
 			if ($pos->{'toplay'} eq 'B') {
 				$score = -$score;
 			}
@@ -1242,6 +814,9 @@ sub book_info {
 
 sub open_engine {
 	my ($cmdline, $tag) = @_;
+
+	return undef if (!defined($cmdline));
+
 	my ($uciread, $uciwrite);
 	my $pid = IPC::Open2::open2($uciread, $uciwrite, $cmdline);
 
@@ -1306,8 +881,3 @@ sub row_letter_to_num {
 	return 7 - (ord(shift) - ord('1'));
 }
 
-sub move_to_uci_notation {
-	my ($from_row, $from_col, $to_row, $to_col, $promo) = @_;
-	$promo //= "";
-	return sprintf("%c%d%c%d%s", ord('a') + $from_col, 8 - $from_row, ord('a') + $to_col, 8 - $to_row, $promo);
-}