X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=remoteglot.pl;h=f42b7244aab08a810b5a0c0981ed22c04c10b2d8;hp=bd10cd020475f50a4b3ca0db6e08108e3babead6;hb=bf26f1b3ef29a518e1ee9f71c42c9cf344d2e987;hpb=9e923c34a6788eb9780a151316b196d4a18c3bbd

diff --git a/remoteglot.pl b/remoteglot.pl
index bd10cd0..f42b724 100755
--- a/remoteglot.pl
+++ b/remoteglot.pl
@@ -13,6 +13,7 @@ use Net::Telnet;
 use FileHandle;
 use IPC::Open2;
 use Time::HiRes;
+use JSON::XS;
 use strict;
 use warnings;
 
@@ -20,9 +21,12 @@ 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 $uci_assume_full_compliance = 0;                    # dangerous :-)
+my $update_max_interval = 2.0;
+my $second_engine_start_depth = 8;
 my @masters = (
 	'Sesse',
 	'Sessse',
@@ -32,7 +36,8 @@ my @masters = (
 );
 
 # Program starts here
-$SIG{ALRM} = sub { output_screen(); };
+$SIG{ALRM} = sub { output(); };
+my $latest_update = undef;
 
 $| = 1;
 
@@ -50,13 +55,13 @@ $| = 1;
 select(STDOUT);
 
 # open the chess engine
-my $engine = open_engine($engine_cmdline);
-my %uciinfo = ();
-my %uciid = ();
+my $engine = open_engine($engine_cmdline, 'E1');
+my $engine2 = open_engine($engine2_cmdline, 'E2');
 my ($last_move, $last_tell);
 my $last_text = '';
 my $last_told_text = '';
-my ($pos_waiting, $pos_calculating);
+my ($pos_waiting, $pos_calculating, $move_calculating_second_engine);
+my %refutation_moves = ();
 
 uciprint($engine, "setoption name UCI_AnalyseMode value true");
 # uciprint($engine, "setoption name NalimovPath value /srv/tablebase");
@@ -65,6 +70,14 @@ 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 2");
+uciprint($engine2, "ucinewgame");
+
 print "Chess engine ready.\n";
 
 # now talk to FICS
@@ -87,6 +100,7 @@ while (1) {
 	my $rin = '';
 	my $rout;
 	vec($rin, fileno($engine->{'read'}), 1) = 1;
+	vec($rin, fileno($engine2->{'read'}), 1) = 1;
 	vec($rin, fileno($t), 1) = 1;
 
 	my ($nfound, $timeleft) = select($rout=$rin, undef, undef, 5.0);
@@ -99,7 +113,7 @@ while (1) {
 		chomp $line;
 		$line =~ tr/\r//d;
 		if ($line =~ /^<12> /) {
-			my $pos = style12_to_fen($line);
+			my $pos = style12_to_pos($line);
 			
 			# if this is already in the queue, ignore it
 			next if (defined($pos_waiting) && $pos->{'fen'} eq $pos_waiting->{'fen'});
@@ -131,7 +145,16 @@ while (1) {
 				$pos_calculating = $pos;
 			}
 
-			%uciinfo = ();
+			%refutation_moves = calculate_refutation_moves($pos);
+			if (defined($move_calculating_second_engine)) {
+				uciprint($engine2, "stop");
+				$move_calculating_second_engine = undef;
+			} else {
+				give_new_move_to_second_engine($pos);
+			}
+
+			$engine->{'info'} = {};
+			$engine2->{'info'} = {};
 			$last_move = time;
 
 			# 
@@ -164,71 +187,77 @@ while (1) {
 	
 	# any fun on the UCI channel?
 	if ($nfound > 0 && vec($rout, fileno($engine->{'read'}), 1) == 1) {
-		# 
-		# Read until we've got a full line -- if the engine sends part of
-		# a line and then stops we're pretty much hosed, but that should
-		# never happen.
-		#
-		my $line = '';
-		while ($line !~ /\n/) {
-			my $tmp;
-			my $ret = sysread $engine->{'read'}, $tmp, 1;
-
-			if (!defined($ret)) {
-				next if ($!{EINTR});
-				die "error in reading from the UCI engine: $!";
-			} elsif ($ret == 0) {
-				die "EOF from UCI engine";
-			}
-
-			$line .= $tmp;
+		my @lines = read_lines($engine);
+		for my $line (@lines) {
+			next if $line =~ /(upper|lower)bound/;
+			handle_uci($engine, $line, 1);
 		}
+		$sleep = 0;
 
-		$line =~ tr/\r\n//d;
-		handle_uci($line);
+		output();
+	}
+	if ($nfound > 0 && vec($rout, fileno($engine2->{'read'}), 1) == 1) {
+		my @lines = read_lines($engine2);
+		for my $line (@lines) {
+			next if $line =~ /(upper|lower)bound/;
+			handle_uci($engine2, $line, 0);
+		}
 		$sleep = 0;
 
-		# don't update too often
-		Time::HiRes::alarm(0.2);
+		output();
 	}
 
 	sleep $sleep;
 }
 
 sub handle_uci {
-	my ($line) = @_;
+	my ($engine, $line, $primary) = @_;
 
 	chomp $line;
 	$line =~ tr/\r//d;
 	$line =~ s/  / /g;  # Sometimes needed for Zappa Mexico
-	print UCILOG localtime() . " <= $line\n";
+	print UCILOG localtime() . " $engine->{'tag'} <= $line\n";
 	if ($line =~ /^info/) {
 		my (@infos) = split / /, $line;
 		shift @infos;
 
-		parse_infos(@infos);
+		parse_infos($engine, @infos);
 	}
 	if ($line =~ /^id/) {
 		my (@ids) = split / /, $line;
 		shift @ids;
 
-		parse_ids(@ids);
+		parse_ids($engine, @ids);
 	}
-	if ($line =~ /^bestmove/ && $uci_assume_full_compliance) {
-		if (defined($pos_waiting)) {
-			uciprint($engine, "position fen " . $pos_waiting->{'fen'});
-			uciprint($engine, "go infinite");
+	if ($line =~ /^bestmove/) {
+		if ($primary) {
+			return if (!$uci_assume_full_compliance);
+			if (defined($pos_waiting)) {
+				uciprint($engine, "position fen " . $pos_waiting->{'fen'});
+				uciprint($engine, "go infinite");
 
-			$pos_calculating = $pos_waiting;
-			$pos_waiting = undef;
+				$pos_calculating = $pos_waiting;
+				$pos_waiting = undef;
+			}
+		} else {
+			if (defined($move_calculating_second_engine)) {	
+				my $move = $refutation_moves{$move_calculating_second_engine};
+				$move->{'pv'} = $engine->{'info'}{'pv'} // $engine->{'info'}{'pv1'};
+				$move->{'score_cp'} = $engine->{'info'}{'score_cp'} // $engine->{'info'}{'score_cp1'} // 0;
+				$move->{'score_mate'} = $engine->{'info'}{'score_mate'} // $engine->{'info'}{'score_mate1'};
+				$move->{'toplay'} = $pos_calculating->{'toplay'};
+			}
+			give_new_move_to_second_engine($pos_waiting // $pos_calculating);
 		}
 	}
 }
 
 sub parse_infos {
-	my (@x) = @_;
+	my ($engine, @x) = @_;
 	my $mpv = '';
 
+	my $info = $engine->{'info'};
+
 	while (scalar @x > 0) {
 		if ($x[0] =~ 'multipv') {
 			shift @x;
@@ -238,28 +267,28 @@ sub parse_infos {
 		if ($x[0] =~ /^(currmove|currmovenumber|cpuload)$/) {
 			my $key = shift @x;
 			my $value = shift @x;
-			$uciinfo{$key} = $value;
+			$info->{$key} = $value;
 			next;
 		}
 		if ($x[0] =~ /^(depth|seldepth|hashfull|time|nodes|nps|tbhits)$/) {
 			my $key = shift @x;
 			my $value = shift @x;
-			$uciinfo{$key . $mpv} = $value;
+			$info->{$key . $mpv} = $value;
 			next;
 		}
 		if ($x[0] eq 'score') {
 			shift @x;
 
-			delete $uciinfo{'score_cp' . $mpv};
-			delete $uciinfo{'score_mate' . $mpv};
+			delete $info->{'score_cp' . $mpv};
+			delete $info->{'score_mate' . $mpv};
 
 			while ($x[0] =~ /^(cp|mate|lowerbound|upperbound)$/) {
 				if ($x[0] eq 'cp') {
 					shift @x;
-					$uciinfo{'score_cp' . $mpv} = shift @x;
+					$info->{'score_cp' . $mpv} = shift @x;
 				} elsif ($x[0] eq 'mate') {
 					shift @x;
-					$uciinfo{'score_mate' . $mpv} = shift @x;
+					$info->{'score_mate' . $mpv} = shift @x;
 				} else {
 					shift @x;
 				}
@@ -267,7 +296,7 @@ sub parse_infos {
 			next;
 		}
 		if ($x[0] eq 'pv') {
-			$uciinfo{'pv' . $mpv} = [ @x[1..$#x] ];
+			$info->{'pv' . $mpv} = [ @x[1..$#x] ];
 			last;
 		}
 		if ($x[0] eq 'string' || $x[0] eq 'UCI_AnalyseMode' || $x[0] eq 'setting' || $x[0] eq 'contempt') {
@@ -282,13 +311,13 @@ sub parse_infos {
 }
 
 sub parse_ids {
-	my (@x) = @_;
+	my ($engine, @x) = @_;
 
 	while (scalar @x > 0) {
 		if ($x[0] =~ /^(name|author)$/) {
 			my $key = shift @x;
 			my $value = join(' ', @x);
-			$uciid{$key} = $value;
+			$engine->{'id'}{$key} = $value;
 			last;
 		}
 
@@ -297,16 +326,31 @@ sub parse_ids {
 	}
 }
 
-sub style12_to_fen {
+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];
+	$pos{'last_move'} = $x[29];
+	$pos{'fen'} = make_fen(\%pos);
+
+	return \%pos;
+}
+
+sub make_fen {
+	my $pos = shift;
+
 	# the board itself
-	my (@board) = @x[1..8];
+	my (@board) = @{$pos->{'board'}};
 	for my $rank (0..7) {
 		$board[$rank] =~ s/(-+)/length($1)/ge;
 	}
@@ -314,14 +358,14 @@ sub style12_to_fen {
 
 	# white/black to move
 	$fen .= " ";
-	$fen .= lc($x[9]);
+	$fen .= lc($pos->{'toplay'});
 
 	# castling
 	my $castling = "";
-	$castling .= "K" if ($x[11] == 1);
-	$castling .= "Q" if ($x[12] == 1);
-	$castling .= "k" if ($x[13] == 1);
-	$castling .= "q" if ($x[14] == 1);
+	$castling .= "K" if ($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 .= " ";
@@ -329,11 +373,11 @@ sub style12_to_fen {
 
 	# en passant
 	my $ep = "-";
-	if ($x[10] != -1) {
-		my $col = $x[10];
+	if ($pos->{'ep_file_num'} != -1) {
+		my $col = $pos->{'ep_file_num'};
 		my $nep = (qw(a b c d e f g h))[$col];
 
-		if ($x[9] eq 'B') {
+		if ($pos->{'toplay'} eq 'B') {
 			$nep .= "3";
 		} else {
 			$nep .= "6";
@@ -346,12 +390,12 @@ sub style12_to_fen {
 		# not, just lie -- it doesn't matter anyway. I'm unsure what's the
 		# "right" thing as per the standard, though.
 		#
-		if ($x[9] 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], $col+1, 1) eq 'p');
+		if ($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');
+			$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 .= " ";
@@ -359,43 +403,27 @@ sub style12_to_fen {
 
 	# half-move clock
 	$fen .= " ";
-	$fen .= $x[15];
+	$fen .= $pos->{'time_to_100move_rule'};
 
 	# full-move clock
 	$fen .= " ";
-	$fen .= $x[26];
+	$fen .= $pos->{'move_num'};
 
-	$pos{'fen'} = $fen;
-	$pos{'move_num'} = $x[26];
-	$pos{'last_move'} = $x[29];
-
-	return \%pos;
+	return $fen;
 }
 
-sub prettyprint_pv {
-	my ($board, @pvs) = @_;
-
-	if (scalar @pvs == 0 || !defined($pvs[0])) {
-		return ();
-	}
-	
-	my @nb = @$board;
-
-	my $pv = shift @pvs;
-	my $from_col = ord(substr($pv, 0, 1)) - ord('a');
-	my $from_row = 7 - (ord(substr($pv, 1, 1)) - ord('1'));
-	my $to_col   = ord(substr($pv, 2, 1)) - ord('a');
-	my $to_row   = 7 - (ord(substr($pv, 3, 1)) - ord('1'));
-
-	my $pretty;
+sub make_move {
+	my ($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 $pv";
+		die "Invalid move $move";
 	}
 
 	# white short castling
-	if ($pv eq 'e1g1' && $piece eq 'K') {
+	if ($move eq 'e1g1' && $piece eq 'K') {
 		# king
 		substr($nb[7], 4, 1, '-');
 		substr($nb[7], 6, 1, $piece);
@@ -404,11 +432,11 @@ sub prettyprint_pv {
 		substr($nb[7], 7, 1, '-');
 		substr($nb[7], 5, 1, 'R');
 				
-		return ('0-0', prettyprint_pv(\@nb, @pvs));
+		return \@nb;
 	}
 
 	# white long castling
-	if ($pv eq 'e1c1' && $piece eq 'K') {
+	if ($move eq 'e1c1' && $piece eq 'K') {
 		# king
 		substr($nb[7], 4, 1, '-');
 		substr($nb[7], 2, 1, $piece);
@@ -417,11 +445,11 @@ sub prettyprint_pv {
 		substr($nb[7], 0, 1, '-');
 		substr($nb[7], 3, 1, 'R');
 				
-		return ('0-0-0', prettyprint_pv(\@nb, @pvs));
+		return \@nb;
 	}
 
 	# black short castling
-	if ($pv eq 'e8g8' && $piece eq 'k') {
+	if ($move eq 'e8g8' && $piece eq 'k') {
 		# king
 		substr($nb[0], 4, 1, '-');
 		substr($nb[0], 6, 1, $piece);
@@ -430,11 +458,11 @@ sub prettyprint_pv {
 		substr($nb[0], 7, 1, '-');
 		substr($nb[0], 5, 1, 'r');
 				
-		return ('0-0', prettyprint_pv(\@nb, @pvs));
+		return \@nb;
 	}
 
 	# black long castling
-	if ($pv eq 'e8c8' && $piece eq 'k') {
+	if ($move eq 'e8c8' && $piece eq 'k') {
 		# king
 		substr($nb[0], 4, 1, '-');
 		substr($nb[0], 2, 1, $piece);
@@ -443,15 +471,13 @@ sub prettyprint_pv {
 		substr($nb[0], 0, 1, '-');
 		substr($nb[0], 3, 1, 'r');
 				
-		return ('0-0-0', prettyprint_pv(\@nb, @pvs));
+		return \@nb;
 	}
 
 	# check if the from-piece is a pawn
 	if (lc($piece) eq 'p') {
 		# attack?
 		if ($from_col != $to_col) {
-			$pretty = substr($pv, 0, 1) . 'x' . substr($pv, 2, 2);
-
 			# en passant?
 			if (substr($board->[$to_row], $to_col, 1) eq '-') {
 				if ($piece eq 'p') {
@@ -460,6 +486,72 @@ sub prettyprint_pv {
 					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) = @_;
+
+	if (scalar @pvs == 0 || !defined($pvs[0])) {
+		return ();
+	}
+
+	my $pv = shift @pvs;
+	my $from_col = col_letter_to_num(substr($pv, 0, 1));
+	my $from_row = row_letter_to_num(substr($pv, 1, 1));
+	my $to_col   = col_letter_to_num(substr($pv, 2, 1));
+	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], $from_col, 1);
+
+	if ($piece eq '-') {
+		die "Invalid move $pv";
+	}
+
+	# white short castling
+	if ($pv eq 'e1g1' && $piece eq 'K') {
+		return ('0-0', prettyprint_pv($nb, @pvs));
+	}
+
+	# white long castling
+	if ($pv eq 'e1c1' && $piece eq 'K') {
+		return ('0-0-0', prettyprint_pv($nb, @pvs));
+	}
+
+	# black short castling
+	if ($pv eq 'e8g8' && $piece eq 'k') {
+		return ('0-0', prettyprint_pv($nb, @pvs));
+	}
+
+	# black long castling
+	if ($pv eq 'e8c8' && $piece eq 'k') {
+		return ('0-0-0', prettyprint_pv($nb, @pvs));
+	}
+
+	my $pretty;
+
+	# check if the from-piece is a pawn
+	if (lc($piece) eq 'p') {
+		# attack?
+		if ($from_col != $to_col) {
+			$pretty = substr($pv, 0, 1) . 'x' . substr($pv, 2, 2);
 		} else {
 			$pretty = substr($pv, 2, 2);
 
@@ -520,24 +612,41 @@ sub prettyprint_pv {
 		$pretty .= substr($pv, 2, 2);
 	}
 
-	# update the board
-	substr($nb[$from_row], $from_col, 1, '-');
-	substr($nb[$to_row], $to_col, 1, $piece);
-
-	if (in_mate(\@nb)) {
+	if (in_mate($nb)) {
 		$pretty .= '#';
-	} elsif (in_check(\@nb) ne 'none') {
+	} elsif (in_check($nb) ne 'none') {
 		$pretty .= '+';
 	}
-
-	return ($pretty, prettyprint_pv(\@nb, @pvs));
+	return ($pretty, prettyprint_pv($nb, @pvs));
 }
 
-sub output_screen {
+sub output {
 	#return;
-	
+
 	return if (!defined($pos_calculating));
 
+	# Don't update too often.
+	my $age = Time::HiRes::tv_interval($latest_update);
+	if ($age < $update_max_interval) {
+		Time::HiRes::alarm($update_max_interval + 0.01 - $age);
+		return;
+	}
+	
+	my $info = $engine->{'info'};
+	
+	#
+	# Some programs _always_ report MultiPV, even with only one PV.
+	# In this case, we simply use that data as if MultiPV was never
+	# specified.
+	#
+	if (exists($info->{'pv1'}) && !exists($info->{'pv2'})) {
+		for my $key (qw(pv score_cp score_mate nodes nps depth seldepth tbhits)) {
+			if (exists($info->{$key . '1'})) {
+				$info->{$key} = $info->{$key . '1'};
+			}
+		}
+	}
+	
 	#
 	# Check the PVs first. if they're invalid, just wait, as our data
 	# is most likely out of sync. This isn't a very good solution, as
@@ -545,21 +654,30 @@ sub output_screen {
 	#
 	eval {
 		my $dummy;
-		if (exists($uciinfo{'pv'})) {
-			$dummy = prettyprint_pv($pos_calculating->{'board'}, @{$uciinfo{'pv'}});
+		if (exists($info->{'pv'})) {
+			$dummy = prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}});
 		}
 	
 		my $mpv = 1;
-		while (exists($uciinfo{'pv' . $mpv})) {
-			$dummy = prettyprint_pv($pos_calculating->{'board'}, @{$uciinfo{'pv' . $mpv}});
+		while (exists($info->{'pv' . $mpv})) {
+			$dummy = prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}});
 			++$mpv;
 		}
 	};
 	if ($@) {
-		%uciinfo = ();
+		$engine->{'info'} = {};
 		return;
 	}
 
+	output_screen();
+	output_json();
+	$latest_update = [Time::HiRes::gettimeofday];
+}
+
+sub output_screen {
+	my $info = $engine->{'info'};
+	my $id = $engine->{'id'};
+
 	my $text = 'Analysis';
 	if ($pos_calculating->{'last_move'} ne 'none') {
 		if ($pos_calculating->{'toplay'} eq 'W') {
@@ -567,85 +685,102 @@ sub output_screen {
 		} else {
 			$text .= sprintf ' after %u. %s', $pos_calculating->{'move_num'}, $pos_calculating->{'last_move'};
 		}
-		if (exists($uciid{'name'})) {
+		if (exists($id->{'name'})) {
 			$text .= ',';
 		}
 	}
 
-	if (exists($uciid{'name'})) {
-		$text .= " by $uciid{'name'}:\n\n";
+	if (exists($id->{'name'})) {
+		$text .= " by $id->{'name'}:\n\n";
 	} else {
 		$text .= ":\n\n";
 	}
 
 	return unless (exists($pos_calculating->{'board'}));
 		
-	#
-	# Some programs _always_ report MultiPV, even with only one PV.
-	# In this case, we simply use that data as if MultiPV was never
-	# specified.
-	#
-	if (exists($uciinfo{'pv1'}) && !exists($uciinfo{'pv2'})) {
-		for my $key qw(pv score_cp score_mate nodes nps depth seldepth tbhits) {
-			if (exists($uciinfo{$key . '1'}) && !exists($uciinfo{$key})) {
-				$uciinfo{$key} = $uciinfo{$key . '1'};
-			}
-		}
-	}
-
-	if (exists($uciinfo{'pv1'}) && exists($uciinfo{'pv2'})) {
+	if (exists($info->{'pv1'}) && exists($info->{'pv2'})) {
 		# multi-PV
 		my $mpv = 1;
-		while (exists($uciinfo{'pv' . $mpv})) {
+		while (exists($info->{'pv' . $mpv})) {
 			$text .= sprintf "  PV%2u", $mpv;
-			my $score = short_score(\%uciinfo, $pos_calculating, $mpv);
+			my $score = short_score($info, $pos_calculating, $mpv);
 			$text .= "  ($score)" if (defined($score));
 
 			my $tbhits = '';
-			if (exists($uciinfo{'tbhits' . $mpv}) && $uciinfo{'tbhits' . $mpv} > 0) {
-				if ($uciinfo{'tbhits' . $mpv} == 1) {
+			if (exists($info->{'tbhits' . $mpv}) && $info->{'tbhits' . $mpv} > 0) {
+				if ($info->{'tbhits' . $mpv} == 1) {
 					$tbhits = ", 1 tbhit";
 				} else {
-					$tbhits = sprintf ", %u tbhits", $uciinfo{'tbhits' . $mpv};
+					$tbhits = sprintf ", %u tbhits", $info->{'tbhits' . $mpv};
 				}
 			}
 
-			if (exists($uciinfo{'nodes' . $mpv}) && exists($uciinfo{'nps' . $mpv}) && exists($uciinfo{'depth' . $mpv})) {
+			if (exists($info->{'nodes' . $mpv}) && exists($info->{'nps' . $mpv}) && exists($info->{'depth' . $mpv})) {
 				$text .= sprintf " (%5u kn, %3u kn/s, %2u ply$tbhits)",
-					$uciinfo{'nodes' . $mpv} / 1000, $uciinfo{'nps' . $mpv} / 1000, $uciinfo{'depth' . $mpv};
+					$info->{'nodes' . $mpv} / 1000, $info->{'nps' . $mpv} / 1000, $info->{'depth' . $mpv};
 			}
 
 			$text .= ":\n";
-			$text .= "  " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$uciinfo{'pv' . $mpv}})) . "\n";
+			$text .= "  " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}})) . "\n";
 			$text .= "\n";
 			++$mpv;
 		}
 	} else {
 		# single-PV
-		my $score = long_score(\%uciinfo, $pos_calculating, '');
+		my $score = long_score($info, $pos_calculating, '');
 		$text .= "  $score\n" if defined($score);
-		$text .=  "  PV: " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$uciinfo{'pv'}}));
+		$text .=  "  PV: " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}}));
 		$text .=  "\n";
 
-		if (exists($uciinfo{'nodes'}) && exists($uciinfo{'nps'}) && exists($uciinfo{'depth'})) {
+		if (exists($info->{'nodes'}) && exists($info->{'nps'}) && exists($info->{'depth'})) {
 			$text .= sprintf "  %u nodes, %7u nodes/sec, depth %u ply",
-				$uciinfo{'nodes'}, $uciinfo{'nps'}, $uciinfo{'depth'};
+				$info->{'nodes'}, $info->{'nps'}, $info->{'depth'};
 		}
-		if (exists($uciinfo{'tbhits'}) && $uciinfo{'tbhits'} > 0) {
-			if ($uciinfo{'tbhits'} == 1) {
+		if (exists($info->{'seldepth'})) {
+			$text .= sprintf " (%u selective)", $info->{'seldepth'};
+		}
+		if (exists($info->{'tbhits'}) && $info->{'tbhits'} > 0) {
+			if ($info->{'tbhits'} == 1) {
 				$text .= ", one Nalimov hit";
 			} else {
-				$text .= sprintf ", %u Nalimov hits", $uciinfo{'tbhits'};
+				$text .= sprintf ", %u Nalimov hits", $info->{'tbhits'};
 			}
 		}
-		if (exists($uciinfo{'seldepth'})) {
-			$text .= sprintf " (%u selective)", $uciinfo{'seldepth'};
-		}
-		$text .=  "\n\n";
+		$text .= "\n\n";
 	}
 
 	#$text .= book_info($pos_calculating->{'fen'}, $pos_calculating->{'board'}, $pos_calculating->{'toplay'});
 
+	my @refutation_lines = ();
+	for my $move (keys %refutation_moves) {
+		eval {
+			my $m = $refutation_moves{$move};
+			die if ($m->{'depth'} < $second_engine_start_depth);
+			my $pretty_move = join('', prettyprint_pv($pos_calculating->{'board'}, $move));
+			my @pretty_pv = prettyprint_pv($pos_calculating->{'board'}, $move, @{$m->{'pv'}});
+			if (scalar @pretty_pv > 5) {
+				@pretty_pv = @pretty_pv[0..4];
+				push @pretty_pv, "...";
+			}
+			#my $key = score_sort_key($refutation_moves{$move}, $pos_calculating, '', 1);
+			my $key = $pretty_move;
+			my $line = sprintf("  %-6s %6s %3s  %s",
+				$pretty_move,
+				short_score($refutation_moves{$move}, $pos_calculating, '', 1),
+				"d" . $m->{'depth'},
+				join(', ', @pretty_pv));
+			push @refutation_lines, [ $key, $line ];
+		};
+	}
+
+	if ($#refutation_lines >= 0) {
+		$text .= "Shallow search of all legal moves:\n\n";
+		for my $line (sort { $a->[0] cmp $b->[0] } @refutation_lines) {
+			$text .= $line->[1] . "\n";
+		}
+		$text .= "\n\n";	
+	}	
+
 	if ($last_text ne $text) {
 		print ""; # clear the screen
 		print $text;
@@ -657,36 +792,36 @@ sub output_screen {
 
 	my $tell_text = '';
 
-	if (exists($uciid{'name'})) {
-		$tell_text .= "Analysis by $uciid{'name'} -- see http://analysis.sesse.net/ for more information\n";
+	if (exists($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($uciinfo{'pv1'}) && exists($uciinfo{'pv2'})) {
+	if (exists($info->{'pv1'}) && exists($info->{'pv2'})) {
 		# multi-PV
 		my $mpv = 1;
-		while (exists($uciinfo{'pv' . $mpv})) {
+		while (exists($info->{'pv' . $mpv})) {
 			$tell_text .= sprintf "  PV%2u", $mpv;
-			my $score = short_score(\%uciinfo, $pos_calculating, $mpv);
+			my $score = short_score($info, $pos_calculating, $mpv);
 			$tell_text .= "  ($score)" if (defined($score));
 
-			if (exists($uciinfo{'depth' . $mpv})) {
-				$tell_text .= sprintf " (%2u ply)", $uciinfo{'depth' . $mpv};
+			if (exists($info->{'depth' . $mpv})) {
+				$tell_text .= sprintf " (%2u ply)", $info->{'depth' . $mpv};
 			}
 
 			$tell_text .= ": ";
-			$tell_text .= join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$uciinfo{'pv' . $mpv}}));
+			$tell_text .= join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}}));
 			$tell_text .= "\n";
 			++$mpv;
 		}
 	} else {
 		# single-PV
-		my $score = long_score(\%uciinfo, $pos_calculating, '');
+		my $score = long_score($info, $pos_calculating, '');
 		$tell_text .= "  $score\n" if defined($score);
-		$tell_text .= "  PV: " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$uciinfo{'pv'}}));
-		if (exists($uciinfo{'depth'})) {
-			$tell_text .= sprintf " (depth %u ply)", $uciinfo{'depth'};
+		$tell_text .= "  PV: " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}}));
+		if (exists($info->{'depth'})) {
+			$tell_text .= sprintf " (depth %u ply)", $info->{'depth'};
 		}
 		$tell_text .=  "\n";
 	}
@@ -711,6 +846,54 @@ sub output_screen {
 	}
 }
 
+sub output_json {
+	my $info = $engine->{'info'};
+
+	my $json = {};
+	$json->{'position'} = $pos_calculating;
+	$json->{'id'} = $engine->{'id'};
+	$json->{'score'} = long_score($info, $pos_calculating, '');
+
+	$json->{'nodes'} = $info->{'nodes'};
+	$json->{'nps'} = $info->{'nps'};
+	$json->{'depth'} = $info->{'depth'};
+	$json->{'tbhits'} = $info->{'tbhits'};
+	$json->{'seldepth'} = $info->{'seldepth'};
+
+	# single-PV only for now
+	$json->{'pv_uci'} = $info->{'pv'};
+	$json->{'pv_pretty'} = [ prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}}) ];
+
+	my %refutation_lines = ();
+	for my $move (keys %refutation_moves) {
+		my $m = $refutation_moves{$move};
+		my $pretty_move = "";
+		my @pretty_pv = ();
+		eval {
+			$pretty_move = join('', prettyprint_pv($pos_calculating->{'board'}, $move));
+			@pretty_pv = prettyprint_pv($pos_calculating->{'board'}, $move, @{$m->{'pv'}});
+		};
+		$refutation_lines{$move} = {
+			sort_key => $pretty_move,
+			depth => $m->{'depth'},
+			score_sort_key => score_sort_key($refutation_moves{$move}, $pos_calculating, '', 1),
+			pretty_score => short_score($refutation_moves{$move}, $pos_calculating, '', 1),
+			pretty_move => $pretty_move,
+			pv_pretty => \@pretty_pv,
+		};
+		eval {
+			$refutation_lines{$move}->{'pv_uci'} = [ $move, @{$m->{'pv'}} ];
+		};
+	}
+	$json->{'refutation_lines'} = \%refutation_lines;
+
+	open my $fh, ">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, $bkc);
@@ -873,11 +1056,17 @@ sub can_reach {
 		return (can_reach($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 '-');
 		}
@@ -888,6 +1077,10 @@ sub can_reach {
 		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 '-');
 		}
@@ -901,18 +1094,30 @@ sub can_reach {
 sub uciprint {
 	my ($engine, $msg) = @_;
 	print { $engine->{'write'} } "$msg\n";
-	print UCILOG localtime() . " => $msg\n";
+	print UCILOG localtime() . " $engine->{'tag'} => $msg\n";
 }
 
 sub short_score {
-	my ($uciinfo, $pos, $mpv) = @_;
+	my ($info, $pos, $mpv, $invert) = @_;
+
+	$invert //= 0;
+	if ($pos->{'toplay'} eq 'B') {
+		$invert = !$invert;
+	}
 
-	if (defined($uciinfo{'score_mate' . $mpv})) {
-		return sprintf "M%3d", $uciinfo{'score_mate' . $mpv};
+	if (defined($info->{'score_mate' . $mpv})) {
+		if ($invert) {
+			return sprintf "M%3d", -$info->{'score_mate' . $mpv};
+		} else {
+			return sprintf "M%3d", $info->{'score_mate' . $mpv};
+		}
 	} else {
-		if (exists($uciinfo{'score_cp' . $mpv})) {
-			my $score = $uciinfo{'score_cp' . $mpv} * 0.01;
-			if ($pos->{'toplay'} eq 'B') {
+		if (exists($info->{'score_cp' . $mpv})) {
+			my $score = $info->{'score_cp' . $mpv} * 0.01;
+			if ($score == 0) {
+				return " 0.00";
+			}
+			if ($invert) {
 				$score = -$score;
 			}
 			return sprintf "%+5.2f", $score;
@@ -922,11 +1127,41 @@ sub short_score {
 	return undef;
 }
 
+sub score_sort_key {
+	my ($info, $pos, $mpv, $invert) = @_;
+
+	$invert //= 0;
+	if ($pos->{'toplay'} eq 'B') {
+		$invert = !$invert;
+	}
+
+	if (defined($info->{'score_mate' . $mpv})) {
+		if ($invert) {
+			return -(99999 - $info->{'score_mate' . $mpv});
+		} else {
+			return 99999 - $info->{'score_mate' . $mpv};
+		}
+	} else {
+		if (exists($info->{'score_cp' . $mpv})) {
+			my $score = $info->{'score_cp' . $mpv};
+			if ($score == 0) {
+				return " 0.00";
+			}
+			if ($invert) {
+				$score = -$score;
+			}
+			return $score;
+		}
+	}
+
+	return undef;
+}
+
 sub long_score {
-	my ($uciinfo, $pos, $mpv) = @_;
+	my ($info, $pos, $mpv) = @_;
 
-	if (defined($uciinfo{'score_mate' . $mpv})) {
-		my $mate = $uciinfo{'score_mate' . $mpv};
+	if (defined($info->{'score_mate' . $mpv})) {
+		my $mate = $info->{'score_mate' . $mpv};
 		if ($pos->{'toplay'} eq 'B') {
 			$mate = -$mate;
 		}
@@ -936,8 +1171,8 @@ sub long_score {
 			return sprintf "Black mates in %u", -$mate;
 		}
 	} else {
-		if (exists($uciinfo{'score_cp' . $mpv})) {
-			my $score = $uciinfo{'score_cp' . $mpv} * 0.01;
+		if (exists($info->{'score_cp' . $mpv})) {
+			my $score = $info->{'score_cp' . $mpv} * 0.01;
 			if ($pos->{'toplay'} eq 'B') {
 				$score = -$score;
 			}
@@ -1001,14 +1236,18 @@ sub book_info {
 }
 
 sub open_engine {
-	my $cmdline = shift;
+	my ($cmdline, $tag) = @_;
 	my ($uciread, $uciwrite);
 	my $pid = IPC::Open2::open2($uciread, $uciwrite, $cmdline);
 
 	my $engine = {
 		pid => $pid,
 		read => $uciread,
-		write => $uciwrite
+		readbuf => '',
+		write => $uciwrite,
+		info => {},
+		ids => {},
+		tag => $tag,
 	};
 
 	uciprint($engine, "uci");
@@ -1016,8 +1255,122 @@ sub open_engine {
 	# gobble the options
 	while (<$uciread>) {
 		/uciok/ && last;
-		handle_uci($_);
+		handle_uci($engine, $_);
 	}
 	
 	return $engine;
 }
+
+sub read_lines {
+	my $engine = shift;
+
+	# 
+	# Read until we've got a full line -- if the engine sends part of
+	# a line and then stops we're pretty much hosed, but that should
+	# never happen.
+	#
+	while ($engine->{'readbuf'} !~ /\n/) {
+		my $tmp;
+		my $ret = sysread $engine->{'read'}, $tmp, 4096;
+
+		if (!defined($ret)) {
+			next if ($!{EINTR});
+			die "error in reading from the UCI engine: $!";
+		} elsif ($ret == 0) {
+			die "EOF from UCI engine";
+		}
+
+		$engine->{'readbuf'} .= $tmp;
+	}
+
+	# Blah.
+	my @lines = ();
+	while ($engine->{'readbuf'} =~ s/^([^\n]*)\n//) {
+		my $line = $1;
+		$line =~ tr/\r\n//d;
+		push @lines, $line;
+	}
+	return @lines;
+}
+
+# Find all possible legal moves.
+sub calculate_refutation_moves {
+	my $pos = shift;
+	my $board = $pos->{'board'};
+	my %refutation_moves = ();
+	for my $col (0..7) {
+		for my $row (0..7) {
+			my $piece = substr($board->[$row], $col, 1);
+
+			# Check that there's a piece of the right color on this square.
+			next if ($piece eq '-');
+			if ($pos->{'toplay'} eq 'W') {
+				next if ($piece ne uc($piece));
+			} else {
+				next if ($piece ne lc($piece));
+			}
+
+			for my $to_col (0..7) {
+				for my $to_row (0..7) {
+					next if ($col == $to_col && $row == $to_row);
+					next unless (can_reach($board, $piece, $row, $col, $to_row, $to_col));
+
+					my $promo = "";  # FIXME
+					my $nb = make_move($board, $row, $col, $to_row, $to_col, $promo);
+					my $check = in_check($nb);
+					next if ($check eq 'both');
+					if ($pos->{'toplay'} eq 'W') {
+						next if ($check eq 'white');
+					} else {
+						next if ($check eq 'black');
+					}
+					my $move = move_to_uci_notation($row, $col, $to_row, $to_col, $promo);
+					$refutation_moves{$move} = { depth => $second_engine_start_depth - 1, score_cp => 0, pv => '' };
+				}
+			}
+		}
+	}
+	return %refutation_moves;
+}
+
+sub give_new_move_to_second_engine {
+	my $pos = shift;
+				
+	# Find the move that's been analyzed the shortest but is most promising.
+	# Tie-break on UCI move representation.
+	my $best_move = undef;
+	for my $move (sort keys %refutation_moves) {
+		if (!defined($best_move)) {
+			$best_move = $move;
+			next;
+		}
+		my $best = $refutation_moves{$best_move};
+		my $this = $refutation_moves{$move};
+
+		if ($this->{'depth'} < $best->{'depth'} ||
+		    ($this->{'depth'} == $best->{'depth'} && $this->{'score_cp'} < $best->{'score_cp'})) {
+			$best_move = $move;
+			next;
+		}
+	}
+
+	my $m = $refutation_moves{$best_move};
+	++$m->{'depth'};
+	uciprint($engine2, "position fen " . $pos->{'fen'} . " moves " . $best_move);
+	uciprint($engine2, "go depth " . $m->{'depth'});
+	$move_calculating_second_engine = $best_move;
+}
+
+sub col_letter_to_num {
+	return ord(shift) - ord('a');
+}
+
+sub row_letter_to_num {
+	return 7 - (ord(shift) - ord('1'));
+}
+
+sub move_to_uci_notation {
+	my ($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);
+}