Make stoppgn more robust.
[remoteglot] / remoteglot.pl
index 1561ac3..f383bb6 100755 (executable)
@@ -9,23 +9,32 @@
 # Licensed under the GNU General Public License, version 2.
 #
 
+use AnyEvent;
+use AnyEvent::Handle;
+use AnyEvent::HTTP;
+use Chess::PGN::Parse;
+use EV;
 use Net::Telnet;
 use FileHandle;
 use IPC::Open2;
 use Time::HiRes;
+use JSON::XS;
+use URI::Escape;
+require 'Position.pm';
+require 'Engine.pm';
+require 'config.pm';
 use strict;
 use warnings;
-
-# Configuration
-my $server = "freechess.org";
-my $target = "Sesse";
-# my $engine = "/usr/games/toga2";
-my $engine = "wine Rybkav2.3.2a.mp.w32.exe";
-my $telltarget = undef;   # undef to be silent
-my @tell_intervals = (5, 20, 60, 120, 240, 480, 960);  # after each move
+no warnings qw(once);
 
 # Program starts here
-$SIG{ALRM} = sub { output_screen(); };
+my $latest_update = undef;
+my $output_timer = undef;
+my $http_timer = undef;
+my $stop_pgn_fetch = 0;
+my $tb_retry_timer = undef;
+my %tb_cache = ();
+my $tb_lookup_running = 0;
 
 $| = 1;
 
@@ -40,41 +49,44 @@ open(UCILOG, ">ucilog.txt")
 print UCILOG "Log starting.\n";
 select(UCILOG);
 $| = 1;
+
+open(TBLOG, ">tblog.txt")
+       or die "tblog.txt: $!";
+print TBLOG "Log starting.\n";
+select(TBLOG);
+$| = 1;
+
 select(STDOUT);
 
 # open the chess engine
-my $pid = IPC::Open2::open2(*UCIREAD, *UCIWRITE, $engine);
-my %uciinfo = ();
-my %uciid = ();
-my %ficsinfo = ();
-my ($last_move, $last_tell);
+my $engine = open_engine($remoteglotconf::engine_cmdline, 'E1', sub { handle_uci(@_, 1); });
+my $engine2 = open_engine($remoteglotconf::engine2_cmdline, 'E2', sub { handle_uci(@_, 0); });
+my $last_move;
 my $last_text = '';
-my $last_told_text = '';
-
-uciprint("uci");
+my ($pos_waiting, $pos_calculating, $pos_calculating_second_engine);
 
-# gobble the options
-while (<UCIREAD>) {
-       /uciok/ && last;
-       handle_uci($_);
+uciprint($engine, "setoption name UCI_AnalyseMode value true");
+while (my ($key, $value) = each %remoteglotconf::engine_config) {
+       uciprint($engine, "setoption name $key value $value");
 }
+uciprint($engine, "ucinewgame");
 
-uciprint("setoption name UCI_AnalyseMode value true");
-uciprint("setoption name NalimovPath value c:\\nalimov");
-uciprint("setoption name NalimovUsage value Rarely");
-uciprint("setoption name Hash value 1024");
-uciprint("setoption name MultiPV value 3");
-# uciprint("setoption name Contempt value 1000");
-# uciprint("setoption name Outlook value Ultra Optimistic");
-uciprint("ucinewgame");
+if (defined($engine2)) {
+       uciprint($engine2, "setoption name UCI_AnalyseMode value true");
+       while (my ($key, $value) = each %remoteglotconf::engine2_config) {
+               uciprint($engine2, "setoption name $key value $value");
+       }
+       uciprint($engine2, "setoption name MultiPV value 500");
+       uciprint($engine2, "ucinewgame");
+}
 
 print "Chess engine ready.\n";
 
 # now talk to FICS
 my $t = Net::Telnet->new(Timeout => 10, Prompt => '/fics% /');
 $t->input_log(\*FICSLOG);
-$t->open($server);
-$t->print("guest");
+$t->open($remoteglotconf::server);
+$t->print($remoteglotconf::nick);
 $t->waitfor('/Press return to enter the server/');
 $t->cmd("");
 
@@ -82,114 +94,327 @@ $t->cmd("");
 $t->cmd("set shout 0");
 $t->cmd("set seek 0");
 $t->cmd("set style 12");
-$t->cmd("observe $target");
 
-# main loop
-print "FICS ready.\n";
-while (1) {
-       my $rin = '';
-       my $rout;
-       vec($rin, fileno(UCIREAD), 1) = 1;
-       vec($rin, fileno($t), 1) = 1;
-
-       my ($nfound, $timeleft) = select($rout=$rin, undef, undef, 5.0);
-       my $sleep = 1.0;
-
-       while (1) {
-               my $line = $t->getline(Timeout => 0, errmode => 'return');
-               last if (!defined($line));
-
-               chomp $line;
-               $line =~ tr/\r//d;
-               if ($line =~ /^<12> /) {
-                       my $fen = style12_to_fen($line);
-                       uciprint("stop");
-                       uciprint("position fen $fen");
-                       uciprint("go infinite");
-
-                       $last_move = time;
-
-                       # 
-                       # Output a command every move to note that we're
-                       # still paying attention -- this is a good tradeoff,
-                       # since if no move has happened in the last half
-                       # hour, the analysis/relay has most likely stopped
-                       # and we should stop hogging server resources.
-                       #
-                       $t->cmd("date");
-               }
-               #print "FICS: [$line]\n";
-               $sleep = 0;
-       }
-       
-       # any fun on the UCI channel?
-       if ($nfound > 0 && vec($rout, fileno(UCIREAD), 1) == 1) {
-               my $line = <UCIREAD>;
-               handle_uci($line);
-               $sleep = 0;
+my $ev1 = AnyEvent->io(
+       fh => fileno($t),
+       poll => 'r',
+       cb => sub {    # what callback to execute
+               while (1) {
+                       my $line = $t->getline(Timeout => 0, errmode => 'return');
+                       return if (!defined($line));
 
-               # don't update too often
-               Time::HiRes::alarm(0.2);
+                       chomp $line;
+                       $line =~ tr/\r//d;
+                       handle_fics($line);
+               }
+       }
+);
+if (defined($remoteglotconf::target)) {
+       if ($remoteglotconf::target =~ /^http:/) {
+               fetch_pgn($remoteglotconf::target);
+       } else {
+               $t->cmd("observe $remoteglotconf::target");
        }
-
-       sleep $sleep;
 }
+print "FICS ready.\n";
+
+# Engine events have already been set up by Engine.pm.
+EV::run;
 
 sub handle_uci {
-       my ($line) = @_;
+       my ($engine, $line, $primary) = @_;
+
+       return if $line =~ /(upper|lower)bound/;
 
-       chomp $line;
-       $line =~ tr/\r//d;
-       print UCILOG "<= $line\n";
+       $line =~ s/  / /g;  # Sometimes needed for Zappa Mexico
+       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/) {
+               if ($primary) {
+                       return if (!$remoteglotconf::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;
+                       }
+               } else {
+                       $engine2->{'info'} = {};
+                       my $pos = $pos_waiting // $pos_calculating;
+                       uciprint($engine2, "position fen " . $pos->fen());
+                       uciprint($engine2, "go infinite");
+                       $pos_calculating_second_engine = $pos;
+               }
+       }
+       output();
+}
+
+my $getting_movelist = 0;
+my $pos_for_movelist = undef;
+my @uci_movelist = ();
+my @pretty_movelist = ();
+
+sub handle_fics {
+       my $line = shift;
+       if ($line =~ /^<12> /) {
+               handle_position(Position->new($line));
+               $t->cmd("moves");
+       }
+       if ($line =~ /^Movelist for game /) {
+               my $pos = $pos_waiting // $pos_calculating;
+               if (defined($pos)) {
+                       @uci_movelist = ();
+                       @pretty_movelist = ();
+                       $pos_for_movelist = Position->start_pos($pos->{'player_w'}, $pos->{'player_b'});
+                       $getting_movelist = 1;
+               }
+       }
+       if ($getting_movelist &&
+           $line =~ /^\s* \d+\. \s+                     # move number
+                       (\S+) \s+ \( [\d:.]+ \) \s*       # first move, then time
+                      (?: (\S+) \s+ \( [\d:.]+ \) )?    # second move, then time 
+                    /x) {
+               eval {
+                       my $uci_move;
+                       ($pos_for_movelist, $uci_move) = $pos_for_movelist->make_pretty_move($1);
+                       push @uci_movelist, $uci_move;
+                       push @pretty_movelist, $1;
+
+                       if (defined($2)) {
+                               ($pos_for_movelist, $uci_move) = $pos_for_movelist->make_pretty_move($2);
+                               push @uci_movelist, $uci_move;
+                               push @pretty_movelist, $2;
+                       }
+               };
+               if ($@) {
+                       warn "Error when getting FICS move history: $@";
+                       $getting_movelist = 0;
+               }
+       }
+       if ($getting_movelist &&
+           $line =~ /^\s+ \{.*\} \s+ (?: \* | 1\/2-1\/2 | 0-1 | 1-0 )/x) {
+               # End of movelist.
+               for my $pos ($pos_waiting, $pos_calculating) {
+                       next if (!defined($pos));
+                       if ($pos->fen() eq $pos_for_movelist->fen()) {
+                               $pos->{'history'} = \@uci_movelist;
+                               $pos->{'pretty_history'} = \@pretty_movelist;
+                       }
+               }
+               $getting_movelist = 0;
+       }
+       if ($line =~ /^([A-Za-z]+)(?:\([A-Z]+\))* tells you: (.*)$/) {
+               my ($who, $msg) = ($1, $2);
+
+               next if (grep { $_ eq $who } (@remoteglotconf::masters) == 0);
+
+               if ($msg =~ /^fics (.*?)$/) {
+                       $t->cmd("tell $who Executing '$1' on FICS.");
+                       $t->cmd($1);
+               } elsif ($msg =~ /^uci (.*?)$/) {
+                       $t->cmd("tell $who Sending '$1' to the engine.");
+                       print { $engine->{'write'} } "$1\n";
+               } elsif ($msg =~ /^pgn (.*?)$/) {
+                       my $url = $1;
+                       $t->cmd("tell $who Starting to poll '$url'.");
+                       fetch_pgn($url);
+               } elsif ($msg =~ /^stoppgn$/) {
+                       $t->cmd("tell $who Stopping poll.");
+                       $stop_pgn_fetch = 1;
+                       $http_timer = undef;
+               } elsif ($msg =~ /^quit$/) {
+                       $t->cmd("tell $who Bye bye.");
+                       exit;
+               } else {
+                       $t->cmd("tell $who Couldn't understand '$msg', sorry.");
+               }
+       }
+       #print "FICS: [$line]\n";
+}
+
+# Starts periodic fetching of PGNs from the given URL.
+sub fetch_pgn {
+       my ($url) = @_;
+       AnyEvent::HTTP::http_get($url, sub {
+               handle_pgn(@_, $url);
+       });
+}
+
+my ($last_pgn_white, $last_pgn_black);
+my @last_pgn_uci_moves = ();
+my $pgn_hysteresis_counter = 0;
+
+sub handle_pgn {
+       my ($body, $header, $url) = @_;
+
+       if ($stop_pgn_fetch) {
+               $stop_pgn_fetch = 0;
+               $http_timer = undef;
+               return;
+       }
+
+       my $pgn = Chess::PGN::Parse->new(undef, $body);
+       if (!defined($pgn) || !$pgn->read_game()) {
+               warn "Error in parsing PGN from $url\n";
+       } else {
+               $pgn->quick_parse_game;
+               my $pos = Position->start_pos($pgn->white, $pgn->black);
+               my $moves = $pgn->moves;
+               my @uci_moves = ();
+               for my $move (@$moves) {
+                       my $uci_move;
+                       ($pos, $uci_move) = $pos->make_pretty_move($move);
+                       push @uci_moves, $uci_move;
+               }
+               $pos->{'history'} = \@uci_moves;
+               $pos->{'pretty_history'} = $moves;
+
+               # Sometimes, PGNs lose a move or two for a short while,
+               # or people push out new ones non-atomically. 
+               # Thus, if we PGN doesn't change names but becomes
+               # shorter, we mistrust it for a few seconds.
+               my $trust_pgn = 1;
+               if (defined($last_pgn_white) && defined($last_pgn_black) &&
+                   $last_pgn_white eq $pgn->white &&
+                   $last_pgn_black eq $pgn->black &&
+                   scalar(@uci_moves) < scalar(@last_pgn_uci_moves)) {
+                       if (++$pgn_hysteresis_counter < 3) {
+                               $trust_pgn = 0; 
+                       }
+               }
+               if ($trust_pgn) {
+                       $last_pgn_white = $pgn->white;
+                       $last_pgn_black = $pgn->black;
+                       @last_pgn_uci_moves = @uci_moves;
+                       $pgn_hysteresis_counter = 0;
+                       handle_position($pos);
+               }
+       }
+       
+       $http_timer = AnyEvent->timer(after => 1.0, cb => sub {
+               fetch_pgn($url);
+       });
+}
+
+sub handle_position {
+       my ($pos) = @_;
+               
+       # if this is already in the queue, ignore it
+       return if (defined($pos_waiting) && $pos->fen() eq $pos_waiting->fen());
+
+       # if we're already chewing on this and there's nothing else in the queue,
+       # also ignore it
+       return if (!defined($pos_waiting) && defined($pos_calculating) &&
+                $pos->fen() eq $pos_calculating->fen());
+
+       # if we're already thinking on something, stop and wait for the engine
+       # to approve
+       if (defined($pos_calculating)) {
+               if (!defined($pos_waiting)) {
+                       uciprint($engine, "stop");
+               }
+               if ($remoteglotconf::uci_assume_full_compliance) {
+                       $pos_waiting = $pos;
+               } else {
+                       uciprint($engine, "position fen " . $pos->fen());
+                       uciprint($engine, "go infinite");
+                       $pos_calculating = $pos;
+               }
+       } else {
+               # it's wrong just to give the FEN (the move history is useful,
+               # and per the UCI spec, we should really have sent "ucinewgame"),
+               # but it's easier
+               uciprint($engine, "position fen " . $pos->fen());
+               uciprint($engine, "go infinite");
+               $pos_calculating = $pos;
+       }
+
+       if (defined($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'} = {};
+       $last_move = time;
+
+       schedule_tb_lookup();
+
+       # 
+       # Output a command every move to note that we're
+       # still paying attention -- this is a good tradeoff,
+       # since if no move has happened in the last half
+       # hour, the analysis/relay has most likely stopped
+       # and we should stop hogging server resources.
+       #
+       $t->cmd("date");
 }
 
 sub parse_infos {
-       my (@x) = @_;
+       my ($engine, @x) = @_;
        my $mpv = '';
 
+       my $info = $engine->{'info'};
+
+       # Search for "multipv" first of all, since e.g. Stockfish doesn't put it first.
+       for my $i (0..$#x - 1) {
+               if ($x[$i] eq 'multipv') {
+                       $mpv = $x[$i + 1];
+                       next;
+               }
+       }
+
        while (scalar @x > 0) {
-               if ($x[0] =~ 'multipv') {
+               if ($x[0] eq 'multipv') {
+                       # Dealt with above
+                       shift @x;
                        shift @x;
-                       $mpv = shift @x;
                        next;
                }
-               if ($x[0] =~ /^(currmove|currmovenumber|cpuload)$/) {
+               if ($x[0] eq 'currmove' || $x[0] eq 'currmovenumber' || $x[0] eq '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)$/) {
+               if ($x[0] eq 'depth' || $x[0] eq 'seldepth' || $x[0] eq 'hashfull' ||
+                   $x[0] eq 'time' || $x[0] eq 'nodes' || $x[0] eq 'nps' ||
+                   $x[0] eq '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 ($x[0] =~ /^(cp|mate|lowerbound|upperbound)$/) {
+                       while ($x[0] eq 'cp' || $x[0] eq 'mate') {
                                if ($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' . $mpv} = shift @x;
                                } else {
                                        shift @x;
                                }
@@ -197,7 +422,7 @@ sub parse_infos {
                        next;
                }
                if ($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') {
@@ -212,13 +437,13 @@ 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;
                }
 
@@ -227,239 +452,100 @@ sub parse_ids {
        }
 }
 
-sub style12_to_fen {
-       my $str = shift; 
-       my (@x) = split / /, $str;
-       
-       $ficsinfo{'board'} = [ @x[1..8] ];
-       $ficsinfo{'toplay'} = $x[9];
-       
-       # the board itself
-       my (@board) = @x[1..8];
-       for my $rank (0..7) {
-               $board[$rank] =~ s/(-+)/length($1)/ge;
-       }
-       my $fen = join('/', @board);
-
-       # white/black to move
-       $fen .= " ";
-       $fen .= lc($x[9]);
-
-       # 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);
-       $castling = "-" if ($castling eq "");
-       $fen .= " ";
-       $fen .= $castling;
-
-       # en passant
-       my $ep = "-";
-       if ($x[10] != -1) {
-               my $col = $x[10];
-               my $nep = (qw(a b c d e f g h))[$col];
-
-               if ($x[9] eq 'B') {
-                       $nep .= "3";
-               } else {
-                       $nep .= "6";
-               }
-               
-               #
-               # Showing the en passant square when actually no capture can be made
-               # seems to confuse at least Rybka. Thus, check if there's actually
-               # a pawn of the opposite side that can do the en passant move, and if
-               # not, just lie -- it doesn't matter anyway. I'm unsure what's the
-               # "right" thing as per the standard, though.
-               #
-               if ($x[9] eq 'B') {
-                       $ep = $nep if ($col > 0 && substr($board[4], $col-1, 1) eq 'p');
-                       $ep = $nep if ($col < 7 && substr($board[4], $col+1, 1) eq 'p');
-               } else {
-                       $ep = $nep if ($col > 0 && substr($board[3], $col-1, 1) eq 'P');
-                       $ep = $nep if ($col < 7 && substr($board[3], $col+1, 1) eq 'P');
-               }
-       }
-       $fen .= " ";
-       $fen .= $ep;
-
-       # half-move clock
-       $fen .= " ";
-       $fen .= $x[15];
+sub prettyprint_pv_no_cache {
+       my ($board, @pvs) = @_;
 
-       # full-move clock
-       $fen .= " ";
-       $fen .= $x[26];
+       if (scalar @pvs == 0 || !defined($pvs[0])) {
+               return ();
+       }
 
-       return $fen;
+       my $pv = shift @pvs;
+       my ($from_col, $from_row, $to_col, $to_row, $promo) = parse_uci_move($pv);
+       my ($pretty, $nb) = $board->prettyprint_move($from_row, $from_col, $to_row, $to_col, $promo);
+       return ( $pretty, prettyprint_pv_no_cache($nb, @pvs) );
 }
 
 sub prettyprint_pv {
-       my ($board, @pvs) = @_;
-       
-       if (scalar @pvs == 0 || !defined($pvs[0])) {
-               return ();
+       my ($pos, @pvs) = @_;
+
+       my $cachekey = join('', @pvs);
+       if (exists($pos->{'prettyprint_cache'}{$cachekey})) {
+               return @{$pos->{'prettyprint_cache'}{$cachekey}};
+       } else {
+               my @res = prettyprint_pv_no_cache($pos->{'board'}, @pvs);
+               $pos->{'prettyprint_cache'}{$cachekey} = \@res;
+               return @res;
        }
-       
-       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'));
+sub output {
+       #return;
 
-       my $pretty;
-       my $piece = substr($board->[$from_row], $from_col, 1);
+       return if (!defined($pos_calculating));
 
-       if ($piece eq '-') {
-               die "Invalid move";
+       # Don't update too often.
+       my $age = Time::HiRes::tv_interval($latest_update);
+       if ($age < $remoteglotconf::update_max_interval) {
+               my $wait = $remoteglotconf::update_max_interval + 0.01 - $age;
+               $output_timer = AnyEvent->timer(after => $wait, cb => \&output);
+               return;
        }
+       
+       my $info = $engine->{'info'};
 
-       # white short castling
-       if ($pv eq 'e1g1' && $piece eq 'K') {
-               # king
-               substr($nb[7], 4, 1, '-');
-               substr($nb[7], 6, 1, $piece);
-               
-               # rook
-               substr($nb[7], 7, 1, '-');
-               substr($nb[7], 5, 1, 'R');
-                               
-               return ('0-0', prettyprint_pv(\@nb, @pvs));
-       }
-
-       # white long castling
-       if ($pv eq 'e1c1' && $piece eq 'K') {
-               # king
-               substr($nb[7], 4, 1, '-');
-               substr($nb[7], 2, 1, $piece);
-               
-               # rook
-               substr($nb[7], 0, 1, '-');
-               substr($nb[7], 3, 1, 'R');
-                               
-               return ('0-0-0', prettyprint_pv(\@nb, @pvs));
-       }
-
-       # black short castling
-       if ($pv eq 'e8g8' && $piece eq 'k') {
-               # king
-               substr($nb[0], 4, 1, '-');
-               substr($nb[0], 6, 1, $piece);
-               
-               # rook
-               substr($nb[0], 7, 1, '-');
-               substr($nb[0], 5, 1, 'r');
-                               
-               return ('0-0', prettyprint_pv(\@nb, @pvs));
-       }
-
-       # black long castling
-       if ($pv eq 'e8c8' && $piece eq 'k') {
-               # king
-               substr($nb[0], 4, 1, '-');
-               substr($nb[0], 2, 1, $piece);
-               
-               # rook
-               substr($nb[0], 0, 1, '-');
-               substr($nb[0], 3, 1, 'r');
-                               
-               return ('0-0-0', prettyprint_pv(\@nb, @pvs));
-       }
-
-       # check if the from-piece is a pawn
-       if (lc($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') {
-                                       substr($nb[$to_row + 1], $to_col, 1, '-');
-                               } else {
-                                       substr($nb[$to_row - 1], $to_col, 1, '-');
-                               }
+       #
+       # If we have tablebase data from a previous lookup, replace the
+       # engine data with the data from the tablebase.
+       #
+       my $fen = $pos_calculating->fen();
+       if (exists($tb_cache{$fen})) {
+               for my $key (qw(pv score_cp score_mate nodes nps depth seldepth tbhits)) {
+                       delete $info->{$key . '1'};
+                       delete $info->{$key};
+               }
+               $info->{'nodes'} = 0;
+               $info->{'nps'} = 0;
+               $info->{'depth'} = 0;
+               $info->{'seldepth'} = 0;
+               $info->{'tbhits'} = 0;
+
+               my $t = $tb_cache{$fen};
+               my $pv = $t->{'pv'};
+               my $matelen = int((1 + scalar @$pv) / 2);
+               if ($t->{'result'} eq '1/2-1/2') {
+                       $info->{'score_cp'} = 0;
+               } elsif ($t->{'result'} eq '1-0') {
+                       if ($pos_calculating->{'toplay'} eq 'B') {
+                               $info->{'score_mate'} = -$matelen;
+                       } else {
+                               $info->{'score_mate'} = $matelen;
                        }
                } else {
-                       $pretty = substr($pv, 2, 2);
-
-                       if (length($pv) == 5) {
-                               # promotion
-                               $pretty .= "=";
-                               $pretty .= uc(substr($pv, 4, 1));
-
-                               if ($piece eq 'p') {
-                                       $piece = substr($pv, 4, 1);
-                               } else {
-                                       $piece = uc(substr($pv, 4, 1));
-                               }
+                       if ($pos_calculating->{'toplay'} eq 'B') {
+                               $info->{'score_mate'} = $matelen;
+                       } else {
+                               $info->{'score_mate'} = -$matelen;
                        }
                }
+               $info->{'pv'} = $pv;
+               $info->{'tablebase'} = 1;
        } else {
-               $pretty = uc($piece);
-
-               # see how many of these pieces could go here, in all
-               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));
-                       }
-               }
-
-               # 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));
-               }
-               
-               # 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, $to_col));
-               }
-               
-               # see if we need to disambiguate
-               if ($num_total > 1) {
-                       if ($num_col == 1) {
-                               $pretty .= substr($pv, 0, 1);
-                       } elsif ($num_row == 1) {
-                               $pretty .= substr($pv, 1, 1);
-                       } else {
-                               $pretty .= substr($pv, 0, 2);
+               $info->{'tablebase'} = 0;
+       }
+       
+       #
+       # Some programs _always_ report MultiPV, even with only one PV.
+       # In this case, we simply use that data as if MultiPV was never
+       # specified.
+       #
+       if (exists($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'};
                        }
                }
-
-               # attack?
-               if (substr($board->[$to_row], $to_col, 1) ne '-') {
-                       $pretty .= 'x';
-               }
-
-               $pretty .= substr($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)) {
-               $pretty .= '#';
-       } elsif (in_check(\@nb) ne 'none') {
-               $pretty .= '+';
        }
-
-       return ($pretty, prettyprint_pv(\@nb, @pvs));
-}
-
-sub output_screen {
-       #return;
-
+       
        #
        # 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
@@ -467,379 +553,445 @@ sub output_screen {
        #
        eval {
                my $dummy;
-               if (exists($uciinfo{'pv'})) {
-                       $dummy = prettyprint_pv($ficsinfo{'board'}, @{$uciinfo{'pv'}});
+               if (exists($info->{'pv'})) {
+                       $dummy = prettyprint_pv($pos_calculating, @{$info->{'pv'}});
                }
        
                my $mpv = 1;
-               while (exists($uciinfo{'pv' . $mpv})) {
-                       $dummy = prettyprint_pv($ficsinfo{'board'}, @{$uciinfo{'pv' . $mpv}});
+               while (exists($info->{'pv' . $mpv})) {
+                       $dummy = prettyprint_pv($pos_calculating, @{$info->{'pv' . $mpv}});
                        ++$mpv;
                }
        };
        if ($@) {
+               $engine->{'info'} = {};
                return;
        }
 
-       my $text = '';
+       output_screen();
+       output_json();
+       $latest_update = [Time::HiRes::gettimeofday];
+}
 
-       if (exists($uciid{'name'})) {
-               $text .= "Analysis by $uciid{'name'}:\n\n";
-       } else {
-               $text .= "Analysis:\n\n";
-       }
+sub output_screen {
+       my $info = $engine->{'info'};
+       my $id = $engine->{'id'};
 
-       return unless (exists($ficsinfo{'board'}));
-               
-       #
-       # Some programs _always_ report MultiPV, even with only one PV.
-       # In this case, we simply use that data as if MultiPV was never
-       # specified.
-       #
-       if (exists($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'};
-                       }
+       my $text = 'Analysis';
+       if ($pos_calculating->{'last_move'} ne 'none') {
+               if ($pos_calculating->{'toplay'} eq 'W') {
+                       $text .= sprintf ' after %u. ... %s', ($pos_calculating->{'move_num'}-1), $pos_calculating->{'last_move'};
+               } else {
+                       $text .= sprintf ' after %u. %s', $pos_calculating->{'move_num'}, $pos_calculating->{'last_move'};
+               }
+               if (exists($id->{'name'})) {
+                       $text .= ',';
                }
        }
 
-       if (exists($uciinfo{'pv1'}) && exists($uciinfo{'pv2'})) {
+       if (exists($id->{'name'})) {
+               $text .= " by $id->{'name'}:\n\n";
+       } else {
+               $text .= ":\n\n";
+       }
+
+       return unless (exists($pos_calculating->{'board'}));
+               
+       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, \%ficsinfo, $mpv);
+                       my $score = short_score($info, $pos_calculating, $mpv);
                        $text .= "  ($score)" if (defined($score));
 
-                       if (exists($uciinfo{'nodes' . $mpv}) && exists($uciinfo{'nps' . $mpv}) && exists($uciinfo{'depth' . $mpv})) {
-                               $text .= sprintf " (%5u kn, %3u kn/s, %2u ply)",
-                                       $uciinfo{'nodes' . $mpv} / 1000, $uciinfo{'nps' . $mpv} / 1000, $uciinfo{'depth' . $mpv};
+                       my $tbhits = '';
+                       if (exists($info->{'tbhits' . $mpv}) && $info->{'tbhits' . $mpv} > 0) {
+                               if ($info->{'tbhits' . $mpv} == 1) {
+                                       $tbhits = ", 1 tbhit";
+                               } else {
+                                       $tbhits = sprintf ", %u tbhits", $info->{'tbhits' . $mpv};
+                               }
+                       }
+
+                       if (exists($info->{'nodes' . $mpv}) && exists($info->{'nps' . $mpv}) && exists($info->{'depth' . $mpv})) {
+                               $text .= sprintf " (%5u kn, %3u kn/s, %2u ply$tbhits)",
+                                       $info->{'nodes' . $mpv} / 1000, $info->{'nps' . $mpv} / 1000, $info->{'depth' . $mpv};
                        }
 
                        $text .= ":\n";
-                       $text .= "  " . join(', ', prettyprint_pv($ficsinfo{'board'}, @{$uciinfo{'pv' . $mpv}})) . "\n";
+                       $text .= "  " . join(', ', prettyprint_pv($pos_calculating, @{$info->{'pv' . $mpv}})) . "\n";
                        $text .= "\n";
                        ++$mpv;
                }
        } else {
                # single-PV
-               my $score = long_score(\%uciinfo, \%ficsinfo, '');
+               my $score = long_score($info, $pos_calculating, '');
                $text .= "  $score\n" if defined($score);
-               $text .=  "  PV: " . join(', ', prettyprint_pv($ficsinfo{'board'}, @{$uciinfo{'pv'}}));
+               $text .=  "  PV: " . join(', ', prettyprint_pv($pos_calculating, @{$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'})) {
-                       $text .= sprintf ", %u Nalimov hits", $uciinfo{'tbhits'};
+               if (exists($info->{'seldepth'})) {
+                       $text .= sprintf " (%u selective)", $info->{'seldepth'};
                }
-               if (exists($uciinfo{'seldepth'})) {
-                       $text .= sprintf " (%u selective)", $uciinfo{'seldepth'};
+               if (exists($info->{'tbhits'}) && $info->{'tbhits'} > 0) {
+                       if ($info->{'tbhits'} == 1) {
+                               $text .= ", one Syzygy hit";
+                       } else {
+                               $text .= sprintf ", %u Syzygy hits", $info->{'tbhits'};
+                       }
+               }
+               $text .= "\n\n";
+       }
+
+       #$text .= book_info($pos_calculating->fen(), $pos_calculating->{'board'}, $pos_calculating->{'toplay'});
+
+       my @refutation_lines = ();
+       if (defined($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, $pv->[0]));
+                               my @pretty_pv = prettyprint_pv($pos_calculating_second_engine, @$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),
+                                       "d" . $info->{'depth' . $mpv},
+                                       join(', ', @pretty_pv));
+                               push @refutation_lines, [ $key, $line ];
+                       };
                }
-               $text .=  "\n\n";
        }
 
+       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 "\e[H\e[2J"; # clear the screen
                print $text;
                $last_text = $text;
        }
+}
 
-       # Now construct the tell text, if any
-       return if (!defined($telltarget));
+sub output_json {
+       my $info = $engine->{'info'};
+
+       my $json = {};
+       $json->{'position'} = $pos_calculating->to_json_hash();
+       $json->{'id'} = $engine->{'id'};
+       $json->{'score'} = long_score($info, $pos_calculating, '');
+       $json->{'short_score'} = short_score($info, $pos_calculating, '');
+
+       $json->{'nodes'} = $info->{'nodes'};
+       $json->{'nps'} = $info->{'nps'};
+       $json->{'depth'} = $info->{'depth'};
+       $json->{'tbhits'} = $info->{'tbhits'};
+       $json->{'seldepth'} = $info->{'seldepth'};
+       $json->{'tablebase'} = $info->{'tablebase'};
+
+       # single-PV only for now
+       $json->{'pv_uci'} = $info->{'pv'};
+       $json->{'pv_pretty'} = [ prettyprint_pv($pos_calculating, @{$info->{'pv'}}) ];
+
+       my %refutation_lines = ();
+       my @refutation_lines = ();
+       if (defined($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, $pv->[0]));
+                               my @pretty_pv = prettyprint_pv($pos_calculating, @$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),
+                                       pretty_move => $pretty_move,
+                                       pv_pretty => \@pretty_pv,
+                               };
+                               $refutation_lines{$pv->[0]}->{'pv_uci'} = $pv;
+                       };
+               }
+       }
+       $json->{'refutation_lines'} = \%refutation_lines;
+
+       open my $fh, ">", $remoteglotconf::json_output . ".tmp"
+               or return;
+       print $fh JSON::XS::encode_json($json);
+       close $fh;
+       rename($remoteglotconf::json_output . ".tmp", $remoteglotconf::json_output);
+}
 
-       my $tell_text = '';
+sub uciprint {
+       my ($engine, $msg) = @_;
+       $engine->print($msg);
+       print UCILOG localtime() . " $engine->{'tag'} => $msg\n";
+}
+
+sub short_score {
+       my ($info, $pos, $mpv) = @_;
 
-       if (exists($uciid{'name'})) {
-               $tell_text .= "Analysis by $uciid{'name'} -- see http://analysis.sesse.net/ for more information\n";
+       my $invert = ($pos->{'toplay'} eq 'B');
+       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 {
-               $tell_text .= "Computer analysis -- http://analysis.sesse.net/ for more information\n";
+               if (exists($info->{'score_cp' . $mpv})) {
+                       my $score = $info->{'score_cp' . $mpv} * 0.01;
+                       if ($score == 0) {
+                               if ($info->{'tablebase'}) {
+                                       return "TB draw";
+                               } else {
+                                       return " 0.00";
+                               }
+                       }
+                       if ($invert) {
+                               $score = -$score;
+                       }
+                       return sprintf "%+5.2f", $score;
+               }
        }
 
-       if (exists($uciinfo{'pv1'}) && exists($uciinfo{'pv2'})) {
-               # multi-PV
-               my $mpv = 1;
-               while (exists($uciinfo{'pv' . $mpv})) {
-                       $tell_text .= sprintf "  PV%2u", $mpv;
-                       my $score = short_score(\%uciinfo, \%ficsinfo, $mpv);
-                       $tell_text .= "  ($score)" if (defined($score));
+       return undef;
+}
 
-                       if (exists($uciinfo{'depth' . $mpv})) {
-                               $tell_text .= sprintf " (%2u ply)", $uciinfo{'depth' . $mpv};
-                       }
+sub score_sort_key {
+       my ($info, $pos, $mpv, $invert) = @_;
 
-                       $tell_text .= ": ";
-                       $tell_text .= join(', ', prettyprint_pv($ficsinfo{'board'}, @{$uciinfo{'pv' . $mpv}}));
-                       $tell_text .= "\n";
-                       ++$mpv;
+       if (defined($info->{'score_mate' . $mpv})) {
+               my $mate = $info->{'score_mate' . $mpv};
+               my $score;
+               if ($mate > 0) {
+                       # Side to move mates
+                       $score = 99999 - $mate;
+               } else {
+                       # Side to move is getting mated (note the double negative for $mate)
+                       $score = -99999 - $mate;
                }
+               if ($invert) {
+                       $score = -$score;
+               }
+               return $score;
        } else {
-               # single-PV
-               my $score = long_score(\%uciinfo, \%ficsinfo, '');
-               $tell_text .= "  $score\n" if defined($score);
-               $tell_text .= "  PV: " . join(', ', prettyprint_pv($ficsinfo{'board'}, @{$uciinfo{'pv'}}));
-               if (exists($uciinfo{'depth'})) {
-                       $tell_text .= sprintf " (depth %u ply)", $uciinfo{'depth'};
+               if (exists($info->{'score_cp' . $mpv})) {
+                       my $score = $info->{'score_cp' . $mpv};
+                       if ($invert) {
+                               $score = -$score;
+                       }
+                       return $score;
                }
-               $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");
-                       }
+       return undef;
+}
 
-                       $last_told_text = $text;
-                       $last_tell = $now;
+sub long_score {
+       my ($info, $pos, $mpv) = @_;
 
-                       last;
+       if (defined($info->{'score_mate' . $mpv})) {
+               my $mate = $info->{'score_mate' . $mpv};
+               if ($pos->{'toplay'} eq 'B') {
+                       $mate = -$mate;
                }
-       }
-}
-
-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, $col);
+               if ($mate > 0) {
+                       return sprintf "White mates in %u", $mate;
+               } else {
+                       return sprintf "Black mates in %u", -$mate;
+               }
+       } else {
+               if (exists($info->{'score_cp' . $mpv})) {
+                       my $score = $info->{'score_cp' . $mpv} * 0.01;
+                       if ($score == 0) {
+                               if ($info->{'tablebase'}) {
+                                       return "Theoretical draw";
+                               } else {
+                                       return "Score:  0.00";
+                               }
                        }
+                       if ($pos->{'toplay'} eq 'B') {
+                               $score = -$score;
+                       }
+                       return sprintf "Score: %+5.2f", $score;
                }
        }
 
-       return ($wkr, $wkc, $bkr, $bkc);
+       return undef;
 }
 
-sub in_mate {
-       my $board = shift;
-       my $check = in_check($board);
-       return 0 if ($check eq 'none');
+my %book_cache = ();
+sub book_info {
+       my ($fen, $board, $toplay) = @_;
 
-       # 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 (exists($book_cache{$fen})) {
+               return $book_cache{$fen};
+       }
 
-                       if ($check eq 'white') {
-                               next if ($piece eq lc($piece));
-                       } else {
-                               next if ($piece eq uc($piece));
-                       }
+       my $ret = `./booklook $fen`;
+       return "" if ($ret =~ /Not found/ || $ret eq '');
 
-                       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 @moves = ();
 
-                                       my @nb = @$board;
-                                       substr($nb[$row], $col, 1, '-');
-                                       substr($nb[$dest_row], $dest_col, 1, $piece);
+       for my $m (split /\n/, $ret) {
+               my ($move, $annotation, $win, $draw, $lose, $rating, $rating_div) = split /,/, $m;
 
-                                       my $new_check = in_check(\@nb);
-                                       return 0 if ($new_check ne $check && $new_check ne 'both');
-                               }
-                       }
+               my $pmove;
+               if ($move eq '')  {
+                       $pmove = '(current)';
+               } else {
+                       ($pmove) = prettyprint_pv_no_cache($board, $move);
+                       $pmove .= $annotation;
                }
-       }
 
-       # 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 '-');
+               my $score;
+               if ($toplay eq 'W') {
+                       $score = 1.0 * $win + 0.5 * $draw + 0.0 * $lose;
+               } else {
+                       $score = 0.0 * $win + 0.5 * $draw + 1.0 * $lose;
+               }
+               my $n = $win + $draw + $lose;
                
-                       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));
-                       }
+               my $percent;
+               if ($n == 0) {
+                       $percent = "     ";
+               } else {
+                       $percent = sprintf "%4u%%", int(100.0 * $score / $n + 0.5);
                }
-       }
 
-       if ($black_check && $white_check) {
-               return 'both';
-       } elsif ($black_check) {
-               return 'black';
-       } elsif ($white_check) {
-               return 'white';
-       } else {
-               return 'none';
+               push @moves, [ $pmove, $n, $percent, $rating ];
        }
-}
 
-sub can_reach {
-       my ($board, $piece, $from_row, $from_col, $to_row, $to_col) = @_;
+       @moves[1..$#moves] = sort { $b->[2] cmp $a->[2] } @moves[1..$#moves];
        
-       # 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)));
+       my $text = "Book moves:\n\n              Perf.     N     Rating\n\n";
+       for my $m (@moves) {
+               $text .= sprintf "  %-10s %s   %6u    %4s\n", $m->[0], $m->[2], $m->[1], $m->[3]
        }
 
-       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);
+       return $text;
+}
 
-               # check that there's a clear passage
-               if ($from_row == $to_row) {
-                       if ($from_col > $to_col) {
-                               ($to_col, $from_col) = ($from_col, $to_col);
-                       }
+sub schedule_tb_lookup {
+       return if (!defined($remoteglotconf::tb_serial_key));
+       my $pos = $pos_waiting // $pos_calculating;
+       return if (exists($tb_cache{$pos->fen()}));
+
+       # If there's more than seven pieces, there's not going to be an answer,
+       # so don't bother.
+       return if ($pos->num_pieces() > 7);
+
+       # Max one at a time. If it's still relevant when it returns,
+       # schedule_tb_lookup() will be called again.
+       return if ($tb_lookup_running);
+
+       $tb_lookup_running = 1;
+       my $url = 'http://158.250.18.203:6904/tasks/addtask?auth.login=' .
+               $remoteglotconf::tb_serial_key .
+               '&auth.password=aquarium&type=0&fen=' . 
+               URI::Escape::uri_escape($pos->fen());
+       print TBLOG "Downloading $url...\n";
+       AnyEvent::HTTP::http_get($url, sub {
+               handle_tb_lookup_return(@_, $pos, $pos->fen());
+       });
+}
 
-                       for my $c (($from_col+1)..($to_col-1)) {
-                               my $middle_piece = substr($board->[$to_row], $c, 1);
-                               return 0 if ($middle_piece ne '-');     
+sub handle_tb_lookup_return {
+       my ($body, $header, $pos, $fen) = @_;
+       print TBLOG "Response for [$fen]:\n";
+       print TBLOG $header . "\n\n";
+       print TBLOG $body . "\n\n";
+       eval {
+               my $response = JSON::XS::decode_json($body);
+               if ($response->{'ErrorCode'} != 0) {
+                       die "Unknown tablebase server error: " . $response->{'ErrorDesc'};
+               }
+               my $state = $response->{'Response'}{'StateString'};
+               if ($state eq 'COMPLETE') {
+                       my $pgn = Chess::PGN::Parse->new(undef, $response->{'Response'}{'Moves'});
+                       if (!defined($pgn) || !$pgn->read_game()) {
+                               warn "Error in parsing PGN\n";
+                       } else {
+                               $pgn->quick_parse_game;
+                               my $pvpos = $pos;
+                               my $moves = $pgn->moves;
+                               my @uci_moves = ();
+                               for my $move (@$moves) {
+                                       my $uci_move;
+                                       ($pvpos, $uci_move) = $pvpos->make_pretty_move($move);
+                                       push @uci_moves, $uci_move;
+                               }
+                               $tb_cache{$fen} = {
+                                       result => $pgn->result,
+                                       pv => \@uci_moves
+                               };
+                               output();
                        }
-
-                       return 1;
+               } elsif ($state =~ /QUEUED/ || $state =~ /PROCESSING/) {
+                       # Try again in a second. Note that if we have changed
+                       # position in the meantime, we might query a completely
+                       # different position! But that's fine.
                } else {
-                       if ($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;
+                       die "Unknown response state " . $state;
                }
-       }
-       if (lc($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;
-               }
+               # Wait a second before we schedule another one.
+               $tb_retry_timer = AnyEvent->timer(after => 1.0, cb => sub {
+                       $tb_lookup_running = 0;
+                       schedule_tb_lookup();
+               });
+       };
+       if ($@) {
+               warn "Error in tablebase lookup: $@";
 
-               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));
+               # Don't try this one again, but don't block new lookups either.
+               $tb_lookup_running = 0;
        }
-       if ($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 'p') {
-               # black pawn
-               if ($to_col == $from_col && $to_row == $from_row + 1) {
-                       return ($dest_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 (abs($to_col - $from_col) == 1 && $to_row == $from_row - 1) {
-                       return ($dest_piece ne '-');
-               }
-               return 0;
-       }
-       
-       # unknown piece
-       return 0;
 }
 
-sub uciprint {
-       my $msg = shift;
-       print UCIWRITE "$msg\n";
-       print UCILOG "=> $msg\n";
+sub open_engine {
+       my ($cmdline, $tag, $cb) = @_;
+       return undef if (!defined($cmdline));
+       return Engine->open($cmdline, $tag, $cb);
 }
 
-sub short_score {
-       my ($uciinfo, $ficsinfo, $mpv) = @_;
-
-       if (defined($uciinfo{'score_mate' . $mpv})) {
-               return sprintf "M%3d", $uciinfo{'score_mate' . $mpv};
-       } else {
-               if (exists($uciinfo{'score_cp' . $mpv})) {
-                       my $score = $uciinfo{'score_cp' . $mpv} * 0.01;
-                       if ($ficsinfo{'toplay'} eq 'B') {
-                               $score = -$score;
-                       }
-                       return sprintf "%+5.2f", $score;
-               }
-       }
-
-       return undef;
+sub col_letter_to_num {
+       return ord(shift) - ord('a');
 }
 
-sub long_score {
-       my ($uciinfo, $ficsinfo, $mpv) = @_;
-
-       if (defined($uciinfo{'score_mate' . $mpv})) {
-               my $mate = $uciinfo{'score_mate' . $mpv};
-               if ($ficsinfo{'toplay'} eq 'B') {
-                       $mate = -$mate;
-               }
-               if ($mate > 0) {
-                       return sprintf "White mates in %u", $mate;
-               } else {
-                       return sprintf "Black mates in %u", -$mate;
-               }
-       } else {
-               if (exists($uciinfo{'score_cp' . $mpv})) {
-                       my $score = $uciinfo{'score_cp' . $mpv} * 0.01;
-                       if ($ficsinfo{'toplay'} eq 'B') {
-                               $score = -$score;
-                       }
-                       return sprintf "Score: %+5.2f", $score;
-               }
-       }
+sub row_letter_to_num {
+       return 7 - (ord(shift) - ord('1'));
+}
 
-       return undef;
+sub parse_uci_move {
+       my $move = shift;
+       my $from_col = col_letter_to_num(substr($move, 0, 1));
+       my $from_row = row_letter_to_num(substr($move, 1, 1));
+       my $to_col   = col_letter_to_num(substr($move, 2, 1));
+       my $to_row   = row_letter_to_num(substr($move, 3, 1));
+       my $promo    = substr($move, 4, 1);
+       return ($from_col, $from_row, $to_col, $to_row, $promo);
 }