Start using Chess.js.
[remoteglot] / remoteglot.pl
index a12797c..62d3aa1 100755 (executable)
 
 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 = "GMCarlsen";
-my $engine_cmdline = "'./Deep Rybka 4 SSE42 x64'";
-my $engine2_cmdline = "./stockfish_13111119_x64_modern_sse42";  # undef for none
-my $uci_assume_full_compliance = 0;                    # dangerous :-)
-my $update_max_interval = 1.0;
-my @masters = (
-       'Sesse',
-       'Sessse',
-       'Sesssse',
-       'greatestguns',
-       'beuki'
-);
+no warnings qw(once);
 
 # Program starts here
-$SIG{ALRM} = sub { output(); };
 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;
 
@@ -54,28 +49,33 @@ 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 $engine = open_engine($engine_cmdline, 'E1', sub { handle_uci(@_, 1); });
-my $engine2 = open_engine($engine2_cmdline, 'E2', sub { handle_uci(@_, 0); });
+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 $last_text = '';
 my ($pos_waiting, $pos_calculating, $pos_calculating_second_engine);
 
 uciprint($engine, "setoption name UCI_AnalyseMode value true");
-# uciprint($engine, "setoption name NalimovPath value /srv/tablebase");
-uciprint($engine, "setoption name NalimovUsage value Rarely");
-uciprint($engine, "setoption name Hash value 1024");
-# uciprint($engine, "setoption name MultiPV value 2");
+while (my ($key, $value) = each %remoteglotconf::engine_config) {
+       uciprint($engine, "setoption name $key value $value");
+}
 uciprint($engine, "ucinewgame");
 
 if (defined($engine2)) {
        uciprint($engine2, "setoption name UCI_AnalyseMode value true");
-       # uciprint($engine2, "setoption name NalimovPath value /srv/tablebase");
-       uciprint($engine2, "setoption name NalimovUsage value Rarely");
-       uciprint($engine2, "setoption name Hash value 1024");
-       uciprint($engine2, "setoption name Threads value 8");
+       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");
 }
@@ -85,8 +85,8 @@ 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("SesseBOT");
+$t->open($remoteglotconf::server);
+$t->print($remoteglotconf::nick);
 $t->waitfor('/Press return to enter the server/');
 $t->cmd("");
 
@@ -94,8 +94,6 @@ $t->cmd("");
 $t->cmd("set shout 0");
 $t->cmd("set seek 0");
 $t->cmd("set style 12");
-$t->cmd("observe $target");
-print "FICS ready.\n";
 
 my $ev1 = AnyEvent->io(
        fh => fileno($t),
@@ -111,12 +109,23 @@ my $ev1 = AnyEvent->io(
                }
        }
 );
+if (defined($remoteglotconf::target)) {
+       if ($remoteglotconf::target =~ /^http:/) {
+               fetch_pgn($remoteglotconf::target);
+       } else {
+               $t->cmd("observe $remoteglotconf::target");
+       }
+}
+print "FICS ready.\n";
+
 # Engine events have already been set up by Engine.pm.
 EV::run;
 
 sub handle_uci {
        my ($engine, $line, $primary) = @_;
 
+       return if $line =~ /(upper|lower)bound/;
+
        $line =~ s/  / /g;  # Sometimes needed for Zappa Mexico
        print UCILOG localtime() . " $engine->{'tag'} <= $line\n";
        if ($line =~ /^info/) {
@@ -133,7 +142,7 @@ sub handle_uci {
        }
        if ($line =~ /^bestmove/) {
                if ($primary) {
-                       return if (!$uci_assume_full_compliance);
+                       return if (!$remoteglotconf::uci_assume_full_compliance);
                        if (defined($pos_waiting)) {
                                uciprint($engine, "position fen " . $pos_waiting->fen());
                                uciprint($engine, "go infinite");
@@ -152,68 +161,63 @@ sub handle_uci {
        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> /) {
-               my $pos = Position->new($line);
-               
-               # if this is already in the queue, ignore it
-               next if (defined($pos_waiting) && $pos->fen() eq $pos_waiting->fen());
-
-               # if we're already chewing on this and there's nothing else in the queue,
-               # also ignore it
-               next if (!defined($pos_waiting) && defined($pos_calculating) &&
-                        $pos->fen() eq $pos_calculating->fen());
-
-               # if we're already thinking on something, stop and wait for the engine
-               # to approve
-               if (defined($pos_calculating)) {
-                       if (!defined($pos_waiting)) {
-                               uciprint($engine, "stop");
-                       }
-                       if ($uci_assume_full_compliance) {
-                               $pos_waiting = $pos;
-                       } else {
-                               uciprint($engine, "position fen " . $pos->fen());
-                               uciprint($engine, "go infinite");
-                               $pos_calculating = $pos;
+               handle_position(Position->new($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, $2;
                        }
-               } else {
-                       # it's wrong just to give the FEN (the move history is useful,
-                       # and per the UCI spec, we should really have sent "ucinewgame"),
-                       # but it's easier
-                       uciprint($engine, "position fen " . $pos->fen());
-                       uciprint($engine, "go infinite");
-                       $pos_calculating = $pos;
+               };
+               if ($@) {
+                       warn "Error when getting FICS move history: $@";
+                       $getting_movelist = 0;
                }
-
-               if (defined($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 = $pos;
+       }
+       if ($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;
                        }
-                       $engine2->{'info'} = {};
                }
-
-               $engine->{'info'} = {};
-               $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");
+               $getting_movelist = 0;
        }
        if ($line =~ /^([A-Za-z]+)(?:\([A-Z]+\))* tells you: (.*)$/) {
                my ($who, $msg) = ($1, $2);
 
-               next if (grep { $_ eq $who } (@masters) == 0);
+               next if (grep { $_ eq $who } (@remoteglotconf::masters) == 0);
 
                if ($msg =~ /^fics (.*?)$/) {
                        $t->cmd("tell $who Executing '$1' on FICS.");
@@ -221,6 +225,17 @@ sub handle_fics {
                } elsif ($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.");
                }
@@ -228,6 +243,133 @@ sub handle_fics {
        #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 {
+               eval {
+                       $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;
+
+                       # 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);
+                       }
+               };
+               if ($@) {
+                       warn "Error in parsing moves from $url\n";
+               }
+       }
+       
+       $http_timer = AnyEvent->timer(after => 1.0, cb => sub {
+               fetch_pgn($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.
+       #
+       $t->cmd("date");
+}
+
 sub parse_infos {
        my ($engine, @x) = @_;
        my $mpv = '';
@@ -236,26 +378,28 @@ sub parse_infos {
 
        # Search for "multipv" first of all, since e.g. Stockfish doesn't put it first.
        for my $i (0..$#x - 1) {
-               if ($x[$i] =~ 'multipv') {
+               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;
                        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;
                        $info->{$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;
                        $info->{$key . $mpv} = $value;
@@ -267,7 +411,7 @@ sub parse_infos {
                        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;
                                        $info->{'score_cp' . $mpv} = shift @x;
@@ -311,7 +455,7 @@ sub parse_ids {
        }
 }
 
-sub prettyprint_pv {
+sub prettyprint_pv_no_cache {
        my ($board, @pvs) = @_;
 
        if (scalar @pvs == 0 || !defined($pvs[0])) {
@@ -321,7 +465,20 @@ sub prettyprint_pv {
        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($nb, @pvs));
+       return ( $pretty, prettyprint_pv_no_cache($nb, @pvs) );
+}
+
+sub prettyprint_pv {
+       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;
+       }
 }
 
 sub output {
@@ -331,12 +488,53 @@ sub output {
 
        # 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 - $age);
+       if ($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'};
+
+       #
+       # 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 + $t->{'score'}) / 2);
+               if ($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'} = $matelen;
+                       }
+               } else {
+                       if ($pos_calculating->{'toplay'} eq 'B') {
+                               $info->{'score_mate'} = $matelen;
+                       } else {
+                               $info->{'score_mate'} = -$matelen;
+                       }
+               }
+               $info->{'pv'} = $pv;
+               $info->{'tablebase'} = 1;
+       } else {
+               $info->{'tablebase'} = 0;
+       }
        
        #
        # Some programs _always_ report MultiPV, even with only one PV.
@@ -359,12 +557,12 @@ sub output {
        eval {
                my $dummy;
                if (exists($info->{'pv'})) {
-                       $dummy = prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}});
+                       $dummy = prettyprint_pv($pos_calculating, @{$info->{'pv'}});
                }
        
                my $mpv = 1;
                while (exists($info->{'pv' . $mpv})) {
-                       $dummy = prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}});
+                       $dummy = prettyprint_pv($pos_calculating, @{$info->{'pv' . $mpv}});
                        ++$mpv;
                }
        };
@@ -425,7 +623,7 @@ sub output_screen {
                        }
 
                        $text .= ":\n";
-                       $text .= "  " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv' . $mpv}})) . "\n";
+                       $text .= "  " . join(', ', prettyprint_pv($pos_calculating, @{$info->{'pv' . $mpv}})) . "\n";
                        $text .= "\n";
                        ++$mpv;
                }
@@ -433,7 +631,7 @@ sub output_screen {
                # single-PV
                my $score = long_score($info, $pos_calculating, '');
                $text .= "  $score\n" if defined($score);
-               $text .=  "  PV: " . join(', ', prettyprint_pv($pos_calculating->{'board'}, @{$info->{'pv'}}));
+               $text .=  "  PV: " . join(', ', prettyprint_pv($pos_calculating, @{$info->{'pv'}}));
                $text .=  "\n";
 
                if (exists($info->{'nodes'}) && exists($info->{'nps'}) && exists($info->{'depth'})) {
@@ -463,8 +661,8 @@ sub output_screen {
                        eval {
                                my $pv = $info->{'pv' . $mpv};
 
-                               my $pretty_move = join('', prettyprint_pv($pos_calculating_second_engine->{'board'}, $pv->[0]));
-                               my @pretty_pv = prettyprint_pv($pos_calculating_second_engine->{'board'}, @$pv);
+                               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, "...";
@@ -472,7 +670,7 @@ sub output_screen {
                                my $key = $pretty_move;
                                my $line = sprintf("  %-6s %6s %3s  %s",
                                        $pretty_move,
-                                       short_score($info, $pos_calculating_second_engine, $mpv, 0),
+                                       short_score($info, $pos_calculating_second_engine, $mpv),
                                        "d" . $info->{'depth' . $mpv},
                                        join(', ', @pretty_pv));
                                push @refutation_lines, [ $key, $line ];
@@ -502,16 +700,17 @@ sub output_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->{'board'}, @{$info->{'pv'}}) ];
 
        my %refutation_lines = ();
        my @refutation_lines = ();
@@ -524,15 +723,14 @@ sub output_json {
 
                        eval {
                                my $pv = $info->{'pv' . $mpv};
-                               my $pretty_move = join('', prettyprint_pv($pos_calculating->{'board'}, $pv->[0]));
-                               my @pretty_pv = prettyprint_pv($pos_calculating->{'board'}, @$pv);
+                               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, $mpv, 0),
+                                       pretty_score => short_score($info, $pos_calculating, $mpv),
                                        pretty_move => $pretty_move,
-                                       pv_pretty => \@pretty_pv,
                                };
                                $refutation_lines{$pv->[0]}->{'pv_uci'} = $pv;
                        };
@@ -540,11 +738,61 @@ sub output_json {
        }
        $json->{'refutation_lines'} = \%refutation_lines;
 
-       open my $fh, ">/srv/analysis.sesse.net/www/analysis.json.tmp"
+       my $encoded = JSON::XS::encode_json($json);
+       atomic_set_contents($remoteglotconf::json_output, $encoded);
+
+       if (exists($pos_calculating->{'history'}) &&
+           defined($remoteglotconf::json_history_dir)) {
+               my $halfmove_num = scalar @{$pos_calculating->{'history'}};
+               (my $fen = $pos_calculating->fen()) =~ tr,/ ,-_,;
+               my $filename = $remoteglotconf::json_history_dir . "/move$halfmove_num-$fen.json";
+
+               # Overwrite old analysis (assuming it exists at all) if we're
+               # using a different engine, or if we've calculated deeper.
+               # nodes is used as a tiebreaker. Don't bother about Multi-PV
+               # data; it's not that important.
+               my ($old_engine, $old_depth, $old_nodes) = get_json_analysis_stats($filename);
+               my $new_depth = $json->{'depth'} // 0;
+               my $new_nodes = $json->{'nodes'} // 0;
+               if (!defined($old_engine) ||
+                   $old_engine ne $json->{'id'}{'name'} ||
+                   $new_depth > $old_depth ||
+                   ($new_depth == $old_depth && $new_nodes >= $old_nodes)) {
+                       atomic_set_contents($filename, $encoded);
+               }
+       }
+}
+
+sub atomic_set_contents {
+       my ($filename, $contents) = @_;
+
+       open my $fh, ">", $filename . ".tmp"
                or return;
-       print $fh JSON::XS::encode_json($json);
+       print $fh $contents;
        close $fh;
-       rename("/srv/analysis.sesse.net/www/analysis.json.tmp", "/srv/analysis.sesse.net/www/analysis.json");
+       rename($filename . ".tmp", $filename);
+}
+
+sub get_json_analysis_stats {
+       my $filename = shift;
+
+       my ($engine, $depth, $nodes);
+
+       open my $fh, "<", $filename
+               or return undef;
+       local $/ = undef;
+       eval {
+               my $json = JSON::XS::decode_json(<$fh>);
+               $engine = $json->{'id'}{'name'} // die;
+               $depth = $json->{'depth'} // 0;
+               $nodes = $json->{'nodes'} // 0;
+       };
+       close $fh;
+       if ($@) {
+               warn "Error in decoding $filename: $@";
+               return undef;
+       }
+       return ($engine, $depth, $nodes);
 }
 
 sub uciprint {
@@ -554,13 +802,9 @@ sub uciprint {
 }
 
 sub short_score {
-       my ($info, $pos, $mpv, $invert) = @_;
-
-       $invert //= 0;
-       if ($pos->{'toplay'} eq 'B') {
-               $invert = !$invert;
-       }
+       my ($info, $pos, $mpv) = @_;
 
+       my $invert = ($pos->{'toplay'} eq 'B');
        if (defined($info->{'score_mate' . $mpv})) {
                if ($invert) {
                        return sprintf "M%3d", -$info->{'score_mate' . $mpv};
@@ -571,7 +815,11 @@ sub short_score {
                if (exists($info->{'score_cp' . $mpv})) {
                        my $score = $info->{'score_cp' . $mpv} * 0.01;
                        if ($score == 0) {
-                               return " 0.00";
+                               if ($info->{'tablebase'}) {
+                                       return "TB draw";
+                               } else {
+                                       return " 0.00";
+                               }
                        }
                        if ($invert) {
                                $score = -$score;
@@ -587,11 +835,19 @@ sub score_sort_key {
        my ($info, $pos, $mpv, $invert) = @_;
 
        if (defined($info->{'score_mate' . $mpv})) {
-               if ($invert) {
-                       return 99999 - $info->{'score_mate' . $mpv};
+               my $mate = $info->{'score_mate' . $mpv};
+               my $score;
+               if ($mate > 0) {
+                       # Side to move mates
+                       $score = 99999 - $mate;
                } else {
-                       return -(99999 - $info->{'score_mate' . $mpv});
+                       # Side to move is getting mated (note the double negative for $mate)
+                       $score = -99999 - $mate;
                }
+               if ($invert) {
+                       $score = -$score;
+               }
+               return $score;
        } else {
                if (exists($info->{'score_cp' . $mpv})) {
                        my $score = $info->{'score_cp' . $mpv};
@@ -622,7 +878,11 @@ sub long_score {
                if (exists($info->{'score_cp' . $mpv})) {
                        my $score = $info->{'score_cp' . $mpv} * 0.01;
                        if ($score == 0) {
-                               return "Score:  0.00";
+                               if ($info->{'tablebase'}) {
+                                       return "Theoretical draw";
+                               } else {
+                                       return "Score:  0.00";
+                               }
                        }
                        if ($pos->{'toplay'} eq 'B') {
                                $score = -$score;
@@ -654,7 +914,7 @@ sub book_info {
                if ($move eq '')  {
                        $pmove = '(current)';
                } else {
-                       ($pmove) = prettyprint_pv($board, $move);
+                       ($pmove) = prettyprint_pv_no_cache($board, $move);
                        $pmove .= $annotation;
                }
 
@@ -686,6 +946,84 @@ sub book_info {
        return $text;
 }
 
+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, $pos->fen());
+       });
+}
+
+sub handle_tb_lookup_return {
+       my ($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,
+                                       score => $response->{'Response'}{'Score'},
+                               };
+                               output();
+                       }
+               } elsif ($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 {
+                       die "Unknown response state " . $state;
+               }
+
+               # 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: $@";
+
+               # Don't try this one again, but don't block new lookups either.
+               $tb_lookup_running = 0;
+       }
+}
+
 sub open_engine {
        my ($cmdline, $tag, $cb) = @_;
        return undef if (!defined($cmdline));