]> git.sesse.net Git - remoteglot/blobdiff - remoteglot.pl
Fix a bug where fathom would cause all winning multi-PV lines to be the same.
[remoteglot] / remoteglot.pl
index e3433aa12414037ff86ba81c5d92e0449514d253..9439a4bc4d0b063c59b1eb2738cc9cd0c4b987d5 100755 (executable)
@@ -5,7 +5,7 @@
 #              analysis, or for live analysis of relayed games. (Do not use for
 #              cheating! Cheating is bad for your karma, and your abuser flag.)
 #
-# Copyright 2007 Steinar H. Gunderson <sgunderson@bigfoot.com>
+# Copyright 2007 Steinar H. Gunderson <steinar+remoteglot@gunderson.no>
 # Licensed under the GNU General Public License, version 2.
 #
 
@@ -15,11 +15,13 @@ use AnyEvent::HTTP;
 use Chess::PGN::Parse;
 use EV;
 use Net::Telnet;
-use FileHandle;
+use File::Slurp;
 use IPC::Open2;
 use Time::HiRes;
 use JSON::XS;
 use URI::Escape;
+use DBI;
+use DBD::Pg;
 require 'Position.pm';
 require 'Engine.pm';
 require 'config.pm';
@@ -35,6 +37,14 @@ my $stop_pgn_fetch = 0;
 my $tb_retry_timer = undef;
 my %tb_cache = ();
 my $tb_lookup_running = 0;
+my $last_written_json = undef;
+
+# Persisted so we can restart.
+# TODO: Figure out an appropriate way to deal with database restarts
+# and/or Postgres going away entirely.
+my $dbh = DBI->connect($remoteglotconf::dbistr, $remoteglotconf::dbiuser, $remoteglotconf::dbipass)
+       or die DBI->errstr;
+$dbh->{RaiseError} = 1;
 
 $| = 1;
 
@@ -57,6 +67,7 @@ select(TBLOG);
 $| = 1;
 
 select(STDOUT);
+umask 0022;
 
 # open the chess engine
 my $engine = open_engine($remoteglotconf::engine_cmdline, 'E1', sub { handle_uci(@_, 1); });
@@ -209,8 +220,7 @@ sub handle_fics {
                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;
+                               $pos->{'history'} = \@pretty_movelist;
                        }
                }
                $getting_movelist = 0;
@@ -266,21 +276,45 @@ sub handle_pgn {
        }
 
        my $pgn = Chess::PGN::Parse->new(undef, $body);
-       if (!defined($pgn) || !$pgn->read_game()) {
-               warn "Error in parsing PGN from $url\n";
+       if (!defined($pgn)) {
+               warn "Error in parsing PGN from $url [body='$body']\n";
+       } elsif (!$pgn->read_game()) {
+               warn "Error in reading PGN game from $url [body='$body']\n";
+       } elsif ($body !~ /^\[/) {
+               warn "Malformed PGN from $url [body='$body']\n";
        } else {
                eval {
-                       $pgn->quick_parse_game;
-                       my $pos = Position->start_pos($pgn->white, $pgn->black);
+                       # Skip to the right game.
+                       while (defined($remoteglotconf::pgn_filter) &&
+                              !&$remoteglotconf::pgn_filter($pgn)) {
+                               $pgn->read_game() or die "Out of games during filtering";
+                       }
+
+                       $pgn->parse_game({ save_comments => 'yes' });
+                       my $white = $pgn->white;
+                       my $black = $pgn->black;
+                       $white =~ s/,.*//;  # Remove first name.
+                       $black =~ s/,.*//;  # Remove first name.
+                       my $pos = Position->start_pos($white, $black);
                        my $moves = $pgn->moves;
                        my @uci_moves = ();
+                       my @repretty_moves = ();
                        for my $move (@$moves) {
-                               my $uci_move;
-                               ($pos, $uci_move) = $pos->make_pretty_move($move);
+                               my ($npos, $uci_move) = $pos->make_pretty_move($move);
                                push @uci_moves, $uci_move;
+
+                               # Re-prettyprint the move.
+                               my ($from_row, $from_col, $to_row, $to_col, $promo) = parse_uci_move($uci_move);
+                               my ($pretty, undef) = $pos->{'board'}->prettyprint_move($from_row, $from_col, $to_row, $to_col, $promo);
+                               push @repretty_moves, $pretty;
+                               $pos = $npos;
+                       }
+                       if ($pgn->result eq '1-0' || $pgn->result eq '1/2-1/2' || $pgn->result eq '0-1') {
+                               $pos->{'result'} = $pgn->result;
                        }
-                       $pos->{'history'} = \@uci_moves;
-                       $pos->{'pretty_history'} = $moves;
+                       $pos->{'history'} = \@repretty_moves;
+
+                       extract_clock($pgn, $pos);
 
                        # Sometimes, PGNs lose a move or two for a short while,
                        # or people push out new ones non-atomically. 
@@ -304,7 +338,7 @@ sub handle_pgn {
                        }
                };
                if ($@) {
-                       warn "Error in parsing moves from $url\n";
+                       warn "Error in parsing moves from $url: $@\n";
                }
        }
        
@@ -315,18 +349,38 @@ sub handle_pgn {
 
 sub handle_position {
        my ($pos) = @_;
+       find_clock_start($pos, $pos_calculating);
                
-       # if this is already in the queue, ignore it
-       return if (defined($pos_waiting) && $pos->fen() eq $pos_waiting->fen());
+       # if this is already in the queue, ignore it (just update the result)
+       if (defined($pos_waiting) && $pos->fen() eq $pos_waiting->fen()) {
+               $pos_waiting->{'result'} = $pos->{'result'};
+               return;
+       }
 
        # 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 $pos_calculating->fen());
+       if (!defined($pos_waiting) && defined($pos_calculating) &&
+           $pos->fen() eq $pos_calculating->fen()) {
+               $pos_calculating->{'result'} = $pos->{'result'};
+               return;
+       }
 
        # if we're already thinking on something, stop and wait for the engine
        # to approve
        if (defined($pos_calculating)) {
+               # Store the final data we have for this position in the history,
+               # with the precise clock information we just got from the new
+               # position. (Historic positions store the clock at the end of
+               # the position.)
+               #
+               # Do not output anything new to the main analysis; that's
+               # going to be obsolete really soon.
+               $pos_calculating->{'white_clock'} = $pos->{'white_clock'};
+               $pos_calculating->{'black_clock'} = $pos->{'black_clock'};
+               delete $pos_calculating->{'white_clock_target'};
+               delete $pos_calculating->{'black_clock_target'};
+               output_json(1);
+
                if (!defined($pos_waiting)) {
                        uciprint($engine, "stop");
                }
@@ -445,10 +499,9 @@ sub parse_ids {
        my ($engine, @x) = @_;
 
        while (scalar @x > 0) {
-               if ($x[0] =~ /^(name|author)$/) {
-                       my $key = shift @x;
+               if ($x[0] eq 'name') {
                        my $value = join(' ', @x);
-                       $engine->{'id'}{$key} = $value;
+                       $engine->{'id'}{'author'} = $value;
                        last;
                }
 
@@ -465,7 +518,7 @@ sub prettyprint_pv_no_cache {
        }
 
        my $pv = shift @pvs;
-       my ($from_col, $from_row, $to_col, $to_row, $promo) = parse_uci_move($pv);
+       my ($from_row, $from_col, $to_row, $to_col, $promo) = parse_uci_move($pv);
        my ($pretty, $nb) = $board->prettyprint_move($from_row, $from_col, $to_row, $to_col, $promo);
        return ( $pretty, prettyprint_pv_no_cache($nb, @pvs) );
 }
@@ -483,6 +536,68 @@ sub prettyprint_pv {
        }
 }
 
+sub complete_using_tbprobe {
+       my ($pos, $info, $mpv) = @_;
+
+       # We need Fathom installed to do standalone TB probes.
+       return if (!defined($remoteglotconf::fathom_cmdline));
+
+       # If we already have a mate, don't bother; in some cases, it would even be
+       # better than a tablebase score.
+       return if defined($info->{'score_mate' . $mpv});
+
+       # If we have a draw or near-draw score, there's also not much interesting
+       # we could add from a tablebase. We only really want mates.
+       return if ($info->{'score_cp' . $mpv} >= -12250 && $info->{'score_cp' . $mpv} <= 12250);
+
+       # Run through the PV until we are at a 6-man position.
+       # TODO: We could in theory only have 5-man data.
+       my @pv = @{$info->{'pv' . $mpv}};
+       my $key = join('', @pv);
+       my @moves = ();
+       if (exists($pos->{'tbprobe_cache'}{$key})) {
+               @moves = $pos->{'tbprobe_cache'}{$key};
+       } else {
+               if ($mpv ne '') {
+                       # Force doing at least one move of the PV.
+                       my $move = shift @pv;
+                       push @moves, $move;
+                       $pos = $pos->make_move(parse_uci_move($move));
+               }
+
+               while ($pos->num_pieces() > 6 && $#pv > -1) {
+                       my $move = shift @pv;
+                       push @moves, $move;
+                       $pos = $pos->make_move(parse_uci_move($move));
+               }
+
+               return if ($pos->num_pieces() > 6);
+
+               my $fen = $pos->fen();
+               my $pgn_text = `fathom --path=/srv/syzygy "$fen"`;
+               my $pgn = Chess::PGN::Parse->new(undef, $pgn_text);
+               return if (!defined($pgn) || !$pgn->read_game() || ($pgn->result ne '0-1' && $pgn->result ne '1-0'));
+               $pgn->quick_parse_game;
+               $info->{'pv' . $mpv} = \@moves;
+
+               # Splice the PV from the tablebase onto what we have so far.
+               for my $move (@{$pgn->moves}) {
+                       my $uci_move;
+                       ($pos, $uci_move) = $pos->make_pretty_move($move);
+                       push @moves, $uci_move;
+               }
+       }
+
+       $info->{'pv' . $mpv} = \@moves;
+
+       my $matelen = int((1 + scalar @moves) / 2);
+       if ((scalar @moves) % 2 == 0) {
+               $info->{'score_mate' . $mpv} = -$matelen;
+       } else {
+               $info->{'score_mate' . $mpv} = $matelen;
+       }
+}
+
 sub output {
        #return;
 
@@ -547,6 +662,8 @@ sub output {
                for my $key (qw(pv score_cp score_mate nodes nps depth seldepth tbhits)) {
                        if (exists($info->{$key . '1'})) {
                                $info->{$key} = $info->{$key . '1'};
+                       } else {
+                               delete $info->{$key};
                        }
                }
        }
@@ -573,8 +690,19 @@ sub output {
                return;
        }
 
+       # Now do our own Syzygy tablebase probes to convert scores like +123.45 to mate.
+       if (exists($info->{'pv'})) {
+               complete_using_tbprobe($pos_calculating, $info, '');
+       }
+
+       my $mpv = 1;
+       while (exists($info->{'pv' . $mpv})) {
+               complete_using_tbprobe($pos_calculating, $info, $mpv);
+               ++$mpv;
+       }
+
        output_screen();
-       output_json();
+       output_json(0);
        $latest_update = [Time::HiRes::gettimeofday];
 }
 
@@ -661,8 +789,8 @@ sub output_screen {
                        my $info = $engine2->{'info'};
                        last if (!exists($info->{'pv' . $mpv}));
                        eval {
+                               complete_using_tbprobe($pos_calculating_second_engine, $info, $mpv);
                                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) {
@@ -696,13 +824,26 @@ sub output_screen {
 }
 
 sub output_json {
+       my $historic_json_only = shift;
        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->{'engine'} = $engine->{'id'};
+       if (defined($remoteglotconf::engine_url)) {
+               $json->{'engine'}{'url'} = $remoteglotconf::engine_url;
+       }
+       if (defined($remoteglotconf::engine_details)) {
+               $json->{'engine'}{'details'} = $remoteglotconf::engine_details;
+       }
+       if (defined($remoteglotconf::move_source)) {
+               $json->{'move_source'} = $remoteglotconf::move_source;
+       }
+       if (defined($remoteglotconf::move_source_url)) {
+               $json->{'move_source_url'} = $remoteglotconf::move_source_url;
+       }
+       $json->{'score'} = score_digest($info, $pos_calculating, '');
+       $json->{'using_lomonosov'} = defined($remoteglotconf::tb_serial_key);
 
        $json->{'nodes'} = $info->{'nodes'};
        $json->{'nps'} = $info->{'nps'};
@@ -710,10 +851,7 @@ sub output_json {
        $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'}}) ];
+       $json->{'pv'} = [ prettyprint_pv($pos_calculating, @{$info->{'pv'}}) ];
 
        my %refutation_lines = ();
        my @refutation_lines = ();
@@ -725,44 +863,141 @@ sub output_json {
                        last if (!exists($info->{'pv' . $mpv}));
 
                        eval {
+                               complete_using_tbprobe($pos_calculating, $info, $mpv);
                                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,
+                               $refutation_lines{$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 => $pretty_move,
-                                       pv_pretty => \@pretty_pv,
+                                       score => score_digest($info, $pos_calculating, $mpv),
+                                       move => $pretty_move,
+                                       pv => \@pretty_pv,
                                };
-                               $refutation_lines{$pv->[0]}->{'pv_uci'} = $pv;
                        };
                }
        }
        $json->{'refutation_lines'} = \%refutation_lines;
 
-       my $encoded = JSON::XS::encode_json($json);
-       atomic_set_contents($remoteglotconf::json_output, $encoded);
+       # Piece together historic score information, to the degree we have it.
+       if (!$historic_json_only && exists($pos_calculating->{'history'})) {
+               my %score_history = ();
+
+               my $q = $dbh->prepare('SELECT * FROM scores WHERE id=?');
+               my $pos = Position->start_pos('white', 'black');
+               my $halfmove_num = 0;
+               for my $move (@{$pos_calculating->{'history'}}) {
+                       my $id = id_for_pos($pos, $halfmove_num);
+                       my $ref = $dbh->selectrow_hashref($q, undef, $id);
+                       if (defined($ref)) {
+                               $score_history{$halfmove_num} = [
+                                       $ref->{'score_type'},
+                                       $ref->{'score_value'}
+                               ];
+                       }
+                       ++$halfmove_num;
+                       ($pos) = $pos->make_pretty_move($move);
+               }
+               $q->finish;
+
+               # If at any point we are missing 10 consecutive moves,
+               # truncate the history there. This is so we don't get into
+               # a situation where we e.g. start analyzing at move 45,
+               # but we have analysis for 1. e4 from some completely different game
+               # and thus show a huge hole.
+               my $consecutive_missing = 0;
+               my $truncate_until = 0;
+               for (my $i = $halfmove_num; $i --> 0; ) {
+                       if ($consecutive_missing >= 10) {
+                               delete $score_history{$i};
+                               next;
+                       }
+                       if (exists($score_history{$i})) {
+                               $consecutive_missing = 0;
+                       } else {
+                               ++$consecutive_missing;
+                       }
+               }
+
+               $json->{'score_history'} = \%score_history;
+       }
+
+       # Give out a list of other games going on. (Empty is fine.)
+       # TODO: Don't bother reading our own file, the data will be stale anyway.
+       if (!$historic_json_only) {
+               my @games = ();
+
+               my $q = $dbh->prepare('SELECT * FROM current_games ORDER BY priority DESC, id');
+               $q->execute;
+               while (my $ref = $q->fetchrow_hashref) {
+                       eval {
+                               my $other_game_contents = File::Slurp::read_file($ref->{'json_path'});
+                               my $other_game_json = JSON::XS::decode_json($other_game_contents);
+
+                               die "Missing position" if (!exists($other_game_json->{'position'}));
+                               my $white = $other_game_json->{'position'}{'player_w'} // die 'Missing white';
+                               my $black = $other_game_json->{'position'}{'player_b'} // die 'Missing black';
+
+                               my $game = {
+                                       id => $ref->{'id'},
+                                       name => "$white–$black",
+                                       url => $ref->{'url'},
+                                       hashurl => $ref->{'hash_url'},
+                               };
+                               if (defined($other_game_json->{'position'}{'result'})) {
+                                       $game->{'result'} = $other_game_json->{'position'}{'result'};
+                               } else {
+                                       $game->{'score'} = $other_game_json->{'score'};
+                               }
+                               push @games, $game;
+                       };
+                       if ($@) {
+                               warn "Could not add external game " . $ref->{'json_path'} . ": $@";
+                       }
+               }
+
+               if (scalar @games > 0) {
+                       $json->{'games'} = \@games;
+               }
+       }
+
+       my $json_enc = JSON::XS->new;
+       $json_enc->canonical(1);
+       my $encoded = $json_enc->encode($json);
+       unless ($historic_json_only || !defined($remoteglotconf::json_output) ||
+               (defined($last_written_json) && $last_written_json eq $encoded)) {
+               atomic_set_contents($remoteglotconf::json_output, $encoded);
+               $last_written_json = $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";
+               my $id = id_for_pos($pos_calculating);
+               my $filename = $remoteglotconf::json_history_dir . "/" . $id . ".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 ($old_engine, $old_depth, $old_nodes) = get_json_analysis_stats($id);
                my $new_depth = $json->{'depth'} // 0;
                my $new_nodes = $json->{'nodes'} // 0;
                if (!defined($old_engine) ||
-                   $old_engine ne $json->{'id'}{'name'} ||
+                   $old_engine ne $json->{'engine'}{'name'} ||
                    $new_depth > $old_depth ||
                    ($new_depth == $old_depth && $new_nodes >= $old_nodes)) {
                        atomic_set_contents($filename, $encoded);
+                       if (defined($json->{'score'})) {
+                               $dbh->do('INSERT INTO scores (id, score_type, score_value, engine, depth, nodes) VALUES (?,?,?,?,?,?) ' .
+                                        '    ON CONFLICT (id) DO UPDATE SET ' .
+                                        '        score_type=EXCLUDED.score_type, ' .
+                                        '        score_value=EXCLUDED.score_value, ' .
+                                        '        engine=EXCLUDED.engine, ' .
+                                        '        depth=EXCLUDED.depth, ' .
+                                        '        nodes=EXCLUDED.nodes',
+                                       undef,
+                                       $id, $json->{'score'}[0], $json->{'score'}[1],
+                                       $json->{'engine'}{'name'}, $new_depth, $new_nodes);
+                       }
                }
        }
 }
@@ -777,26 +1012,22 @@ sub atomic_set_contents {
        rename($filename . ".tmp", $filename);
 }
 
-sub get_json_analysis_stats {
-       my $filename = shift;
+sub id_for_pos {
+       my ($pos, $halfmove_num) = @_;
 
-       my ($engine, $depth, $nodes);
+       $halfmove_num //= scalar @{$pos->{'history'}};
+       (my $fen = $pos->fen()) =~ tr,/ ,-_,;
+       return "move$halfmove_num-$fen";
+}
 
-       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;
+sub get_json_analysis_stats {
+       my $id = shift;
+       my $ref = $dbh->selectrow_hashref('SELECT * FROM scores WHERE id=?', undef, $id);
+       if (defined($ref)) {
+               return ($ref->{'engine'}, $ref->{'depth'}, $ref->{'nodes'});
+       } else {
+               return ('', 0, 0);
        }
-       return ($engine, $depth, $nodes);
 }
 
 sub uciprint {
@@ -835,30 +1066,28 @@ sub short_score {
        return undef;
 }
 
-sub score_sort_key {
-       my ($info, $pos, $mpv, $invert) = @_;
+# Sufficient for computing long_score, short_score, plot_score and
+# (with side-to-play information) score_sort_key.
+sub score_digest {
+       my ($info, $pos, $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;
+               if ($pos->{'toplay'} eq 'B') {
+                       $mate = -$mate;
                }
-               return $score;
+               return ['m', $mate];
        } else {
                if (exists($info->{'score_cp' . $mpv})) {
                        my $score = $info->{'score_cp' . $mpv};
-                       if ($invert) {
+                       if ($pos->{'toplay'} eq 'B') {
                                $score = -$score;
                        }
-                       return $score;
+                       if ($score == 0 && $info->{'tablebase'}) {
+                               return ['d', undef];
+                       } else {
+                               return ['cp', $score];
+                       }
                }
        }
 
@@ -898,6 +1127,36 @@ sub long_score {
        return undef;
 }
 
+# For graphs; a single number in centipawns, capped at +/- 500.
+sub plot_score {
+       my ($info, $pos, $mpv) = @_;
+
+       my $invert = ($pos->{'toplay'} eq 'B');
+       if (defined($info->{'score_mate' . $mpv})) {
+               my $mate = $info->{'score_mate' . $mpv};
+               if ($invert) {
+                       $mate = -$mate;
+               }
+               if ($mate > 0) {
+                       return 500;
+               } else {
+                       return -500;
+               }
+       } else {
+               if (exists($info->{'score_cp' . $mpv})) {
+                       my $score = $info->{'score_cp' . $mpv};
+                       if ($invert) {
+                               $score = -$score;
+                       }
+                       $score = 500 if ($score > 500);
+                       $score = -500 if ($score < -500);
+                       return int($score);
+               }
+       }
+
+       return undef;
+}
+
 my %book_cache = ();
 sub book_info {
        my ($fen, $board, $toplay) = @_;
@@ -950,6 +1209,124 @@ sub book_info {
        return $text;
 }
 
+sub extract_clock {
+       my ($pgn, $pos) = @_;
+
+       # Look for extended PGN clock tags.
+       my $tags = $pgn->tags;
+       if (exists($tags->{'WhiteClock'}) && exists($tags->{'BlackClock'})) {
+               $pos->{'white_clock'} = hms_to_sec($tags->{'WhiteClock'});
+               $pos->{'black_clock'} = hms_to_sec($tags->{'BlackClock'});
+               return;
+       }
+
+       # Look for TCEC-style time comments.
+       my $moves = $pgn->moves;
+       my $comments = $pgn->comments;
+       my $last_black_move = int((scalar @$moves) / 2);
+       my $last_white_move = int((1 + scalar @$moves) / 2);
+
+       my $black_key = $last_black_move . "b";
+       my $white_key = $last_white_move . "w";
+
+       if (exists($comments->{$white_key}) &&
+           exists($comments->{$black_key}) &&
+           $comments->{$white_key} =~ /(?:tl=|clk )(\d+:\d+:\d+)/ &&
+           $comments->{$black_key} =~ /(?:tl=|clk )(\d+:\d+:\d+)/) {
+               $comments->{$white_key} =~ /(?:tl=|clk )(\d+:\d+:\d+)/;
+               $pos->{'white_clock'} = hms_to_sec($1);
+               $comments->{$black_key} =~ /(?:tl=|clk )(\d+:\d+:\d+)/;
+               $pos->{'black_clock'} = hms_to_sec($1);
+               return;
+       }
+
+       delete $pos->{'white_clock'};
+       delete $pos->{'black_clock'};
+}
+
+sub hms_to_sec {
+       my $hms = shift;
+       return undef if (!defined($hms));
+       $hms =~ /(\d+):(\d+):(\d+)/;
+       return $1 * 3600 + $2 * 60 + $3;
+}
+
+sub find_clock_start {
+       my ($pos, $prev_pos) = @_;
+
+       # If the game is over, the clock is stopped.
+       if (exists($pos->{'result'}) &&
+           ($pos->{'result'} eq '1-0' ||
+            $pos->{'result'} eq '1/2-1/2' ||
+            $pos->{'result'} eq '0-1')) {
+               return;
+       }
+
+       # When we don't have any moves, we assume the clock hasn't started yet.
+       if ($pos->{'move_num'} == 1 && $pos->{'toplay'} eq 'W') {
+               if (defined($remoteglotconf::adjust_clocks_before_move)) {
+                       &$remoteglotconf::adjust_clocks_before_move(\$pos->{'white_clock'}, \$pos->{'black_clock'}, 1, 'W');
+               }
+               return;
+       }
+
+       # TODO(sesse): Maybe we can get the number of moves somehow else for FICS games.
+       # The history is needed for id_for_pos.
+       if (!exists($pos->{'history'})) {
+               return;
+       }
+
+       my $id = id_for_pos($pos);
+       my $clock_info = $dbh->selectrow_hashref('SELECT * FROM clock_info WHERE id=?', undef, $id);
+       if (defined($clock_info)) {
+               $pos->{'white_clock'} //= $clock_info->{'white_clock'};
+               $pos->{'black_clock'} //= $clock_info->{'black_clock'};
+               if ($pos->{'toplay'} eq 'W') {
+                       $pos->{'white_clock_target'} = $clock_info->{'white_clock_target'};
+               } else {
+                       $pos->{'black_clock_target'} = $clock_info->{'black_clock_target'};
+               }
+               return;
+       }
+
+       # OK, we haven't seen this position before, so we assume the move
+       # happened right now.
+
+       # See if we should do our own clock management (ie., clock information
+       # is spurious or non-existent).
+       if (defined($remoteglotconf::adjust_clocks_before_move)) {
+               my $wc = $pos->{'white_clock'} // $prev_pos->{'white_clock'};
+               my $bc = $pos->{'black_clock'} // $prev_pos->{'black_clock'};
+               if (defined($prev_pos->{'white_clock_target'})) {
+                       $wc = $prev_pos->{'white_clock_target'} - time;
+               }
+               if (defined($prev_pos->{'black_clock_target'})) {
+                       $bc = $prev_pos->{'black_clock_target'} - time;
+               }
+               &$remoteglotconf::adjust_clocks_before_move(\$wc, \$bc, $pos->{'move_num'}, $pos->{'toplay'});
+               $pos->{'white_clock'} = $wc;
+               $pos->{'black_clock'} = $bc;
+       }
+
+       my $key = ($pos->{'toplay'} eq 'W') ? 'white_clock' : 'black_clock';
+       if (!exists($pos->{$key})) {
+               # No clock information.
+               return;
+       }
+       my $time_left = $pos->{$key};
+       my ($white_clock_target, $black_clock_target);
+       if ($pos->{'toplay'} eq 'W') {
+               $white_clock_target = $pos->{'white_clock_target'} = time + $time_left;
+       } else {
+               $black_clock_target = $pos->{'black_clock_target'} = time + $time_left;
+       }
+       local $dbh->{AutoCommit} = 0;
+       $dbh->do('DELETE FROM clock_info WHERE id=?', undef, $id);
+       $dbh->do('INSERT INTO clock_info (id, white_clock, black_clock, white_clock_target, black_clock_target) VALUES (?, ?, ?, ?, ?)', undef,
+               $id, $pos->{'white_clock'}, $pos->{'black_clock'}, $white_clock_target, $black_clock_target);
+       $dbh->commit;
+}
+
 sub schedule_tb_lookup {
        return if (!defined($remoteglotconf::tb_serial_key));
        my $pos = $pos_waiting // $pos_calculating;
@@ -1049,5 +1426,5 @@ sub parse_uci_move {
        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, $promo);
+       return ($from_row, $from_col, $to_row, $to_col, $promo);
 }