git.sesse.net Git - remoteglot/blob - remoteglot.pl

   1 #! /usr/bin/perl
   2
   3 #
   4 # remoteglot - Connects an abitrary UCI-speaking engine to ICS for easier post-game
   5 #              analysis, or for live analysis of relayed games. (Do not use for
   6 #              cheating! Cheating is bad for your karma, and your abuser flag.)
   7 #
   8 # Copyright 2007 Steinar H. Gunderson <sgunderson@bigfoot.com>
   9 # Licensed under the GNU General Public License, version 2.
  10 #
  11
  12 use AnyEvent;
  13 use AnyEvent::Handle;
  14 use AnyEvent::HTTP;
  15 use Chess::PGN::Parse;
  16 use EV;
  17 use Net::Telnet;
  18 use FileHandle;
  19 use IPC::Open2;
  20 use Time::HiRes;
  21 use JSON::XS;
  22 use URI::Escape;
  23 use Tie::Persistent;
  24 use DBI;
  25 use DBD::Pg;
  26 require 'Position.pm';
  27 require 'Engine.pm';
  28 require 'config.pm';
  29 use strict;
  30 use warnings;
  31 no warnings qw(once);
  32
  33 # Program starts here
  34 my $latest_update = undef;
  35 my $output_timer = undef;
  36 my $http_timer = undef;
  37 my $stop_pgn_fetch = 0;
  38 my $tb_retry_timer = undef;
  39 my %tb_cache = ();
  40 my $tb_lookup_running = 0;
  41 my $last_written_json = undef;
  42
  43 # Persisted so we can restart.
  44 # TODO: Figure out an appropriate way to deal with database restarts
  45 # and/or Postgres going away entirely.
  46 my $dbh = DBI->connect($remoteglotconf::dbistr, $remoteglotconf::dbiuser, $remoteglotconf::dbipass)
  47         or die DBI->errstr;
  48 $dbh->{RaiseError} = 1;
  49
  50 $| = 1;
  51
  52 open(FICSLOG, ">ficslog.txt")
  53         or die "ficslog.txt: $!";
  54 print FICSLOG "Log starting.\n";
  55 select(FICSLOG);
  56 $| = 1;
  57
  58 open(UCILOG, ">ucilog.txt")
  59         or die "ucilog.txt: $!";
  60 print UCILOG "Log starting.\n";
  61 select(UCILOG);
  62 $| = 1;
  63
  64 open(TBLOG, ">tblog.txt")
  65         or die "tblog.txt: $!";
  66 print TBLOG "Log starting.\n";
  67 select(TBLOG);
  68 $| = 1;
  69
  70 select(STDOUT);
  71
  72 # open the chess engine
  73 my $engine = open_engine($remoteglotconf::engine_cmdline, 'E1', sub { handle_uci(@_, 1); });
  74 my $engine2 = open_engine($remoteglotconf::engine2_cmdline, 'E2', sub { handle_uci(@_, 0); });
  75 my $last_move;
  76 my $last_text = '';
  77 my ($pos_waiting, $pos_calculating, $pos_calculating_second_engine);
  78
  79 uciprint($engine, "setoption name UCI_AnalyseMode value true");
  80 while (my ($key, $value) = each %remoteglotconf::engine_config) {
  81         uciprint($engine, "setoption name $key value $value");
  82 }
  83 uciprint($engine, "ucinewgame");
  84
  85 if (defined($engine2)) {
  86         uciprint($engine2, "setoption name UCI_AnalyseMode value true");
  87         while (my ($key, $value) = each %remoteglotconf::engine2_config) {
  88                 uciprint($engine2, "setoption name $key value $value");
  89         }
  90         uciprint($engine2, "setoption name MultiPV value 500");
  91         uciprint($engine2, "ucinewgame");
  92 }
  93
  94 print "Chess engine ready.\n";
  95
  96 # now talk to FICS
  97 my $t = Net::Telnet->new(Timeout => 10, Prompt => '/fics% /');
  98 $t->input_log(\*FICSLOG);
  99 $t->open($remoteglotconf::server);
 100 $t->print($remoteglotconf::nick);
 101 $t->waitfor('/Press return to enter the server/');
 102 $t->cmd("");
 103
 104 # set some options
 105 $t->cmd("set shout 0");
 106 $t->cmd("set seek 0");
 107 $t->cmd("set style 12");
 108
 109 my $ev1 = AnyEvent->io(
 110         fh => fileno($t),
 111         poll => 'r',
 112         cb => sub {    # what callback to execute
 113                 while (1) {
 114                         my $line = $t->getline(Timeout => 0, errmode => 'return');
 115                         return if (!defined($line));
 116
 117                         chomp $line;
 118                         $line =~ tr/\r//d;
 119                         handle_fics($line);
 120                 }
 121         }
 122 );
 123 if (defined($remoteglotconf::target)) {
 124         if ($remoteglotconf::target =~ /^http:/) {
 125                 fetch_pgn($remoteglotconf::target);
 126         } else {
 127                 $t->cmd("observe $remoteglotconf::target");
 128         }
 129 }
 130 print "FICS ready.\n";
 131
 132 # Engine events have already been set up by Engine.pm.
 133 EV::run;
 134
 135 sub handle_uci {
 136         my ($engine, $line, $primary) = @_;
 137
 138         return if $line =~ /(upper|lower)bound/;
 139
 140         $line =~ s/  / /g;  # Sometimes needed for Zappa Mexico
 141         print UCILOG localtime() . " $engine->{'tag'} <= $line\n";
 142         if ($line =~ /^info/) {
 143                 my (@infos) = split / /, $line;
 144                 shift @infos;
 145
 146                 parse_infos($engine, @infos);
 147         }
 148         if ($line =~ /^id/) {
 149                 my (@ids) = split / /, $line;
 150                 shift @ids;
 151
 152                 parse_ids($engine, @ids);
 153         }
 154         if ($line =~ /^bestmove/) {
 155                 if ($primary) {
 156                         return if (!$remoteglotconf::uci_assume_full_compliance);
 157                         if (defined($pos_waiting)) {
 158                                 uciprint($engine, "position fen " . $pos_waiting->fen());
 159                                 uciprint($engine, "go infinite");
 160
 161                                 $pos_calculating = $pos_waiting;
 162                                 $pos_waiting = undef;
 163                         }
 164                 } else {
 165                         $engine2->{'info'} = {};
 166                         my $pos = $pos_waiting // $pos_calculating;
 167                         uciprint($engine2, "position fen " . $pos->fen());
 168                         uciprint($engine2, "go infinite");
 169                         $pos_calculating_second_engine = $pos;
 170                 }
 171         }
 172         output();
 173 }
 174
 175 my $getting_movelist = 0;
 176 my $pos_for_movelist = undef;
 177 my @uci_movelist = ();
 178 my @pretty_movelist = ();
 179
 180 sub handle_fics {
 181         my $line = shift;
 182         if ($line =~ /^<12> /) {
 183                 handle_position(Position->new($line));
 184                 $t->cmd("moves");
 185         }
 186         if ($line =~ /^Movelist for game /) {
 187                 my $pos = $pos_waiting // $pos_calculating;
 188                 if (defined($pos)) {
 189                         @uci_movelist = ();
 190                         @pretty_movelist = ();
 191                         $pos_for_movelist = Position->start_pos($pos->{'player_w'}, $pos->{'player_b'});
 192                         $getting_movelist = 1;
 193                 }
 194         }
 195         if ($getting_movelist &&
 196             $line =~ /^\s* \d+\. \s+                     # move number
 197                        (\S+) \s+ \( [\d:.]+ \) \s*       # first move, then time
 198                        (?: (\S+) \s+ \( [\d:.]+ \) )?    # second move, then time
 199                      /x) {
 200                 eval {
 201                         my $uci_move;
 202                         ($pos_for_movelist, $uci_move) = $pos_for_movelist->make_pretty_move($1);
 203                         push @uci_movelist, $uci_move;
 204                         push @pretty_movelist, $1;
 205
 206                         if (defined($2)) {
 207                                 ($pos_for_movelist, $uci_move) = $pos_for_movelist->make_pretty_move($2);
 208                                 push @uci_movelist, $uci_move;
 209                                 push @pretty_movelist, $2;
 210                         }
 211                 };
 212                 if ($@) {
 213                         warn "Error when getting FICS move history: $@";
 214                         $getting_movelist = 0;
 215                 }
 216         }
 217         if ($getting_movelist &&
 218             $line =~ /^\s+ \{.*\} \s+ (?: \* | 1\/2-1\/2 | 0-1 | 1-0 )/x) {
 219                 # End of movelist.
 220                 for my $pos ($pos_waiting, $pos_calculating) {
 221                         next if (!defined($pos));
 222                         if ($pos->fen() eq $pos_for_movelist->fen()) {
 223                                 $pos->{'pretty_history'} = \@pretty_movelist;
 224                         }
 225                 }
 226                 $getting_movelist = 0;
 227         }
 228         if ($line =~ /^([A-Za-z]+)(?:\([A-Z]+\))* tells you: (.*)$/) {
 229                 my ($who, $msg) = ($1, $2);
 230
 231                 next if (grep { $_ eq $who } (@remoteglotconf::masters) == 0);
 232
 233                 if ($msg =~ /^fics (.*?)$/) {
 234                         $t->cmd("tell $who Executing '$1' on FICS.");
 235                         $t->cmd($1);
 236                 } elsif ($msg =~ /^uci (.*?)$/) {
 237                         $t->cmd("tell $who Sending '$1' to the engine.");
 238                         print { $engine->{'write'} } "$1\n";
 239                 } elsif ($msg =~ /^pgn (.*?)$/) {
 240                         my $url = $1;
 241                         $t->cmd("tell $who Starting to poll '$url'.");
 242                         fetch_pgn($url);
 243                 } elsif ($msg =~ /^stoppgn$/) {
 244                         $t->cmd("tell $who Stopping poll.");
 245                         $stop_pgn_fetch = 1;
 246                         $http_timer = undef;
 247                 } elsif ($msg =~ /^quit$/) {
 248                         $t->cmd("tell $who Bye bye.");
 249                         exit;
 250                 } else {
 251                         $t->cmd("tell $who Couldn't understand '$msg', sorry.");
 252                 }
 253         }
 254         #print "FICS: [$line]\n";
 255 }
 256
 257 # Starts periodic fetching of PGNs from the given URL.
 258 sub fetch_pgn {
 259         my ($url) = @_;
 260         AnyEvent::HTTP::http_get($url, sub {
 261                 handle_pgn(@_, $url);
 262         });
 263 }
 264
 265 my ($last_pgn_white, $last_pgn_black);
 266 my @last_pgn_uci_moves = ();
 267 my $pgn_hysteresis_counter = 0;
 268
 269 sub handle_pgn {
 270         my ($body, $header, $url) = @_;
 271
 272         if ($stop_pgn_fetch) {
 273                 $stop_pgn_fetch = 0;
 274                 $http_timer = undef;
 275                 return;
 276         }
 277
 278         my $pgn = Chess::PGN::Parse->new(undef, $body);
 279         if (!defined($pgn) || !$pgn->read_game() || $body !~ /^\[/) {
 280                 warn "Error in parsing PGN from $url\n";
 281         } else {
 282                 eval {
 283                         # Skip to the right game.
 284                         while (defined($remoteglotconf::pgn_filter) &&
 285                                !&$remoteglotconf::pgn_filter($pgn)) {
 286                                 $pgn->read_game() or die "Out of games during filtering";
 287                         }
 288
 289                         $pgn->parse_game({ save_comments => 'yes' });
 290                         my $pos = Position->start_pos($pgn->white, $pgn->black);
 291                         my $moves = $pgn->moves;
 292                         my @uci_moves = ();
 293                         for my $move (@$moves) {
 294                                 my $uci_move;
 295                                 ($pos, $uci_move) = $pos->make_pretty_move($move);
 296                                 push @uci_moves, $uci_move;
 297                         }
 298                         $pos->{'result'} = $pgn->result;
 299                         $pos->{'pretty_history'} = $moves;
 300
 301                         extract_clock($pgn, $pos);
 302
 303                         # Sometimes, PGNs lose a move or two for a short while,
 304                         # or people push out new ones non-atomically.
 305                         # Thus, if we PGN doesn't change names but becomes
 306                         # shorter, we mistrust it for a few seconds.
 307                         my $trust_pgn = 1;
 308                         if (defined($last_pgn_white) && defined($last_pgn_black) &&
 309                             $last_pgn_white eq $pgn->white &&
 310                             $last_pgn_black eq $pgn->black &&
 311                             scalar(@uci_moves) < scalar(@last_pgn_uci_moves)) {
 312                                 if (++$pgn_hysteresis_counter < 3) {
 313                                         $trust_pgn = 0;
 314                                 }
 315                         }
 316                         if ($trust_pgn) {
 317                                 $last_pgn_white = $pgn->white;
 318                                 $last_pgn_black = $pgn->black;
 319                                 @last_pgn_uci_moves = @uci_moves;
 320                                 $pgn_hysteresis_counter = 0;
 321                                 handle_position($pos);
 322                         }
 323                 };
 324                 if ($@) {
 325                         warn "Error in parsing moves from $url: $@\n";
 326                 }
 327         }
 328
 329         $http_timer = AnyEvent->timer(after => 1.0, cb => sub {
 330                 fetch_pgn($url);
 331         });
 332 }
 333
 334 sub handle_position {
 335         my ($pos) = @_;
 336         find_clock_start($pos, $pos_calculating);
 337
 338         # if this is already in the queue, ignore it (just update the result)
 339         if (defined($pos_waiting) && $pos->fen() eq $pos_waiting->fen()) {
 340                 $pos_waiting->{'result'} = $pos->{'result'};
 341                 return;
 342         }
 343
 344         # if we're already chewing on this and there's nothing else in the queue,
 345         # also ignore it
 346         if (!defined($pos_waiting) && defined($pos_calculating) &&
 347             $pos->fen() eq $pos_calculating->fen()) {
 348                 $pos_calculating->{'result'} = $pos->{'result'};
 349                 return;
 350         }
 351
 352         # if we're already thinking on something, stop and wait for the engine
 353         # to approve
 354         if (defined($pos_calculating)) {
 355                 # Store the final data we have for this position in the history,
 356                 # with the precise clock information we just got from the new
 357                 # position. (Historic positions store the clock at the end of
 358                 # the position.)
 359                 #
 360                 # Do not output anything new to the main analysis; that's
 361                 # going to be obsolete really soon.
 362                 $pos_calculating->{'white_clock'} = $pos->{'white_clock'};
 363                 $pos_calculating->{'black_clock'} = $pos->{'black_clock'};
 364                 delete $pos_calculating->{'white_clock_target'};
 365                 delete $pos_calculating->{'black_clock_target'};
 366                 output_json(1);
 367
 368                 if (!defined($pos_waiting)) {
 369                         uciprint($engine, "stop");
 370                 }
 371                 if ($remoteglotconf::uci_assume_full_compliance) {
 372                         $pos_waiting = $pos;
 373                 } else {
 374                         uciprint($engine, "position fen " . $pos->fen());
 375                         uciprint($engine, "go infinite");
 376                         $pos_calculating = $pos;
 377                 }
 378         } else {
 379                 # it's wrong just to give the FEN (the move history is useful,
 380                 # and per the UCI spec, we should really have sent "ucinewgame"),
 381                 # but it's easier
 382                 uciprint($engine, "position fen " . $pos->fen());
 383                 uciprint($engine, "go infinite");
 384                 $pos_calculating = $pos;
 385         }
 386
 387         if (defined($engine2)) {
 388                 if (defined($pos_calculating_second_engine)) {
 389                         uciprint($engine2, "stop");
 390                 } else {
 391                         uciprint($engine2, "position fen " . $pos->fen());
 392                         uciprint($engine2, "go infinite");
 393                         $pos_calculating_second_engine = $pos;
 394                 }
 395                 $engine2->{'info'} = {};
 396         }
 397
 398         $engine->{'info'} = {};
 399         $last_move = time;
 400
 401         schedule_tb_lookup();
 402
 403         #
 404         # Output a command every move to note that we're
 405         # still paying attention -- this is a good tradeoff,
 406         # since if no move has happened in the last half
 407         # hour, the analysis/relay has most likely stopped
 408         # and we should stop hogging server resources.
 409         #
 410         $t->cmd("date");
 411 }
 412
 413 sub parse_infos {
 414         my ($engine, @x) = @_;
 415         my $mpv = '';
 416
 417         my $info = $engine->{'info'};
 418
 419         # Search for "multipv" first of all, since e.g. Stockfish doesn't put it first.
 420         for my $i (0..$#x - 1) {
 421                 if ($x[$i] eq 'multipv') {
 422                         $mpv = $x[$i + 1];
 423                         next;
 424                 }
 425         }
 426
 427         while (scalar @x > 0) {
 428                 if ($x[0] eq 'multipv') {
 429                         # Dealt with above
 430                         shift @x;
 431                         shift @x;
 432                         next;
 433                 }
 434                 if ($x[0] eq 'currmove' || $x[0] eq 'currmovenumber' || $x[0] eq 'cpuload') {
 435                         my $key = shift @x;
 436                         my $value = shift @x;
 437                         $info->{$key} = $value;
 438                         next;
 439                 }
 440                 if ($x[0] eq 'depth' || $x[0] eq 'seldepth' || $x[0] eq 'hashfull' ||
 441                     $x[0] eq 'time' || $x[0] eq 'nodes' || $x[0] eq 'nps' ||
 442                     $x[0] eq 'tbhits') {
 443                         my $key = shift @x;
 444                         my $value = shift @x;
 445                         $info->{$key . $mpv} = $value;
 446                         next;
 447                 }
 448                 if ($x[0] eq 'score') {
 449                         shift @x;
 450
 451                         delete $info->{'score_cp' . $mpv};
 452                         delete $info->{'score_mate' . $mpv};
 453
 454                         while ($x[0] eq 'cp' || $x[0] eq 'mate') {
 455                                 if ($x[0] eq 'cp') {
 456                                         shift @x;
 457                                         $info->{'score_cp' . $mpv} = shift @x;
 458                                 } elsif ($x[0] eq 'mate') {
 459                                         shift @x;
 460                                         $info->{'score_mate' . $mpv} = shift @x;
 461                                 } else {
 462                                         shift @x;
 463                                 }
 464                         }
 465                         next;
 466                 }
 467                 if ($x[0] eq 'pv') {
 468                         $info->{'pv' . $mpv} = [ @x[1..$#x] ];
 469                         last;
 470                 }
 471                 if ($x[0] eq 'string' || $x[0] eq 'UCI_AnalyseMode' || $x[0] eq 'setting' || $x[0] eq 'contempt') {
 472                         last;
 473                 }
 474
 475                 #print "unknown info '$x[0]', trying to recover...\n";
 476                 #shift @x;
 477                 die "Unknown info '" . join(',', @x) . "'";
 478
 479         }
 480 }
 481
 482 sub parse_ids {
 483         my ($engine, @x) = @_;
 484
 485         while (scalar @x > 0) {
 486                 if ($x[0] =~ /^(name|author)$/) {
 487                         my $key = shift @x;
 488                         my $value = join(' ', @x);
 489                         $engine->{'id'}{$key} = $value;
 490                         last;
 491                 }
 492
 493                 # unknown
 494                 shift @x;
 495         }
 496 }
 497
 498 sub prettyprint_pv_no_cache {
 499         my ($board, @pvs) = @_;
 500
 501         if (scalar @pvs == 0 || !defined($pvs[0])) {
 502                 return ();
 503         }
 504
 505         my $pv = shift @pvs;
 506         my ($from_col, $from_row, $to_col, $to_row, $promo) = parse_uci_move($pv);
 507         my ($pretty, $nb) = $board->prettyprint_move($from_row, $from_col, $to_row, $to_col, $promo);
 508         return ( $pretty, prettyprint_pv_no_cache($nb, @pvs) );
 509 }
 510
 511 sub prettyprint_pv {
 512         my ($pos, @pvs) = @_;
 513
 514         my $cachekey = join('', @pvs);
 515         if (exists($pos->{'prettyprint_cache'}{$cachekey})) {
 516                 return @{$pos->{'prettyprint_cache'}{$cachekey}};
 517         } else {
 518                 my @res = prettyprint_pv_no_cache($pos->{'board'}, @pvs);
 519                 $pos->{'prettyprint_cache'}{$cachekey} = \@res;
 520                 return @res;
 521         }
 522 }
 523
 524 sub output {
 525         #return;
 526
 527         return if (!defined($pos_calculating));
 528
 529         # Don't update too often.
 530         my $age = Time::HiRes::tv_interval($latest_update);
 531         if ($age < $remoteglotconf::update_max_interval) {
 532                 my $wait = $remoteglotconf::update_max_interval + 0.01 - $age;
 533                 $output_timer = AnyEvent->timer(after => $wait, cb => \&output);
 534                 return;
 535         }
 536
 537         my $info = $engine->{'info'};
 538
 539         #
 540         # If we have tablebase data from a previous lookup, replace the
 541         # engine data with the data from the tablebase.
 542         #
 543         my $fen = $pos_calculating->fen();
 544         if (exists($tb_cache{$fen})) {
 545                 for my $key (qw(pv score_cp score_mate nodes nps depth seldepth tbhits)) {
 546                         delete $info->{$key . '1'};
 547                         delete $info->{$key};
 548                 }
 549                 $info->{'nodes'} = 0;
 550                 $info->{'nps'} = 0;
 551                 $info->{'depth'} = 0;
 552                 $info->{'seldepth'} = 0;
 553                 $info->{'tbhits'} = 0;
 554
 555                 my $t = $tb_cache{$fen};
 556                 my $pv = $t->{'pv'};
 557                 my $matelen = int((1 + $t->{'score'}) / 2);
 558                 if ($t->{'result'} eq '1/2-1/2') {
 559                         $info->{'score_cp'} = 0;
 560                 } elsif ($t->{'result'} eq '1-0') {
 561                         if ($pos_calculating->{'toplay'} eq 'B') {
 562                                 $info->{'score_mate'} = -$matelen;
 563                         } else {
 564                                 $info->{'score_mate'} = $matelen;
 565                         }
 566                 } else {
 567                         if ($pos_calculating->{'toplay'} eq 'B') {
 568                                 $info->{'score_mate'} = $matelen;
 569                         } else {
 570                                 $info->{'score_mate'} = -$matelen;
 571                         }
 572                 }
 573                 $info->{'pv'} = $pv;
 574                 $info->{'tablebase'} = 1;
 575         } else {
 576                 $info->{'tablebase'} = 0;
 577         }
 578
 579         #
 580         # Some programs _always_ report MultiPV, even with only one PV.
 581         # In this case, we simply use that data as if MultiPV was never
 582         # specified.
 583         #
 584         if (exists($info->{'pv1'}) && !exists($info->{'pv2'})) {
 585                 for my $key (qw(pv score_cp score_mate nodes nps depth seldepth tbhits)) {
 586                         if (exists($info->{$key . '1'})) {
 587                                 $info->{$key} = $info->{$key . '1'};
 588                         }
 589                 }
 590         }
 591
 592         #
 593         # Check the PVs first. if they're invalid, just wait, as our data
 594         # is most likely out of sync. This isn't a very good solution, as
 595         # it can frequently miss stuff, but it's good enough for most users.
 596         #
 597         eval {
 598                 my $dummy;
 599                 if (exists($info->{'pv'})) {
 600                         $dummy = prettyprint_pv($pos_calculating, @{$info->{'pv'}});
 601                 }
 602
 603                 my $mpv = 1;
 604                 while (exists($info->{'pv' . $mpv})) {
 605                         $dummy = prettyprint_pv($pos_calculating, @{$info->{'pv' . $mpv}});
 606                         ++$mpv;
 607                 }
 608         };
 609         if ($@) {
 610                 $engine->{'info'} = {};
 611                 return;
 612         }
 613
 614         output_screen();
 615         output_json(0);
 616         $latest_update = [Time::HiRes::gettimeofday];
 617 }
 618
 619 sub output_screen {
 620         my $info = $engine->{'info'};
 621         my $id = $engine->{'id'};
 622
 623         my $text = 'Analysis';
 624         if ($pos_calculating->{'last_move'} ne 'none') {
 625                 if ($pos_calculating->{'toplay'} eq 'W') {
 626                         $text .= sprintf ' after %u. ... %s', ($pos_calculating->{'move_num'}-1), $pos_calculating->{'last_move'};
 627                 } else {
 628                         $text .= sprintf ' after %u. %s', $pos_calculating->{'move_num'}, $pos_calculating->{'last_move'};
 629                 }
 630                 if (exists($id->{'name'})) {
 631                         $text .= ',';
 632                 }
 633         }
 634
 635         if (exists($id->{'name'})) {
 636                 $text .= " by $id->{'name'}:\n\n";
 637         } else {
 638                 $text .= ":\n\n";
 639         }
 640
 641         return unless (exists($pos_calculating->{'board'}));
 642
 643         if (exists($info->{'pv1'}) && exists($info->{'pv2'})) {
 644                 # multi-PV
 645                 my $mpv = 1;
 646                 while (exists($info->{'pv' . $mpv})) {
 647                         $text .= sprintf "  PV%2u", $mpv;
 648                         my $score = short_score($info, $pos_calculating, $mpv);
 649                         $text .= "  ($score)" if (defined($score));
 650
 651                         my $tbhits = '';
 652                         if (exists($info->{'tbhits' . $mpv}) && $info->{'tbhits' . $mpv} > 0) {
 653                                 if ($info->{'tbhits' . $mpv} == 1) {
 654                                         $tbhits = ", 1 tbhit";
 655                                 } else {
 656                                         $tbhits = sprintf ", %u tbhits", $info->{'tbhits' . $mpv};
 657                                 }
 658                         }
 659
 660                         if (exists($info->{'nodes' . $mpv}) && exists($info->{'nps' . $mpv}) && exists($info->{'depth' . $mpv})) {
 661                                 $text .= sprintf " (%5u kn, %3u kn/s, %2u ply$tbhits)",
 662                                         $info->{'nodes' . $mpv} / 1000, $info->{'nps' . $mpv} / 1000, $info->{'depth' . $mpv};
 663                         }
 664
 665                         $text .= ":\n";
 666                         $text .= "  " . join(', ', prettyprint_pv($pos_calculating, @{$info->{'pv' . $mpv}})) . "\n";
 667                         $text .= "\n";
 668                         ++$mpv;
 669                 }
 670         } else {
 671                 # single-PV
 672                 my $score = long_score($info, $pos_calculating, '');
 673                 $text .= "  $score\n" if defined($score);
 674                 $text .=  "  PV: " . join(', ', prettyprint_pv($pos_calculating, @{$info->{'pv'}}));
 675                 $text .=  "\n";
 676
 677                 if (exists($info->{'nodes'}) && exists($info->{'nps'}) && exists($info->{'depth'})) {
 678                         $text .= sprintf "  %u nodes, %7u nodes/sec, depth %u ply",
 679                                 $info->{'nodes'}, $info->{'nps'}, $info->{'depth'};
 680                 }
 681                 if (exists($info->{'seldepth'})) {
 682                         $text .= sprintf " (%u selective)", $info->{'seldepth'};
 683                 }
 684                 if (exists($info->{'tbhits'}) && $info->{'tbhits'} > 0) {
 685                         if ($info->{'tbhits'} == 1) {
 686                                 $text .= ", one Syzygy hit";
 687                         } else {
 688                                 $text .= sprintf ", %u Syzygy hits", $info->{'tbhits'};
 689                         }
 690                 }
 691                 $text .= "\n\n";
 692         }
 693
 694         #$text .= book_info($pos_calculating->fen(), $pos_calculating->{'board'}, $pos_calculating->{'toplay'});
 695
 696         my @refutation_lines = ();
 697         if (defined($engine2)) {
 698                 for (my $mpv = 1; $mpv < 500; ++$mpv) {
 699                         my $info = $engine2->{'info'};
 700                         last if (!exists($info->{'pv' . $mpv}));
 701                         eval {
 702                                 my $pv = $info->{'pv' . $mpv};
 703
 704                                 my $pretty_move = join('', prettyprint_pv($pos_calculating_second_engine, $pv->[0]));
 705                                 my @pretty_pv = prettyprint_pv($pos_calculating_second_engine, @$pv);
 706                                 if (scalar @pretty_pv > 5) {
 707                                         @pretty_pv = @pretty_pv[0..4];
 708                                         push @pretty_pv, "...";
 709                                 }
 710                                 my $key = $pretty_move;
 711                                 my $line = sprintf("  %-6s %6s %3s  %s",
 712                                         $pretty_move,
 713                                         short_score($info, $pos_calculating_second_engine, $mpv),
 714                                         "d" . $info->{'depth' . $mpv},
 715                                         join(', ', @pretty_pv));
 716                                 push @refutation_lines, [ $key, $line ];
 717                         };
 718                 }
 719         }
 720
 721         if ($#refutation_lines >= 0) {
 722                 $text .= "Shallow search of all legal moves:\n\n";
 723                 for my $line (sort { $a->[0] cmp $b->[0] } @refutation_lines) {
 724                         $text .= $line->[1] . "\n";
 725                 }
 726                 $text .= "\n\n";
 727         }
 728
 729         if ($last_text ne $text) {
 730                 print "\e[H\e[2J"; # clear the screen
 731                 print $text;
 732                 $last_text = $text;
 733         }
 734 }
 735
 736 sub output_json {
 737         my $historic_json_only = shift;
 738         my $info = $engine->{'info'};
 739
 740         my $json = {};
 741         $json->{'position'} = $pos_calculating->to_json_hash();
 742         $json->{'id'} = $engine->{'id'};
 743         $json->{'score'} = long_score($info, $pos_calculating, '');
 744         $json->{'short_score'} = short_score($info, $pos_calculating, '');
 745         $json->{'plot_score'} = plot_score($info, $pos_calculating, '');
 746
 747         $json->{'nodes'} = $info->{'nodes'};
 748         $json->{'nps'} = $info->{'nps'};
 749         $json->{'depth'} = $info->{'depth'};
 750         $json->{'tbhits'} = $info->{'tbhits'};
 751         $json->{'seldepth'} = $info->{'seldepth'};
 752         $json->{'tablebase'} = $info->{'tablebase'};
 753
 754         $json->{'pv_uci'} = $info->{'pv'};  # Still needs to be there for the JS to calculate arrows; only for the primary PV, though!
 755         $json->{'pv_pretty'} = [ prettyprint_pv($pos_calculating, @{$info->{'pv'}}) ];
 756
 757         my %refutation_lines = ();
 758         my @refutation_lines = ();
 759         if (defined($engine2)) {
 760                 for (my $mpv = 1; $mpv < 500; ++$mpv) {
 761                         my $info = $engine2->{'info'};
 762                         my $pretty_move = "";
 763                         my @pretty_pv = ();
 764                         last if (!exists($info->{'pv' . $mpv}));
 765
 766                         eval {
 767                                 my $pv = $info->{'pv' . $mpv};
 768                                 my $pretty_move = join('', prettyprint_pv($pos_calculating, $pv->[0]));
 769                                 my @pretty_pv = prettyprint_pv($pos_calculating, @$pv);
 770                                 $refutation_lines{$pv->[0]} = {
 771                                         sort_key => $pretty_move,
 772                                         depth => $info->{'depth' . $mpv},
 773                                         score_sort_key => score_sort_key($info, $pos_calculating, $mpv, 0),
 774                                         pretty_score => short_score($info, $pos_calculating, $mpv),
 775                                         pretty_move => $pretty_move,
 776                                         pv_pretty => \@pretty_pv,
 777                                 };
 778                         };
 779                 }
 780         }
 781         $json->{'refutation_lines'} = \%refutation_lines;
 782
 783         # Piece together historic score information, to the degree we have it.
 784         if (!$historic_json_only && exists($pos_calculating->{'pretty_history'})) {
 785                 my %score_history = ();
 786
 787                 my $q = $dbh->prepare('SELECT * FROM scores WHERE id=?');
 788                 my $pos = Position->start_pos('white', 'black');
 789                 my $halfmove_num = 0;
 790                 for my $move (@{$pos_calculating->{'pretty_history'}}) {
 791                         my $id = id_for_pos($pos, $halfmove_num);
 792                         my $ref = $dbh->selectrow_hashref($q, undef, $id);
 793                         if (defined($ref)) {
 794                                 $score_history{$halfmove_num} = [
 795                                         $ref->{'plot_score'},
 796                                         $ref->{'short_score'}
 797                                 ];
 798                         }
 799                         ++$halfmove_num;
 800                         ($pos) = $pos->make_pretty_move($move);
 801                 }
 802                 $q->finish;
 803
 804                 # If at any point we are missing 10 consecutive moves,
 805                 # truncate the history there. This is so we don't get into
 806                 # a situation where we e.g. start analyzing at move 45,
 807                 # but we have analysis for 1. e4 from some completely different game
 808                 # and thus show a huge hole.
 809                 my $consecutive_missing = 0;
 810                 my $truncate_until = 0;
 811                 for (my $i = $halfmove_num; $i --> 0; ) {
 812                         if ($consecutive_missing >= 10) {
 813                                 delete $score_history{$i};
 814                                 next;
 815                         }
 816                         if (exists($score_history{$i})) {
 817                                 $consecutive_missing = 0;
 818                         } else {
 819                                 ++$consecutive_missing;
 820                         }
 821                 }
 822
 823                 $json->{'score_history'} = \%score_history;
 824         }
 825
 826         my $json_enc = JSON::XS->new;
 827         $json_enc->canonical(1);
 828         my $encoded = $json_enc->encode($json);
 829         unless ($historic_json_only || !defined($remoteglotconf::json_output) ||
 830                 (defined($last_written_json) && $last_written_json eq $encoded)) {
 831                 atomic_set_contents($remoteglotconf::json_output, $encoded);
 832                 $last_written_json = $encoded;
 833         }
 834
 835         if (exists($pos_calculating->{'pretty_history'}) &&
 836             defined($remoteglotconf::json_history_dir)) {
 837                 my $id = id_for_pos($pos_calculating);
 838                 my $filename = $remoteglotconf::json_history_dir . "/" . $id . ".json";
 839
 840                 # Overwrite old analysis (assuming it exists at all) if we're
 841                 # using a different engine, or if we've calculated deeper.
 842                 # nodes is used as a tiebreaker. Don't bother about Multi-PV
 843                 # data; it's not that important.
 844                 my ($old_engine, $old_depth, $old_nodes) = get_json_analysis_stats($id);
 845                 my $new_depth = $json->{'depth'} // 0;
 846                 my $new_nodes = $json->{'nodes'} // 0;
 847                 if (!defined($old_engine) ||
 848                     $old_engine ne $json->{'id'}{'name'} ||
 849                     $new_depth > $old_depth ||
 850                     ($new_depth == $old_depth && $new_nodes >= $old_nodes)) {
 851                         atomic_set_contents($filename, $encoded);
 852                         if (defined($json->{'plot_score'})) {
 853                                 local $dbh->{AutoCommit} = 0;
 854                                 $dbh->do('DELETE FROM scores WHERE id=?', undef, $id);
 855                                 $dbh->do('INSERT INTO scores (id, plot_score, short_score, engine, depth, nodes) VALUES (?,?,?,?,?,?)', undef,
 856                                         $id, $json->{'plot_score'}, $json->{'short_score'},
 857                                         $json->{'id'}{'name'}, $new_depth, $new_nodes);
 858                                 $dbh->commit;
 859                         }
 860                 }
 861         }
 862 }
 863
 864 sub atomic_set_contents {
 865         my ($filename, $contents) = @_;
 866
 867         open my $fh, ">", $filename . ".tmp"
 868                 or return;
 869         print $fh $contents;
 870         close $fh;
 871         rename($filename . ".tmp", $filename);
 872 }
 873
 874 sub id_for_pos {
 875         my ($pos, $halfmove_num) = @_;
 876
 877         $halfmove_num //= scalar @{$pos->{'pretty_history'}};
 878         (my $fen = $pos->fen()) =~ tr,/ ,-_,;
 879         return "move$halfmove_num-$fen";
 880 }
 881
 882 sub get_json_analysis_stats {
 883         my $id = shift;
 884         my $ref = $dbh->selectrow_hashref('SELECT * FROM scores WHERE id=?', undef, $id);
 885         if (defined($ref)) {
 886                 return ($ref->{'engine'}, $ref->{'depth'}, $ref->{'nodes'});
 887         } else {
 888                 return ('', 0, 0);
 889         }
 890 }
 891
 892 sub uciprint {
 893         my ($engine, $msg) = @_;
 894         $engine->print($msg);
 895         print UCILOG localtime() . " $engine->{'tag'} => $msg\n";
 896 }
 897
 898 sub short_score {
 899         my ($info, $pos, $mpv) = @_;
 900
 901         my $invert = ($pos->{'toplay'} eq 'B');
 902         if (defined($info->{'score_mate' . $mpv})) {
 903                 if ($invert) {
 904                         return sprintf "M%3d", -$info->{'score_mate' . $mpv};
 905                 } else {
 906                         return sprintf "M%3d", $info->{'score_mate' . $mpv};
 907                 }
 908         } else {
 909                 if (exists($info->{'score_cp' . $mpv})) {
 910                         my $score = $info->{'score_cp' . $mpv} * 0.01;
 911                         if ($score == 0) {
 912                                 if ($info->{'tablebase'}) {
 913                                         return "TB draw";
 914                                 } else {
 915                                         return " 0.00";
 916                                 }
 917                         }
 918                         if ($invert) {
 919                                 $score = -$score;
 920                         }
 921                         return sprintf "%+5.2f", $score;
 922                 }
 923         }
 924
 925         return undef;
 926 }
 927
 928 sub score_sort_key {
 929         my ($info, $pos, $mpv, $invert) = @_;
 930
 931         if (defined($info->{'score_mate' . $mpv})) {
 932                 my $mate = $info->{'score_mate' . $mpv};
 933                 my $score;
 934                 if ($mate > 0) {
 935                         # Side to move mates
 936                         $score = 99999 - $mate;
 937                 } else {
 938                         # Side to move is getting mated (note the double negative for $mate)
 939                         $score = -99999 - $mate;
 940                 }
 941                 if ($invert) {
 942                         $score = -$score;
 943                 }
 944                 return $score;
 945         } else {
 946                 if (exists($info->{'score_cp' . $mpv})) {
 947                         my $score = $info->{'score_cp' . $mpv};
 948                         if ($invert) {
 949                                 $score = -$score;
 950                         }
 951                         return $score;
 952                 }
 953         }
 954
 955         return undef;
 956 }
 957
 958 sub long_score {
 959         my ($info, $pos, $mpv) = @_;
 960
 961         if (defined($info->{'score_mate' . $mpv})) {
 962                 my $mate = $info->{'score_mate' . $mpv};
 963                 if ($pos->{'toplay'} eq 'B') {
 964                         $mate = -$mate;
 965                 }
 966                 if ($mate > 0) {
 967                         return sprintf "White mates in %u", $mate;
 968                 } else {
 969                         return sprintf "Black mates in %u", -$mate;
 970                 }
 971         } else {
 972                 if (exists($info->{'score_cp' . $mpv})) {
 973                         my $score = $info->{'score_cp' . $mpv} * 0.01;
 974                         if ($score == 0) {
 975                                 if ($info->{'tablebase'}) {
 976                                         return "Theoretical draw";
 977                                 } else {
 978                                         return "Score:  0.00";
 979                                 }
 980                         }
 981                         if ($pos->{'toplay'} eq 'B') {
 982                                 $score = -$score;
 983                         }
 984                         return sprintf "Score: %+5.2f", $score;
 985                 }
 986         }
 987
 988         return undef;
 989 }
 990
 991 # For graphs; a single number in centipawns, capped at +/- 500.
 992 sub plot_score {
 993         my ($info, $pos, $mpv) = @_;
 994
 995         my $invert = ($pos->{'toplay'} eq 'B');
 996         if (defined($info->{'score_mate' . $mpv})) {
 997                 my $mate = $info->{'score_mate' . $mpv};
 998                 if ($invert) {
 999                         $mate = -$mate;
1000                 }
1001                 if ($mate > 0) {
1002                         return 500;
1003                 } else {
1004                         return -500;
1005                 }
1006         } else {
1007                 if (exists($info->{'score_cp' . $mpv})) {
1008                         my $score = $info->{'score_cp' . $mpv};
1009                         if ($invert) {
1010                                 $score = -$score;
1011                         }
1012                         $score = 500 if ($score > 500);
1013                         $score = -500 if ($score < -500);
1014                         return int($score);
1015                 }
1016         }
1017
1018         return undef;
1019 }
1020
1021 my %book_cache = ();
1022 sub book_info {
1023         my ($fen, $board, $toplay) = @_;
1024
1025         if (exists($book_cache{$fen})) {
1026                 return $book_cache{$fen};
1027         }
1028
1029         my $ret = `./booklook $fen`;
1030         return "" if ($ret =~ /Not found/ || $ret eq '');
1031
1032         my @moves = ();
1033
1034         for my $m (split /\n/, $ret) {
1035                 my ($move, $annotation, $win, $draw, $lose, $rating, $rating_div) = split /,/, $m;
1036
1037                 my $pmove;
1038                 if ($move eq '')  {
1039                         $pmove = '(current)';
1040                 } else {
1041                         ($pmove) = prettyprint_pv_no_cache($board, $move);
1042                         $pmove .= $annotation;
1043                 }
1044
1045                 my $score;
1046                 if ($toplay eq 'W') {
1047                         $score = 1.0 * $win + 0.5 * $draw + 0.0 * $lose;
1048                 } else {
1049                         $score = 0.0 * $win + 0.5 * $draw + 1.0 * $lose;
1050                 }
1051                 my $n = $win + $draw + $lose;
1052
1053                 my $percent;
1054                 if ($n == 0) {
1055                         $percent = "     ";
1056                 } else {
1057                         $percent = sprintf "%4u%%", int(100.0 * $score / $n + 0.5);
1058                 }
1059
1060                 push @moves, [ $pmove, $n, $percent, $rating ];
1061         }
1062
1063         @moves[1..$#moves] = sort { $b->[2] cmp $a->[2] } @moves[1..$#moves];
1064
1065         my $text = "Book moves:\n\n              Perf.     N     Rating\n\n";
1066         for my $m (@moves) {
1067                 $text .= sprintf "  %-10s %s   %6u    %4s\n", $m->[0], $m->[2], $m->[1], $m->[3]
1068         }
1069
1070         return $text;
1071 }
1072
1073 sub extract_clock {
1074         my ($pgn, $pos) = @_;
1075
1076         # Look for extended PGN clock tags.
1077         my $tags = $pgn->tags;
1078         if (exists($tags->{'WhiteClock'}) && exists($tags->{'BlackClock'})) {
1079                 $pos->{'white_clock'} = hms_to_sec($tags->{'WhiteClock'});
1080                 $pos->{'black_clock'} = hms_to_sec($tags->{'BlackClock'});
1081                 return;
1082         }
1083
1084         # Look for TCEC-style time comments.
1085         my $moves = $pgn->moves;
1086         my $comments = $pgn->comments;
1087         my $last_black_move = int((scalar @$moves) / 2);
1088         my $last_white_move = int((1 + scalar @$moves) / 2);
1089
1090         my $black_key = $last_black_move . "b";
1091         my $white_key = $last_white_move . "w";
1092
1093         if (exists($comments->{$white_key}) &&
1094             exists($comments->{$black_key}) &&
1095             $comments->{$white_key} =~ /(?:tl=|clk )(\d+:\d+:\d+)/ &&
1096             $comments->{$black_key} =~ /(?:tl=|clk )(\d+:\d+:\d+)/) {
1097                 $comments->{$white_key} =~ /(?:tl=|clk )(\d+:\d+:\d+)/;
1098                 $pos->{'white_clock'} = hms_to_sec($1);
1099                 $comments->{$black_key} =~ /(?:tl=|clk )(\d+:\d+:\d+)/;
1100                 $pos->{'black_clock'} = hms_to_sec($1);
1101                 return;
1102         }
1103
1104         delete $pos->{'white_clock'};
1105         delete $pos->{'black_clock'};
1106 }
1107
1108 sub hms_to_sec {
1109         my $hms = shift;
1110         return undef if (!defined($hms));
1111         $hms =~ /(\d+):(\d+):(\d+)/;
1112         return $1 * 3600 + $2 * 60 + $3;
1113 }
1114
1115 sub find_clock_start {
1116         my ($pos, $prev_pos) = @_;
1117
1118         # If the game is over, the clock is stopped.
1119         if (exists($pos->{'result'}) &&
1120             ($pos->{'result'} eq '1-0' ||
1121              $pos->{'result'} eq '1/2-1/2' ||
1122              $pos->{'result'} eq '0-1')) {
1123                 return;
1124         }
1125
1126         # When we don't have any moves, we assume the clock hasn't started yet.
1127         if ($pos->{'move_num'} == 1 && $pos->{'toplay'} eq 'W') {
1128                 if (defined($remoteglotconf::adjust_clocks_before_move)) {
1129                         &$remoteglotconf::adjust_clocks_before_move(\$pos->{'white_clock'}, \$pos->{'black_clock'}, 1, 'W');
1130                 }
1131                 return;
1132         }
1133
1134         # TODO(sesse): Maybe we can get the number of moves somehow else for FICS games.
1135         # The history is needed for id_for_pos.
1136         if (!exists($pos->{'pretty_history'})) {
1137                 return;
1138         }
1139
1140         my $id = id_for_pos($pos);
1141         my $clock_info = $dbh->selectrow_hashref('SELECT * FROM clock_info WHERE id=?', undef, $id);
1142         if (defined($clock_info)) {
1143                 $pos->{'white_clock'} //= $clock_info->{'white_clock'};
1144                 $pos->{'black_clock'} //= $clock_info->{'black_clock'};
1145                 if ($pos->{'toplay'} eq 'W') {
1146                         $pos->{'white_clock_target'} = $clock_info->{'white_clock_target'};
1147                 } else {
1148                         $pos->{'black_clock_target'} = $clock_info->{'black_clock_target'};
1149                 }
1150                 return;
1151         }
1152
1153         # OK, we haven't seen this position before, so we assume the move
1154         # happened right now.
1155
1156         # See if we should do our own clock management (ie., clock information
1157         # is spurious or non-existent).
1158         if (defined($remoteglotconf::adjust_clocks_before_move)) {
1159                 my $wc = $pos->{'white_clock'} // $prev_pos->{'white_clock'};
1160                 my $bc = $pos->{'black_clock'} // $prev_pos->{'black_clock'};
1161                 if (defined($prev_pos->{'white_clock_target'})) {
1162                         $wc = $prev_pos->{'white_clock_target'} - time;
1163                 }
1164                 if (defined($prev_pos->{'black_clock_target'})) {
1165                         $bc = $prev_pos->{'black_clock_target'} - time;
1166                 }
1167                 &$remoteglotconf::adjust_clocks_before_move(\$wc, \$bc, $pos->{'move_num'}, $pos->{'toplay'});
1168                 $pos->{'white_clock'} = $wc;
1169                 $pos->{'black_clock'} = $bc;
1170         }
1171
1172         my $key = ($pos->{'toplay'} eq 'W') ? 'white_clock' : 'black_clock';
1173         if (!exists($pos->{$key})) {
1174                 # No clock information.
1175                 return;
1176         }
1177         my $time_left = $pos->{$key};
1178         my ($white_clock_target, $black_clock_target);
1179         if ($pos->{'toplay'} eq 'W') {
1180                 $white_clock_target = $pos->{'white_clock_target'} = time + $time_left;
1181         } else {
1182                 $black_clock_target = $pos->{'black_clock_target'} = time + $time_left;
1183         }
1184         local $dbh->{AutoCommit} = 0;
1185         $dbh->do('DELETE FROM clock_info WHERE id=?', undef, $id);
1186         $dbh->do('INSERT INTO clock_info (id, white_clock, black_clock, white_clock_target, black_clock_target) VALUES (?, ?, ?, ?, ?)', undef,
1187                 $id, $pos->{'white_clock'}, $pos->{'black_clock'}, $white_clock_target, $black_clock_target);
1188         $dbh->commit;
1189 }
1190
1191 sub schedule_tb_lookup {
1192         return if (!defined($remoteglotconf::tb_serial_key));
1193         my $pos = $pos_waiting // $pos_calculating;
1194         return if (exists($tb_cache{$pos->fen()}));
1195
1196         # If there's more than seven pieces, there's not going to be an answer,
1197         # so don't bother.
1198         return if ($pos->num_pieces() > 7);
1199
1200         # Max one at a time. If it's still relevant when it returns,
1201         # schedule_tb_lookup() will be called again.
1202         return if ($tb_lookup_running);
1203
1204         $tb_lookup_running = 1;
1205         my $url = 'http://158.250.18.203:6904/tasks/addtask?auth.login=' .
1206                 $remoteglotconf::tb_serial_key .
1207                 '&auth.password=aquarium&type=0&fen=' .
1208                 URI::Escape::uri_escape($pos->fen());
1209         print TBLOG "Downloading $url...\n";
1210         AnyEvent::HTTP::http_get($url, sub {
1211                 handle_tb_lookup_return(@_, $pos, $pos->fen());
1212         });
1213 }
1214
1215 sub handle_tb_lookup_return {
1216         my ($body, $header, $pos, $fen) = @_;
1217         print TBLOG "Response for [$fen]:\n";
1218         print TBLOG $header . "\n\n";
1219         print TBLOG $body . "\n\n";
1220         eval {
1221                 my $response = JSON::XS::decode_json($body);
1222                 if ($response->{'ErrorCode'} != 0) {
1223                         die "Unknown tablebase server error: " . $response->{'ErrorDesc'};
1224                 }
1225                 my $state = $response->{'Response'}{'StateString'};
1226                 if ($state eq 'COMPLETE') {
1227                         my $pgn = Chess::PGN::Parse->new(undef, $response->{'Response'}{'Moves'});
1228                         if (!defined($pgn) || !$pgn->read_game()) {
1229                                 warn "Error in parsing PGN\n";
1230                         } else {
1231                                 $pgn->quick_parse_game;
1232                                 my $pvpos = $pos;
1233                                 my $moves = $pgn->moves;
1234                                 my @uci_moves = ();
1235                                 for my $move (@$moves) {
1236                                         my $uci_move;
1237                                         ($pvpos, $uci_move) = $pvpos->make_pretty_move($move);
1238                                         push @uci_moves, $uci_move;
1239                                 }
1240                                 $tb_cache{$fen} = {
1241                                         result => $pgn->result,
1242                                         pv => \@uci_moves,
1243                                         score => $response->{'Response'}{'Score'},
1244                                 };
1245                                 output();
1246                         }
1247                 } elsif ($state =~ /QUEUED/ || $state =~ /PROCESSING/) {
1248                         # Try again in a second. Note that if we have changed
1249                         # position in the meantime, we might query a completely
1250                         # different position! But that's fine.
1251                 } else {
1252                         die "Unknown response state " . $state;
1253                 }
1254
1255                 # Wait a second before we schedule another one.
1256                 $tb_retry_timer = AnyEvent->timer(after => 1.0, cb => sub {
1257                         $tb_lookup_running = 0;
1258                         schedule_tb_lookup();
1259                 });
1260         };
1261         if ($@) {
1262                 warn "Error in tablebase lookup: $@";
1263
1264                 # Don't try this one again, but don't block new lookups either.
1265                 $tb_lookup_running = 0;
1266         }
1267 }
1268
1269 sub open_engine {
1270         my ($cmdline, $tag, $cb) = @_;
1271         return undef if (!defined($cmdline));
1272         return Engine->open($cmdline, $tag, $cb);
1273 }
1274
1275 sub col_letter_to_num {
1276         return ord(shift) - ord('a');
1277 }
1278
1279 sub row_letter_to_num {
1280         return 7 - (ord(shift) - ord('1'));
1281 }
1282
1283 sub parse_uci_move {
1284         my $move = shift;
1285         my $from_col = col_letter_to_num(substr($move, 0, 1));
1286         my $from_row = row_letter_to_num(substr($move, 1, 1));
1287         my $to_col   = col_letter_to_num(substr($move, 2, 1));
1288         my $to_row   = row_letter_to_num(substr($move, 3, 1));
1289         my $promo    = substr($move, 4, 1);
1290         return ($from_col, $from_row, $to_col, $to_row, $promo);
1291 }