Add some PGN hysteresis to guard against truncated PGNs.

[remoteglot] / remoteglot.pl

diff --git a/remoteglot.pl b/remoteglot.pl
index 76163703bcf033921780c2496c550169511ef863..ec26401a6cbcd296341ce616e69f32ed94738189 100755 (executable)
--- a/remoteglot.pl
+++ b/remoteglot.pl
@@ -93,7 +93,13 @@ $t->cmd("");
 $t->cmd("set shout 0");
 $t->cmd("set seek 0");
 $t->cmd("set style 12");
-$t->cmd("observe $remoteglotconf::target");
+if (defined($remoteglotconf::target)) {
+       if ($remoteglotconf::target =~ /^http:/) {
+               fetch_pgn($remoteglotconf::target);
+       } else {
+               $t->cmd("observe $remoteglotconf::target");
+       }
+}
 print "FICS ready.\n";
 
 my $ev1 = AnyEvent->io(
@@ -172,9 +178,7 @@ sub handle_fics {
                } elsif ($msg =~ /^pgn (.*?)$/) {
                        my $url = $1;
                        $t->cmd("tell $who Starting to poll '$url'.");
-                       AnyEvent::HTTP::http_get($url, sub {
-                               handle_pgn(@_, $url);
-                       });
+                       fetch_pgn($url);
                } elsif ($msg =~ /^stoppgn$/) {
                        $t->cmd("tell $who Stopping poll.");
                        $http_timer = undef;
@@ -188,6 +192,18 @@ sub handle_fics {
        #print "FICS: [$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) = @_;
        my $pgn = Chess::PGN::Parse->new(undef, $body);
@@ -205,13 +221,31 @@ sub handle_pgn {
                }
                $pos->{'history'} = \@uci_moves;
                $pos->{'pretty_history'} = $moves;
-               handle_position($pos);
+
+               # Sometimes, PGNs lose a move or two for a short while,
+               # or people push out new ones non-atomically. 
+               # Thus, if we PGN doesn't change names but becomes
+               # shorter, we mistrust it for a few seconds.
+               my $trust_pgn = 1;
+               if (defined($last_pgn_white) && defined($last_pgn_black) &&
+                   $last_pgn_white eq $pgn->white &&
+                   $last_pgn_black eq $pgn->black &&
+                   scalar(@uci_moves) < scalar(@last_pgn_uci_moves)) {
+                       if (++$pgn_hysteresis_counter < 3) {
+                               $trust_pgn = 0; 
+                       }
+               }
+               if ($trust_pgn) {
+                       $last_pgn_white = $pgn->white;
+                       $last_pgn_black = $pgn->black;
+                       @last_pgn_uci_moves = @uci_moves;
+                       $pgn_hysteresis_counter = 0;
+                       handle_position($pos);
+               }
        }
        
        $http_timer = AnyEvent->timer(after => 1.0, cb => sub {
-               AnyEvent::HTTP::http_get($url, sub {
-                       handle_pgn(@_, $url);
-               });
+               fetch_pgn($url);
        });
 }
 
@@ -694,10 +728,10 @@ sub score_sort_key {
                my $score;
                if ($mate > 0) {
                        # Side to move mates
-                       $mate = 99999 - $mate;
+                       $score = 99999 - $mate;
                } else {
                        # Side to move is getting mated (note the double negative for $mate)
-                       $mate = -99999 - $mate;
+                       $score = -99999 - $mate;
                }
                if ($invert) {
                        $score = -$score;
@@ -861,7 +895,7 @@ sub handle_tb_lookup_return {
                        # position in the meantime, we might query a completely
                        # different position! But that's fine.
                } else {
-                       die "Unknown response state state " . $response->{'Response'}{'StateString'};
+                       die "Unknown response state " . $state;
                }
 
                # Wait a second before we schedule another one.