+\f
+############################################################################
+#
+# Pick images from Twitter's list of recently-posted updates.
+#
+############################################################################
+
+# With most of our image sources, we get a random page and then select
+# from the images on it. However, in the case of Twitter, the page
+# of images only updates once a minute; so we'll remember the last N entries
+# on it and randomly select from those, to get a wider variety each time.
+
+my $twitter_img_url = "http://api.twitter.com/1/statuses/" .
+ "public_timeline.json" .
+ "?include_entities=true" .
+ "&include_rts=true" .
+ "&count=200";
+
+my $twitter_cache_size = 1000;
+
+my @twitter_cache = (); # fifo, for ordering by age
+my %twitter_cache = (); # hash, for detecting dups
+
+
+# twitter
+sub pick_from_twitter_images($) {
+ my ($timeout) = @_;
+
+ $last_search = $twitter_img_url; # for warnings
+
+ my ( $base, $body ) = get_document ($twitter_img_url, undef, $timeout);
+ # Update the cache.
+
+ if ($body) {
+ $body =~ s/[\r\n]+/ /gs;
+
+ # Parsing JSON is a pain in the ass. So we halfass it as usual.
+ $body =~ s/^\[|\]$//s;
+ $body =~ s/(\[.*?\])/{ $_ = $1; s@\},@\} @gs; $_; }/gsexi;
+ my @items = split (/},{/, $body);
+ foreach (@items) {
+ my ($name) = m@"screen_name":"([^\"]+)"@si;
+ my ($img) = m@"media_url":"([^\"]+)"@si;
+ my ($page) = m@"display_url":"([^\"]+)"@si;
+ next unless ($name && $img && $page);
+ foreach ($img, $page) {
+ s/\\//gs;
+ $_ = "http://$_" unless (m/^http/si);
+ }
+
+ next if ($twitter_cache{$page}); # already have it
+
+ LOG ($verbose_filter, " candidate: $page - $img");
+ push @twitter_cache, $page;
+ $twitter_cache{$page} = $img;
+ }
+ }
+
+ # Pull from the cache.
+
+ return () if ($#twitter_cache == -1);
+
+ my $n = $#twitter_cache+1;
+ my $i = int(rand($n));
+ my $page = $twitter_cache[$i];
+ my $url = $twitter_cache{$page};
+
+ # delete this one from @twitter_cache and from %twitter_cache.
+ #
+ @twitter_cache = ( @twitter_cache[0 .. $i-1],
+ @twitter_cache[$i+1 .. $#twitter_cache] );
+ delete $twitter_cache{$page};
+
+ # Keep the size of the cache under the limit by nuking older entries
+ #
+ while ($#twitter_cache >= $twitter_cache_size) {
+ my $page = shift @twitter_cache;
+ delete $twitter_cache{$page};
+ }
+
+ LOG ($verbose_load, "picked page $url");
+
+ $suppress_audit = 1;
+
+ return ($page, $url);
+}
+