www: workaround for malformed NNTP links

[public-inbox.git] / lib / PublicInbox / NewsWWW.pm

diff --git a/lib/PublicInbox/NewsWWW.pm b/lib/PublicInbox/NewsWWW.pm
new file mode 100644 (file)
index 0000000..e19765c
--- /dev/null
+++ b/lib/PublicInbox/NewsWWW.pm
@@ -0,0 +1,80 @@
+# Copyright (C) 2016 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+#
+# Plack app redirector for mapping /$NEWSGROUP requests to
+# the appropriate /$LISTNAME in PublicInbox::WWW because some
+# auto-linkifiers cannot handle nntp:// redirects properly.
+# This is also used directly by PublicInbox::WWW
+package PublicInbox::NewsWWW;
+use strict;
+use warnings;
+use PublicInbox::Config;
+use URI::Escape qw(uri_escape_utf8);
+
+sub new {
+       my ($class, $pi_config) = @_;
+       $pi_config ||= PublicInbox::Config->new;
+       bless { pi_config => $pi_config }, $class;
+}
+
+sub call {
+       my ($self, $env) = @_;
+       my $ng_map = $self->newsgroup_map;
+       my $path = $env->{PATH_INFO};
+       $path =~ s!\A/+!!;
+       $path =~ s!/+\z!!;
+
+       # some links may have the article number in them:
+       # /inbox.foo.bar/123456
+       my ($ng, $article) = split(m!/+!, $path, 2);
+       if (my $info = $ng_map->{$ng}) {
+               my $url = PublicInbox::Hval::prurl($env, $info->{url});
+               my $code = 301;
+               my $h = [ Location => $url, 'Content-Type' => 'text/plain' ];
+               if (defined $article && $article =~ /\A\d+\z/) {
+                       my $mid = eval { ng_mid_for($ng, $info, $article) };
+                       if (defined $mid) {
+                               # article IDs are not stable across clones,
+                               # do not encourage caching/bookmarking them
+                               $code = 302;
+                               $url .= uri_escape_utf8($mid) . '/';
+                       }
+               }
+
+               return [ $code, $h, [ "Redirecting to $url\n" ] ]
+       }
+       [ 404, [ 'Content-Length' => 'text/plain' ], [] ];
+}
+
+sub ng_mid_for {
+       my ($ng, $info, $article) = @_;
+       # may fail due to lack of Danga::Socket
+       # for defer_weaken:
+       require PublicInbox::NewsGroup;
+       $ng = $info->{ng} ||=
+               PublicInbox::NewsGroup->new($ng, $info->{git_dir}, '');
+       $ng->mm->mid_for($article);
+}
+
+sub newsgroup_map {
+       my ($self) = @_;
+       my $rv;
+       $rv = $self->{ng_map} and return $rv;
+       my $pi_config = $self->{pi_config};
+       my %ng_map;
+       foreach my $k (keys %$pi_config) {
+               $k =~ /\Apublicinbox\.([^\.]+)\.mainrepo\z/ or next;
+               my $listname = $1;
+               my $git_dir = $pi_config->{"publicinbox.$listname.mainrepo"};
+               my $url = $pi_config->{"publicinbox.$listname.url"};
+               defined $url or next;
+               my $ng = $pi_config->{"publicinbox.$listname.newsgroup"};
+               next if (!defined $ng) || ($ng eq ''); # disabled
+
+               $url =~ m!/\z! or $url .= '/';
+               $ng_map{$ng} = { url => $url, git_dir => $git_dir };
+       }
+       $self->{ng_map} = \%ng_map;
+}
+
+1;