mbox: generate Archived-At, List-Post, List-Archive headers

Downloaded mboxen can be archived/stored indefinitely, try to
make it easy for future archaelogists to find the online
archive location.

2 files changed, 21 insertions, 5 deletions

diff --git a/lib/PublicInbox/Mbox.pm b/lib/PublicInbox/Mbox.pm
index 6aa05170..80e8efc9 100644
--- a/lib/PublicInbox/Mbox.pm
+++ b/lib/PublicInbox/Mbox.pm
@@ -4,7 +4,8 @@
 package PublicInbox::Mbox;
 use strict;
 use warnings;
-use PublicInbox::MID qw/mid2path/;
+use PublicInbox::MID qw/mid2path mid_clean/;
+use URI::Escape qw/uri_escape_utf8/;
 require Email::Simple;
 
 sub thread_mbox {
@@ -17,17 +18,18 @@ sub thread_mbox {
 
 sub emit1 {
         my $simple = Email::Simple->new(pop);
+        my $ctx = pop;
         sub {
                 my ($response) = @_;
                 # single message should be easily renderable in browsers
                 my $fh = $response->([200, ['Content-Type'=>'text/plain']]);
-                emit_msg($fh, $simple);
+                emit_msg($ctx, $fh, $simple);
                 $fh->close;
         }
 }
 
 sub emit_msg {
-        my ($fh, $simple) = @_; # Email::Simple object
+        my ($ctx, $fh, $simple) = @_; # Email::Simple object
         my $header_obj = $simple->header_obj;
 
         # drop potentially confusing headers, ssoma already should've dropped
@@ -35,6 +37,20 @@ sub emit_msg {
         foreach my $d (qw(Lines Bytes Content-Length Status)) {
                 $header_obj->header_set($d);
         }
+        my $feed_opts = $ctx->{feed_opts};
+        unless ($feed_opts) {
+                require PublicInbox::Feed; # FIXME: gross
+                $feed_opts = PublicInbox::Feed::get_feedopts($ctx);
+                $ctx->{feed_opts} = $feed_opts;
+        }
+        my $base = $feed_opts->{url};
+        my $mid = mid_clean($header_obj->header('Message-ID'));
+        $mid = uri_escape_utf8($mid);
+        my @archived_at = $header_obj->header('Archived-At');
+        push @archived_at, "<$base$mid/>";
+        $header_obj->header_set('Archived-At', @archived_at);
+        $header_obj->header_set('List-Archive', "<$base>");
+        $header_obj->header_set('List-Post', "<mailto:$feed_opts->{id_addr}>");
 
         my $buf = $header_obj->as_string;
         unless ($buf =~ /\AFrom /) {
@@ -82,7 +98,7 @@ sub emit_mbox {
                                 my $p = 'HEAD:'.mid2path($smsg->mid);
                                 Email::Simple->new($git->cat_file($p));
                         };
-                        emit_msg($fh, $msg) if $msg;
+                        emit_msg($ctx, $fh, $msg) if $msg;
                 }
 
                 $opts{offset} += $nr;
diff --git a/lib/PublicInbox/WWW.pm b/lib/PublicInbox/WWW.pm
index 58a4256a..fb57163e 100644
--- a/lib/PublicInbox/WWW.pm
+++ b/lib/PublicInbox/WWW.pm
@@ -163,7 +163,7 @@ sub get_mid_txt {
         my ($ctx) = @_;
         my $x = mid2blob($ctx) or return r404($ctx);
         require PublicInbox::Mbox;
-        PublicInbox::Mbox::emit1($x);
+        PublicInbox::Mbox::emit1($ctx, $x);
 }
 
 # /$LISTNAME/$MESSAGE_ID/                   -> HTML content (short quotes)