view: /$INBOX/: show "messages from $old to $new"

With the ViewVCS commit view using /$INBOX/?t=YYYYMMDDhhmmss-
links, the use of `t=' may not be immediately obvious to a
reader and confuse them into thinking the inbox hasn't been
updated in a while.

So add a header to the top of the page whenever the `t=' query
parameter is used.

And kill a couple of redundant variable assignments while we're
at it.

1 files changed, 20 insertions, 15 deletions

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 466ec6cf..11ed2d76 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -20,6 +20,7 @@ use PublicInbox::WwwStream qw(html_oneshot);
 use PublicInbox::Reply;
 use PublicInbox::ViewDiff qw(flush_diff);
 use PublicInbox::Eml;
+use POSIX qw(strftime);
 use Time::Local qw(timegm);
 use PublicInbox::Smsg qw(subject_normalized);
 use PublicInbox::ContentHash qw(content_hash);
@@ -1161,9 +1162,10 @@ sub dump_topics {
         }
 
         my @out;
-        my $ibx = $ctx->{ibx};
-        my $obfs_ibx = $ibx->{obfuscate} ? $ibx : undef;
-
+        my $obfs_ibx = $ctx->{ibx}->{obfuscate} ? $ctx->{ibx} : undef;
+        if (my $note = delete $ctx->{t_note}) {
+                push @out, $note; # "messages from ... to ..."
+        }
         # sort by recency, this allows new posts to "bump" old topics...
         foreach my $topic (sort { $b->[0] <=> $a->[0] } @$order) {
                 my ($ds, $n, $seen, $top_subj, @extra) = @$topic;
@@ -1222,7 +1224,7 @@ sub pagination_footer ($$) {
                 $next = $next ? "$next | " : '             | ';
                 $prev .= qq[ | <a\nhref="$latest">latest</a>];
         }
-        ($next || $prev) ? "<hr><pre>page: $next$prev</pre>" : '';
+        ($next || $prev) ? "<hr><pre id=nav>page: $next$prev</pre>" : '';
 }
 
 sub paginate_recent ($$) {
@@ -1238,21 +1240,29 @@ sub paginate_recent ($$) {
         $t =~ /\A([0-9]{8,14})\z/ and $before = str2ts($1);
 
         my $msgs = $ctx->{ibx}->over->recent($opts, $after, $before);
-        my $nr = scalar @$msgs;
-        if ($nr < $lim && defined($after)) {
+        if (defined($after) && scalar(@$msgs) < $lim) {
                 $after = $before = undef;
                 $msgs = $ctx->{ibx}->over->recent($opts);
-                $nr = scalar @$msgs;
         }
-        my $more = $nr == $lim;
+        my $more = scalar(@$msgs) == $lim;
         my ($newest, $oldest);
-        if ($nr) {
+        if (@$msgs) {
                 $newest = $msgs->[0]->{ts};
                 $oldest = $msgs->[-1]->{ts};
                 # if we only had $after, our SQL query in ->recent ordered
                 if ($newest < $oldest) {
                         ($oldest, $newest) = ($newest, $oldest);
-                        $more = 0 if defined($after) && $after < $oldest;
+                        $more = undef if defined($after) && $after < $oldest;
+                }
+                if (defined($after // $before)) {
+                        my $n = strftime('%Y-%m-%d %H:%M:%S', gmtime($newest));
+                        my $o = strftime('%Y-%m-%d %H:%M:%S', gmtime($oldest));
+                        $ctx->{t_note} = <<EOM;
+ messages from $o to $n UTC, [<a href="#nav">more...</a>]
+EOM
+                        my $s = ts2str($newest);
+                        $ctx->{prev_page} = qq[<a\nhref="?t=$s-"\nrel=prev>] .
+                                                'prev (newer)</a>';
                 }
         }
         if (defined($oldest) && $more) {
@@ -1260,11 +1270,6 @@ sub paginate_recent ($$) {
                 $ctx->{next_page} = qq[<a\nhref="?t=$s"\nrel=next>] .
                                         'next (older)</a>';
         }
-        if (defined($newest) && (defined($before) || defined($after))) {
-                my $s = ts2str($newest);
-                $ctx->{prev_page} = qq[<a\nhref="?t=$s-"\nrel=prev>] .
-                                        'prev (newer)</a>';
-        }
         $msgs;
 }