X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FView.pm;h=8969e17576f60de54152ebb2d4502571610801ef;hb=f76f265a851944b5dedcc3be5f3b5224b6ebda89;hp=fcc98ab80b60adf0f4dfd39ddcd408e44ff1bb15;hpb=226657eb31e326cc8329229e8ba0f63ff4c75083;p=public-inbox.git

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index fcc98ab8..8969e175 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -1,20 +1,25 @@
-# Copyright (C) 2014, Eric Wong <normalperson@yhbt.net> and all contributors
+# Copyright (C) 2014-2015 all contributors <meta@public-inbox.org>
 # License: AGPLv3 or later (https://www.gnu.org/licenses/agpl-3.0.txt)
 package PublicInbox::View;
 use strict;
 use warnings;
 use URI::Escape qw/uri_escape_utf8/;
+use Date::Parse qw/str2time/;
 use Encode qw/find_encoding/;
 use Encode::MIME::Header;
 use Email::MIME::ContentType qw/parse_content_type/;
 use PublicInbox::Hval;
-use PublicInbox::MID qw/mid_clean mid_compressed/;
+use PublicInbox::MID qw/mid_clean mid_compress mid2path/;
+use Digest::SHA qw/sha1_hex/;
+my $SALT = rand;
 require POSIX;
 
 # TODO: make these constants tunable
 use constant MAX_INLINE_QUOTED => 12; # half an 80x24 terminal
 use constant MAX_TRUNC_LEN => 72;
 use constant PRE_WRAP => "<pre\nstyle=\"white-space:pre-wrap\">";
+use constant T_ANCHOR => '#u';
+use constant INDENT => '  ';
 
 *ascii_html = *PublicInbox::Hval::ascii_html;
 
@@ -22,16 +27,17 @@ my $enc_utf8 = find_encoding('UTF-8');
 
 # public functions:
 sub msg_html {
-	my ($class, $mime, $full_pfx, $footer, $srch) = @_;
+	my ($ctx, $mime, $full_pfx, $footer) = @_;
 	if (defined $footer) {
 		$footer = "\n" . $footer;
 	} else {
 		$footer = '';
 	}
-	headers_to_html_header($mime, $full_pfx) .
+	headers_to_html_header($mime, $full_pfx, $ctx) .
 		multipart_text_as_html($mime, $full_pfx) .
 		'</pre><hr />' . PRE_WRAP .
-		html_footer($mime, 1, $full_pfx, $srch) . $footer .
+		html_footer($mime, 1, $full_pfx, $ctx) .
+		$footer .
 		'</pre></body></html>';
 }
 
@@ -41,113 +47,186 @@ sub feed_entry {
 	PRE_WRAP . multipart_text_as_html($mime, $full_pfx) . '</pre>';
 }
 
+sub in_reply_to {
+	my ($header_obj) = @_;
+	my $irt = $header_obj->header('In-Reply-To');
+
+	return mid_clean($irt) if (defined $irt);
+
+	my $refs = $header_obj->header('References');
+	if ($refs && $refs =~ /<([^>]+)>\s*\z/s) {
+		return $1;
+	}
+	undef;
+}
+
 # this is already inside a <pre>
 sub index_entry {
-	my ($class, $mime, $level, $state) = @_;
-	my ($now, $seen, $first) = @$state;
-	my $midx = $state->[3]++;
+	my ($fh, $mime, $level, $state) = @_;
+	my $midx = $state->{anchor_idx}++;
+	my $ctx = $state->{ctx};
+	my $srch = $ctx->{srch};
 	my ($prev, $next) = ($midx - 1, $midx + 1);
-	my $rv = '';
 	my $part_nr = 0;
-	my $enc_msg = enc_for($mime->header("Content-Type"));
+	my $enc = enc_for($mime->header("Content-Type"));
 	my $subj = $mime->header('Subject');
 	my $header_obj = $mime->header_obj;
 
-	my $mid_raw = $header_obj->header_raw('Message-ID');
+	my $mid_raw = $header_obj->header('Message-ID');
 	my $id = anchor_for($mid_raw);
-	$seen->{$id} = "#$id"; # save the anchor for later
+	my $seen = $state->{seen};
+	$seen->{$id} = "#$id"; # save the anchor for children, later
 
 	my $mid = PublicInbox::Hval->new_msgid($mid_raw);
 	my $from = PublicInbox::Hval->new_oneline($mime->header('From'))->raw;
 	my @from = Email::Address->parse($from);
 	$from = $from[0]->name;
-	(defined($from) && length($from)) or $from = $from[0]->address;
 
 	$from = PublicInbox::Hval->new_oneline($from)->as_html;
 	$subj = PublicInbox::Hval->new_oneline($subj)->as_html;
-	my $pfx = ('  ' x $level);
+	my $more = 'permalink';
+	my $root_anchor = $state->{root_anchor} || '';
+	my $path = $root_anchor ? '../../' : '';
+	my $href = $mid->as_href;
+	my $irt = in_reply_to($header_obj);
+	my $parent_anchor = $seen->{anchor_for($irt)} if defined $irt;
 
-	my $ts = $mime->header('X-PI-Date');
-	my $fmt = '%Y-%m-%d %H:%M UTC';
-	$ts = POSIX::strftime($fmt, gmtime($ts));
+	if ($srch) {
+		my $t = $ctx->{flat} ? 'T' : 't';
+		$subj = "<a\nhref=\"${path}$href/$t/#u\">$subj</a>";
+	}
+	if ($root_anchor eq $id) {
+		$subj = "<u\nid=\"u\">$subj</u>";
+	}
 
-	$rv .= "$pfx<b\nid=\"$id\">$subj</b>\n$pfx";
-	$rv .= "- by $from @ $ts - ";
-	$rv .= "<a\nid=\"s$midx\"\nhref=\"#s$next\">next</a>";
+	my $ts = _msg_date($mime);
+	my $rv = "<table\nsummary=l$level><tr>";
+	if ($level) {
+		$rv .= '<td><pre>' . (INDENT x $level) . '</pre></td>';
+	}
+	$rv .= "<td\nid=s$midx>" . PRE_WRAP;
+	$rv .= "<b\nid=\"$id\">$subj</b>\n";
+	$rv .= "- by $from @ $ts UTC - ";
+	$rv .= "<a\nhref=\"#s$next\">next</a>";
 	if ($prev >= 0) {
 		$rv .= "/<a\nhref=\"#s$prev\">prev</a>";
 	}
-	$rv .= "\n\n";
+	$fh->write($rv .= "\n\n");
+
+	my ($fhref, $more_ref);
+	my $mhref = "${path}$href/";
 
-	my $irp = $header_obj->header_raw('In-Reply-To');
-	my ($anchor_idx, $anchor);
-	if (defined $irp) {
-		$anchor_idx = anchor_for($irp);
-		$anchor = $seen->{$anchor_idx};
+	# show full message if it's our root message
+	if ($root_anchor ne $id) {
+		$fhref = "${path}$href/f/";
+		$more_ref = \$more;
 	}
-	my $href = $mid->as_href;
-	my $mhref = "m/$href.html";
-	my $fhref = "f/$href.html";
-	my $more = 'message';
 	# scan through all parts, looking for displayable text
 	$mime->walk_parts(sub {
-		my ($part) = @_;
-		return if $part->subparts; # walk_parts already recurses
-		my $ct = $part->content_type;
-
-		# account for filter bugs...
-		return if defined $ct && $ct =~ m!\btext/[xh]+tml\b!i;
+		index_walk($fh, $_[0], $enc, \$part_nr, $fhref, $more_ref);
+	});
+	$mime->body_set('');
 
-		my $enc = enc_for($ct, $enc_msg);
+	my $txt = "${path}$href/raw";
+	$rv = "\n<a\nhref=\"$mhref\">$more</a> <a\nhref=\"$txt\">raw</a> ";
+	$rv .= html_footer($mime, 0, undef, $ctx);
 
-		if ($part_nr > 0) {
-			my $fn = $part->filename;
-			defined($fn) or $fn = "part #" . ($part_nr + 1);
-			$rv .= $pfx . add_filename_line($enc->decode($fn));
+	if (defined $irt) {
+		unless (defined $parent_anchor) {
+			my $v = PublicInbox::Hval->new_msgid($irt, 1);
+			$v = $v->as_href;
+			$parent_anchor = "${path}$v/";
+		}
+		$rv .= " <a\nhref=\"$parent_anchor\">parent</a>";
+	}
+	if ($srch) {
+		if ($ctx->{flat}) {
+			$rv .= " [<a\nhref=\"${path}$href/t/#u\">threaded</a>" .
+				"|<b>flat</b>]";
+		} else {
+			$rv .= " [<b>threaded</b>|" .
+				"<a\nhref=\"${path}$href/T/#u\">flat</a>]";
 		}
+	}
 
-		my $s = add_text_body_short($enc, $part, $part_nr, $fhref);
+	$fh->write($rv .= '</pre></td></tr></table>');
+}
 
-		# drop the remainder of git patches, they're usually better
-		# to review when the full message is viewed
-		$s =~ s!^---+\n.*\z!!ms and $more = 'more...';
+sub thread_html {
+	my ($ctx, $foot, $srch) = @_;
+	sub { emit_thread_html($_[0], $ctx, $foot, $srch) }
+}
 
-		# Drop signatures
-		$s =~ s/^-- \n.*\z//ms and $more = 'more...';
+# only private functions below.
 
-		# kill any leading or trailing whitespace
-		$s =~ s/\A\s+//s;
-		$s =~ s/\s+\z//s;
+sub emit_thread_html {
+	my ($cb, $ctx, $foot, $srch) = @_;
+	my $mid = $ctx->{mid};
+	my $res = $srch->get_thread($mid);
+	my $msgs = load_results($res);
+	my $nr = scalar @$msgs;
+	return missing_thread($cb, $ctx) if $nr == 0;
+	my $flat = $ctx->{flat};
+	my $orig_cb = $cb;
+	my $seen = {};
+	my $state = {
+		ctx => $ctx,
+		seen => $seen,
+		root_anchor => anchor_for($mid),
+		anchor_idx => 0,
+	};
+
+	require PublicInbox::GitCatFile;
+	my $git = PublicInbox::GitCatFile->new($ctx->{git_dir});
+	if ($flat) {
+		pre_anchor_entry($seen, $_) for (@$msgs);
+		__thread_entry(\$cb, $git, $state, $_, 0) for (@$msgs);
+	} else {
+		my $th = thread_results($msgs);
+		thread_entry(\$cb, $git, $state, $_, 0) for $th->rootset;
+	}
+	$git = undef;
+	Email::Address->purge_cache;
+
+	# there could be a race due to a message being deleted in git
+	# but still being in the Xapian index:
+	return missing_thread($cb, $ctx) if ($orig_cb eq $cb);
+
+	my $final_anchor = $state->{anchor_idx};
+	my $next = "<a\nid=\"s$final_anchor\">";
+	$next .= $final_anchor == 1 ? 'only message in' : 'end of';
+	$next .= " thread</a>, back to <a\nhref=\"../../\">index</a>";
+	$next .= "\ndownload thread: <a\nhref=\"../t.mbox.gz\">mbox.gz</a>";
+	$next .= " / follow: <a\nhref=\"../t.atom\">Atom feed</a>";
+	$cb->write("<hr />" . PRE_WRAP . $next . "\n\n". $foot .
+		   "</pre></body></html>");
+	$cb->close;
+}
 
-		if (length $s) {
-			# add prefix:
-			$s =~ s/^/$pfx/sgm;
+sub index_walk {
+	my ($fh, $part, $enc, $part_nr, $fhref, $more) = @_;
+	my $s = add_text_body($enc, $part, $part_nr, $fhref);
 
-			$rv .= $s . "\n";
-		}
-		++$part_nr;
-	});
+	if ($more) {
+		# drop the remainder of git patches, they're usually better
+		# to review when the full message is viewed
+		$s =~ s!^---+\n.*\z!!ms and $$more = 'more...';
 
-	$rv .= "\n$pfx<a\nhref=\"$mhref\">$more</a> ";
-	my $txt = "m/$href.txt";
-	$rv .= "<a\nhref=\"$txt\">raw</a> ";
-	$rv .= html_footer($mime, 0);
-
-	if (defined $irp) {
-		unless (defined $anchor) {
-			my $v = PublicInbox::Hval->new_msgid($irp);
-			my $html = $v->as_html;
-			$anchor = 'm/' . $v->as_href . '.html';
-			$seen->{$anchor_idx} = $anchor;
-		}
-		$rv .= " <a\nhref=\"$anchor\">parent</a>";
+		# Drop signatures
+		$s =~ s/^-- \n.*\z//ms and $$more = 'more...';
 	}
-	$rv .= " <a\nhref=\"?r=$first#$id\">threadlink</a>";
 
-	$rv . "\n\n";
-}
+	# kill any leading or trailing whitespace lines
+	$s =~ s/^\s*$//sgm;
+	$s =~ s/\s+\z//s;
 
-# only private functions below.
+	if ($s ne '') {
+		# kill per-line trailing whitespace
+		$s =~ s/[ \t]+$//sgm;
+		$s .= "\n" unless $s =~ /\n\z/s;
+	}
+	$fh->write($s);
+}
 
 sub enc_for {
 	my ($ct, $default) = @_;
@@ -164,174 +243,278 @@ sub enc_for {
 }
 
 sub multipart_text_as_html {
-	my ($mime, $full_pfx) = @_;
+	my ($mime, $full_pfx, $srch) = @_;
 	my $rv = "";
 	my $part_nr = 0;
-	my $enc_msg = enc_for($mime->header("Content-Type"));
+	my $enc = enc_for($mime->header("Content-Type"));
 
 	# scan through all parts, looking for displayable text
 	$mime->walk_parts(sub {
 		my ($part) = @_;
-		return if $part->subparts; # walk_parts already recurses
-		my $ct = $part->content_type;
-
-		# account for filter bugs...
-		return if defined $ct && $ct =~ m!\btext/[xh]+tml\b!i;
-
-		my $enc = enc_for($ct, $enc_msg);
-
-		if ($part_nr > 0) {
-			my $fn = $part->filename;
-			defined($fn) or $fn = "part #" . ($part_nr + 1);
-			$rv .= add_filename_line($enc->decode($fn));
-		}
-
-		if (defined $full_pfx) {
-			$rv .= add_text_body_short($enc, $part, $part_nr,
-						$full_pfx);
-		} else {
-			$rv .= add_text_body_full($enc, $part, $part_nr);
-		}
-		$rv .= "\n" unless $rv =~ /\n\z/s;
-		++$part_nr;
+		$rv .= add_text_body($enc, $part, \$part_nr, $full_pfx, 1);
 	});
+	$mime->body_set('');
 	$rv;
 }
 
 sub add_filename_line {
-	my ($fn) = @_;
+	my ($enc, $fn) = @_;
 	my $len = 72;
 	my $pad = "-";
-
+	$fn = $enc->decode($fn);
 	$len -= length($fn);
 	$pad x= ($len/2) if ($len > 0);
 	"$pad " . ascii_html($fn) . " $pad\n";
 }
 
-my $LINK_RE = qr!\b((?:ftp|https?|nntp)://[@\w\+\&\?\.\%\;/#=-]+)!;
-
-sub linkify {
-	# no newlines added here since it'd break the splitting we do
-	# to fold quotes
-	$_[0] =~ s!$LINK_RE!<a href="$1">$1</a>!g;
+my $LINK_RE = qr!\b((?:ftp|https?|nntp)://
+		 [\@:\w\.-]+/
+		 ?[\@\w\+\&\?\.\%\;/#=-]*)!x;
+
+sub linkify_1 {
+	my ($link_map, $s) = @_;
+	$s =~ s!$LINK_RE!
+		my $url = $1;
+		# salt this, as this could be exploited to show
+		# links in the HTML which don't show up in the raw mail.
+		my $key = sha1_hex($url . $SALT);
+		$link_map->{$key} = $url;
+		'PI-LINK-'. $key;
+	!ge;
+	$s;
 }
 
-sub add_text_body_short {
-	my ($enc, $part, $part_nr, $full_pfx) = @_;
-	my $n = 0;
-	my $s = ascii_html($enc->decode($part->body));
-	linkify($s);
-	$s =~ s!^((?:(?:&gt;[^\n]*)\n)+)!
-		my $cur = $1;
-		my @lines = split(/\n/, $cur);
-		if (@lines > MAX_INLINE_QUOTED) {
-			# show a short snippet of quoted text
-			$cur = join(' ', @lines);
-			$cur =~ s/^&gt;\s*//;
-
-			my @sum = split(/\s+/, $cur);
-			$cur = '';
-			do {
-				my $tmp = shift(@sum);
-				my $len = length($tmp) + length($cur);
-				if ($len > MAX_TRUNC_LEN) {
-					@sum = ();
-				} else {
-					$cur .= $tmp . ' ';
-				}
-			} while (@sum && length($cur) < MAX_TRUNC_LEN);
-			$cur =~ s/ \z/ .../;
-			"&gt; &lt;<a\nhref=\"${full_pfx}#q${part_nr}_" . $n++ .
-				"\">$cur<\/a>&gt;\n";
+sub linkify_2 {
+	my ($link_map, $s) = @_;
+
+	# Added "PI-LINK-" prefix to avoid false-positives on git commits
+	$s =~ s!\bPI-LINK-([a-f0-9]{40})\b!
+		my $key = $1;
+		my $url = $link_map->{$key};
+		if (defined $url) {
+			$url = ascii_html($url);
+			"<a\nhref=\"$url\">$url</a>";
 		} else {
-			$cur;
+			# false positive or somebody tried to mess with us
+			$key;
 		}
-	!emg;
+	!ge;
 	$s;
 }
 
-sub add_text_body_full {
-	my ($enc, $part, $part_nr) = @_;
+sub flush_quote {
+	my ($quot, $n, $part_nr, $full_pfx, $final, $do_anchor) = @_;
+
+	if ($full_pfx) {
+		if (!$final && scalar(@$quot) <= MAX_INLINE_QUOTED) {
+			# show quote inline
+			my %l;
+			my $rv = join('', map { linkify_1(\%l, $_) } @$quot);
+			@$quot = ();
+			$rv = ascii_html($rv);
+			return linkify_2(\%l, $rv);
+		}
+
+		# show a short snippet of quoted text and link to full version:
+		@$quot = map { s/^(?:>\s*)+//gm; $_ } @$quot;
+		my $cur = join(' ', @$quot);
+		@$quot = split(/\s+/, $cur);
+		$cur = '';
+		do {
+			my $tmp = shift(@$quot);
+			my $len = length($tmp) + length($cur);
+			if ($len > MAX_TRUNC_LEN) {
+				@$quot = ();
+			} else {
+				$cur .= $tmp . ' ';
+			}
+		} while (@$quot && length($cur) < MAX_TRUNC_LEN);
+		@$quot = ();
+		$cur =~ s/ \z/ .../s;
+		$cur = ascii_html($cur);
+		my $nr = ++$$n;
+		"&gt; [<a\nhref=\"$full_pfx#q${part_nr}_$nr\">$cur</a>]\n";
+	} else {
+		# show everything in the full version with anchor from
+		# short version (see above)
+		my %l;
+		my $rv .= join('', map { linkify_1(\%l, $_) } @$quot);
+		@$quot = ();
+		$rv = ascii_html($rv);
+		return linkify_2(\%l, $rv) unless $do_anchor;
+		my $nr = ++$$n;
+		"<a\nid=q${part_nr}_$nr></a>" . linkify_2(\%l, $rv);
+	}
+}
+
+sub add_text_body {
+	my ($enc_msg, $part, $part_nr, $full_pfx, $do_anchor) = @_;
+	return '' if $part->subparts;
+
+	my $ct = $part->content_type;
+	# account for filter bugs...
+	if (defined $ct && $ct =~ m!\btext/[xh]+tml\b!i) {
+		$part->body_set('');
+		return '';
+	}
+	my $enc = enc_for($ct, $enc_msg);
 	my $n = 0;
-	my $s = ascii_html($enc->decode($part->body));
-	linkify($s);
-	$s =~ s!^((?:(?:&gt;[^\n]*)\n)+)!
-		my $cur = $1;
-		my @lines = split(/\n/, $cur);
-		if (@lines > MAX_INLINE_QUOTED) {
-			"<a\nid=q${part_nr}_" . $n++ . ">$cur</a>";
+	my $nr = 0;
+	my $s = $part->body;
+	$part->body_set('');
+	$s = $enc->decode($s);
+	my @lines = split(/^/m, $s);
+	$s = '';
+
+	if ($$part_nr > 0) {
+		my $fn = $part->filename;
+		defined($fn) or $fn = "part #" . ($$part_nr + 1);
+		$s .= add_filename_line($enc, $fn);
+	}
+
+	my @quot;
+	while (defined(my $cur = shift @lines)) {
+		if ($cur !~ /^>/) {
+			# show the previously buffered quote inline
+			if (scalar @quot) {
+				$s .= flush_quote(\@quot, \$n, $$part_nr,
+						  $full_pfx, 0, $do_anchor);
+			}
+
+			# regular line, OK
+			my %l;
+			$cur = linkify_1(\%l, $cur);
+			$cur = ascii_html($cur);
+			$s .= linkify_2(\%l, $cur);
 		} else {
-			$cur;
+			push @quot, $cur;
 		}
-	!emg;
+	}
+	if (scalar @quot) {
+		$s .= flush_quote(\@quot, \$n, $$part_nr, $full_pfx, 1,
+				  $do_anchor);
+	}
+	$s .= "\n" unless $s =~ /\n\z/s;
+	++$$part_nr;
 	$s;
 }
 
 sub headers_to_html_header {
-	my ($mime, $full_pfx) = @_;
-
+	my ($mime, $full_pfx, $ctx) = @_;
+	my $srch = $ctx->{srch} if $ctx;
 	my $rv = "";
 	my @title;
+	my $header_obj = $mime->header_obj;
+	my $mid = $header_obj->header('Message-ID');
+	$mid = PublicInbox::Hval->new_msgid($mid);
+	my $mid_href = $mid->as_href;
 	foreach my $h (qw(From To Cc Subject Date)) {
 		my $v = $mime->header($h);
-		defined($v) && length($v) or next;
+		defined($v) && ($v ne '') or next;
 		$v = PublicInbox::Hval->new_oneline($v);
-		$rv .= "$h: " . $v->as_html . "\n";
 
 		if ($h eq 'From') {
 			my @from = Email::Address->parse($v->raw);
-			$v = $from[0]->name;
-			unless (defined($v) && length($v)) {
-				$v = '<' . $from[0]->address . '>';
-			}
-			$title[1] = ascii_html($v);
+			$title[1] = ascii_html($from[0]->name);
 		} elsif ($h eq 'Subject') {
 			$title[0] = $v->as_html;
+			if ($srch) {
+				my $p = $full_pfx ? '' : '../';
+				$rv .= "$h: <a\nid=\"t\"\nhref=\"${p}t/#u\">";
+				$rv .= $v->as_html . "</a>\n";
+				next;
+			}
 		}
+		$rv .= "$h: " . $v->as_html . "\n";
+
+	}
+	$rv .= 'Message-ID: &lt;' . $mid->as_html . '&gt; ';
+	my $raw_ref = $full_pfx ? 'raw' : '../raw';
+	$rv .= "(<a\nhref=\"$raw_ref\">raw</a>)\n";
+	if ($srch) {
+		$rv .= "<a\nhref=\"#r\">References: [see below]</a>\n";
+	} else {
+		$rv .= _parent_headers_nosrch($header_obj);
 	}
+	$rv .= "\n";
 
-	my $header_obj = $mime->header_obj;
-	my $mid = $header_obj->header_raw('Message-ID');
-	if (defined $mid) {
-		$mid = PublicInbox::Hval->new_msgid($mid);
-		$rv .= 'Message-ID: &lt;' . $mid->as_html . '&gt; ';
-		my $href = $mid->as_href;
-		$href = "../m/$href" unless $full_pfx;
-		$rv .= "(<a\nhref=\"$href.txt\">raw</a>)\n";
-	}
-
-	my $irp = $header_obj->header_raw('In-Reply-To');
-	if (defined $irp) {
-		my $v = PublicInbox::Hval->new_msgid($irp);
+	("<html><head><title>".  join(' - ', @title) .
+	 '</title></head><body>' . PRE_WRAP . $rv);
+}
+
+sub thread_inline {
+	my ($dst, $ctx, $cur, $full_pfx) = @_;
+	my $srch = $ctx->{srch};
+	my $mid = mid_clean($cur->header('Message-ID'));
+	my $res = $srch->get_thread($mid);
+	my $nr = $res->{total};
+
+	if ($nr <= 1) {
+		$$dst .= "\n[no followups, yet]\n";
+		return (undef, in_reply_to($cur));
+	}
+	my $upfx = $full_pfx ? '' : '../';
+
+	$$dst .= "\n\n~$nr messages in thread: ".
+		 "(<a\nhref=\"${upfx}t/#u\">expand</a>)\n";
+	my $subj = $srch->subject_path($cur->header('Subject'));
+	my $parent = in_reply_to($cur);
+	my $state = {
+		seen => { $subj => 1 },
+		srch => $srch,
+		cur => $mid,
+		parent_cmp => defined $parent ? $parent : '',
+		parent => $parent,
+		prev_attr => '',
+		prev_level => 0,
+	};
+	for (thread_results(load_results($res))->rootset) {
+		inline_dump($dst, $state, $upfx, $_, 0);
+	}
+	($state->{next_msg}, $state->{parent});
+}
+
+sub _parent_headers_nosrch {
+	my ($header_obj) = @_;
+	my $rv = '';
+
+	my $irt = in_reply_to($header_obj);
+	if (defined $irt) {
+		my $v = PublicInbox::Hval->new_msgid($irt, 1);
 		my $html = $v->as_html;
 		my $href = $v->as_href;
 		$rv .= "In-Reply-To: &lt;";
-		$rv .= "<a\nhref=\"$href.html\">$html</a>&gt;\n";
+		$rv .= "<a\nhref=\"../$href/\">$html</a>&gt;\n";
 	}
 
-	my $refs = $header_obj->header_raw('References');
+	my $refs = $header_obj->header('References');
 	if ($refs) {
-		$refs =~ s/\s*\Q$irp\E\s*// if (defined $irp);
-		my @refs = ($refs =~ /<([^>]+)>/g);
+		# avoid redundant URLs wasting bandwidth
+		my %seen;
+		$seen{$irt} = 1 if defined $irt;
+		my @refs;
+		my @raw_refs = ($refs =~ /<([^>]+)>/g);
+		foreach my $ref (@raw_refs) {
+			next if $seen{$ref};
+			$seen{$ref} = 1;
+			push @refs, linkify_ref_nosrch($ref);
+		}
+
 		if (@refs) {
-			$rv .= 'References: '. linkify_refs(@refs) . "\n";
+			$rv .= 'References: '. join(' ', @refs) . "\n";
 		}
 	}
-
-	$rv .= "\n";
-
-	("<html><head><title>".  join(' - ', @title) .
-	 '</title></head><body>' . PRE_WRAP . $rv);
+	$rv;
 }
 
 sub html_footer {
-	my ($mime, $standalone, $full_pfx, $srch) = @_;
+	my ($mime, $standalone, $full_pfx, $ctx) = @_;
 	my %cc; # everyone else
 	my $to; # this is the From address
 
 	foreach my $h (qw(From To Cc)) {
 		my $v = $mime->header($h);
-		defined($v) && length($v) or next;
+		defined($v) && ($v ne '') or next;
 		my @addrs = Email::Address->parse($v);
 		foreach my $recip (@addrs) {
 			my $address = $recip->address;
@@ -343,108 +526,353 @@ sub html_footer {
 	Email::Address->purge_cache if $standalone;
 
 	my $subj = $mime->header('Subject') || '';
-	$subj = "Re: $subj" unless $subj =~ /\bRe:/;
-	my $mid = $mime->header_obj->header_raw('Message-ID');
-	my $irp = uri_escape_utf8($mid);
+	$subj = "Re: $subj" unless $subj =~ /\bRe:/i;
+	my $mid = $mime->header('Message-ID');
+	my $irt = uri_escape_utf8($mid);
 	delete $cc{$to};
 	$to = uri_escape_utf8($to);
 	$subj = uri_escape_utf8($subj);
 
 	my $cc = uri_escape_utf8(join(',', sort values %cc));
-	my $href = "mailto:$to?In-Reply-To=$irp&Cc=${cc}&Subject=$subj";
+	my $href = "mailto:$to?In-Reply-To=$irt&Cc=${cc}&Subject=$subj";
 
-	my $irt = '';
-	my $idx = $standalone ? " <a\nhref=\"../\">index</a>" : '';
+	my $srch = $ctx->{srch} if $ctx;
+	my $upfx = $full_pfx ? '../' : '../../';
+	my $idx = $standalone ? " <a\nhref=\"$upfx\">index</a>" : '';
 	if ($idx && $srch) {
-		my $res = $srch->get_replies($mid);
-		if (my $c = $res->{count}) {
-			$c = $c == 1 ? '1 reply' : "$c replies";
-			$idx .= "\n$c:\n";
-			thread_replies(\$idx, $mime, $res);
+		my ($next, $p) = thread_inline(\$idx, $ctx, $mime, $full_pfx);
+		if (defined $p) {
+			$p = PublicInbox::Hval->new_oneline($p);
+			$p = $p->as_href;
+			$irt = "<a\nhref=\"$upfx$p/\">parent</a> ";
 		} else {
-			$idx .= "\n(no replies yet)\n";
+			$irt = ' ' x length('parent ');
 		}
-		$irt = $mime->header_obj->header_raw('In-Reply-To');
-		if ($irt) {
-			$irt = PublicInbox::Hval->new_msgid($irt);
-			$irt = $irt->as_href;
-			$irt = "<a\nhref=\"$irt\">parent</a> ";
+		if ($next) {
+			$irt .= "<a\nhref=\"$upfx$next/\">next</a> ";
 		} else {
-			$irt = ' ' x length('parent ');
+			$irt .= '     ';
 		}
+	} else {
+		$irt = '';
 	}
 
 	"$irt<a\nhref=\"" . ascii_html($href) . '">reply</a>' . $idx;
 }
 
-sub linkify_refs {
-	join(' ', map {
-		my $v = PublicInbox::Hval->new_msgid($_);
-		my $html = $v->as_html;
-		my $href = $v->as_href;
-		"&lt;<a\nhref=\"$href.html\">$html</a>&gt;";
-	} @_);
+sub linkify_ref_nosrch {
+	my $v = PublicInbox::Hval->new_msgid($_[0], 1);
+	my $html = $v->as_html;
+	my $href = $v->as_href;
+	"&lt;<a\nhref=\"../$href/\">$html</a>&gt;";
 }
 
 sub anchor_for {
 	my ($msgid) = @_;
-	'm' . mid_compressed(mid_clean($msgid));
+	my $id = $msgid;
+	if ($id !~ /\A[a-f0-9]{40}\z/) {
+		$id = mid_compress(mid_clean($id), 1);
+	}
+	'm' . $id;
+}
+
+sub thread_html_head {
+	my ($cb, $mime) = @_;
+	$$cb = $$cb->([200, ['Content-Type'=> 'text/html; charset=UTF-8']]);
+
+	my $s = PublicInbox::Hval->new_oneline($mime->header('Subject'));
+	$s = $s->as_html;
+	$$cb->write("<html><head><title>$s</title></head><body>");
+}
+
+sub pre_anchor_entry {
+	my ($seen, $mime) = @_;
+	my $id = anchor_for($mime->header('Message-ID'));
+	$seen->{$id} = "#$id"; # save the anchor for children, later
+}
+
+sub ghost_parent {
+	my ($upfx, $mid) = @_;
+	# 'subject dummy' is used internally by Mail::Thread
+	return '[no common parent]' if ($mid eq 'subject dummy');
+
+	$mid = PublicInbox::Hval->new_msgid($mid);
+	my $href = $mid->as_href;
+	my $html = $mid->as_html;
+	qq{[parent not found: &lt;<a\nhref="$upfx../$href/">$html</a>&gt;]};
+}
+
+sub __thread_entry {
+	my ($cb, $git, $state, $mime, $level) = @_;
+
+	# lazy load the full message from mini_mime:
+	$mime = eval {
+		my $path = mid2path(mid_clean($mime->header('Message-ID')));
+		Email::MIME->new($git->cat_file('HEAD:'.$path));
+	} or return;
+
+	if ($state->{anchor_idx} == 0) {
+		thread_html_head($cb, $mime, $state);
+	}
+
+	if (my $ghost = delete $state->{ghost}) {
+		# n.b. ghost messages may only be parents, not children
+		foreach my $g (@$ghost) {
+			$$cb->write("<table\nsummary=ghost><tr><td>" .
+				(INDENT x $g->[1]) . "</td><td>" .
+				PRE_WRAP . ghost_parent('../', $g->[0]) .
+				'</pre></td></table>');
+		}
+	}
+	index_entry($$cb, $mime, $level, $state);
+	1;
+}
+
+sub __ghost_entry {
+	my ($state, $node, $level) = @_;
+	my $ghost = $state->{ghost} ||= [];
+	push @$ghost, [ $node->messageid, $level ];
+}
+
+sub thread_entry {
+	my ($cb, $git, $state, $node, $level) = @_;
+	return unless $node;
+	if (my $mime = $node->message) {
+		unless (__thread_entry($cb, $git, $state, $mime, $level)) {
+			__ghost_entry($state, $node, $level);
+		}
+	} else {
+		__ghost_entry($state, $node, $level);
+	}
+
+	thread_entry($cb, $git, $state, $node->child, $level + 1);
+	thread_entry($cb, $git, $state, $node->next, $level);
 }
 
-# children are chronological
-sub simple_sort_children {
+sub load_results {
+	my ($res) = @_;
+
+	[ map { $_->mini_mime } @{delete $res->{msgs}} ];
+}
+
+sub msg_timestamp {
+	my ($mime) = @_;
+	my $ts = eval { str2time($mime->header('Date')) };
+	defined($ts) ? $ts : 0;
+}
+
+sub thread_results {
+	my ($msgs, $nosubject) = @_;
+	require PublicInbox::Thread;
+	my $th = PublicInbox::Thread->new(@$msgs);
+	no warnings 'once';
+	$Mail::Thread::nosubject = $nosubject;
+	$th->thread;
+	$th->order(*sort_ts);
+	$th
+}
+
+sub missing_thread {
+	my ($cb, $ctx) = @_;
+	require PublicInbox::ExtMsg;
+
+	$cb->(PublicInbox::ExtMsg::ext_msg($ctx))
+}
+
+sub _msg_date {
+	my ($mime) = @_;
+	my $ts = $mime->header('X-PI-TS') || msg_timestamp($mime);
+	POSIX::strftime('%Y-%m-%d %H:%M', gmtime($ts));
+}
+
+sub _inline_header {
+	my ($dst, $state, $upfx, $mime, $level) = @_;
+	my $pfx = INDENT x ($level - 1);
+	my $dot = $level == 0 ? '' : '` ';
+
+	my $cur = $state->{cur};
+	my $mid = mid_clean($mime->header('Message-ID'));
+	my $f = $mime->header('X-PI-From');
+	my $d = _msg_date($mime);
+	$f = PublicInbox::Hval->new($f)->as_html;
+	$d = PublicInbox::Hval->new($d)->as_html;
+	my $attr = "$f @ $d";
+	$state->{first_level} ||= $level;
+	if ($attr ne $state->{prev_attr} || $state->{prev_level} > $level) {
+		$state->{prev_attr} = $attr;
+		$attr = ' - ' . $attr;
+		$attr .= ' UTC' if $level >= $state->{first_level};
+	} else {
+		$attr = '';
+	}
+	$state->{prev_level} = $level;
+
+	if ($cur) {
+		if ($cur eq $mid) {
+			delete $state->{cur};
+			$$dst .= "$pfx$dot<b><a\nid=\"r\"\nhref=\"#t\">".
+				 "[this message]</a></b>$attr\n";
+
+			return;
+		}
+	} else {
+		$state->{next_msg} ||= $mid;
+	}
+
+	# Subject is never undef, this mail was loaded from
+	# our Xapian which would've resulted in '' if it were
+	# really missing (and Filter rejects empty subjects)
+	my $s = $mime->header('Subject');
+	my $h = $state->{srch}->subject_path($s);
+	if ($state->{seen}->{$h}) {
+		$s = undef;
+	} else {
+		$state->{seen}->{$h} = 1;
+		$s = PublicInbox::Hval->new($s);
+		$s = $s->as_html;
+	}
+	my $m = PublicInbox::Hval->new_msgid($mid);
+	$m = $upfx . '../' . $m->as_href . '/';
+	if (defined $s) {
+		$$dst .= "$pfx$dot<a\nhref=\"$m\">$s</a>$attr\n";
+	} else {
+		$$dst .= "$pfx$dot<a\nhref=\"$m\">$f @ $d</a>\n";
+	}
+}
+
+sub inline_dump {
+	my ($dst, $state, $upfx, $node, $level) = @_;
+	return unless $node;
+	if (my $mime = $node->message) {
+		my $mid = mid_clean($mime->header('Message-ID'));
+		if ($mid eq $state->{parent_cmp}) {
+			$state->{parent} = $mid;
+		}
+		_inline_header($dst, $state, $upfx, $mime, $level);
+	} else {
+		my $dot = $level == 0 ? '' : '` ';
+		my $pfx = (INDENT x $level) . $dot;
+		$$dst .= $pfx . ghost_parent($upfx, $node->messageid) . "\n";
+	}
+	inline_dump($dst, $state, $upfx, $node->child, $level+1);
+	inline_dump($dst, $state, $upfx, $node->next, $level);
+}
+
+sub sort_ts {
 	sort {
 		(eval { $a->topmost->message->header('X-PI-TS') } || 0) <=>
 		(eval { $b->topmost->message->header('X-PI-TS') } || 0)
 	} @_;
 }
 
-sub simple_dump {
-	my ($dst, $root, $node, $level) = @_;
-	$$dst .= '  ' x $level;
+sub rsort_ts {
+	sort {
+		(eval { $b->topmost->message->header('X-PI-TS') } || 0) <=>
+		(eval { $a->topmost->message->header('X-PI-TS') } || 0)
+	} @_;
+}
+
+# accumulate recent topics if search is supported
+# returns 1 if done, undef if not
+sub add_topic {
+	my ($state, $node, $level) = @_;
+	return unless $node;
+	my $child_adjust = 1;
+
 	if (my $x = $node->message) {
-		my $mid = $x->header('Message-ID');
-		if ($root->[0] ne $mid) {
-			my $s = clean_subj($x->header('Subject'));
-			if ($root->[1] eq $s) {
-				$s = '  ';
-			} else {
-				$s = PublicInbox::Hval->new($s);
-				$s = $s->as_html . ' ';
-			}
-			my $m = PublicInbox::Hval->new_msgid($mid);
-			my $f = PublicInbox::Hval->new($x->header('X-PI-From'));
-			my $d = PublicInbox::Hval->new($x->header('X-PI-Date'));
-			$m = $m->as_href . '.html';
-			$f = $f->as_html;
-			$d = $d->as_html;
-			$$dst .= "` <a\nhref=\"$m\">$s$f @ $d UTC</a>\n";
+		$x = $x->header_obj;
+		my ($topic, $subj);
+
+		$subj = $x->header('Subject');
+		$subj = $state->{srch}->subject_normalized($subj);
+		$topic = $subj;
+
+		# kill "[PATCH v2]" etc. for summarization
+		$topic =~ s/\A\s*\[[^\]]+\]\s*//g;
+		$topic = substr($topic, 0, 30);
+
+		if (++$state->{subjs}->{$topic} == 1) {
+			push @{$state->{order}}, [ $level, $subj, $topic ];
 		}
+
+		my $mid = mid_clean($x->header('Message-ID'));
+
+		my $u = $x->header('X-PI-From');
+		my $ts = $x->header('X-PI-TS');
+		$state->{latest}->{$topic} = [ $mid, $u, $ts ];
+	} else {
+		# ghost message, do not bump level
+		$child_adjust = 0;
 	}
-	simple_dump($dst, $root, $node->child, $level + 1) if $node->child;
-	simple_dump($dst, $root, $node->next, $level) if $node->next;
+
+	add_topic($state, $node->child, $level + $child_adjust);
+	add_topic($state, $node->next, $level);
 }
 
-sub clean_subj {
-	my ($subj) = @_;
-	$subj =~ s/\A\s+//;
-	$subj =~ s/\s+\z//;
-	$subj =~ s/^(?:re|aw):\s*//i; # remove reply prefix (aw: German)
-	$subj =~ s/\s+/ /;
-	$subj;
+sub dump_topics {
+	my ($state) = @_;
+	my $order = $state->{order};
+	my $subjs = $state->{subjs};
+	my $latest = $state->{latest};
+	return "\n[No recent topics]</pre>" unless (scalar @$order);
+	my $dst = '';
+	my $pfx;
+	my $prev = 0;
+	my $prev_attr = '';
+	while (defined(my $info = shift @$order)) {
+		my ($level, $subj, $topic) = @$info;
+		my $n = delete $subjs->{$topic};
+		my ($mid, $u, $ts) = @{delete $latest->{$topic}};
+		$mid = PublicInbox::Hval->new($mid)->as_href;
+		$subj = PublicInbox::Hval->new($subj)->as_html;
+		$u = PublicInbox::Hval->new($u)->as_html;
+		$pfx = INDENT x ($level - 1);
+		my $nl = $level == $prev ? "\n" : '';
+		my $dot = $level == 0 ? '' : '` ';
+		$dst .= "$nl$pfx$dot<a\nhref=\"$mid/t/#u\"><b>$subj</b></a>\n";
+
+		my $attr;
+		$ts = POSIX::strftime('%Y-%m-%d %H:%M', gmtime($ts));
+		if ($n == 1) {
+			$attr = "created by $u @ $ts UTC";
+			$n = "\n";
+		} else {
+			# $n isn't the total number of posts on the topic,
+			# just the number of posts in the current results
+			# window, so leave it unlabeled
+			$attr = "updated by $u @ $ts UTC";
+			$n = " ($n)\n";
+		}
+		if ($level == 0 || $attr ne $prev_attr) {
+			$pfx .= INDENT if $level > 0;
+			$dst .= "$pfx- ". $attr . $n;
+			$prev_attr = $attr;
+		}
+	}
+	$dst .= '</pre>';
 }
 
-sub thread_replies {
-	my ($dst, $root, $res) = @_;
-	my @msgs = map { $_->mini_mime } @{$res->{msgs}};
-	require PublicInbox::Thread;
-	$root->header_set('X-PI-TS', '0');
-	my $th = PublicInbox::Thread->new($root, @msgs);
-	$th->thread;
-	$th->order(sub { simple_sort_children(@_) });
-	$root = [ $root->header('Message-ID'),
-		  clean_subj($root->header('Subject')) ];
-	simple_dump($dst, $root, $_, 0) for $th->rootset;
+sub emit_index_topics {
+	my ($state, $fh) = @_;
+	my $off = $state->{ctx}->{cgi}->param('o');
+	$off = 0 unless defined $off;
+	$state->{order} = [];
+	$state->{subjs} = {};
+	$state->{latest} = {};
+	my $max = 25;
+	my %opts = ( offset => int $off, limit => $max * 4 );
+	while (scalar @{$state->{order}} < $max) {
+		my $res = $state->{srch}->query('', \%opts);
+		my $nr = scalar @{$res->{msgs}} or last;
+
+		for (rsort_ts(thread_results(load_results($res), 1)->rootset)) {
+			add_topic($state, $_, 0);
+		}
+		$opts{offset} += $nr;
+	}
+
+	$fh->write(dump_topics($state));
+	$opts{offset};
 }
 
 1;