From cf0a2370a57fe49d0fca149409f98d2907efeb15 Mon Sep 17 00:00:00 2001
From: Eric Wong <normalperson@yhbt.net>
Date: Mon, 24 Mar 2014 20:17:11 +0000
Subject: initial cut at Atom feed generation

This should make it easier for non-ssoma users to follow.
---
 lib/PublicInbox/Feed.pm | 186 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 186 insertions(+)
 create mode 100644 lib/PublicInbox/Feed.pm

(limited to 'lib')

diff --git a/lib/PublicInbox/Feed.pm b/lib/PublicInbox/Feed.pm
new file mode 100644
index 00000000..da877f3f
--- /dev/null
+++ b/lib/PublicInbox/Feed.pm
@@ -0,0 +1,186 @@
+# Copyright (C) 2013, Eric Wong <normalperson@yhbt.net> and all contributors
+# License: AGPLv3 or later (https://www.gnu.org/licenses/agpl-3.0.txt)
+package PublicInbox::Feed;
+use strict;
+use warnings;
+use XML::Atom::SimpleFeed;
+use Email::MIME;
+use Email::Address;
+use URI::Escape qw/uri_escape/;
+use Encode qw/encode decode/;
+use Encode::MIME::Header;
+use DateTime::Format::Mail;
+use CGI qw(escapeHTML);
+use POSIX qw(strftime);
+use constant DATEFMT => '%Y-%m-%dT%H:%M:%SZ';
+our $dt_parser = DateTime::Format::Mail->new(loose => 1);
+
+# main function
+sub generate {
+	my ($class, $git_dir, $max) = @_;
+	$max ||= 25;
+
+	local $ENV{GIT_DIR} = $git_dir;
+	my $feed_opts = get_feedopts();
+
+	my $feed = XML::Atom::SimpleFeed->new(
+		title => $feed_opts->{title},
+		link => $feed_opts->{url} || "http://example.com/",
+		link => {
+			rel => 'self',
+			href => $feed_opts->{atomUrl} ||
+				"http://example.com/atom",
+		},
+		id => $feed_opts->{email} || 'public-inbox@example.com',
+		updated => strftime(DATEFMT, gmtime),
+	);
+
+	my @entries;
+
+	# get recent messages
+	# we could use git log -z, but, we already know ssoma will not
+	# leave us with filenames with spaces in them..
+	my $cmd = "git log --no-color --raw -r --no-abbrev HEAD |";
+	my $pid = open my $log, $cmd or die "open `$cmd' pipe failed: $!\n";
+	my %deleted;
+	my $nr = 0;
+	foreach my $line (<$log>) {
+		if ($line =~ /^:000000 100644 0{40} ([a-f0-9]{40})/) {
+			my $add = $1;
+			next if $deleted{$add};
+			$nr += add_to_feed($feed_opts, $feed, $add);
+			last if $nr >= $max;
+		} elsif ($line =~ /^:100644 000000 ([a-f0-9]{40}) 0{40}/) {
+			$deleted{$1} = 1;
+		}
+	}
+	close $log;
+
+	$feed->as_string;
+}
+
+# private functions below
+sub get_feedopts {
+	my %rv;
+	foreach my $key (qw(title url atomUrl email)) {
+		my $tmp = `git config publicInboxFeed.$key`;
+		chomp $tmp;
+		$rv{$key} = $tmp;
+	}
+	\%rv;
+}
+
+sub utf8_header {
+	my ($mime, $name) = @_;
+	encode('utf8', decode('MIME-Header', $mime->header($name)));
+}
+
+sub feed_date {
+	my ($date) = @_;
+	my $dt = $dt_parser->parse_datetime($date);
+        $dt ? $dt->strftime(DATEFMT) : 0;
+}
+
+# returns 0 (skipped) or 1 (added)
+sub add_to_feed {
+	my ($feed_opts, $feed, $add) = @_;
+
+	# we can use git cat-file --batch if performance becomes a
+	# problem, but I doubt it...
+	my $str = `git cat-file blob $add`;
+	return 0 if $? != 0;
+	my $mime = Email::MIME->new($str);
+
+	my $content = msg_content($mime);
+	defined($content) or return 0;
+
+	my $mid_url = $feed_opts->{mid_url} || "http://example.com/mid/%s";
+	my $mid = utf8_header($mime, "Message-ID") or return 0;
+	$mid =~ s/\A<//;
+	$mid =~ s/>\z//;
+
+	my $subject = utf8_header($mime, "Subject") || "";
+	defined($subject) && length($subject) or return 0;
+
+	my $from = utf8_header($mime, "From") or return 0;
+
+	my @from = Email::Address->parse($from);
+	my $name = $from[0]->name;
+	defined $name or $name = "";
+	my $email = $from[0]->address;
+	defined $email or $email = "";
+
+	my $url = sprintf($mid_url, uri_escape($mid));
+	my $date = utf8_header($mime, "Date");
+	$date or return 0;
+	$date = feed_date($date) or return 0;
+	$feed->add_entry(
+		author => { name => $name, email => $email },
+		title => $subject,
+		updated => $date,
+		content => { type => "html", content => $content },
+		link => $url,
+		id => $add,
+	);
+	1;
+}
+
+# returns a plain-text message body without quoted text
+# returns undef if there was nothing
+sub msg_content {
+	my ($mime) = @_;
+	my $rv;
+
+	# scan through all parts, looking for displayable text
+	$mime->walk_parts(sub {
+		return if $rv;
+		my ($part) = @_;
+		return if $part->subparts; # walk_parts already recurses
+		my $ct = $part->content_type || 'text/plain';
+		return if $ct !~ m!\btext/[a-z0-9\+\._-]+\b!i;
+		my @body;
+		my $killed_wrote; # omit "So-and-so wrote:" line
+
+		# no quoted text in Atom feed summary
+		# $part->body should already be decoded for us (no QP)
+
+		my $state = 0; # 0: beginning, 1: keep, 2: quoted
+		foreach my $l (split(/\r?\n/, $part->body)) {
+			if ($state == 0) {
+				# drop leading blank lines
+				next if $l =~ /\A\s*\z/;
+
+				$state = ($l =~ /\A>/) ? 2 : 1; # fall-through
+			}
+			if ($state == 2) { # quoted text, drop it
+				if ($l !~ /\A>/) {
+					push @body, "<quoted text snipped>";
+					if ($l =~ /\S/) {
+						push @body, $l;
+					}
+					$state = 1;
+				}
+			}
+			if ($state == 1) { # stuff we may keep
+				if ($l =~ /\A>/) {
+					# drop "So-and-so wrote:" line
+					if (@body && !$killed_wrote &&
+					    $body[-1] =~ /:\z/) {
+						$killed_wrote = 1;
+						pop @body;
+					}
+					$state = 2;
+				} else {
+					push @body, $l;
+				}
+			}
+		}
+		$rv = "<pre>" .
+			join("\n", map { escapeHTML($_) } @body) .
+			"</pre>";
+	});
+
+	$rv;
+}
+
+1;
-- 
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