#! /usr/bin/perl -w
use strict;

my $server="mailserver2002";   # NNTP server
my $group="frontier.misc";     # group
my $summarylength = 60;        # maximum summary length, in characters
my $since = 24*60*60;          # retrieve messages up to this many seconds ago
my $appendCGIheader = 1;       # append CGI header?


# -------------------
my $CRLF = "\015\012";

sub QuoteHtml 
{
  my ($html) = @_;

  $html =~ s/&/&/g;
  $html =~ s/</&lt;/g;
  $html =~ s/>/&gt;/g;
  if (1) {   # Make an official option?
    $html =~ s/&amp;([#a-zA-Z0-9]+);/&$1;/g;  # Allow character references
  }
  $html =~ s/[\x80-\xFF]//g;
  return $html;
}


use Net::NNTP;

my $nntp = Net::NNTP->new($server);
my $timenow = $nntp->date();

$nntp->group($group);
my $msgids = $nntp->newnews($timenow - $since);

if($appendCGIheader)
{
  print "Content-Type: text/xml".$CRLF.$CRLF;
}

print <<HEADER
<?xml version="1.0"?>
<rss version="2.0">

<channel>
<title>$group</title>
<link>news:$group</link>
<description>RSS feed of newsgroup $group on $server.</description>
<generator>nntp2rss.pl (moonshadow at toothycat.net)</generator>

HEADER
;

foreach my $msgid(@$msgids)
{
  my $header = $nntp->head($msgid);
  my $body = $nntp->body($msgid);

  my $date='';
  my $subject='';

  my $summary = '';

  # Join up body. Attempt to cull quoted text.
  foreach my $line(@$body)
  {
    if(($line =~ /^\>/) || ($line =~ /\> wrote in message/))
	{
	  # $summary .= '.';
	}
	else
	{
	  $summary .= $line;
	}
  }

  # Cull line breaks.
  $summary =~ s/\r//g;
  $summary =~ s/\n/ /g;

  # Trim to maximum length.
  if((length $summary) > $summarylength)
  {
    $summary = substr($summary, 0, $summarylength-3) . '...';
  }

  # Cull illegal chars
  $summary = &QuoteHtml($summary);

  foreach my $headerline(@$header)
  {
	$headerline = &QuoteHtml($headerline);

    if ($headerline =~ /^Date: (.+)/)
	{
	  $date = $1;
	}
	elsif ($headerline =~ /^Subject: (.+)/)
	{
	  $subject = $1;
	}
  }

  print "<item>\n <title>$subject</title>\n <pubDate>$date</pubDate>\n <description>$summary</description>\n</item>\n\n";
}

print "</channel></rss>";

$nntp->quit;