Mail::Folder::NNTP - An NNTP folder interface for Mail::Folder.

# -*-perl-*-
#
# Copyright (c) 1997-1998 Kevin Johnson <kjj@pobox.com>.
#
# All rights reserved. This program is free software; you can
# redistribute it and/or modify it under the same terms as Perl
# itself.
#
# $Id: NNTP.pm,v 1.3 1998/04/05 17:21:53 kjj Exp $

require 5.00397;
package Mail::Folder::NNTP;
use strict;
use vars qw($VERSION @ISA);
use Net::NNTP;
use Mail::Header;

@ISA = qw(Mail::Folder);
$VERSION = '0.07';

Mail::Folder->register_type('news');

use Mail::Folder;
use Mail::Internet;
use Mail::Header;
use MIME::Head;

use Carp;

sub open {
  my $self = shift;
  my $foldername = shift;

  return 0 unless $self->SUPER::open($foldername);

  is_valid_folder_format($foldername)
    or croak "$foldername isn't valid for an news folder";

  # these two extractions should never be fatal since is_valid_folder_format
  # should have detected any structural problems with the folder name
  $self->{NNTP_Host} = _extract_hostname($foldername)
    or croak "can't extract hostname from $foldername";
  $self->{NNTP_Newsgroup} = _extract_newsgroup_name($foldername)
    or croak "can't extract newsgroup from $foldername";

  my $timeout = $self->get_option('Timeout');
  $timeout ||= 120;		# default it if no Timeout option specified
  $self->{NNTP_Connection} = new Net::NNTP($self->{NNTP_Host},
					   Timeout => $timeout)
    or return 0;

  return 0 if (!defined($self->_absorb_folder($foldername)));

  $self->current_message($self->first_message);

  return 1;
}

sub close {
  my $self = shift;

  $self->{NNTP_Connection}->quit;
  return $self->SUPER::close;
}

sub sync {
  my $self = shift;

  return 0;
}

sub pack {
  my $self = shift;

  return 1;
}

sub get_message {
  my $self = shift;
  my $key = shift;

  return undef unless $self->SUPER::get_message($key);

  my $article = $self->{NNTP_Connection}->article($key)
    or return undef;

  my $mref = new Mail::Internet($article,
				Modify => 0)
    or return undef;

  my $href = $mref->head;
  $self->cache_header($key, $href);
  $self->add_label($key, 'seen');

  return $mref;
}

sub get_message_file {
  my $self = shift;
  my $key = shift;

  return undef;
}

sub get_header {
  my $self = shift;
  my $key = shift;

  my $hdr = $self->SUPER::get_header($key);
  return $hdr if defined($hdr);

  # return undef unless ($self->SUPER::get_header($key));

  # return $self->{Messages}{$key}{Header} if ($self->{Messages}{$key}{Header});

  if (my $header = $self->{NNTP_Connection}->head($key)) {
    my $href = new Mail::Header($header, Modify => 0) or return undef;
    $self->cache_header($key, $href);
    return $href;
  }

  return undef;
}

sub append_message {
  my $self = shift;
  my $mref = shift;

  return 0;
}

sub update_message {
  my $self = shift;
  my $key = shift;
  my $mref = shift;

  return 0;
}

sub is_valid_folder_format($foldername) {
  my $foldername = shift;

  return (($foldername =~ /^news:\/\//) ||
	  (($foldername =~ /^\#news:/) && defined($ENV{NNTPSERVER})));
}

sub create {
  my $self = shift;
  my $foldername = shift;

  return 0;
}
###############################################################################
sub _absorb_folder {
  my $self = shift;
  my $foldername = shift;

  my $qty_new_articles = 0;

  my @group = $self->{NNTP_Connection}->group($self->{NNTP_Newsgroup})
    or return undef;

  for my $msg ($group[1] .. $group[2]) {
    next if defined($self->{Messages}{$msg});
    $self->remember_message($msg);
    $self->get_header($msg);
    $qty_new_articles++;
  }

  return $qty_new_articles;
}

sub _extract_hostname {
  my $foldername = shift;

  return $1 if ($foldername =~ /^news:\/\/([^\/]+)\//);
  return $ENV{NNTPSERVER} if ($foldername =~ /^\#news:/);
  return undef;
}

sub _extract_newsgroup_name {
  my $foldername = shift;

  return $1 if ($foldername =~ /^news:\/\/[^\/]+\/(.+)$/);
  return $1 if ($foldername =~ /^\#news:(.*)$/);
  return undef;
}
###############################################################################

1;