package Yuki::RSS;
use strict;
use vars qw($VERSION);

$VERSION = '0.2';

=head1 NAME

Yuki::RSS - The smallest module to generate RSS 1.0. 
It is downward compatible to XML::RSS.

=head1 SYNOPSIS

    use strict;
    use Yuki::RSS;

    my $rss = new Yuki::RSS(
        version => '1.0',
        encoding => 'Shift_JIS'
    );

    $rss->channel(
        title => "Site Title",
        link => "http://url.of.your.site/",
        description  => "The description of your site",
    );

    $rss->add_item(
        title => "Item Title",
        link => "http://url.of.your/item.html",
        description => "Yoo, hoo, hoo",
    );

    print $rss->as_string;

=head1 DESCRIPTION

Yuki::RSS is the smallest RSS 1.0 generator.
This module helps you to create the minimum document of RSS 1.0.
If you need more than that, use XML::RSS.

=head1 METHODS

=over 4

=item new Yuki::RSS (version => $version, encoding => $encoding)

Constructor for Yuki::RSS.
It returns a reference to a Yuki::RSS object.
B<version> must be 1.0.
B<encoding> will be inserted output document as a XML encoding.
This module does not convert to this encoding.

=item add_item (title => $title, link => $link, description => $description)

Adds an item to the Yuki::RSS object.

=item as_string

Returns the RSS string.

=item channel (title => $title, link => $link, description => $desc)

Channel information of RSS.

=head1 SEE ALSO

=over 4

=item L<XML::RSS>

=back

=head1 AUTHOR

Hiroshi Yuki <hyuki@hyuki.com> http://www.hyuki.com/

=head1 LICENSE

Copyright (C) 2001 by Hiroshi Yuki.

This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

=cut

# The constructor.
sub new {
    my ($class, %hash) = @_;
    my $self = {
        version => $hash{version},
        encoding => $hash{encoding},
        channel => { },
        items => [],
    };
    return bless $self, $class;
}

# Setting channel.
sub channel {
    my ($self, %hash) = @_;
    foreach (keys %hash) {
        $self->{channel}->{$_} = $hash{$_};
    }
    return $self->{channel};
}

# Adding item.
sub add_item {
    my ($self, %hash) = @_;
    push(@{$self->{items}}, \%hash);
    return $self->{items};
}

sub stylesheet ($%) {
  my $self = shift;
  $self->{stylesheet} = {@_};
}

# 
sub as_string {
    my ($self) = @_;
    unless ($self->{channel}->{'dc:date'}) {
      $self->{channel}->{'dc:date'} = _rfc3339_date (time);
    } else {
      $self->{channel}->{'dc:date'} = _rfc3339_date ($self->{channel}->{'dc:date'});
    }
    my $doc = <<"EOD";
<?xml version="1.0" encoding="$self->{encoding}" ?>
@{[ ref ($self->{stylesheet}) ?
  '<?xml-stylesheet '.(join (' ', map {qq($_="@{[&_escape($self->{stylesheet}->{$_})]}")} keys %{$self->{stylesheet}})).'?>':''
]}
<rdf:RDF
 xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
 xmlns="http://purl.org/rss/1.0/"
 xmlns:dc="http://purl.org/dc/elements/1.1/"
>

<channel rdf:about="@{[&_escape($self->{channel}->{link})]}">
 <title>@{[&_escape($self->{channel}->{title})]}</title>
 <link>@{[&_escape($self->{channel}->{link})]}</link>
 <description>@{[&_escape($self->{channel}->{description})]}</description>
 <dc:language>@{[&_escape($self->{channel}->{'dc:language'})]}</dc:language>
 <dc:date>$self->{channel}->{'dc:date'}</dc:date>
 <items>
  <rdf:Seq>
   @{[
    map {
     qq{<rdf:li rdf:resource="@{[&_escape($_->{link})]}" />}
    } @{$self->{items}}
   ]}
  </rdf:Seq>
 </items>
</channel>
@{[
 map { do {
  my $r = qq{<item rdf:about="@{[&_escape($_->{link})]}">\n};
  for my $element (keys %{$_}) {
    my $c = $_->{$element};
    $c = _rfc3339_date ($c) if $element eq 'dc:date';
    $r .= qq{	<$element>@{[&_escape($c)]}</$element>\n};
  }
  $r . "</item>\n";
 }} @{$self->{items}}
]}
</rdf:RDF>
EOD
}

sub _escape {
    my $s = shift;
    $s =~ s|&|&amp;|g;
    $s =~ s|<|&lt;|g;
    $s =~ s|>|&gt;|g;
    $s =~ s|"|&quot;|g;
    return $s;
}

sub _rfc3339_date ($) {
  my @time = gmtime (shift);
  sprintf '%04d-%02d-%02dT%02d:%02d:%02d+00:00', $time[5]+1900,$time[4]+1,@time[3,2,1,0];
}

1; # $Date: 2003/01/01 11:48:28 $