package SWISH::Filters::ODF2xml;
use strict;
use XML::Parser;
use Archive::Zip qw( :ERROR_CODES );

use vars qw/ $VERSION /;

$VERSION = '0.02';

# the file must be unzipped to extract these three files:
#	content.xml, meta.xml, and mimetype

my @parsed = ();

sub new {
    my ( $class ) = @_;

    my $self = bless {
        mimetypes   => [ 
	 qr!^application/vnd\.oasis\.opendocument\.text!,
	 qr!^application/vnd\.oasis\.opendocument\.text-template!,
	 qr!^application/vnd\.oasis\.opendocument\.spreadsheet!,
	 qr!^application/vnd\.oasis\.opendocument\.spreadsheet-template!,
	 qr!^application/vnd\.oasis\.opendocument\.presentation!,
	 qr!^application/vnd\.oasis\.opendocument\.presentation-template!,
	 qr!^application/vnd\.oasis\.opendocument\.text-master!,
	 qr!^application/vnd\.oasis\.opendocument\.text-web!,
	 qr!^application/vnd\.oasis\.opendocument\.graphics!,
	 qr!^application/vnd\.oasis\.opendocument\.graphics-template!,
	 qr!^application/vnd\.oasis\.opendocument\.chart!,
	 qr!^application/vnd\.oasis\.opendocument\.chart-template!,
	 qr!^application/vnd\.oasis\.opendocument\.image!,
	 qr!^application/vnd\.oasis\.opendocument\.image-template!,
	 qr!^application/vnd\.oasis\.opendocument\.formula!,
	 qr!^application/vnd\.oasis\.opendocument\.formula-template!,
	],
    }, $class;

    return $self->set_programs( 'unzip' );
}

sub filter {
    my ( $self, $doc ) = @_;

    open ( OUT, ">/tmp/x"); print OUT "YO\n",`date`,"\n"; close ( OUT );

    # We need a file name to pass to the conversion function
    my $file = $doc->fetch_filename;

    $doc->set_content_type( 'text/xml' );

    my ( $mimetype, $metadata, $content ) = &Unzip_file( $file );

    $mimetype = qq(<dc.format scheme="IMT">$mimetype</dc.format>);

    my $document = <<EOF;
<?xml version="1.0" encoding="utf-8"?>
<wrapper>$mimetype$metadata$content</wrapper>
EOF
#    open ( OUT, ">>/tmp/x"); print OUT $document; close ( OUT );

    return \$document;
}

sub Unzip_file {

    my ( $file ) = ( @_ );

    my $zip = Archive::Zip->new();
    die ('read error') unless ( $zip->read( $file ) == AZ_OK );

    my $content  = $zip->contents( 'content.xml' ) 
	or die ("Failed to extract content\n");

    $content = &Parse_XML ( $content, 0 );

    my $metadata = $zip->contents( 'meta.xml' ) or
	die ("Failed to extract metadata\n");

    $metadata = &Parse_XML ( $metadata, 1 );

    my $mimetype = $zip->contents( 'mimetype' ) or
	die ("Failed to extract mimetype\n");

#     open (OUT, ">>/tmp/x");print OUT qq(MIME===$mimetype\n\n);close(OUT);

    return ( $mimetype, $metadata, $content );

}

sub Parse_XML {
    my ( $xml, $meta ) = @_;

    @parsed = ();	# clear buffer

    my $p = XML::Parser->new();

    $p->setHandlers (
			 Comment => sub {''},
			 Proc    => sub {''},
			 Doctype => sub {''},
			 XMLDecl => sub {''},
			 End     => \&End,
			 Default => \&Default,
			 );

    $p->setHandlers(Start => \&Start_meta) if ( $meta );
    
    $p->parse ( $xml );

    return join('', @parsed);
}

sub Default {
    my $expat = shift; my $data = shift;

    push ( @parsed, $data );
}

sub Start {
    shift; my $element = shift;

    my $el = qq(<$element);
    my $attribute = ''; my $value = '';
    while ( $attribute = shift ) {
	$value = shift;
	$el .= qq( $attribute="$value");
    }
    $el .= qq(>);

    push ( @parsed, $el );
}

sub Start_meta {
    shift; my $element = shift;

    my %attr = ();
    my @element = ();

    my $attribute = ''; my $value = '';
    while ( $attribute = shift ) {
        $value = shift;
        push ( @element, qq( $attribute="$value") );
        $attr{$attribute} = $value;
    }
    push ( @element, qq(>) );

    if ( $element ne 'meta:user-defined' ) {
        unshift ( @element, qq(<$element) );    # all other metadata

    } else {
        $value = lc $attr{'meta:name'};         # user-defined metadata
        $value =~ s/\s/-/g;	
	$value =~ tr/-/-/s;
	
	if ( $value ) {
	    unshift ( @element, qq(<$value) );      #
	} else {
	    unshift ( @element, qq(<$element) );    # all other metadata
	}
    }

    push ( @parsed, join('', @element) );
}

sub End {
    shift; my $data = shift;
    push (@parsed, qq(</$data>));
}


1;
__END__

=head1 NAME

SWISH::Filters::ODF2xml - Perl extension for filtering OpenDocument v 1.0 documents with Swish-e

=head1 DESCRIPTION

This plug-in module uses the Archive::Zip and XML::Parser modules from CPAN to convert OpenDocument to a flat XML stream for indexing by Swish-e.  

Three parts (mimetype, meta.xml, and content.xml) are extracted and processed.

=head2 METADATA

The MetaNameAlias directive must be used in swish.conf to index the 
document titles and other metadata properly.  e.g:

    MetaNameAlias swishtitle dc:title
    MetaNameAlias keyword meta:keyword dc:subject
    MetaNameAlias swishdescription dc:description

Any user-defined metadata should also be mapped with MetaNameAlias if needed.
For example, if field "Info 1" is renamed "DC:Creator" then it will be parsed as "dc:creator" and need to be recognized in swish.conf

=head1 AUTHOR

Lars Noodén

=head1 SEE ALSO

<SWISH::Filter>