# plugin which process an HTML book directory

package GMLPlug;

use html;
use BasPlug;
use util;
use doc;


sub BEGIN {
    @ISA = ('BasPlug');
}

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

    return bless $self, $class;
}

sub is_recursive {
    my $self = shift (@_);

    return 0; # this is not a recursive plugin
}

sub _unescape_text {
    my ($text) = @_;

    # special characters in the gml encoding
    $text =~ s/&lt;/</g;
    $text =~ s/&gt;/>/g;
    $text =~ s/&quot;/\"/g;
    $text =~ s/&amp;/&/g; # this has to be last...

    return $text;
}

# return number of files processed, undef if can't process
# Note that $base_dir might be "" and that $file might 
# include directories
sub read {
    my $self = shift (@_);
    my ($pluginfo, $base_dir, $file, $metadata, $processor) = @_;
    my $fullname = &util::filename_cat ($base_dir, $file);

    # see if this is a gml book
    return undef unless (-f $fullname && $fullname =~ /\.gml$/i);

    my ($parent_dir) = $fullname =~ /^(.*)\/[^\/]+.gml$/;

    # create a new document
    my $doc_obj = new doc ();
    my $section = $doc_obj->get_top_section();

    print STDERR "GMLPlug: processing $file\n";

    # read in the document
    my $gml = "";
    my $line = "";
    if (!open (INFILE, $fullname)) {
	print STDERR "GMLPlug::read - couldn't read $fullname\n";
	return undef;
    }
    while (defined ($line = <INFILE>)) {
	$gml .= $line;
    }
    close (INFILE);

    # process the document
    my $firstsection = 1;
    while ($gml =~ /\S/) {
	if ($gml =~ s/^\s*<gsdlsection([^>]*)>(.*?)(<\/?gsdlsection)/$3/is) {
	    my $tags = $1;
	    $tags = "" unless defined $tags;
	    my $text = &_unescape_text($2);

	    # create the section (unless this is the first section)
	    if (!$firstsection) {
		$tags =~ s/gsdlnum\s*=\s*\"?(\d+)\"?//i;
		if (defined $1) {
		    $section .= ".$1";
		    $doc_obj->create_named_section($section);
		} else {
		    $section = $doc_obj->insert_section($doc_obj->get_end_child($section));
		}
	    }
	    $firstsection = 0;

	    # add the tags
	    while ((defined $tags) && ($tags =~ s/^\s*(\w+)\s*=\s*\"([^\"]*)\"//)) {
		$doc_obj->add_utf8_metadata($section, $1 , &_unescape_text($2)) 
		    if (defined $1 and defined $2);
	    }

	    # add the text
	    $doc_obj->add_utf8_text($section, $text) 
		if ((defined $text) && ($text ne ""));

	} elsif ($gml =~ s/^\s*<\/gsdlsection>//) {
	    $section = $doc_obj->get_parent_section ($section);

	} else {
	    print STDERR "GMLPlug::read - error in file $fullname\n";
	    print STDERR "text: \"$gml\"\n";
	    last;
	}
    }

    # add the associated files
    $assoc_files = $doc_obj->get_metadata($doc_obj->get_top_section(), "gsdlassocfile");
    my ($assoc_file_info);
    foreach $assoc_file_info (@$assoc_files) {
	my ($assoc_file, $mime_type) = split (":", $assoc_file_info);
	$doc_obj->associate_file(&util::filename_cat($parent_dir, $assoc_file),
				 $assoc_file, $mime_type);
				 
    }
    $doc_obj->delete_metadata($doc_obj->get_top_section(), "gsdlassocfile");

    # add metadata
    foreach $field (keys(%$metadata)) {
	# $metadata->{$field} may be an array reference
	if (ref ($metadata->{$field}) eq "ARRAY") {
	    map { 
		$doc_obj->add_metadata ($doc_obj->get_top_section(), $field, $_); 
	    } @{$metadata->{$field}};
	} else {
	    $doc_obj->add_metadata ($doc_obj->get_top_section(), $field, $metadata->{$field}); 
	}
    }


    # assume the document has an OID

    # process the document
    $processor->process($doc_obj, $file);
        
    return 1; # processed the file
}


1;