###########################################################################
#
# BNContentePlug.pm -- plugin for import the BN-Portugal Collection
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the 
# University of Waikato, New Zealand.
#
# Copyright (C) 1999 New Zealand Digital Library Project
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
###########################################################################

# BNContentePlug - 11/2004
# 
#
# This plugin takes "mets.xml" and "record/NCB_***.xml: the file contain MARC details
# about BN-Portugal ccllection. The intension is to import such a collection into GS2.

package BNContentePlug;

use BasPlug;
use plugin;
#use ghtml;
use XMLParser;
use XML::Parser;

sub BEGIN {
    @ISA = ('BasPlug');
    unshift (@INC, "$ENV{'GSDLHOME'}/perllib/cpan");
}

my $arguments =
    [ { 'name' => "process_exp",
	'desc' => "{BasPlug.process_exp}",
	'type' => "string",
	'deft' => &get_default_process_exp(),
	'reqd' => "no" },
      { 'name' => "only_first_doc",
	'desc' => "{BNContentePlug.only_first_doc}",
	'type' => "flag",
	'reqd' => "no" },
      { 'name' => "first_inoder_ext",
	'desc' => "{BNContentePlug.first_inorder_ext}",
	'type' => "flag",
	'reqd' => "no" },
      { 'name' => "first_inorder_mime",
	'desc' => "{BNContentePlug.first_inorder_mime}",
	'type' => "flag",
	'reqd' => "no" },
      { 'name' => "block_exp",
	'desc' => "{BasPlug.block_exp}",
	'type' => "string",
	'deft' => &get_default_block_exp(),
	'reqd' => "no" }];

my $options = { 'name'     => "BNContentePlug",
		'desc'     => "{BNContentePlug.desc}",
		'inherits' => "yes",
		'args'     => $arguments };

# Important variation to regular plugin structure.  Need to desclare
# $self as global variable to file so XMLParser callback routines
# can access the content of the object. 
my ($self); 

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

    return q^(?i)(metsHTML\.xml)$^;
}

# block files
sub get_default_block_exp {
    my $self = shift (@_);
    
    # Block all files besides contents
    #return q^(?i)(metsHTML\.xml|)$^;
    return q^(?i)((.*?)\.(.*?))$^;
}

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

    $self = new BasPlug ($class, @_);
    $self->{'plugin_type'} = "BNContentePlug";

    my $option_list = $self->{'option_list'};
    push( @{$option_list}, $options );
 
    if (!parsargv::parse(\@_,
			 "allow_extra_options")) {
	print STDERR "\nBNContentePlug uses an incorrect option.\n";
	print STDERR "Check your collect.cfg configuration file.\n\n";
	$self->print_txt_usage("");  # Use default resource bundle
	die "\n";
    }
    
    #create XML::Parser object for parsing metsHTML.xml, NCB_???.xml files
    my $mets_parser = new XML::Parser('Style' => 'Stream',
				      'Handlers' => {'Doctype' => \&METS_Doctype,
						     'Start' => \&METS_StartTag,
						     'End' => \&METS_EndTag
						     });
    
    my $marc_parser = new XML::Parser('Style' => 'Stream',
				      'Handlers' => {'Char' => \&Char,
						     'Doctype' => \&MARC_Doctype,
						     'Start' => \&MARC_StartTag,
						     'End' => \&MARC_EndTag
						     });
    $self->{'mets_parser'} = $mets_parser;
    $self->{'marc_parser'} = $marc_parser;

    $self->{'index_file'} = "";

    return bless $self, $class;
}

sub read_marc_content {
    my $self = shift (@_);
    my ($marc_file) = @_;
    
    # parse the Marc_file: NCB_???.xml
    eval{
	$self->{'marc_parser'}->parsefile($marc_file);
    };
    
    if ($@) {
	die "BNContentePlug: ERROR $marc_file is not a well formed XML file ($@)\n";
    }  
}

# Read metsHTML.xml from BN-Portugal collection 
sub metadata_read {
    my $self = shift (@_);
    my ($pluginfo, $base_dir, $file, $metadata, $extrametakeys, $extrametadata, $processor, $maxdocs) = @_;

    my $outhandle = $self->{'outhandle'};
    
    my $filename = &util::filename_cat($base_dir, $file);

    if ($filename !~ /metsHTML\.xml$/ || !-f $filename) {
	if ($filename =~ /\.xml$/i || $filename =~ /log\.txt$/i || $filename =~ /isbd\.html$/i) {
	    $self->{'file_blocks'}->{$filename}=1;
	}
	return undef;
    } else {
	$self->{'file_blocks'}->{$filename}=1;	
    }
  
    print $outhandle "BNContentePlug: extracting metadata from $filename\n"
	if $self->{'verbosity'} > 1;
   
    my ($dir) = $filename =~ /^(.*?)[^\/\\]*$/;
    $self->{'dir'} = $dir;

    eval {
	$self->{'mets_parser'}->parsefile($filename);
    };
    
    if ($@) {
	die "BNContentePlug: ERROR $filename is not a well formed XML file ($@)\n";
    }
    
    # read NCB_???.xml to parse MARC records and save as metadata
    my $marc_file = &util::filename_cat($dir,$self->{'marc_file'});
    $self->read_marc_content ($marc_file);

    if (defined $self->{'index_file'} && $self->{'index_file'} ne "") {
	my $index_file = $self->{'index_file'};
	push(@$extrametakeys,$index_file);
	$extrametadata->{$index_file} = $self->{'saved_metadata'};
    } else {
	print STDERR "####Warning can't find main index file\n";
    }
    return 1;
}

# The BNContentePlug read() function. This function does all the right things
# to make general options work for a given plugin. It calls the process()
# function which does all the work specific to a plugin (like the old
# read functions used to do). Most plugins should define their own 
# process() function and let this read() function keep control.
#
# Return number of files processed, undef if can't process
# Note that $base_dir might be "" and that $file might 
# include directories

sub readxxx {
    my $self = shift (@_);
    my ($pluginfo, $base_dir, $file, $metadata, $processor, $maxdocs) = @_;
    my $outhandle = $self->{'outhandle'};
    
    my $filename = &util::filename_cat($base_dir, $file);
    #return 0 if $self->{'block_exp'} ne "" && $filename =~ /$self->{'block_exp'}/;
    
    #return 0 if ($filename =~ /metsHTML\.xml$/);
    return 0 if ($filename =~ /\.xml$/);
    return 0 if (defined $self->{'file_blocks'}->{'filename'});
    
    return undef;
}

# do plugin specific processing of doc_obj
sub process {
    my $self = shift (@_);
    my ($textref, $pluginfo, $base_dir, $file, $metadata, $doc_obj) = @_;
    my $outhandle = $self->{'outhandle'};
    
    return 1;
}

sub METS_Doctype {
    my ($expat, $name, $sysid, $pubid, $internal) = @_;
    die if ($name !~ /^metsHTML\.xml$/);
}

sub MARC_Doctype {
    my ($expat, $name, $sysid, $pubid, $internal) = @_;
    print STDERR "###MARC Name =$name\n";
    #die if ($name !~ /^metsHTML\.xml$/);
    #die if (!$name);
}

sub METS_StartTag {
    my ($expat, $element, %attr) = @_;
    my @file_blocks;
    if ($element eq "dmdSec") {
	$self->{'marc_file'} = "";
    } elsif ($element eq "mdRef") {
	my $marc_href = $attr{'xlink:href'};
	$self->{'marc_file'} = $marc_href;
    } elsif ($element eq "FLocat"){
 	my $assocfiles = $attr{'xlink:href'};
 	if ($assocfiles =~ /index\.html$/) {
 	    my $index_file = &util::filename_cat($self->{'dir'}, $assocfiles);
 	    $self->{'index_file'} = $index_file;
 	} else {
	    my $link = &util::filename_cat($self->{'dir'}, $assocfiles);
	    #$self->{'file_blocks'}->{$link} = 1;
	}
    }
}

sub METS_EndTag {
    my ($expat, $element, %attr) = @_;
}

sub MARC_StartTag {
    my ($expat, $element, %attr) = @_;

    if ($element eq "record") {
	$self->{'saved_metadata'} = {};
    }
    elsif ($element eq "datafield") {
	$self->{'metaname'} = $element;
	$self->{'datafield'} = $attr{'tag'};
    }
    elsif ($element eq "subfield") {
	$self->{'subfield'} = $attr{'code'};
	$self->{'text'} = "";
    }
}

sub MARC_EndTag {
    my ($expat, $element) = @_;

    if ($element eq "datafield") {
	$self->{'metaname'} = "";
    }
    elsif ($element eq "subfield") {
	my $mvalue = $self->{'text'};
	my $mname = $self->{'datafield'}."^".$self->{'subfield'};
	#print STDERR "**** $mname = $mvalue\n";
	
	$mvalue =~ s/\[/&\#91;/g;
	$mvalue =~ s/\[/&\#93;/g;
	

	if (defined $self->{'saved_metadata'}->{$mname}) {
	    # accumulate - add value to existing value(s)
	    if (ref ($self->{'saved_metadata'}->{$mname}) eq "ARRAY") {
		push (@{$self->{'saved_metadata'}->{$mname}}, $mvalue);
	    } else {
		$self->{'saved_metadata'}->{$mname} = 
		    [$self->{'saved_metadata'}->{$mname}, $mvalue];
	    }
	} else {
	    # accumulate - add value into (currently empty) array
	    $self->{'saved_metadata'}->{$mname} = [$mvalue];
	}
	# store something here 
	$self->{'subfield'} = "";
	$self->{'text'} = "";
    }

}


# This Char function overrides the one in XML::Parser::Stream to overcome a
# problem where $expat->{Text} is treated as the return value, slowing
# things down significantly in some cases.
sub Char {
    $_[0]->{'Text'} .= $_[1];
    if ((defined $self->{'subfield'} && ($self->{'subfield'} ne ""))) {
	$self->{'text'} .= $_[1];
    }
    return undef;
}

1;