source: gsdl/trunk/perllib/plugins/ISISPlugin.pm@ 16935

###########################################################################
#
# ISISPlugin.pm -- A plugin for CDS/ISIS databases
#
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the 
# University of Waikato, New Zealand.
#
# Copyright 1999-2004 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.
#
###########################################################################

package ISISPlugin;


use multiread;
use SplitTextFile;

use strict;
no strict 'refs'; # allow filehandles to be variables and viceversa

# ISISPlugin is a sub-class of SplitTextFile.
sub BEGIN {
    @ISISPlugin::ISA = ('SplitTextFile');
}


my $arguments = 
    [ { 'name' => "process_exp",
    'desc' => "{BasePlugin.process_exp}",
    'type' => "regexp",
    'reqd' => "no",
    'deft' => &get_default_process_exp() },
      { 'name' => "block_exp",
    'desc' => "{BasePlugin.block_exp}",
    'type' => "regexp",
    'reqd' => "no",
    'deft' => &get_default_block_exp(),
    'hiddengli' => "yes" },
      { 'name' => "split_exp",
    'desc' => "{SplitTextFile.split_exp}",
    'type' => "regexp",
    'reqd' => "no",
    'deft' => &get_default_split_exp(),
        'hiddengli' => "yes" },

      # The interesting options
      { 'name' => "entry_separator",
    'desc' => "{ISISPlugin.entry_separator}",
    'type' => "string",
    'reqd' => "no",
    'deft' => "<br>" },
      { 'name' => "subfield_separator",
    'desc' => "{ISISPlugin.subfield_separator}",
    'type' => "string",
    'reqd' => "no",
    'deft' => ", " }
      ];

my $options = { 'name'     => "ISISPlugin",
        'desc'     => "{ISISPlugin.desc}",
        'abstract' => "no",
        'inherits' => "yes",
        'explodes' => "yes",
        'args'     => $arguments };


# This plugin processes files with the suffix ".mst"
sub get_default_process_exp {
    return q^(?i)(\.mst)$^;
}


# This plugin blocks files with the suffix ".fdt" and ".xrf"
sub get_default_block_exp {
    #return q^(?i)(\.fdt|\.xrf)$^;
    return "";
}

    
# This plugin splits the input text at the "----------" lines
sub get_default_split_exp {
    return q^\r?\n----------\r?\n^;
}


sub new
{
    my ($class) = shift (@_);
    my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
    push(@$pluginlist, $class);

    push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
    push(@{$hashArgOptLists->{"OptList"}},$options);

    my $self = new SplitTextFile($pluginlist, $inputargs, $hashArgOptLists);

    if ($self->{'info_only'}) {
    # don't worry about any options etc
    return bless $self, $class;
    }

    # isis plug doesn't care about encoding - it assumes ascii unless the user
    # has specified an encoding
    if ($self->{'input_encoding'} eq "auto") {
    $self->{'input_encoding'} = "ascii";
    }
    return bless $self, $class;
}

# we block the corresponding fdt and xrf
sub store_block_files {
    
    my $self =shift (@_);
    my ($filename_full_path, $block_hash) = @_;
    
    $self->check_auxiliary_files($filename_full_path);
    if (-e $self->{'fdt_file_path'}) {
    my $fdt_file = $self->{'fdt_file_path'};
    $block_hash->{'file_blocks'}->{$fdt_file} = 1;
    }
    if (-e $self->{'xrf_file_path'}) {
    my $xrf_file = $self->{'xrf_file_path'};
    $block_hash->{'file_blocks'}->{$xrf_file} = 1;
    }
    

}

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

    my ($database_file_path_root) = ($filename =~ /(.*)\.mst$/i);
    # Check the associated .fdt and .xrf files exist
    $self->{'fdt_file_path'} = $database_file_path_root . ".FDT";
    if (!-e $self->{'fdt_file_path'}) {
    $self->{'fdt_file_path'} = $database_file_path_root . ".fdt";
    }
    $self->{'xrf_file_path'} = $database_file_path_root . ".XRF";
    if (!-e $self->{'xrf_file_path'}) {
    $self->{'xrf_file_path'} = $database_file_path_root . ".xrf";
    }
}
    

sub read_file
{
    my $self = shift (@_);
    my ($filename, $encoding, $language, $textref) = @_;
    my $outhandle = $self->{'outhandle'};

    my ($database_file_path_root) = ($filename =~ /(.*)\.mst$/i);
    my $mst_file_path_relative = $filename;
    $mst_file_path_relative =~ s/^.+import.(.*?)$/$1/;

    # Check the associated .fdt and .xrf files exist
    $self->check_auxiliary_files($filename);
    
    if (!-e $self->{'fdt_file_path'}) {
    print STDERR "<ProcessingError n='$mst_file_path_relative' r='Could not find ISIS FDT file $self->{'fdt_file_path'}'>\n" if ($self->{'gli'});
    print $outhandle "Error: Could not find ISIS FDT file " . $self->{'fdt_file_path'} . ".\n";
    return;
    }
    if (!-e $self->{'xrf_file_path'}) {
    print STDERR "<ProcessingError n='$mst_file_path_relative' r='Could not find ISIS XRF file $self->{'xrf_file_path'}'>\n" if ($self->{'gli'});
    print $outhandle "Error: Could not find ISIS XRF file " . $self->{'xrf_file_path'} . ".\n";
    return;
    }

    # The text to split is exported from the database by the IsisGdl program
    open(FILE, "IsisGdl \"$filename\" |");

    my $reader = new multiread();
    $reader->set_handle('ISISPlugin::FILE');
    $reader->set_encoding($encoding);
    $reader->read_file($textref);

    close(FILE);

    # Parse the associated ISIS database Field Definition Table file (.fdt)
    my %fdt_mapping = &parse_field_definition_table($self->{'fdt_file_path'}, $encoding);
    $self->{'fdt_mapping'} = \%fdt_mapping;

    # Remove the line at the start, and any blank lines, so the data is split and processed properly
    $$textref =~ s/^----------\n//;
    $$textref =~ s/\n\n/\n/g;
}


sub process
{
    my $self = shift (@_);
    my ($textref, $pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli) = @_;
    my $outhandle = $self->{'outhandle'};

    my $section = $doc_obj->get_top_section();
    my $fdt_mapping = $self->{'fdt_mapping'};
    my $subfield_separator = $self->{'subfield_separator'};
    my $entry_separator = $self->{'entry_separator'};
    my $isis_record_html_metadata_value = "<table cellpadding=\"4\" cellspacing=\"0\">";

    # Process each line of the ISIS record, one at a time
    foreach my $line (split(/\n/, $$textref)) {
    $line =~ s/(\s*)$//;  # Remove any nasty whitespace (very important for Windows)
    $line =~ /^tag=(.*) data=(.+)$/;
    my $tag = $1;
    my $tag_data = $2;
        # print STDERR "\nTag: $tag, Data: $tag_data\n";

    # Convert the tag number into a name, and remove any invalid characters
    my $raw_metadata_name = $fdt_mapping->{$tag}{'name'} || "";
    $raw_metadata_name =~ s/[,&\#\.\-\/]/ /g;
    next if ($raw_metadata_name eq "");

    # Metadata field names: title case, then remove spaces
    my $metadata_name = "";
    foreach my $word (split(/\s+/, $raw_metadata_name)) {
        substr($word, 0, 1) =~ tr/a-z/A-Z/;
        $metadata_name .= $word;
    }

    my $all_metadata_name = $metadata_name . "^all";
    my $all_metadata_value = "";

    # Handle repeatable fields
    if ($fdt_mapping->{$tag}{'repeatable'}) {
        # Multiple values are separated using the '%' character
        foreach my $raw_metadata_value (split(/%/, $tag_data)) {
        my $metadata_value = "";

        # Handle subfields
        while ($raw_metadata_value ne "") {
            # If there is a subfield specifier, parse it off
            my $sub_metadata_name = $metadata_name;
            if ($raw_metadata_value =~ s/^\^// && $raw_metadata_value =~ s/^([a-z])//) {
            $sub_metadata_name .= "^$1";
            }

            # Parse the value off and add it as metadata
            $raw_metadata_value =~ s/^([^\^]*)//;
            my $sub_metadata_value = &escape_metadata_value($1);

            # print STDERR "Sub metadata name: $sub_metadata_name, value: $sub_metadata_value\n";
            if ($sub_metadata_name ne $metadata_name) {
            $doc_obj->add_utf8_metadata($section, $sub_metadata_name, $sub_metadata_value); 
            }

            # If this tag has subfields and this is the first, use the value for the CDS/ISIS ^* field
            if ($fdt_mapping->{$tag}{'subfields'} ne "" && $metadata_value eq "") {
            $doc_obj->add_utf8_metadata($section, $metadata_name . "^*", $sub_metadata_value); 
            }

            $metadata_value .= $subfield_separator unless ($metadata_value eq "");
            $metadata_value .= $sub_metadata_value;
        }

        # Add the metadata value
        # print STDERR "Metadata name: $metadata_name, value: $metadata_value\n";
        $doc_obj->add_utf8_metadata($section, $metadata_name, $metadata_value); 

        $all_metadata_value .= $entry_separator unless ($all_metadata_value eq "");
        $all_metadata_value .= $metadata_value;
        }
    }

    # Handle non-repeatable fields
    else {
        my $raw_metadata_value = $tag_data;
        my $metadata_value = "";

        # Handle subfields
        while ($raw_metadata_value ne "") {
        # If there is a subfield specifier, parse it off
        my $sub_metadata_name = $metadata_name;
        if ($raw_metadata_value =~ s/^\^// && $raw_metadata_value =~ s/^([a-z])//) {
            $sub_metadata_name .= "^$1";
        }

        # Parse the value off and add it as metadata
        $raw_metadata_value =~ s/^([^\^]*)//;
        my $sub_metadata_value = $1;

        # Deal with the case when multiple values are specified using <...>
        if ($sub_metadata_value =~ /\<(.+)\>/) {
            my $sub_sub_metadata_name = $sub_metadata_name . "^sub";
            my $tmp_sub_metadata_value = $sub_metadata_value;
            while ($tmp_sub_metadata_value =~ s/\<(.+?)\>//) {
            my $sub_sub_metadata_value = $1;
            $doc_obj->add_utf8_metadata($section, $sub_sub_metadata_name, $sub_sub_metadata_value); 
            }
        }
        # Deal with the legacy case when multiple values are specified using /.../
        elsif ($sub_metadata_value =~ /\/(.+)\//) {
            my $sub_sub_metadata_name = $sub_metadata_name . "^sub";
            my $tmp_sub_metadata_value = $sub_metadata_value;
            while ($tmp_sub_metadata_value =~ s/\/(.+?)\///) {
            my $sub_sub_metadata_value = $1;
            $doc_obj->add_utf8_metadata($section, $sub_sub_metadata_name, $sub_sub_metadata_value); 
            }
        }

        # Escape the metadata value so it appears correctly in the final collection
        $sub_metadata_value = &escape_metadata_value($sub_metadata_value);

        # print STDERR "Sub metadata name: $sub_metadata_name, value: $sub_metadata_value\n";
        if ($sub_metadata_name ne $metadata_name) {
            $doc_obj->add_utf8_metadata($section, $sub_metadata_name, $sub_metadata_value); 
        }

        # If this tag has subfields and this is the first, use the value for the CDS/ISIS ^* field
        if ($fdt_mapping->{$tag}{'subfields'} ne "" && $metadata_value eq "") {
            $doc_obj->add_utf8_metadata($section, $metadata_name . "^*", $sub_metadata_value); 
        }

        $metadata_value .= $subfield_separator unless ($metadata_value eq "");
        $metadata_value .= $sub_metadata_value;
        }

        # Add the metadata value
        # print STDERR "Metadata name: $metadata_name, value: $metadata_value\n";
        $doc_obj->add_utf8_metadata($section, $metadata_name, $metadata_value); 

        $all_metadata_value .= $entry_separator unless ($all_metadata_value eq "");
        $all_metadata_value .= $metadata_value;
    }

    # Add the "^all" metadata value
    # print STDERR "All metadata name: $all_metadata_name, value: $all_metadata_value\n";
    $doc_obj->add_utf8_metadata($section, $all_metadata_name, $all_metadata_value); 

    $isis_record_html_metadata_value .= "<tr><td valign=top><nobr><b>" . $fdt_mapping->{$tag}{'name'} . "</b></nobr></td><td valign=top>" . $all_metadata_value . "</td></tr>";
    }

    # Add a reasonably formatted HTML table view of the record as the document text
    $isis_record_html_metadata_value .= "</table>";
    $doc_obj->add_utf8_text($section, $isis_record_html_metadata_value);

    # Add the full raw record as metadata
    my $isis_raw_record_metadata_value = &escape_metadata_value($$textref);
    $doc_obj->add_utf8_metadata($section, "ISISRawRecord", $isis_raw_record_metadata_value);

    # Add FileFormat metadata
    $doc_obj->add_utf8_metadata($section, "FileFormat", "CDS/ISIS");

    # Record was processed successfully
    return 1;
}


sub parse_field_definition_table
{
    my $fdtfilename = shift(@_);
    my $encoding = shift(@_);

    my %fdtmapping = ();

    open(FDT_FILE, "<$fdtfilename") || die "Error: Could not open file $fdtfilename.\n";

    my $fdtfiletext = "";
    my $reader = new multiread();
    $reader->set_handle('ISISPlugin::FDT_FILE');
    $reader->set_encoding($encoding);
    $reader->read_file($fdtfiletext);

    my $amongstdefinitions = 0;
    foreach my $fdtfileline (split(/\n/, $$fdtfiletext)) {
    $fdtfileline =~ s/(\s*)$//;  # Remove any nasty spaces at the end of the lines

    if ($amongstdefinitions) {
        my $fieldname      = &unicode::substr($fdtfileline,  0, 30);
        my $fieldsubfields = &unicode::substr($fdtfileline, 30, 20);
        my $fieldspecs     = &unicode::substr($fdtfileline, 50, 50);

        # Remove extra spaces
        $fieldname =~ s/(\s*)$//;
        $fieldsubfields =~ s/(\s*)$//;
        $fieldspecs =~ s/(\s*)$//;

        # Map from tag number to metadata field title, subfields, and repeatability
        my $fieldtag = (split(/ /, $fieldspecs))[0];
        my $fieldrepeatable = (split(/ /, $fieldspecs))[3];
        $fdtmapping{$fieldtag} = { 'name' => $fieldname,
                       'subfields' => $fieldsubfields,
                       'repeatable' => $fieldrepeatable };
    }
    elsif ($fdtfileline eq "***") {
        $amongstdefinitions = 1;
    }
    }

    close(FDT_FILE);

    return %fdtmapping;
}


sub escape_metadata_value
{
    my $value = shift(@_);
    $value =~ s/\</&lt;/g;
    $value =~ s/\>/&gt;/g;
    $value =~ s/\\/\\\\/g;
    return $value;
}


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

    # Delete the FDT and XRF files too
    &util::rm($self->{'fdt_file_path'});
    &util::rm($self->{'xrf_file_path'});
}


1;