source: main/trunk/greenstone2/perllib/plugins/MetadataCSVPlugin.pm@ 34249

###########################################################################
#
# MetadataCSVPlugin.pm -- A plugin for metadata in comma-separated value format
#
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the 
# University of Waikato, New Zealand.
#
# Copyright 2006 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 MetadataCSVPlugin;


use BaseImporter;
use MetadataRead;
use CSVFieldSeparator;

use strict;
no strict 'refs';

use extrametautil;
use multiread;
use util;

use Encode;
use Text::CSV;

# methods with identical signatures take precedence in the order given in the ISA list.
sub BEGIN {
    @MetadataCSVPlugin::ISA = ('MetadataRead', 'BaseImporter', 'CSVFieldSeparator');
}



my $arguments = [
      { 'name' => "process_exp",
    'desc' => "{BaseImporter.process_exp}",
    'type' => "regexp",
    'reqd' => "no",
    'deft' => &get_default_process_exp() }

];


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


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

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

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

    return bless $self, $class;
}


sub get_default_process_exp
{
    return q^(?i)\.csv$^;
}

sub file_block_read {
    my $self = shift (@_);
    my ($pluginfo, $base_dir, $file, $block_hash, $metadata, $gli) = @_;

    my ($filename_full_path, $filename_no_path) = &util::get_full_filenames($base_dir, $file);

    if (!-f $filename_full_path || !$self->can_process_this_file($filename_full_path)) {
    return undef; # can't recognise
    }

    # set this so we know this is a metadata file - needed for incremental 
    # build
    # if this file changes, then we need to reimport everything
    $block_hash->{'metadata_files'}->{$filename_full_path} = 1;

    return 1;
}

sub metadata_read
{
    my $self = shift (@_);
    my ($pluginfo, $base_dir, $file, $block_hash, 
    $extrametakeys, $extrametadata, $extrametafile,
    $processor, $gli, $aux) = @_;

    # can we process this file??
    my ($filename_full_path, $filename_no_path) = &util::get_full_filenames($base_dir, $file);
    return undef unless $self->can_process_this_file_for_metadata($filename_full_path);
    
    print STDERR "\n<Processing n='$file' p='MetadataCSVPlugin'>\n" if ($gli);
    print STDERR "MetadataCSVPlugin: processing $file\n" if ($self->{'verbosity'}) > 1;

    my $outhandle = $self->{'outhandle'};
    my $failhandle = $self->{'failhandle'};

    # add the file to the block list so that it won't be processed in read, as we will do all we can with it here
    $self->block_raw_filename($block_hash,$filename_full_path);


    # Read the CSV file to get the metadata
    my $csv_file_content;
    open(CSV_FILE, "$filename_full_path");
    my $csv_file_reader = new multiread();
    $csv_file_reader->set_handle('MetadataCSVPlugin::CSV_FILE');
    $csv_file_reader->read_file(\$csv_file_content);

    # Would be nice if MetadataCSVPlugin was extended to support a minus
    # option to choose the character encoding the CSV file is in 
    # For now we will assume it is always in UTF8
    $csv_file_content = decode("utf8",$csv_file_content);

    close(CSV_FILE);

    # Split the file into lines and read the first line (contains the metadata names)
    $csv_file_content =~ s/\r/\n/g;  # Handle non-Unix line endings
    $csv_file_content =~ s/\n+/\n/g;

    my $separate_char = $self->{'csv_field_separator'};

    my $md_val_sep = $self->{'metadata_value_separator'};
    undef $md_val_sep if ($md_val_sep eq "");

    my @csv_file_lines = split(/\n/, $csv_file_content);
    my $csv_file_field_line = shift(@csv_file_lines);

    if ($separate_char =~ m/^auto$/i) {
    $separate_char = $self->resolve_auto($csv_file_field_line,$self->{'plugin_type'});
    }

    my $csv = Text::CSV->new();
    $csv->sep_char($separate_char);
 
    my @csv_file_fields = undef;
    if ($csv->parse($csv_file_field_line)) {
    @csv_file_fields = $csv->fields;
    }
    else {
    $self->print_error($outhandle, $failhandle, $gli, $filename_full_path, "Error: Badly formatted CSV header line: $csv_file_field_line");
    return -1;
    }

    my $found_filename_field = 0;
    for (my $i = 0; $i < scalar(@csv_file_fields); $i++) {
    # Remove any spaces from the field names, and surrounding quotes too
    $csv_file_fields[$i] =~ s/ //g;
    $csv_file_fields[$i] =~ s/^"//;
    $csv_file_fields[$i] =~ s/"$//;

    if ($csv_file_fields[$i] eq "Filename") {
        $found_filename_field = 1;
    }
    }

    if (!$found_filename_field) {
    $self->print_error($outhandle, $failhandle, $gli, $filename_full_path, "No Filename field in CSV file");
    return -1; # error
    }
    # Read each line of the file and assign the metadata appropriately
    foreach my $csv_line (@csv_file_lines) {
    # Ignore lines containing only whitespace
    next if ($csv_line =~ /^\s*$/);
    my $orig_csv_line = $csv_line;

    # Build a hash of metadata name to metadata value for this line
    my %csv_line_metadata;

    if ($csv->parse($csv_line)) {
        my @md_vals = $csv->fields;
        my $md_vals_len = scalar(@md_vals);
        
        for (my $i=0; $i<$md_vals_len; $i++) {
        my $md_val = $md_vals[$i];
        # Only bother with non-empty values
        if ($md_val ne "" && defined($csv_file_fields[$i])) {

            my $md_name = $csv_file_fields[$i];

            if (!defined $md_name) {
            $csv_line_metadata{$md_name} = [];
            }

            if (defined $md_val_sep) {          
            
            my @within_md_vals = split(/${md_val_sep}/,$md_val);
            #push (@{$csv_line_metadata{$md_name}}, @within_md_vals);

            # protect square brackets in metadata values by hex entity encoding them
            # As unescaped square bracket chars in metadata
            # have special meaning in GS' Java runtime code
            my @escaped_within_md_vals = ();
            for my $meta_value (@within_md_vals) {
                $meta_value =~ s/\[/&\#091;/g;
                $meta_value =~ s/\]/&\#093;/g;
                push(@escaped_within_md_vals, $meta_value);
            }
            push (@{$csv_line_metadata{$md_name}}, @escaped_within_md_vals);

#           foreach my $within_md_val (@within_md_vals) {
#               push (@{$csv_line_metadata{$md_name}}, $within_md_val);
#           }
            }
            else {
            #push (@{$csv_line_metadata{$md_name}}, $md_val);
            # protect square brackets in metadata values by hex entity encoding them
            my $escaped_metadata_value = $md_val;
            $escaped_metadata_value =~ s/\[/&\#091;/g;
            $escaped_metadata_value =~ s/\]/&\#093;/g;
            push (@{$csv_line_metadata{$md_name}}, $escaped_metadata_value);
            }
        }
        }
    }
    else {
        $self->print_error($outhandle, $failhandle, $gli, $filename_full_path, "Badly formatted CSV line: $csv_line");
        last;
    }

    # We can't associate any metadata without knowing the file to associate it with
    my $csv_line_filename_array = $csv_line_metadata{"Filename"};
    if (!defined $csv_line_filename_array) {
        $self->print_error($outhandle, $failhandle, $gli, $filename_full_path, "No Filename metadata in CSV line: $orig_csv_line");
        next;
    }
    my $csv_line_filename = shift(@$csv_line_filename_array);
    delete $csv_line_metadata{"Filename"};

    my $csv_line_section_array = $csv_line_metadata{"Section"};
    my $section_suffix = "";
    if (defined $csv_line_section_array) {
        my $section_value = shift(@$csv_line_section_array);
        if ($section_value =~ /[\d.]+/m){
            my $section_suffix = "///Section/" . $section_value;
            foreach my $metaname (keys %csv_line_metadata) {
                my $new_name = $metaname . $section_suffix;
                $csv_line_metadata{$new_name} = delete $csv_line_metadata{$metaname};
            }
        } else{
            unshift(@$csv_line_section_array, $section_value);
        }
    }


    # Associate the metadata now
    # Indexing into the extrameta data structures requires the filename's style of slashes to be in URL format
    # Then need to convert the filename to a regex, no longer to protect windows directory chars \, but for
    # protecting special characters like brackets in the filepath such as "C:\Program Files (x86)\Greenstone".
    $csv_line_filename = &util::filepath_to_url_format($csv_line_filename);
    $csv_line_filename = &util::filename_to_regex($csv_line_filename);

    if (defined &extrametautil::getmetadata($extrametadata, $csv_line_filename)) { # merge with existing meta    

        my $file_metadata_table = &extrametautil::getmetadata($extrametadata, $csv_line_filename);
        
        foreach my $metaname (keys %csv_line_metadata) {
        # will create new entry if one does not already exist
        push(@{$file_metadata_table->{$metaname}}, @{$csv_line_metadata{$metaname}});       
        }
        
        # no need to push $file on to $extrametakeys as it is already in the list
    } else { # add as new meta
        
        &extrametautil::setmetadata($extrametadata, $csv_line_filename, \%csv_line_metadata);
        &extrametautil::addmetakey($extrametakeys, $csv_line_filename);
    }
    # record which file the metadata came from 
    if (!defined &extrametautil::getmetafile($extrametafile, $csv_line_filename)) {
        &extrametautil::setmetafile($extrametafile, $csv_line_filename, {});
    }
    # maps the file to full path
    &extrametautil::setmetafile_for_named_file($extrametafile, $csv_line_filename, $file, $filename_full_path);
    }
}

sub print_error
{

    my $self = shift(@_);
    my ($outhandle, $failhandle, $gli, $file, $error) = @_;

    print $outhandle "MetadataCSVPlugin Error: $file: $error\n";
    print $failhandle "MetadataCSVPlugin Error: $file: $error\n";
    print STDERR "<ProcessingError n='$file' r='$error'/>\n" if ($gli);
}
1;