sub _find_duplicate_authority_try {

    my ($try, $authorityfield, $authtypecode) = @_;

    my $filtervalues =

        qr([\001-\040\!\'\"\`\#\$\%\&\*\+,\-\./:;<=>\?\@\(\)\{\[\]\}_\|\~]);

    # build a request for SearchAuthorities

    my $query = "at=$authtypecode";

    foreach my $s ($authorityfield->subfields()) {

        next unless ($s->[0] =~ /[A-z]/);

        $s->[1] =~ s/$filtervalues/ /g;

        $query .= qq{ and $try->{index}="$s->[1]"};

    }

    my $duplicaterecord;

    if ($try->{field} and $try->{subfields}) {

        my $maxresults = C4::Context->preference('FindDuplicateMaxResults') || 10;

        my ($error, $results, $total_hits) =

            C4::Search::SimpleSearch($query, 0, $maxresults, ["authorityserver"]);

        return unless (!defined $error and @{$results});

        foreach my $result (@$results) {

            my $marcrecord = MARC::File::USMARC::decode($result);

            my @marcfields = $marcrecord->field($try->{field});

            next if (scalar @marcfields == 0);

            my $stillmatch = 1;

            foreach my $marcfield (@marcfields) {

                foreach my $subfield (@{ $try->{subfields} }) {

                    my $authoritysubfield = $authorityfield->subfield($subfield);

                    my $marcsubfield = $marcfield->subfield($subfield);

                    if ( (defined $authoritysubfield xor defined $marcsubfield)

                      or (defined $authoritysubfield

                        and $authoritysubfield ne $marcsubfield)

                    ) {

                        $stillmatch = 0;

                        last;

                    }

                }

                last unless $stillmatch;

            }

            if ($stillmatch) {

                $duplicaterecord = $marcrecord;

                last;

            }

        }

    } else {

        my ($error, $results, $total_hits) =

            C4::Search::SimpleSearch( $query, 0, 1, ["authorityserver"] );

        if (!defined $error and @{$results}) {

            $duplicaterecord = MARC::File::USMARC::decode($results->[0]);

        }

    }

    return $duplicaterecord;

}

    my ($record, $authtypecode) = @_;

    return unless $record;

    my $opts = C4::Context->preference('FindDuplicateOptions');

    return unless $opts;

    if ($duplicaterecord) {

        my $authid = $duplicaterecord->field('001')->data;

        return $authid, BuildSummary($duplicaterecord, $authid, $authtypecode);

    }

INSERT INTO systempreferences (variable,value,explanation,options,type) VALUES('FindDuplicateOptions','he,wrdl','Options to determine how to search for duplicate authorities. General form: "index1/XXXcc|index2" where indexX is the index where we want to search, and XXXcc the field(s) and subfield(s) we want to check for each search results (if omitted, the first result is returned as duplicate)',NULL,'Free');

INSERT INTO systempreferences (variable,value,explanation,options,type) VALUES('FindDuplicateMaxResults','10','Maximum number of results fetched when searching a duplicate',NULL,'Free');

$DBversion = "XXX";

if (C4::Context->preference("Version") < TransformToNum($DBversion)) {

    $dbh->do(qq{

        INSERT INTO systempreferences (variable, value, explanation, options, type)

        VALUES ('FindDuplicateOptions', 'he,wrdl', 'Options to determine how to search for duplicate authorities. General form: "index1/XXXcc#index2" where indexX is the index where we want to search, and XXXcc the field(s) and subfield(s) we want to check for each search results (if omitted, the first result is returned as duplicate)', NULL, 'Free');

    });

    $dbh->do(qq{

        INSERT INTO systempreferences (variable, value, explanation, options, type)

        VALUES ('FindDuplicateMaxResults', '10', 'Maximum number of results fetched when searching a duplicate', NULL, 'Integer');

    });

    print "Upgrade to $DBversion done (Added system preference FindDuplicateOptions)\n";

    SetVersion($DBversion);

}

        -

            - pref: FindDuplicateOptions

              class: long

            - '<br />Options to determine how to search for duplicate authorities when creating new authorities. General form: "index1/XXXcc | index2" where indexX is the index where we want to search, and XXXcc the field(s) and subfield(s) we want to check for each search results (if omitted, the first result is returned as duplicate)'

            - '<br />Examples:'

            - '<br />- <tt>he,wrdl</tt>: Search in "he" index, do not check subfields data in search results, the first result is returned as a duplicate (default).'

            - '<br />- <tt>he,wrdl/2..ab</tt>: Search in "he" index, and compare 2XX$a and 2XX$b of search results with XXX$a and XXX$b of created authority (XXX is the "Authority field to copy"). The first matching authority is returned as duplicate.'

            - '<br />- <tt>he,wrdl | See,wrdl/4..ab</tt>: Search in "he" index and do not check subfields. If there is no results, search in "See" index and compare 4XX$a and 4XX$b of search results with XXX$a and XXX$b of created authority.'

            - '<br />Notes:'

            - '<br />- only authorities of the same type are returned by the search'

            - '<br />- if compared subfields are repeatable, only the first of each field is checked'

        -

            - 'Maximum number of results fetched when searching a duplicate:'

            - pref: FindDuplicateMaxResults

              class: integer

            - "It's only used when FindDuplicateOptions contains fields and subfields to check against (default: 10)"