BEGIN;

INSERT INTO config.upgrade_log (version) VALUES ('0465'); -- dbs

CREATE OR REPLACE FUNCTION maintain_control_numbers() RETURNS TRIGGER AS $func$
use strict;
use MARC::Record;
use MARC::File::XML (BinaryEncoding => 'UTF-8');
use Encode;
use Unicode::Normalize;

my $record = MARC::Record->new_from_xml($_TD->{new}{marc});
my $schema = $_TD->{table_schema};
my $rec_id = $_TD->{new}{id};

# Short-circuit if maintaining control numbers per MARC21 spec is not enabled
my $enable = spi_exec_query("SELECT enabled FROM config.global_flag WHERE name = 'cat.maintain_control_numbers'");
if (!($enable->{processed}) or $enable->{rows}[0]->{enabled} eq 'f') {
    return;
}

# Get the control number identifier from an OU setting based on $_TD->{new}{owner}
my $ou_cni = 'EVRGRN';

my $owner;
if ($schema eq 'serial') {
    $owner = $_TD->{new}{owning_lib};
} else {
    # are.owner and bre.owner can be null, so fall back to the consortial setting
    $owner = $_TD->{new}{owner} || 1;
}

my $ous_rv = spi_exec_query("SELECT value FROM actor.org_unit_ancestor_setting('cat.marc_control_number_identifier', $owner)");
if ($ous_rv->{processed}) {
    $ou_cni = $ous_rv->{rows}[0]->{value};
    $ou_cni =~ s/"//g; # Stupid VIM syntax highlighting"
} else {
    # Fall back to the shortname of the OU if there was no OU setting
    $ous_rv = spi_exec_query("SELECT shortname FROM actor.org_unit WHERE id = $owner");
    if ($ous_rv->{processed}) {
        $ou_cni = $ous_rv->{rows}[0]->{shortname};
    }
}

my ($create, $munge) = (0, 0);

my @scns = $record->field('035');

foreach my $id_field ('001', '003') {
    my $spec_value;
    my @controls = $record->field($id_field);

    if ($id_field eq '001') {
        $spec_value = $rec_id;
    } else {
        $spec_value = $ou_cni;
    }

    # Create the 001/003 if none exist
    if (scalar(@controls) == 1) {
        # Only one field; check to see if we need to munge it
        unless (grep $_->data() eq $spec_value, @controls) {
            $munge = 1;
        }
    } else {
        # Delete the other fields, as with more than 1 001/003 we do not know which 003/001 to match
        foreach my $control (@controls) {
            unless ($control->data() eq $spec_value) {
                $record->delete_field($control);
            }
        }
        $record->insert_fields_ordered(MARC::Field->new($id_field, $spec_value));
        $create = 1;
    }
}

# Now, if we need to munge the 001, we will first push the existing 001/003
# into the 035; but if the record did not have one (and one only) 001 and 003
# to begin with, skip this process
if ($munge and not $create) {
    my $scn = "(" . $record->field('003')->data() . ")" . $record->field('001')->data();

    # Do not create duplicate 035 fields
    unless (grep $_->subfield('a') eq $scn, @scns) {
        $record->insert_fields_ordered(MARC::Field->new('035', '', '', 'a' => $scn));
    }
}

# Set the 001/003 and update the MARC
if ($create or $munge) {
    $record->field('001')->data($rec_id);
    $record->field('003')->data($ou_cni);

    my $xml = $record->as_xml_record();
    $xml =~ s/\n//sgo;
    $xml =~ s/^<\?xml.+\?\s*>//go;
    $xml =~ s/>\s+</></go;
    $xml =~ s/\p{Cc}//go;

    # Embed a version of OpenILS::Application::AppUtils->entityize()
    # to avoid having to set PERL5LIB for PostgreSQL as well

    # If we are going to convert non-ASCII characters to XML entities,
    # we had better be dealing with a UTF8 string to begin with
    $xml = decode_utf8($xml);

    $xml = NFC($xml);

    # Convert raw ampersands to entities
    $xml =~ s/&(?!\S+;)/&amp;/gso;

    # Convert Unicode characters to entities
    $xml =~ s/([\x{0080}-\x{fffd}])/sprintf('&#x%X;',ord($1))/sgoe;

    $xml =~ s/[\x00-\x1f]//go;
    $_TD->{new}{marc} = $xml;

    return "MODIFY";
}

return;
$func$ LANGUAGE PLPERLU;

COMMIT;
