package Koha::BiblioUtils;

# This contains functions to do with managing biblio records.

# Copyright 2014 Catalyst IT
#
# This file is part of Koha.
#
# Koha 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 3 of the License, or (at your option) any later
# version.
#
# Koha 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 Koha; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

=head1 NAME

Koha::BiblioUtils - contains fundamental biblio-related functions

=head1 DESCRIPTION

This contains functions for normal operations on biblio records.

Note: really, C4::Biblio does the main functions, but the Koha namespace is
the new thing that should be used.

=cut

use C4::Biblio; # EmbedItemsInMarcBiblio
use Koha::MetadataIterator;
use Koha::Database;
use Modern::Perl;

use Data::Dumper; # TODO remove

use base qw(Koha::MetadataRecord);

__PACKAGE__->mk_accessors(qw( record schema id datatype ));

=head1 FUNCTIONS

=head2 new

    my $biblio = Koha::BiblioUtils->new($marc_record, [$biblionumber]);

Creates an instance of C<Koha::BiblioUtils> based on the marc record. If known,
the biblionumber can be provided too.

=cut

sub new {
    my $class = shift;
    my $record = shift;
    my $biblionumber = shift;

    my $self = $class->SUPER::new(
        {
            'record'   => $record,
            'schema'   => lc C4::Context->preference("marcflavour"),
            'id'       => $biblionumber,
            'datatype' => 'biblio',
        }
    );
    bless $self, $class;
    return $self;
}

=head2 get_from_biblionumber

    my $biblio = Koha::BiblioUtils->get_from_biblionumber($biblionumber, %options);

This will give you an instance of L<Koha::BiblioUtils> that is the biblio that
you requested.

Options are:

=over 4

=item C<$item_data>

If true, then the item data will be merged into the record when it's loaded.

=back

It will return C<undef> if the biblio doesn't exist.

=cut

sub get_from_biblionumber {
    my ($class, $bibnum, %options) = @_;

    my $marc = $class->get_marc_biblio($bibnum, %options);
    return $class->new($marc, $bibnum);
}

=head2 get_all_biblios_iterator

    my $it = Koha::BiblioUtils->get_all_biblios_iterator();

This will provide an iterator object that will, one by one, provide the
Koha::BiblioUtils of each biblio. This will include the item data.

The iterator is a Koha::MetadataIterator object.

=cut

sub get_all_biblios_iterator {
    my $database = Koha::Database->new();
    my $schema   = $database->schema();
    my $rs =
      $schema->resultset('Biblio')->search( {},
        { columns => [qw/ biblionumber /] } );
    my $next_func = sub {
        # Warn and skip bad records, otherwise we break the loop
        while (1) {
            my $row = $rs->next();
            return if !$row;
            my $marc = C4::Biblio::GetMarcBiblio({
                biblionumber => $row->biblionumber,
                embed_items  => 1 });
            my $next = eval {
                __PACKAGE__->new($marc, $row->biblionumber);
            };
            if ($@) {
                warn "Something went wrong reading record for biblio $row->biblionumber: $@\n";
                next;
            }
            return $next;
        }
    };
    return Koha::MetadataIterator->new($next_func);
}

=head2 get_marc_biblio

    my $marc = Koha::BiblioUtils->get_marc_biblio($bibnum, %options);

This non-class function fetches the MARC::Record for the given biblio number.
Nothing is returned if the biblionumber couldn't be found (or it somehow has no
MARC data.)

Options are:

=over 4

=item item_data

If set to true, item data is embedded in the record. Default is to not do this.

=back

=cut

sub get_marc_biblio {
    my ($class, $bibnum, %options) = @_;

    return C4::Biblio::GetMarcBiblio({
        biblionumber => $bibnum,
        embed_items  => ($options{item_data} ? 1 : 0 ) });
}

1;