#!/usr/bin/perl
use strict;
use warnings;

use XML::Twig;
use YAML;
use JSON;

my $marcxml = shift;

open HOLDINGS, '>', "holdings";
open X, '>', "holdings.x";
open Z, '>', "holdings.z";
open ALL852, '>', "holdings.all852";

my $holdings = {};
my $copyid = 0;
my %all852 = ( x => {}, z => {} ); # hash of all subfields in all 852s

my $t = XML::Twig->new( twig_handlers => { record => \&record } );
$t->parsefile($marcxml);
#print ALL852 to_json(\%all852);
print ALL852 Dump(%all852);

sub record {
    my($t, $r)= @_;
    $holdings = { copies => [] };

    my @dfields = $r->children('datafield');
    for my $d (@dfields) {
        process_datafields($d) 
    }

    for my $copy (@{$holdings->{copies}})
      { print_reports($copy) }
    $r->purge;
}

sub process_datafields {
    my ($d) = @_;
    # get 903
    if ($d->{'att'}->{'tag'} == 903) {
        my $s = $d->first_child('subfield');
        $holdings->{id} = $s->text;;
    }

    # and holdings data
    if ($d->{'att'}->{'tag'} == 852) {
        push @{$holdings->{copies}}, { x =>[], z => [] };
        $holdings->{copies}[-1]{copyid} = $copyid;
        my @subs = $d->children('subfield');
        for my $s (@subs) 
          { process_subs($s) }
        $copyid++;
    }
}

sub process_subs {
    my ($s) = @_;
    my $copy = $holdings->{copies}[-1];

    my $code = $s->{'att'}->{'code'};
    my $value = $s->text;

    if ($code eq 'x' or $code eq 'z') {
        push @{$copy->{$code}}, $value;
        my ($k,$v) = split /:/, $value;
        $all852{$code}{$k} = $v;
    } else {        
        $copy->{$code} = $value;
        $all852{$code} = $value;
    }
}

sub print_reports {
    my ($copy) = @_;
    my $note = 0;
    for (@{$copy->{x}}) {
        print X join("\t", $holdings->{id}, $copy->{copyid}, $note, $_), "\n";
        $note++;
    }
    $note = 0;
    for (@{$copy->{z}}) {
        print Z join("\t", $holdings->{id}, $copy->{copyid}, $note, $_), "\n";
        $note++;
    }
    print HOLDINGS join("\t", $holdings->{id}, $copy->{copyid},
                        $copy->{b}, $copy->{p}, $copy->{h}, $copy->{9}), "\n";
}