#!/usr/local/bin/perl

# oclc980.pl
# desc: split oclc promptcat file into invoice files based on 980 |f fields
# wordsettings:
# end_autoz

use strict;

if ($#ARGV < 0) {usage();}
my $marcfile = $ARGV[0];

my ($mctr, $fopen, $plural, $strptr, $marcrec);
my ($bibbaseaddr, $bibtaglen, $biboffset);
my @bibtagid = ();
my @bibtagdata = ();
my @chunk = ();
my %invhash = ();
my %allinv = ();
my $subfdelim = chr(0x1f);
my $fdelim = chr(0x1e);
my $recdelim = chr(0x1d);
my ($idx, $thisinvnum, $tag980, $outfile);
my $filext = 'marc';

# set up MARC end-of-record character; needed for reading the MARC file
$/ = chr(0x1d);

$fopen = sprintf("Cannot open file %s for input\n", $marcfile);
open(marcfile, $marcfile) or die $fopen;

$mctr = 0;
while ($marcrec = <marcfile>)
{
  $bibbaseaddr = substr($marcrec, 12, 5) - 1;
  $strptr = 24;
  $idx = 0;
  while ($strptr < $bibbaseaddr-1)
  {
    $bibtagid[$idx] = substr($marcrec, $strptr, 3);
    if ($bibtagid[$idx] eq '980') {$tag980 = $idx;}
    $bibtaglen = substr($marcrec, $strptr+3, 4);
    $biboffset = substr($marcrec, $strptr+7, 5);
    $bibtagdata[$idx] = substr($marcrec, $bibbaseaddr+$biboffset, $bibtaglen);
    $strptr+= 12;
    $idx++;
  }

  @chunk = split /\x1f/, $bibtagdata[$tag980];
  $idx = 0;
  while ($idx < @chunk)
  {
    if (substr($chunk[$idx], 0, 1) eq 'f')
    {
      $thisinvnum = substr($chunk[$idx], 1);
      if (!exists($invhash{$thisinvnum}))
      {
        $invhash{$thisinvnum} = 1;
        $allinv{$thisinvnum} = $thisinvnum;
      }
      else {$invhash{$thisinvnum}++;}

      $outfile = "$thisinvnum.marc";
      $fopen = sprintf("Cannot open %s for append output\n", $outfile);
      open(outfile, ">>$outfile") or die $fopen;
      print outfile $marcrec;
      close(outfile);
    }
    $idx++;
  }
  $mctr++;
}
close(marcfile);

print "\n";
print "$mctr records read\n";

print "Output is...\n";
foreach $thisinvnum (sort keys %allinv)
{
  print "Invoice # $thisinvnum has $invhash{$thisinvnum} record(s) in file $thisinvnum.$filext\n";
}


sub usage()
{
  printf ("\nUsage: oclc980.pl promptcatfile\n");
  printf ("       where promptcatfile is that file from OCLC.\n");
  printf ("       An output file will be generated for each unique 980 |f.\n");
  printf ("       Records with 980 |f fields matching the file name will be\n");
  printf ("       put in that file.\n");
  exit(0);
}