#!/usr/bin/perl 

# Sort an IMMA file into date order

use strict;
use warnings;
use lib "/home/hc1300/hadpb/tasks/digitisation/imma/";
use IMMA;
use FindBin;
use Time::Local;

my @Records;
while ( my $Ob =imma_read( \*STDIN ) ) { push @Records, $Ob; }
@Records = sort iSort @Records;
foreach my $Ob (@Records) { 
    $Ob->write( \*STDOUT );
}

# Special Perl sort routine
sub iSort {

    # Undefined dates preceed all defined dates
    my $aYR = $a->{YR};
    unless ( defined($aYR) ) { $aYR = 0; }
    my $aMO = $a->{MO};
    unless ( defined($aMO) ) { $aMO = 0; }
    my $aDY = $a->{DY};
    unless ( defined($aDY) ) { $aDY = 0; }
    my $aHR = $a->{HR};
    unless ( defined($aHR) ) { $aHR = 0; }
    my $bYR = $b->{YR};
    unless ( defined($bYR) ) { $bYR = 0; }
    my $bMO = $b->{MO};
    unless ( defined($bMO) ) { $bMO = 0; }
    my $bDY = $b->{DY};
    unless ( defined($bDY) ) { $bDY = 0; }
    my $bHR = $b->{HR};
    unless ( defined($bHR) ) { $bHR = 0; }

    # Compare
         $aYR <=> $bYR
      or $aMO <=> $bMO
      or $aDY <=> $bDY
      or $aHR <=> $bHR;
}