#!/usr/bin/perl 

# Extract Antarctic data from IMMA records

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

my $Year = $ARGV[0];

for ( my $i = 1 ; $i <= 12 ; $i++ ) {
    my $Yr    = $Year;
    my $Month = $i + 6;
    if ( $Month > 12 ) {
        $Month -= 12;
        $Yr++;
    }
    open( DIN, sprintf "/var/tmp/hadpb/IMMA.%04d.%02d", $Yr, $Month )
      or die "No obs for $Yr $Month";
  lo_ob: while ( my $ob = imma_read( \*DIN ) ) {

        foreach (qw(YR MO DY HR LAT LON)) {
            unless ( defined( $ob->{$_} ) ) { next lo_ob; }
        }

        # Antarctic data only
        if ( $ob->{LAT} >= -55 ) { next lo_ob; }

        # Discard traffic round Cape Horn
        if ( $ob->{LON} > 200 && $ob->{LON} < 320 && $ob->{LAT} > -63 ) {
            next lo_ob;
        }
        $ob->write( \*STDOUT );
    }
    close(DIN);
}