#!/usr/bin/perl

use strict;
use warnings;
use 5.010;

use autodie;

use JSON;

sub parse_json_file {
	my ($filename) = @_;

	local $/;
	open my $fh, '<', $filename;

	my $json_text = <$fh>;

	my $json = decode_json($json_text) or die;
	return $json;
}

sub output_json_file {
	my ($json, $filename) = @_;

	open my $out, '>', $filename;

	my $json_text = encode_json($json);

	print {$out} $json_text;
}

my $json_1 = parse_json_file('grace_1.json');
my $json_2 = parse_json_file('grace_2.json');

my $data_1 = $json_1->{data};
my $data_2 = $json_2->{data};

my $min = 0;
my $max = 0;

foreach my $x (0..$#{ $data_1 }) {
	foreach my $y (0..$#{ $data_1->[$x] }) {
		foreach my $z (0..$#{ $data_1->[$x][$y] }) {
			my $datum_1 = $data_1->[$x][$y][$z];
			my $datum_2 = $data_2->[$x][$y][$z];
			my $datum
				= $data_2->[$x][$y][$z]
				- $data_1->[$x][$y][$z];
			$datum = 32767 if ($datum_1 == 32767 or $datum_2 == 32767);
			$data_1->[$x][$y][$z] = $datum;

			$min = $datum if $datum < $min;
			$max = $datum if $datum > $max;
		}
	}
}

output_json_file($json_1, 'grace_1_2_diff_v2.json');



# use Data::Dumper;
# 
# print Data::Dumper->Dump([parse_json_file('grace_1.json')], [qw/json/]);