#!/home/ben/software/install/bin/perl
use warnings;
use strict;
use JSON;
use FindBin '$Bin';

# Test file

my $file = "$Bin/tantei-san.png";
my $file_size = -s $file;
print "Size of $file is $file_size.\n";

# Read in file

open my $in, "<:raw", $file or die $!;
my $bytes = read ($in, my $data, -s $file);
if ($bytes != $file_size) {
    die "Bad no. of bytes $bytes should be $file_size";
}
close $in or die $!;

# Make JSON & print it to a file.

my $json_data = $data;
$json_data =~ s/(.)/sprintf ("%02X", ord ($1))/ge;
my $json = { png => $json_data };
my $outfile = 'out.json.gz';
open my $out, ">:gzip", $outfile or die $!;
print $out to_json ($json);
close $out or die $!;
print "Size of $outfile is ", -s $outfile, ".\n";

# Check it all worked by reading it back in again.

open my $inagain, "<:gzip", $outfile or die $!;
my $json2 = '';
while (<$inagain>) {
    $json2 .= $_;
}
my $png = from_json ($json2);
my $pngdata = $png->{png};
$pngdata =~ s/([0-9A-F]{2})/chr (hex ($1))/eg;
if ($pngdata eq $data) {
    print "OK\n";
}
else {
    print "mismatch\n";
}