use v5.36;
use rlib '.';

use Carp;
use Data::Dumper;

use feature "signatures";
no warnings "experimental::signatures";

my $coords_regex = qr/^\s*(-?\d+)\s*,\s*(-?\d+)\s*$/;

my %regions_to_tiles;
my %tiles_to_regions;

my $input_file = shift;
open (my $input_fh, $input_file);

my $output_file = shift // "$input_file.out";
open (my $output_fh, ">$output_file");

while (my $line = <$input_fh>)
{
	my @fields = split '; ', $line;
	print $output_fh (shift @fields) . "; "; #region name
	print $output_fh (shift @fields) . "; "; #background colour
	my @expanded_tile_specs = ();
	foreach my $coords (@fields)
	{
		do { carp "Skipping bad spec: $coords"; next; } unless $coords =~ $coords_regex;
		my $nw_base = $1 * 3;
		my $sw_base = $2 * 3;

		my @new = ("$nw_base,$sw_base");
		push @new, ($nw_base+1) . "," . ($sw_base);
		push @new, ($nw_base-1) . "," . ($sw_base);
		push @new, ($nw_base) . "," . ($sw_base+1);
		push @new, ($nw_base) . "," . ($sw_base-1);
		push @new, ($nw_base+1) . "," . ($sw_base-1);
		push @new, ($nw_base-1) . "," . ($sw_base+1);

		push @expanded_tile_specs, (join "; ", @new);
	}
	say $output_fh (join "; ", @expanded_tile_specs);
}

close $input_fh;
close $output_fh;