#!perl

use 5.014; # //, strict, say, s///r
use warnings;

use Digest::CRC;

my ($crc, $input, $width, $init, $xorout, $refout, $poly, $refin, $cont, $digest, $ctx, $exp);

$width  = 16;
$init   = 0xffff;
$xorout = 0xffff;
$refout = 1;
$poly   = 0x1021;
$refin  = 1;
$cont   = 0;      # ???

$input = 0xaabbccdd;

$ctx = Digest::CRC->new(width=>$width, init=>$init, xorout=>$xorout,
         refout=>$refout, poly=>$poly, refin=>$refin, cont=>$cont);
$ctx->add($input);

$digest = $ctx->hexdigest;

say $digest;


use Test::More;
use feature 'fc';
use Data::Dump qw/pp/;
sub test_it {
    my($in, $cont, $expect) = @_;
    my $ctx = Digest::CRC->new(width=>$width, init=>$init, xorout=>$xorout,
         refout=>$refout, poly=>$poly, refin=>$refin, cont=>$cont);
    $ctx->add($in);
    my $got = $ctx->hexdigest;
    is fc($got), fc($expect), sprintf("test_it(%s, %s, %s)", pp($in), $cont, $expect);
}
test_it("AABBCCDD", 0, '1D8D'); # https://crccalc.com/?crc=AABBCCDD&method=CRC-16/X-25&datatype=ascii&outtype=0
test_it("\xAA", 0, 'FA28');     # https://crccalc.com/?crc=AA&method=CRC-16/X-25&datatype=hex&outtype=0
test_it("\xAA\xBB\xCC\xDD", 0, '4FCB');  # https://crccalc.com/?crc=AABBCCDD&method=CRC-16/X-25&datatype=hex&outtype=0
test_it("\xDD\xCC\xBB\xAA", 0, 'F486');  # https://crccalc.com/?crc=DDCCBBAA&method=CRC-16/X-25&datatype=hex&outtype=0
test_it(0xAABBCCDD, 0, '1680'); # 2864434397
test_it(2864434397, 0, '1680'); # 2864434397
test_it("2864434397", 0, '1680'); # https://crccalc.com/?crc=2864434397&method=CRC-16/X-25&datatype=ascii&outtype=0
done_testing;