use Modern::Perl;

use LWP::UserAgent;
use JSON;
use Digest::SHA qw(hmac_sha256_base64 hmac_sha256_hex hmac_sha256);
use MIME::Base64;
use Time::Piece;

my $uri        = 'https://api-public.sandbox.pro.coinbase.com';
my $api_key    = '6dc071df2d42724c019f79a53464d006';
my $secret     = 'vjYZFn39LEFfbJ5z9QzdWt+HsahYTPvXInoYMD9Gq754FJL0evlGnHcTiaaITGF+6GfbyYnxoyCXji9OR1iEMw==';
my $passphrase = "There is no passphrase.",

my $now            = gmtime;
my $timestamp      = $now->datetime . ".000000Z";
my $request_method = "GET";
my $request_path   = '/products';
my $body           = '';
my $message        = $timestamp . $request_method . $request_path . $body;

my $decoded_secret = decode_base64($secret);

my $signature_b64 = encode_base64( hmac_sha256($message, $decoded_secret) );
chomp($signature_b64);

my $ua = LWP::UserAgent->new;
$ua->agent ('Stock/1.0');
my $res = $ua->get(
    "$uri$request_path",
    'CB-ACCESS-SIGN'       => $signature_b64,
    'CB-ACCESS-TIMESTAMP'  => $timestamp,
    'CB-ACCESS-KEY'        => $api_key,
    'CB-ACCESS-PASSPHRASE' => $passphrase,
    'Content-Type'         => 'application/json'
    );

if ($res->is_success) {
    say $res->decoded_content;
} else {
    say "request failed.";
    say "status:", $res->as_string;
}