#!/usr/bin/env perl

use strict;
use warnings;

use Time::HiRes qw{usleep};
use Time::Piece;

my ($countdown, $check) = @ARGV;
$countdown = 60 unless defined $countdown;
$check ||= 10;  # Avoid "Illegal modulus zero" error
my $countdown_remaining = Time::Piece->strptime(0 => '%S');
$countdown_remaining += $countdown;
my $continue_re = qr{(?:^$|^[Yy])};

print_timestamp('Started');

{
    local $| = 1;

    do {
        print_countdown($countdown_remaining);
        my $seconds_remaining = $countdown_remaining->epoch;
        print "\n" and last unless $seconds_remaining;

        if (($countdown - $seconds_remaining) % $check == 0
             &&
             $countdown > $seconds_remaining
        ) {
            print_timestamp("\nPaused ");
            print "Continue? ([Y]/n): ";
            chomp(my $reply = <STDIN>);
            last unless $reply =~ $continue_re;
            print_timestamp('Resumed');
        }

        usleep 1_000_000;
    } while $countdown_remaining--;
}

print_timestamp("Finished");

sub print_countdown {
    printf "\r%s" => shift->strftime('%H:%M:%S');
}

sub print_timestamp {
    print shift, ' at: ', scalar(localtime), "\n";
}