#!/usr/bin/perl

use strict;
use warnings;
use IPC::Open2;
use Term::ReadKey;
use threads;
use threads::shared;

my $pid = open2(\*Reader, \*Writer,
                "driver.exe")
    or die "Failed to open pipe! $!";

ReadMode('cbreak');

my $state : shared = 0;
my $i : shared = 0;
my $thr = threads->new(\&read_in)->detach;

while (1) {
    # Continue reading the spam from the driver
    if ($state == 0) {
        my $got = <Reader>;
        
        if (defined $got) {
            print $got;
        }
    }
    #User paused spam reading, changed value of $i, and
    #needs to pipe it to the driver, spam output will be updated
    elsif ($state == 1) {
        $state = 0; #reset state
        print Writer "$i\n";
    }
    #User quit! 
    elsif ($state == 2) {
        print Writer "quit\n";
        
        # Before the driver exits, it does output a message, which
        # for some reason does not get grabbed here
        my $goodbye = <Reader>;
        print $goodbye;
        
        last;
    }
}

ReadMode('normal');

sub read_in {
    while (1) {
        my $char = 0;
        
        # A key was pressed to change state
        if (defined ($char = ReadKey(0))) {
            # 'p' was pressed to signal paramter change, stop
            # outputting from driver output, get new value from console,
            # and update it
            if ($char eq 'p') {
                $state = 1;
                
                # How to make this work?
                $i = <STDIN>;
                chomp $i;
            }
            # User quit
            elsif ($char eq 'q') {
                $state = 2;
            }
        }
        
    }
    
}

waitpid($pid, 0);

__END__