#!/usr/bin/env perl

use strict;
use warnings;

use Tk;
use IO::Socket;

my $status = '';

my $mw = MainWindow->new;

my $control_F = $mw->Frame()->pack(-side => 'bottom');
$control_F->Button(-text => 'Listen',
                   -command => sub { start_server(\$mw, \$status) }
    )->pack(-side => 'left');
$control_F->Button(-text => 'Quit', -command => sub { exit }
    )->pack(-side => 'left');

my $status_F = $mw->Frame()->pack(-side => 'top');
$status_F->Label(-text => 'Status:')->pack(-side => 'left');
$status_F->Label(-textvariable => \$status)->pack(-side => 'left');

MainLoop;

sub start_server {
    my ($mw_ref, $status_ref) = @_;

    my $server = IO::Socket::INET::->new(
        Proto     => 'tcp',
        LocalPort => 55555,
        Listen    => SOMAXCONN,
        Reuse     => 1
    ) or die "Server can't start: $!";

    my $client = $server->accept();
    $client->autoflush;

    $$mw_ref->fileevent($client, 'readable', sub {
        if (defined(my $read = <$client>)) {
            chomp $read;
            $$status_ref = $read;
        }
    });
}