use English;
use strict;
use warnings;

use Tk;
use POE;
use POE::Wheel::Run;

# Setup program to run...
my $PGM = 'ls';
if ($OSNAME eq 'MSWin32') { $PGM = 'dir & pause' };
#if ($OSNAME eq 'MSWin32') { $PGM = 'dir' };  # This doesn't work!
print STDERR "$OSNAME PGM=$PGM\n";

my $TEXT;		# Global for text widget...

# Setup POE session...
my $session = _poeSetup();

# Create dummy postback so the session won't die once input is done...
my $subref = $session->postback('DontDie');

# Go...
$poe_kernel->run();

#################
# POE Subroutines
#################
sub _poeSetup {
	my $session = POE::Session->create(
		inline_states=>{
			_start => \&_startUp,
			KidOut => \&_GetStdout,
			KidErr => \&_GetStderr,
			KidClose => \&_DoClose,
		},
	);
	return($session);
}

# POE Session Supporting Routines...
sub _startUp {
	$TEXT=$poe_main_window->Scrolled('Text', -wrap=>'none')->pack;
	$poe_main_window->update;

	my $child = POE::Wheel::Run->new(
		Program => $PGM,
		StdoutEvent => 'KidOut',
		StderrEvent => 'KidErr',
		CloseEvent => 'KidClose',
	);
	$_[KERNEL]->sig_child($child->PID, '_DoSig');
	$_[HEAP]{Kids}{WID}{$child->ID} = $child;
	$_[HEAP]{Kids}{PID}{$child->PID} = $child;
}

sub _GetStdout {
	my ($line, $wid) = @_[ARG0, ARG1];
	my $child = $_[HEAP]{Kids}{WID}{$wid};
	$TEXT->insert('end', $child->PID . " OUT: $line\n");
	$TEXT->see('end');
	$poe_main_window->update;
}

sub _GetStderr {
	my ($line, $wid) = @_[ARG0, ARG1];
	my $child = $_[HEAP]{Kids}{WID}{$wid};
	$TEXT->insert('end', $child->PID . " ERR: $line\n");
	$TEXT->see('end');
	$poe_main_window->update;
}

sub _DoClose {
	my $wid = $_[ARG0];
	my $child = $_[HEAP]{Kids}{WID}{$wid};

	unless (defined $child) {
		print STDERR "wid $wid closed all pipes.\n";
		return;
	}

	print STDERR "wid $wid closed all pipes.\n";
	delete $_[HEAP]{Kids}{PID}{$child->PID};
}

sub _DoSig {
	print STDERR "pid $_[ARG1] exited with status $_[ARG2].\n";
	my $child = delete $_[HEAP]{Kids}{PID}{$_[ARG1]};

	return unless defined $child;

	delete $_[HEAP]{Kids}{WID}{$child->ID};
}