#!/usr/bin/env perl
use Mojolicious::Lite -signatures;
use Data::Dump qw/dd pp/;

# morbo --listen='http://localhost:3000' serv.pl
# This code assumes a single thread / no forking!

my $single_client;
websocket '/' => sub ($c) {
	if ( defined $single_client ) {
		$c->app->log->debug('WebSocket opened, rejecting');
		$c->send("Too many client connections");
		$c->tx->finish;
		return;
	}
	$c->app->log->debug('WebSocket opened');
	$c->inactivity_timeout(45);
	$single_client = $c->tx;
	my $timer_id;
	$c->on(message => sub ($c, $msg) {
		if ( uc $msg eq "RUN" ) {
			if ( !defined $timer_id ) {
				$c->send("Starting to run");
				$timer_id = Mojo::IOLoop->recurring( 1 => sub {
					# pretend to be a fragile server
					if ( rand > 0.97 ) {
						$c->app->log->warn('Oops, disconnecting!');
						$single_client->finish;
					}
					elsif ( rand > 0.95 ) {
						$c->app->log->warn('Oops, freezing!');
						Mojo::IOLoop->remove($timer_id);
					}
					else { $c->send("Running ".(time-$^T)) }
				} );
			}
			else { $c->send("Already running") }
		}
		elsif ( uc $msg eq "STOP" ) {
			if ( defined $timer_id ) {
				$c->send("Stopping...");
				Mojo::IOLoop->remove($timer_id);
				$timer_id = undef;
			}
			else { $c->send("Not running") }
		}
		elsif ( uc $msg eq "HEARTBEAT" ) { }
		else { $c->send("Unknown command: $msg") }
	});
	$c->on(finish => sub ($c, $code, $reason=undef) {
		$c->app->log->debug("WebSocket closed ".pp($code, $reason));
		Mojo::IOLoop->remove($timer_id);
		$single_client = undef;
	});
	$c->send("Connected... RUN|STOP");
};
app->start

##</code><code>##

#!/usr/bin/env perl
use Mojo::Base -strict, -signatures;
use Mojo::UserAgent;
use Mojo::IOLoop;
use Data::Dump qw/dd pp/;

# To connect to mux.pl: perl cli.pl ws://localhost:3001
my $ADDR = @ARGV ? $ARGV[0] : 'ws://localhost:3000';

say "Opening WebSocket...";
my $ua = Mojo::UserAgent->new;
$ua->inactivity_timeout(10); # must be more than mux's timeout
$ua->websocket($ADDR => sub ($ua, $tx) {
	die 'WebSocket handshake failed!'.pp($tx)
		unless $tx->is_websocket;
	my $timer_id = Mojo::IOLoop->recurring( 30 => sub {
		say "Sending heartbeat";
		$tx->send('HEARTBEAT');
	} );
	$tx->on(finish => sub ($tx, $code, $reason=undef) {
		say "WebSocket closed ".pp($code, $reason);
		Mojo::IOLoop->remove($timer_id);
	});
	$tx->on(message => sub ($tx, $msg) {
		say "RX: ".pp($msg);
	});
	$tx->send('RUN');
});

Mojo::IOLoop->start unless Mojo::IOLoop->is_running;

##</code><code>##

#!/usr/bin/env perl
use Mojolicious::Lite -signatures;
use Mojo::UserAgent;
use Mojo::EventEmitter;
use Data::Dump qw/dd pp/;

# morbo --listen='http://localhost:3001' mux.pl
# This code assumes a single thread / no forking!

my $event = Mojo::EventEmitter->new;

sub open_server_conn {
	state $ua = Mojo::UserAgent->new;
	$ua->inactivity_timeout(5); # must be less than client's timeout
	app->log->debug("Opening WebSocket to server...");
	$ua->websocket('ws://localhost:3000' => sub ($ua, $tx) {
		die 'WebSocket handshake failed!'.pp($tx)
			unless $tx->is_websocket;
		my $timer_id = Mojo::IOLoop->recurring( 30 => sub {
			app->log->debug("Sending heartbeat");
			$tx->send('HEARTBEAT');
		} );
		$tx->on(finish => sub ($tx, $code, $reason=undef) {
			app->log->debug("Server WebSocket closed "
				.pp($code, $reason));
			Mojo::IOLoop->remove($timer_id);
			open_server_conn(); # reopen
		});
		$tx->on(message => sub ($tx, $msg) { # message from server
			return if $msg=~/^Connected\b|^Starting\b/;
			return unless $event->has_subscribers('message');
			app->log->debug("Relaying ".pp($msg));
			$event->emit( message => $msg );
		});
		$tx->send('RUN');
	});
}
Mojo::IOLoop->next_tick(\&open_server_conn);

websocket '/' => sub ($c) { # client connections
	$c->app->log->debug('Client connected');
	$c->inactivity_timeout(45);
	my $tx = $c->tx; # client transaction
	my $cb = $event->on(message => sub ($e,$msg) { $tx->send($msg) });
	$c->on(message => sub ($c, $msg) { # message from client
		if ( uc $msg eq "RUN" ) { } # ignore client messages (for now)
		elsif ( uc $msg eq "STOP" ) { }
		elsif ( uc $msg eq "HEARTBEAT" ) { }
		else { $tx->send("Unknown command: $msg") }
	});
	$c->on(finish => sub ($c, $code, $reason=undef) {
		$c->app->log->debug("Client disconn ".pp($code, $reason));
		$event->unsubscribe(message => $cb);
		($tx,$cb) = ();
	});
	$c->send("Connected... RUN|STOP");
};
app->start