Stupid Bot Tricks Part I

I thought I’d take a stab at showing off a bot framework I’d written at the hackathon during the first Frozen Perl.

The framework is known as either Adam or Moses depending on who you’re talking to, and is available on GitHub Adam lays all the framework and Moses brings in the declarative sugar and magic. So let’s take a look at a quick bot I wrote to query GitHub’s API and display user information.

package UniBlab;
use 5.10.0;

We start of defining a package for our Bot. Adam expects your package name to be the Bot name, though you can override this later. Also we require 5.10.0 because we’re gonna use the new given/when syntax, and because working in a modern Perl won’t make us cry.

use Moses;
use namespace::autoclean;

Moses exports all the Moose, POE, and POE::Component::IRC::Common sugar that we’ll need later on. It also resets our base class to Adam, which is the default bot. namespace::autoclean will remove our sugar when we’re done just as it does in any Moose examples you may have seen.

use POE::Component::Github;

We’re going to be accessing the GitHub API so we’ll use Chris Williams’s POE::Component::GitHub. Chris is also one of the main developers for POE::Component::IRC which is the basis for Adam.

Next we specify which IRC server to join, and what channels we want to join on that network.

server 'irc.perl.org';
channels '#bots';

Now we start implementing the bot itself. At this point it looks a lot like your standard MooseX::POE class which really shouldn’t be surprising since it is. We create an attribute to store our GitHub POE component.

has github => (
    isa        => 'POE::Component::Github',
    is         => 'ro',
    lazy_build => 1,
);

sub _build_github { POE::Component::Github->spawn() }

We set up a method for searching for users, and an event to catch the return value and do something with it.

sub show_user {
    my ( $self, $name, $nick, $channel ) = @_;
    $self->debug("searching for $name");
    $self->github->yield(
        'user', 'show',
        {
            event    => '_show_user',
            user     => $name,
            _channel => $channel,
            _nick    => $nick
        }
    );
}

event _show_user => sub {
    my ( $self, $resp ) = @_[ OBJECT, ARG0 ];
    my $d = $resp->{data}{user};
    $self->privmsg( $resp->{_channel} =>
            "$resp->{_nick}: $d->{login} is $d->{name} ($d->{location}) $d->{email} $d->{blog}"
    );
};

Finally we set up a hook to POE::Component::IRC to catch our commands. This is where the given/when syntax really comes into play for our command dispatcher.

event irc_bot_addressed => sub {
    my ( $self, $nickstr, $channel, $msg ) = @_[ OBJECT, ARG0, ARG1, ARG2 ];
    my $nick = parse_user($nickstr);
    given ($msg) {
        when (/^show user (.*)/) {
            $self->show_user( $1, $nick, $channel );
        }
        default {
            $self->privmsg( $channel =>
                    "$nick: Sorry I'm not sure what to do with that" );
        }
    }
};

Finally we set up a little call to the run method defined in Adam that will start up our bot and connect it to IRC.

__PACKAGE__->run;
1;
__END__

There you go, under 60 lines and you have an IRC bot that will query GitHub for user details. An example of it’s output:

19:32 <@perigrin> UniBlab: show user perigrin
19:32 < UniBlab> perigrin: perigrin is Chris Prather (Oralndo) chris@prather.org http://chris.prather.org
19:32 <@perigrin> UniBlab: show user bingos
19:32 < UniBlab> perigrin: bingos is Chris Williams ()  http://use.perl.org/~bingos/journal/
19:32 <@perigrin> UniBlab: show user nothingmuch
19:32 < UniBlab> perigrin: nothingmuch is Yuval Kogman (The Intertubes) nothingmuch@woobling.org
                 http://nothingmuch.woobling.org

I’ll leave it as an exercise for the reader to expand this example to lookup repository information. The code is available on GitHub.