pbot/lib/PBot/Modules.pm

# File: Modules.pm
#
# Purpose: Modules are command-line programs and scripts that can be loaded
# via PBot factoids. Command arguments are passed as command-line arguments.
# The standard output from the script is returned as the bot command result.
# The standard error output is stored in a file named <module>-stderr in the
# modules/ directory.

# SPDX-FileCopyrightText: 2021 Pragmatic Software <pragma78@gmail.com>
# SPDX-License-Identifier: MIT

package PBot::Modules;
use parent 'PBot::Class';

use PBot::Imports;

use IPC::Run qw/run timeout/;
use Encode;

sub initialize {
    my ($self, %conf) = @_;

    # bot commands to load and unload modules
    $self->{pbot}->{commands}->register(sub { $self->cmd_load(@_) },   "load",   1);
    $self->{pbot}->{commands}->register(sub { $self->cmd_unload(@_) }, "unload", 1);
}

sub cmd_load {
    my ($self, $context) = @_;

    my ($keyword, $module) = $self->{pbot}->{interpreter}->split_args($context->{arglist}, 2);

    return "Usage: load <keyword> <module>" if not defined $module;

    my $factoids = $self->{pbot}->{factoids}->{storage};

    if ($factoids->exists('.*', $keyword)) {
        return 'There is already a keyword named ' . $factoids->get_data('.*', $keyword, '_name') . '.';
    }

    $self->{pbot}->{factoids}->add_factoid('module', '.*', $context->{hostmask}, $keyword, $module, 1);

    $factoids->set('.*', $keyword, 'add_nick',   1, 1);
    $factoids->set('.*', $keyword, 'nooverride', 1);

    $self->{pbot}->{logger}->log("$context->{hostmask} loaded module $keyword => $module\n");

    return "Loaded module $keyword => $module";
}

sub cmd_unload {
    my ($self, $context) = @_;

    my $module = $self->{pbot}->{interpreter}->shift_arg($context->{arglist});

    return "Usage: unload <keyword>" if not defined $module;

    my $factoids = $self->{pbot}->{factoids}->{storage};

    if (not $factoids->exists('.*', $module)) {
        return "/say $module not found.";
    }

    if ($factoids->get_data('.*', $module, 'type') ne 'module') {
        return "/say " . $factoids->get_data('.*', $module, '_name') . ' is not a module.';
    }

    my $name = $factoids->get_data('.*', $module, '_name');

    $factoids->remove('.*', $module);

    $self->{pbot}->{logger}->log("$context->{hostmask} unloaded module $module\n");

    return "/say $name unloaded.";
}

sub execute_module {
    my ($self, $context) = @_;
    my $text;

    if ($self->{pbot}->{registry}->get_value('general', 'debugcontext')) {
        use Data::Dumper;
        $Data::Dumper::Sortkeys = 1;
        $self->{pbot}->{logger}->log("execute_module\n");
        $self->{pbot}->{logger}->log(Dumper $context);
    }

    $self->{pbot}->{process_manager}->execute_process($context, sub { $self->launch_module(@_) });
}

sub launch_module {
    my ($self, $context) = @_;

    $context->{arguments} //= '';

    my @factoids = $self->{pbot}->{factoids}->find_factoid($context->{from}, $context->{keyword}, exact_channel => 2, exact_trigger => 2);

    if (not @factoids or not $factoids[0]) {
        $context->{checkflood} = 1;
        $self->{pbot}->{interpreter}->handle_result($context, "/msg $context->{nick} Failed to find module for '$context->{keyword}' in channel $context->{from}\n");
        return;
    }

    my ($channel, $trigger) = ($factoids[0]->[0], $factoids[0]->[1]);

    $context->{channel} = $channel;
    $context->{keyword} = $trigger;
    $context->{trigger} = $trigger;

    my $module = $self->{pbot}->{factoids}->{storage}->get_data($channel, $trigger, 'action');

    $self->{pbot}->{logger}->log(
        '(' . (defined $context->{from} ? $context->{from} : "(undef)") . '): '
        . "$context->{hostmask}: Executing module [$context->{command}] $module $context->{arguments}\n"
    );

    $context->{arguments} = $self->{pbot}->{factoids}->expand_factoid_vars($context, $context->{arguments});

    my $module_dir = $self->{pbot}->{registry}->get_value('general', 'module_dir');

    if (not chdir $module_dir) {
        $self->{pbot}->{logger}->log("Could not chdir to '$module_dir': $!\n");
        Carp::croak("Could not chdir to '$module_dir': $!");
    }

    if ($self->{pbot}->{factoids}->{storage}->exists($channel, $trigger, 'workdir')) {
        chdir $self->{pbot}->{factoids}->{storage}->get_data($channel, $trigger, 'workdir');
    }

    # FIXME -- add check to ensure $module exists

    my ($exitval, $stdout, $stderr) = eval {
        my $args = $context->{arguments};

        if (not $context->{args_utf8}) {
            $args = encode('UTF-8', $args);
        }

        my @cmdline = ("./$module", $self->{pbot}->{interpreter}->split_line($args));

        my $timeout = $self->{pbot}->{registry}->get_value('general', 'module_timeout') // 30;

        my ($stdin, $stdout, $stderr);

        run \@cmdline, \$stdin, \$stdout, \$stderr, timeout($timeout);

        my $exitval = $? >> 8;

        utf8::decode $stdout;
        utf8::decode $stderr;

        return ($exitval, $stdout, $stderr);
    };

    if ($@) {
        my $error = $@;
        if ($error =~ m/timeout on timer/) {
            ($exitval, $stdout, $stderr) = (-1, "$context->{trigger}: timed-out", '');
        } else {
            ($exitval, $stdout, $stderr) = (-1, '', $error);
            $self->{pbot}->{logger}->log("$context->{trigger}: error executing module: $error\n");
        }
    }

    if (length $stderr) {
        if (open(my $fh, '>>', "$module-stderr")) {
            print $fh $stderr;
            close $fh;
        } else {
            $self->{pbot}->{logger}->log("Failed to open $module-stderr: $!\n");
        }
    }

    $context->{result} = $stdout;
    chomp $context->{result};
}

1;