plugin_base.py

from sqlalchemy.ext.declarative import declarative_base

# pylint: disable=invalid-name
DeclarativeBase = declarative_base()


class GladosPluginBase(object):
    # set true if the event should not continue propogating
    consumes_message = False

    def __init__(self, db_session, send_fn, **kwargs):
        self.send = send_fn
        self.db_session = db_session
        for attr_name, attr in kwargs.items():
            setattr(self, attr_name, attr)

    def setup(self):
        '''
            Perform any necessary setup before this plugin runs
        '''
        pass

    def teardown(self):
        '''
            Perform any necessary teardown before this plugin exits
            The DB session will be committed, so you don't have to worry about
            that.
        '''
        pass

    def can_handle_message(self, msg):
        '''
            Return something that evaluates to true if this plugin should
            handle this message.
        '''
        raise NotImplementedError

    def handle_message(self, msg):
        '''
            Handle the message
        '''
        raise NotImplementedError

    @property
    def help_text(self):
        '''
            Return text giving help about this plugin.
            Will be accessed by 'glados help PLUGIN' (lower cased)
            The 'plugin_name' property will be used.
            Otherwise, the plugin class name will be used.
            Subclasses MUST implement this.
        '''
        raise NotImplementedError('You must implement a help function')

    @property
    def plugin_name(self):
        '''
            Return a friendly name of this plugin.
        '''
        return self.__class__.__name__


class TimedPluginBase(GladosPluginBase):
    '''
        A "Timed Plugin". Timed plugins have the functionality of normal
        plugins, but also specify an interval (using cron syntax) at which
        they should receive a signal and perform some action.
    '''

    def __init__(self, *args, **kwargs):
        self.last_run_time = None
        super().__init__(*args, **kwargs)

    @property
    def interval(self):
        '''
            Timed Plugins must include an "interval" property that returns
            a cron syntax interval (as usable by croniter) at which to run
            the `timed_event` method. Plugins may specify this as an attribute.
            The 'base' time will be the time the GLaDOS daemon started.
        '''
        raise NotImplementedError('Timed plugins must include an interval!')

    def run_timed_event(self):
        '''
            The event to run at the interval specified by `interval`
        '''
        raise NotImplementedError('Timed plugins must include a timed event!')