.. _Scheduler-Example-Agent:

=======================
Scheduler Example Agent
=======================

The Scheduler Example Agent demonstrates how to use the scheduling feature of the :ref`Actuator Agent <Actuator-Agent>`
as well as how to send a command.  This agent publishes a request for a reservation on a (fake) device then takes an
action when it's scheduled time appears.  The ActuatorAgent must be running to exercise this example.

.. Note::

    Since there is no actual device, an error is produced when the agent attempts to take its action.

.. code-block:: python

    def publish_schedule(self):
        '''Periodically publish a schedule request'''
        headers = {
            'AgentID': agent_id,
            'type': 'NEW_SCHEDULE',
            'requesterID': agent_id, #The name of the requesting agent.
            'taskID': agent_id + "-ExampleTask", #The desired task ID for this task. It must be unique among all other scheduled tasks.
            'priority': 'LOW', #The desired task priority, must be 'HIGH', 'LOW', or 'LOW_PREEMPT'
            } 

        start = str(datetime.datetime.now())
        end = str(datetime.datetime.now() + datetime.timedelta(minutes=1))


        msg = [
           ['campus/building/unit',start,end]
        ]
        self.vip.pubsub.publish(
        'pubsub', topics.ACTUATOR_SCHEDULE_REQUEST, headers, msg)

The agent listens to schedule announcements from the actuator and then issues a command:

.. code-block:: python

    @PubSub.subscribe('pubsub', topics.ACTUATOR_SCHEDULE_ANNOUNCE(campus='campus',
                                         building='building',unit='unit'))
    def actuate(self, peer, sender, bus,  topic, headers, message):
        print("response:", topic, headers, message)
        if headers[headers_mod.REQUESTER_ID] != agent_id:
            return
        '''Match the announce for our fake device with our ID
        Then take an action. Note, this command will fail since there is no
        actual device'''
        headers = {
                    'requesterID': agent_id,
                   }
        self.vip.pubsub.publish(
        'pubsub', topics.ACTUATOR_SET(campus='campus',
                                         building='building',unit='unit',
                                         point='point'),
                                         headers, 0.0)