observation.py

# -*- coding: utf-8 -*-
#
# This file is part of the LOFAR2.0 Station Control project.
#
# Distributed under the terms of the APACHE license.
# See LICENSE.txt for more info.

"""
Contains class for pythonic interface with observations
"""

from json import dumps
import logging

from tango import DeviceProxy

logger = logging.getLogger()


class Observation:
    """
    This class provides a pythonic interface to the
    ObservationControl and Observation devices on a station.
    """

    def __init__(
        self,
        specification: dict,
        host: str = "databaseds.tangonet:10000",
        station="STAT",
    ):

        # create device proxies to station at "host"
        self._observation_control_dev = DeviceProxy(
            f"tango://{host}/{station}/ObservationControl/1"
        )
        self.host = host
        self.station = station

        # convert specification dict to json
        self._specification = dumps(specification)

        # get the ID
        self._id = int(specification["observation_id"])

    def observation_id(self) -> int:
        """
        Returns the observation ID of this observation
        """
        return self._id

    def start(self):
        """
        Starts this observation
        """
        self._observation_control_dev.start_observation(self._specification)

    def abort(self):
        """
        Aborts this observation
        """
        self._observation_control_dev.stop_observation(self._id)

    def observation_proxy(self):
        """
        Returns the DeviceProxy of this observation
        """
        # return a proxy to the correct Observation device on the station (
        # "STAT/Observation/{observation_id}")
        return DeviceProxy(f"tango://{self.host}/{self.station}/Observation/{self._id}")

    def is_running(self):
        """
        Returns whether this observation is currently running or not
        """
        # return whether the observation is still running (
        # ObservationControl.is_observation_running command)
        return self._observation_control_dev.is_observation_running(self._id)