"""Core Ros3D controller logic"""
from __future__ import absolute_import
import logging
import datetime
from ros3ddevcontroller.param.store import ParametersStore, ParameterSnapshotter
from ros3ddevcontroller.param.backends import FileSnapshotBackend
from ros3ddevcontroller.util import make_dir


class Controller(object):
    def __init__(self):
        self.logger = logging.getLogger(__name__)
        self.servo = None
        self.snapshots_location = None
        self.snapshots_backend = None

    def set_servo(self, servo):
        """Servo interface"""
        self.logger.debug('setting servo to %s', servo)
        self.servo = servo

    def set_snapshots_location(self, loc):
        """Set location of snapshots"""
        self.snapshots_location = loc
        make_dir(self.snapshots_location)

        # update snapshots backend
        self.snapshots_backend = FileSnapshotBackend(self.snapshots_location)

    def is_servo_parameter(self, param):
        """Return true if parameter is applicable to servo"""
        return ParametersStore.is_servo_parameter(param.name)

    def apply_servo_parameter(self, param):
        """Apply parameter to servo

        :param param Parameter: parameter to apply
        :rtype: bool
        :return: True if successful"""
        raise NotImplemented('not implemented')
    def is_camera_parameter(self, param):
        """Return True if parameter is applicable to camera"""
        return ParametersStore.is_camera_parameter(param.name)

    def apply_camera_parameter(self, param):
        """Apply camera parameter

        :param param Parameter: parameter to apply
        :rtype: bool
        :return: True if successful"""
        raise NotImplementedError('not implemented')

    def apply_other_parameter(self, param):
        """Apply parameter directly in parameter store, i.e. skipping any
        interaction with external devices.

        :param param Parameter:
        :rtype: bool
        :return: True"""
        value = param.value
        name = param.name
        ParametersStore.set(name, value)
        return True

    def apply_single_parameter(self, param):
        """Apply single parameter

        :param param Parameter: parameter descriptor"""
        if self.is_servo_parameter(param):
            status = self.apply_servo_parameter(param)
        elif self.is_camera_parameter(param):
            status = self.apply_camera_parameter(param)
        else:
            status = self.apply_other_parameter(param)
        return status

    def apply_parameters(self, params):
        """Apply a parameter set

        :param params list of ParamDesc: list of parameters to apply
        :rtype: list(Parameter)
        :return: list of parameters applied"""
        # record changed parameter descriptors
        changed_params = []

        # apply parameters serially, note that if any parameter takes
        # longer to aplly this will contribute to wait time of the
        # whole request
        for param in params:
            applied = self.apply_single_parameter(param)

            # param validation was successful and was applied to servo
            if applied:
                par = ParametersStore.get(param.name)
                changed_params.append(par)

        return changed_params

    def get_parameters(self):
        """Return a dict with all parameters in the system"""
        return ParametersStore.parameters_as_dict()

    def _record_timestamp(self):
        """Helper for updating current timestamp in parameters"""
        now = datetime.datetime.now()
        ParametersStore.set('record_date', str(now),
                            notify=False)

    def take_snapshot(self):
        """Record a snapshot of current parameter set
        :return: ID of snapshot
        """
        # record timestamp
        self._record_timestamp()

        return ParameterSnapshotter.save(self.snapshots_backend)

    def list_snapshots(self):
        """List IDs of available snapshots

        :rtype list(int):
        :return: list of snapshot IDs
        """
        snapshots = self.snapshots_backend.list_snapshots()
        self.logger.debug('snapshots: %s', snapshots)
        return snapshots

    def get_snapshot(self, snapshot_id):
        """Obtain data of snapshot `snapshot_id`. Returns a dictionary with
        parameters stored in the snapshot

        :param snapshot_id int: ID of snapshot
        :rtype dict:

        """
        self.logger.debug('load snapshot %d', snapshot_id)
        sdata = self.snapshots_backend.load(snapshot_id)
        if not sdata:
            self.logger.error('failed to load snapshot data for ID %d', snapshot_id)
        return sdata

    def delete_snapshot(self, snapshot_id):
        """Remove snapshot snapshot `snapshot_id`.

        :param snapshot_id int: ID of snapshot
        :return: ID of removed snapshot

        """
        self.logger.debug('delete snapshot %d', snapshot_id)
        return self.snapshots_backend.delete(snapshot_id)

    def delete_all(self):
        """Remove all snapshots.

        :return: list of removed snapshot IDs

        """
        return self.snapshots_backend.delete_all()

@@ -244,16 +244,57 @@
 Backend%0A
+from ros3ddevcontroller.bus import servo%0A
 from ros
@@ -1330,48 +1330,510 @@
     
-raise NotImplemented('not implemented
+value = param.value%0A        name = param.name%0A        self.logger.debug('set servo param')%0A        try:%0A            if self.servo.is_active():%0A                res = self.servo.change_param(param.name, value)%0A                self.logger.debug('apply result: %25s', res)%0A                return res%0A            else:%0A                return self.apply_other_parameter(param)%0A        except servo.ParamApplyError:%0A            self.logger.exception('error when applying a parameter
 ')%0A
+            return False%0A%0A
     

implement servo parameter application