#!/usr/bin/env python
#
# Copyright 2017 the original author or authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

"""
Voltha internal diagnostics
"""
import arrow
import gc
import structlog
import resource

from simplejson import dumps
from twisted.internet.defer import Deferred
from twisted.internet.task import LoopingCall
from zope.interface import implementer

from common.event_bus import EventBusClient
from voltha.registry import IComponent, registry

log = structlog.get_logger()


@implementer(IComponent)
class Diagnostics(object):

    def __init__(self, config):
        self.config = config
        self.periodic_check_interval = config.get(
            'periodic_check_interval', 15)
        self.periodic_checks = None
        self.event_bus = EventBusClient()
        self.instance_id = registry('main').get_args().instance_id

    def start(self):
        log.debug('starting')
        self.periodic_checks = LoopingCall(self.run_periodic_checks)
        self.periodic_checks.start(self.periodic_check_interval)
        log.info('started')
        return self

    def stop(self):
        log.debug('stopping')
        if self.periodic_checks is not None:
            self.periodic_checks.stop()
        log.info('stopped')

    def run_periodic_checks(self):

        ts = arrow.utcnow().timestamp

        def deferreds():
            return len(gc.get_referrers(Deferred))

        def rss_mb():
            return resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024/1024

        data = dict(
            type='slice',
            ts=ts,
            data={
                'voltha.internal.{}'.format(self.instance_id): {
                    'deferreds': deferreds(),
                    'rss-mb': rss_mb(),
                }
            }
        )
        self.event_bus.publish('kpis', dumps(data))
        log.debug('periodic-check', ts=ts)