#!/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.
#

"""Virtual OLT Hardware Abstraction main entry point"""

import argparse
import arrow
import os
import time

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

from common.event_bus import EventBusClient
from common.manhole import Manhole
from common.structlog_setup import setup_logging, update_logging
from common.utils.dockerhelpers import get_my_containers_name
from common.utils.nethelpers import get_my_primary_interface, \
    get_my_primary_local_ipv4
from voltha.adapters.loader import AdapterLoader
from voltha.coordinator import Coordinator
from voltha.coordinator_etcd import CoordinatorEtcd
from voltha.core.core import VolthaCore
from voltha.core.config.config_backend import load_backend
from voltha.northbound.diagnostics import Diagnostics
from voltha.northbound.grpc.grpc_server import VolthaGrpcServer
from voltha.northbound.kafka.kafka_proxy import KafkaProxy, get_kafka_proxy
from voltha.northbound.rest.health_check import init_rest_service
from voltha.protos.common_pb2 import LogLevel
from voltha.registry import registry, IComponent
from common.frameio.frameio import FrameIOManager

VERSION = '0.9.0'


defs = dict(
    config=os.environ.get('CONFIG', './voltha.yml'),
    consul=os.environ.get('CONSUL', 'localhost:8500'),
    etcd=os.environ.get('ETCD', 'localhost:2379'),
    inter_core_subnet=os.environ.get('INTER_CORE_SUBNET', None),
    pon_subnet=os.environ.get('PON_SUBNET', None),
    external_host_address=os.environ.get('EXTERNAL_HOST_ADDRESS',
                                         get_my_primary_local_ipv4()),
    fluentd=os.environ.get('FLUENTD', None),
    grpc_port=os.environ.get('GRPC_PORT', 50055),
    instance_id=os.environ.get('INSTANCE_ID', os.environ.get('HOSTNAME', '1')),
    internal_host_address=os.environ.get('INTERNAL_HOST_ADDRESS',
                                         get_my_primary_local_ipv4()),
    interface=os.environ.get('INTERFACE', get_my_primary_interface()),
    rest_port=os.environ.get('REST_PORT', 8880),
    kafka=os.environ.get('KAFKA', 'localhost:9092'),
    manhole_port=os.environ.get('MANHOLE_PORT', 12222),
    backend=os.environ.get('BACKEND', 'none'),
)


def parse_args():
    parser = argparse.ArgumentParser()

    _help = ('Path to voltha.yml config file (default: %s). '
             'If relative, it is relative to main.py of voltha.'
             % defs['config'])
    parser.add_argument('-c', '--config',
                        dest='config',
                        action='store',
                        default=defs['config'],
                        help=_help)

    _help = '<hostname>:<port> to consul agent (default: %s)' % defs['consul']
    parser.add_argument(
        '-C', '--consul', dest='consul', action='store',
        default=defs['consul'],
        help=_help)

    _help = '<hostname>:<port> to etcd server (default: %s)' % defs['etcd']
    parser.add_argument(
        '-e', '--etcd', dest='etcd', action='store',
        default=defs['etcd'],
        help=_help)

    _help = ('<inter_core_subnet> is the subnet connecting all the voltha '
             'instances in a cluster (default: %s)' % defs['inter_core_subnet'])
    parser.add_argument('-V', '--inter-core-subnet',
                        dest='inter_core_subnet',
                        action='store',
                        default=defs['inter_core_subnet'],
                        help=_help)

    _help = ('<pon subnet> is the subnet connecting the voltha instances'
             'with the PON network (default: %s)' % defs['pon_subnet'])
    parser.add_argument('-P', '--pon-subnet',
                        dest='pon_subnet',
                        action='store',
                        default=defs['pon_subnet'],
                        help=_help)

    _help = ('<hostname> or <ip> at which Voltha is reachable from outside '
             'the cluster (default: %s)' % defs['external_host_address'])
    parser.add_argument('-E', '--external-host-address',
                        dest='external_host_address',
                        action='store',
                        default=defs['external_host_address'],
                        help=_help)

    _help = ('port number of the GRPC service exposed by voltha (default: %s)'
             % defs['grpc_port'])
    parser.add_argument('-g', '--grpc-port',
                        dest='grpc_port',
                        action='store',
                        default=defs['grpc_port'],
                        help=_help)

    _help = ('<hostname>:<port> to fluentd server (default: %s). (If not '
             'specified (None), the address from the config file is used'
             % defs['fluentd'])
    parser.add_argument('-F', '--fluentd',
                        dest='fluentd',
                        action='store',
                        default=defs['fluentd'],
                        help=_help)

    _help = ('<hostname> or <ip> at which Voltha is reachable from inside the'
             'cluster (default: %s)' % defs['internal_host_address'])
    parser.add_argument('-H', '--internal-host-address',
                        dest='internal_host_address',
                        action='store',
                        default=defs['internal_host_address'],
                        help=_help)

    _help = ('unique string id of this voltha instance (default: %s)'
             % defs['instance_id'])
    parser.add_argument('-i', '--instance-id',
                        dest='instance_id',
                        action='store',
                        default=defs['instance_id'],
                        help=_help)

    _help = 'ETH interface to recieve (default: %s)' % defs['interface']
    parser.add_argument('-I', '--interface',
                        dest='interface',
                        action='store',
                        default=defs['interface'],
                        help=_help)

    _help = 'open ssh manhole at given port'
    parser.add_argument('-m', '--manhole-port',
                        dest='manhole_port',
                        action='store',
                        type=int,
                        default=None,
                        help=_help)

    _help = 'omit startup banner log lines'
    parser.add_argument('-n', '--no-banner',
                        dest='no_banner',
                        action='store_true',
                        default=False,
                        help=_help)

    _help = 'do not emit periodic heartbeat log messages'
    parser.add_argument('-N', '--no-heartbeat',
                        dest='no_heartbeat',
                        action='store_true',
                        default=False,
                        help=_help)

    _help = ('port number for the rest service (default: %d)'
             % defs['rest_port'])
    parser.add_argument('-R', '--rest-port',
                        dest='rest_port',
                        action='store',
                        type=int,
                        default=defs['rest_port'],
                        help=_help)

    _help = "suppress debug and info logs"
    parser.add_argument('-q', '--quiet',
                        dest='quiet',
                        action='count',
                        help=_help)

    _help = 'enable verbose logging'
    parser.add_argument('-v', '--verbose',
                        dest='verbose',
                        action='count',
                        help=_help)

    _help = ('use docker container name as voltha instance id'
             ' (overrides -i/--instance-id option)')
    parser.add_argument('--instance-id-is-container-name',
                        dest='instance_id_is_container_name',
                        action='store_true',
                        default=False,
                        help=_help)

    _help = ('<hostname>:<port> of the kafka broker (default: %s). (If not '
             'specified (None), the address from the config file is used'
             % defs['kafka'])
    parser.add_argument('-K', '--kafka',
                        dest='kafka',
                        action='store',
                        default=defs['kafka'],
                        help=_help)

    _help = 'backend to use for config persitence'
    parser.add_argument('-b', '--backend',
                        default=defs['backend'],
                        choices=['none', 'consul', 'etcd'],
                        help=_help)

    args = parser.parse_args()

    # post-processing

    if args.instance_id_is_container_name:
        args.instance_id = get_my_containers_name()

    """ 
    The container external, internal IP and PON interface needs to be 
    set based on the subnet data.  At this time the internal IP is not used. 
    The external IP is used for inter-core communications.  If the subnets are
    set then they take precedence over the other relevant arguments (
    external and internal host as well as interface
    """
    if args.inter_core_subnet:
        m_ip = get_my_primary_local_ipv4(inter_core_subnet=args.inter_core_subnet)
        args.external_host_address = m_ip
        args.internal_host_address = m_ip

    if args.pon_subnet:
        args.interface = get_my_primary_interface(args.pon_subnet)

    return args


def load_config(args):
    path = args.config
    if path.startswith('.'):
        dir = os.path.dirname(os.path.abspath(__file__))
        path = os.path.join(dir, path)
    path = os.path.abspath(path)
    with open(path) as fd:
        config = yaml.load(fd)
    return config


def print_banner(log):
    log.info(' _    ______  __  ________  _____ ')
    log.info('| |  / / __ \/ / /_  __/ / / /   |')
    log.info('| | / / / / / /   / / / /_/ / /| |')
    log.info('| |/ / /_/ / /___/ / / __  / ___ |')
    log.info('|___/\____/_____/_/ /_/ /_/_/  |_|')
    log.info('(to stop: press Ctrl-C)')


@implementer(IComponent)
class Main(object):

    def __init__(self):

        self.args = args = parse_args()
        self.config = load_config(args)

        verbosity_adjust = (args.verbose or 0) - (args.quiet or 0)
        self.log = setup_logging(self.config.get('logging', {}),
                                 args.instance_id,
                                 verbosity_adjust=verbosity_adjust,
                                 fluentd=args.fluentd)

        # configurable variables from voltha.yml file
        #self.configurable_vars = self.config.get('Constants', {})

        if not args.no_banner:
            print_banner(self.log)

        # Create a unique instnce id using the passed-in instanceid and
        # UTC timestamp
        current_time = arrow.utcnow().timestamp
        self.instance_id = self.args.instance_id + '_' + str(current_time)

        # Every voltha instance is given a core_storage id where the
        # instance data is stored
        self.core_store_id = None

        self.startup_components()

        if not args.no_heartbeat:
            self.start_heartbeat()
            self.start_kafka_heartbeat(self.instance_id)

        self.manhole = None

    def start(self):
        self.start_reactor()  # will not return except Keyboard interrupt

    def stop(self):
        pass

    def get_args(self):
        """Allow access to command line args"""
        return self.args

    def get_config(self):
        """Allow access to content of config file"""
        return self.config

    @inlineCallbacks
    def startup_components(self):
        try:
            self.log.info('starting-internal-components',
                          internal_host=self.args.internal_host_address,
                          external_host=self.args.external_host_address,
                          interface=self.args.interface,
                          consul=self.args.consul,
                          etcd=self.args.etcd)

            registry.register('main', self)

            if self.args.backend == 'consul':
                yield registry.register(
                    'coordinator',
                    Coordinator(
                        internal_host_address=self.args.internal_host_address,
                        external_host_address=self.args.external_host_address,
                        rest_port=self.args.rest_port,
                        instance_id=self.instance_id,
                        config=self.config,
                        consul=self.args.consul)
                ).start()
            elif self.args.backend == 'etcd':
                yield registry.register(
                    'coordinator',
                    CoordinatorEtcd(
                        internal_host_address=self.args.internal_host_address,
                        external_host_address=self.args.external_host_address,
                        rest_port=self.args.rest_port,
                        instance_id=self.instance_id,
                        config=self.config,
                        consul=self.args.consul,
                        etcd=self.args.etcd)
                ).start()

            self.log.info('waiting-for-config-assignment')

            # Wait until we get a config id before we proceed
            self.core_store_id, store_prefix = \
                yield registry('coordinator').get_core_store_id_and_prefix()

            self.log.info('store-id', core_store_id=self.core_store_id)

            # Update the logger to output the vcore id.
            self.log = update_logging(instance_id=self.instance_id, vcore_id=self.core_store_id)

            yield registry.register(
                'grpc_server',
                VolthaGrpcServer(self.args.grpc_port)
            ).start()

            yield registry.register(
                'core',
                VolthaCore(
                    instance_id=self.instance_id,
                    core_store_id = self.core_store_id,
                    grpc_port=self.args.grpc_port,
                    version=VERSION,
                    log_level=LogLevel.INFO
                )
            ).start(config_backend=load_backend(store_id=self.core_store_id,
                                                store_prefix=store_prefix,
                                                args=self.args))

            init_rest_service(self.args.rest_port)

            yield registry.register(
                'kafka_proxy',
                KafkaProxy(
                    self.args.consul,
                    self.args.kafka,
                    config=self.config.get('kafka-proxy', {})
                )
            ).start()

            yield registry.register(
                'frameio',
                FrameIOManager()
            ).start()

            yield registry.register(
                'adapter_loader',
                AdapterLoader(config=self.config.get('adapter_loader', {}))
            ).start()

            yield registry.register(
                'diag',
                Diagnostics(config=self.config.get('diagnostics', {}))
            ).start()

            if self.args.manhole_port is not None:
                self.start_manhole(self.args.manhole_port)

            # Now that all components are loaded, in the scenario where this
            # voltha instance is picking up an existing set of data (from a
            # voltha instance that dies/stopped) then we need to setup this
            # instance from where the previous one left

            yield registry('core').reconcile_data()

            # Now that the data is in memory and the reconcile process
            # within the core has completed (the reconciliation may still be
            #  in progress with the adapters) we expose the NBI of voltha core
            yield registry('core').register_grpc_service()

            self.log.info('started-internal-services')

        except Exception as e:
            self.log.exception('Failure-to-start-all-components', e=e)

    def start_manhole(self, port):
        self.manhole = Manhole(
            port,
            pws=dict(admin='adminpw'),
            eventbus = EventBusClient(),
            **registry.components
        )

    @inlineCallbacks
    def shutdown_components(self):
        """Execute before the reactor is shut down"""
        self.log.info('exiting-on-keyboard-interrupt')
        for component in reversed(registry.iterate()):
            yield component.stop()

        import threading
        self.log.info('THREADS:')
        main_thread = threading.current_thread()
        for t in threading.enumerate():
            if t is main_thread:
                continue
            if not t.isDaemon():
                continue
            self.log.info('joining thread {} {}'.format(
                t.getName(), "daemon" if t.isDaemon() else "not-daemon"))
            t.join()

    def start_reactor(self):
        from twisted.internet import reactor
        reactor.callWhenRunning(
            lambda: self.log.info('twisted-reactor-started'))
        reactor.addSystemEventTrigger('before', 'shutdown',
                                      self.shutdown_components)
        reactor.run()

    def start_heartbeat(self):

        t0 = time.time()
        t0s = time.ctime(t0)

        def heartbeat():
            self.log.debug(status='up', since=t0s, uptime=time.time() - t0)

        lc = LoopingCall(heartbeat)
        lc.start(10)

    # Temporary function to send a heartbeat message to the external kafka
    # broker
    def start_kafka_heartbeat(self, instance_id):
        # For heartbeat we will send a message to a specific "voltha-heartbeat"
        #  topic.  The message is a protocol buf
        # message
        message = dict(
            type='heartbeat',
            voltha_instance=instance_id,
            ip=get_my_primary_local_ipv4()
        )
        topic = "voltha.heartbeat"

        def send_msg():
            try:
                kafka_proxy = get_kafka_proxy()
                if kafka_proxy and not kafka_proxy.is_faulty():
                    self.log.debug('kafka-proxy-available')
                    message['ts'] = arrow.utcnow().timestamp
                    self.log.debug('start-kafka-heartbeat')
                    kafka_proxy.send_message(topic, dumps(message))
                else:
                    self.log.error('kafka-proxy-unavailable')
            except Exception, e:
                self.log.exception('failed-sending-message-heartbeat', e=e)

        try:
            lc = LoopingCall(send_msg)
            lc.start(10)
        except Exception, e:
            self.log.exception('failed-kafka-heartbeat', e=e)


if __name__ == '__main__':
    Main().start()