#
# Copyright 2018 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.
#

import structlog
import threading
import grpc
import collections
import time

from twisted.internet import reactor
from scapy.layers.l2 import Ether, Dot1Q
import binascii

from voltha.protos.device_pb2 import Port, Device
from voltha.protos.common_pb2 import OperStatus, AdminState, ConnectStatus
from voltha.protos.logical_device_pb2 import LogicalDevice
from voltha.protos.openflow_13_pb2 import OFPPS_LIVE, OFPPF_FIBER, OFPPS_LINK_DOWN, \
    OFPPF_1GB_FD, OFPC_GROUP_STATS, OFPC_PORT_STATS, OFPC_TABLE_STATS, \
    OFPC_FLOW_STATS, ofp_switch_features, ofp_desc, ofp_port, \
    OFPXMC_OPENFLOW_BASIC
from voltha.protos.logical_device_pb2 import LogicalPort, LogicalDevice
from voltha.core.logical_device_agent import mac_str_to_tuple
from voltha.registry import registry
from voltha.adapters.openolt.protos import openolt_pb2_grpc, openolt_pb2
from voltha.protos.bbf_fiber_tcont_body_pb2 import TcontsConfigData
import voltha.core.flow_decomposer as fd

HSIA_FLOW_INDEX = 0 # FIXME
DHCP_FLOW_INDEX = 1 # FIXME
EAPOL_FLOW_INDEX = 2 # FIXME
EAPOL_DOWNLINK_FLOW_INDEX = 3 # FIXME

# FIXME - see also BRDCM_DEFAULT_VLAN in broadcom_onu.py
DEFAULT_MGMT_VLAN = 4091

OnuKey = collections.namedtuple('OnuKey', ['intf_id', 'onu_id'])
OnuRec = collections.namedtuple('OnuRec', ['serial_number', 'state'])

"""
Encoding of identifiers
=======================

GEM port ID

    GEM port id is unique per PON port

     10              3      0
    +--+--------------+------+
    |1 |     onu id   | GEM  |
    |  |              | idx  |
    +--+--------------+------+

    GEM port id range (0, 1023) is reserved
    onu id = 7 bits = 128 ONUs per PON
    GEM index = 3 bits = 8 GEM ports per ONU

Alloc ID

    Uniquely identifies a T-CONT
    Ranges from 0 to 4095
    Unique per PON interface

     12         6            0
    +------------+------------+
    |   onu id   | Alloc idx  |
    +------------+------------+

    onu id = 7 bits = 128 ONUs per PON
    Alloc index = 6 bits = 64 GEM ports per ONU

Flow id

    Identifies a flow within a single OLT
    Flow Id is unique per OLT
    Multiple GEM ports can map to same flow id

     13    11              4      0
    +--------+--------------+------+
    | pon id |    onu id    | Flow |
    |        |              | idx  |
    +--------+--------------+------+

    14 bits = 16384 flows (per OLT).

    pon id = 4 bits = 16 PON ports
    onu id = 7 bits = 128 ONUss per PON port
    Flow index = 3 bits = 4 bi-directional flows per ONU
                        = 8 uni-directional flows per ONU


Logical (OF) UNI port number

    OpenFlow port number corresponding to PON UNI

     15       11              4      0
    +--+--------+--------------+------+
    |0 | pon id |    onu id    |   0  |
    +--+--------+--------------+------+

    pon id = 4 bits = 16 PON ports
    onu id = 7 bits = 128 ONUs per PON port


PON OLT (OF) port number

    OpenFlow port number corresponding to PON OLT ports

     31    28                                 0
    +--------+------------------------~~~------+
    |  0x2   |          pon intf id            |
    +--------+------------------------~~~------+

"""

"""
OpenoltDevice represents an OLT.
"""
class OpenoltDevice(object):

    def __init__(self, **kwargs):
        super(OpenoltDevice, self).__init__()

        self.adapter_agent = kwargs['adapter_agent']
        self.device_num = kwargs['device_num']
        device = kwargs['device']
        self.device_id = device.id
        self.host_and_port = device.host_and_port
        self.log = structlog.get_logger(id=self.device_id, ip=self.host_and_port)
        self.nni_oper_state = dict() #intf_id -> oper_state
        self.onus = {} # OnuKey -> OnuRec

        # Update device
        device.root = True
        device.serial_number = self.host_and_port # FIXME
        device.connect_status = ConnectStatus.REACHABLE
        device.oper_status = OperStatus.ACTIVATING
        self.adapter_agent.update_device(device)

        # Initialize gRPC
        self.channel = grpc.insecure_channel(self.host_and_port)
        self.channel_ready_future = grpc.channel_ready_future(self.channel)

        # Start indications thread
        self.indications_thread = threading.Thread(target=self.process_indications)
        self.indications_thread.daemon = True
        self.indications_thread.start()

    def process_indications(self):
        self.channel_ready_future.result() # blocks till gRPC connection is complete
        self.stub = openolt_pb2_grpc.OpenoltStub(self.channel)
        self.indications = self.stub.EnableIndication(openolt_pb2.Empty())
        while True:
            # get the next indication from olt
            ind = next(self.indications)
            self.log.debug("rx indication", indication=ind)

            # indication handlers run in the main event loop
            if ind.HasField('olt_ind'):
                reactor.callFromThread(self.olt_indication, ind.olt_ind)
            elif ind.HasField('intf_ind'):
                reactor.callFromThread(self.intf_indication, ind.intf_ind)
            elif ind.HasField('intf_oper_ind'):
                reactor.callFromThread(self.intf_oper_indication,
                        ind.intf_oper_ind)
            elif ind.HasField('onu_disc_ind'):
                reactor.callFromThread(self.onu_discovery_indication,
                        ind.onu_disc_ind)
            elif ind.HasField('onu_ind'):
                reactor.callFromThread(self.onu_indication, ind.onu_ind)
            elif ind.HasField('omci_ind'):
                reactor.callFromThread(self.omci_indication, ind.omci_ind)
            elif ind.HasField('pkt_ind'):
                reactor.callFromThread(self.packet_indication, ind.pkt_ind)

    def olt_indication(self, olt_indication):
	self.log.debug("olt indication", olt_ind=olt_indication)

        # FIXME
        if olt_indication.oper_state == "down":
	    self.log.error("ignore olt oper state down", olt_ind=olt_indication)
            return

        if not hasattr(olt_indication, 'mac') or \
                not olt_indication.mac:
            mac = '00:00:00:00:00:' + '{:02x}'.format(self.device_num)
        else:
            mac = olt_indication.mac

        # Create logical OF device
        ld = LogicalDevice(root_device_id=self.device_id)
        ld_initialized = self.adapter_agent.create_logical_device(ld, dpid=mac)
        self.logical_device_id = ld_initialized.id

        # Update phys OF device
        device = self.adapter_agent.get_device(self.device_id)
        device.parent_id = self.logical_device_id
        device.oper_status = OperStatus.ACTIVE
        self.adapter_agent.update_device(device)


    def intf_indication(self, intf_indication):
	self.log.debug("intf indication", intf_id=intf_indication.intf_id,
            oper_state=intf_indication.oper_state)

        if intf_indication.oper_state == "up":
            oper_status = OperStatus.ACTIVE
        else:
            oper_status = OperStatus.DISCOVERED

        # FIXME - If port exists, update oper state
        self.add_port(intf_indication.intf_id, Port.PON_OLT, oper_status)

    def intf_oper_indication(self, intf_oper_indication):
	self.log.debug("Received interface oper state change indication",
                intf_id=intf_oper_indication.intf_id,
                type=intf_oper_indication.type,
                oper_state=intf_oper_indication.oper_state)

        if intf_oper_indication.oper_state == "up":
            oper_state = OperStatus.ACTIVE
        else:
            oper_state = OperStatus.DISCOVERED

        if intf_oper_indication.type == "nni":

            # FIXME - creating logical port for 2nd interface throws exception!
            if intf_oper_indication.intf_id != 0:
                return

            if intf_oper_indication.intf_id not in self.nni_oper_state:
                self.nni_oper_state[intf_oper_indication.intf_id] = oper_state
                port_no, label = self.add_port(intf_oper_indication.intf_id, Port.ETHERNET_NNI, oper_state)
	        self.log.debug("int_oper_indication", port_no=port_no, label=label)
                self.add_logical_port(port_no, intf_oper_indication.intf_id) # FIXME - add oper_state
            elif intf_oper_indication.intf_id != self.nni_oper_state:
                # FIXME - handle subsequent NNI oper state change
                pass

        elif intf_oper_indication.type == "pon":
            # FIXME - handle PON oper state change
            pass

    def onu_discovery_indication(self, onu_disc_indication):
        intf_id = onu_disc_indication.intf_id
        serial_number=onu_disc_indication.serial_number

	self.log.debug("onu discovery indication", intf_id=intf_id,
            serial_number=serial_number)

        key = self.lookup_key(serial_number=serial_number)

        if key is None:
            onu_id = self.new_onu_id(intf_id)
            try:
                self.add_onu_device(intf_id,
                        self.intf_id_to_port_no(intf_id, Port.PON_OLT),
                        onu_id, serial_number)
            except Exception as e:
                self.log.exception('onu activation failed', e=e)
            else:
		self.log.info("activate onu", intf_id=intf_id, onu_id=onu_id,
                        serial_number=serial_number)
                self.onus[OnuKey(intf_id=intf_id, onu_id=onu_id)] \
                        = OnuRec(serial_number=serial_number, state='discovered')
		onu = openolt_pb2.Onu(intf_id=intf_id, onu_id=onu_id,
			serial_number=serial_number)
		self.stub.ActivateOnu(onu)
        else:
            # FIXME - handle onu discover indication for a discovered/activated onu
            onu_id = key.onu_id
            intf_id = key.intf_id
            if self.onus[key].state == 'discovered' or \
                    self.onus[key].state == 'active':
	        self.log.info("ignore onu discovery indication", intf_id=intf_id,
                        onu_id=onu_id, state=self.onus[key].state)

    def mk_uni_port_num(self, intf_id, onu_id):
        return intf_id << 11 | onu_id << 4

    def onu_id_from_port_num(self, port_num):
        return (port_num >> 4) & 0x7F

    def intf_id_from_port_num(self, port_num):
        return (port_num >> 11) & 0xF

    def onu_indication(self, onu_indication):
        self.log.debug("onu indication", intf_id=onu_indication.intf_id,
                onu_id=onu_indication.onu_id)

        key = self.lookup_key(serial_number=onu_indication.serial_number)

        # FIXME - handle serial_number mismatch
        assert key is not None

        # FIXME - handle intf_id mismatch (ONU move?)
        assert onu_indication.intf_id == key.intf_id

        # FIXME - handle onu id mismatch
        assert onu_indication.onu_id == key.onu_id

        if self.onus[key].state is not 'discovered':
            self.log.debug("ignore onu indication",
                    intf_id=onu_indication.intf_id,
                    onu_id=onu_indication.onu_id,
                    state=self.onus[key].state)
            return

        self.onus[key] = self.onus[key]._replace(state='active')

        onu_device = self.adapter_agent.get_child_device(self.device_id,
                onu_id=onu_indication.onu_id)
        assert onu_device is not None

        msg = {'proxy_address':onu_device.proxy_address,
               'event':'activation-completed',
               'event_data':{'activation_successful':True}}
        self.adapter_agent.publish_inter_adapter_message(onu_device.id, msg)

        #
        # tcont create (onu)
        #
        alloc_id = self.mk_alloc_id(onu_indication.onu_id)
        msg = {'proxy_address':onu_device.proxy_address,
               'event':'create-tcont',
               'event_data':{'alloc_id':alloc_id}}
        self.adapter_agent.publish_inter_adapter_message(onu_device.id, msg)

        #
        # v_enet create (olt)
        #
        uni_no = self.mk_uni_port_num(onu_indication.intf_id, onu_indication.onu_id)
        uni_name = self.port_name(uni_no, Port.ETHERNET_UNI)
	self.adapter_agent.add_port(
            self.device_id,
            Port(
                port_no=uni_no,
                label=uni_name,
                type=Port.ETHERNET_UNI,
                admin_state=AdminState.ENABLED,
                oper_status=OperStatus.ACTIVE))

        #
        # v_enet create (onu)
        #
        interface_name = self.port_name(onu_indication.intf_id, Port.PON_OLT, onu_indication.intf_id)
        msg = {'proxy_address':onu_device.proxy_address,
               'event':'create-venet',
               'event_data':{'uni_name':uni_name, 'interface_name':uni_name}}
        self.adapter_agent.publish_inter_adapter_message(onu_device.id, msg)

        #
        # gem port create
        #
        gemport_id = self.mk_gemport_id(onu_indication.onu_id)
        msg = {'proxy_address':onu_device.proxy_address,
               'event':'create-gemport',
               'event_data':{'gemport_id':gemport_id}}
        self.adapter_agent.publish_inter_adapter_message(onu_device.id, msg)

    def mk_gemport_id(self, onu_id, idx=0):
        return 1<<10 | onu_id<<3 | idx

    def onu_id_from_gemport_id(self, gemport_id):
        return (gemport_id & ~(1<<10)) >> 3

    def mk_alloc_id(self, onu_id, idx=0):
        # FIXME - driver should do prefixing 1 << 10 as it is Maple specific
        #return 1<<10 | onu_id<<6 | idx
        return 1023 + onu_id # FIXME


    def omci_indication(self, omci_indication):

        self.log.debug("omci indication", intf_id=omci_indication.intf_id,
                onu_id=omci_indication.onu_id)

        onu_device = self.adapter_agent.get_child_device(self.device_id,
                onu_id=omci_indication.onu_id)

        self.adapter_agent.receive_proxied_message(onu_device.proxy_address,
                omci_indication.pkt)

    def packet_indication(self, pkt_indication):

        self.log.debug("packet indication", intf_id=pkt_indication.intf_id,
                gemport_id=pkt_indication.gemport_id,
                flow_id=pkt_indication.flow_id)

        onu_id = self.onu_id_from_gemport_id(pkt_indication.gemport_id)
        logical_port_num = self.mk_uni_port_num(pkt_indication.intf_id, onu_id)

        pkt = Ether(pkt_indication.pkt)
        kw = dict(logical_device_id=self.logical_device_id,
                logical_port_no=logical_port_num)
        self.adapter_agent.send_packet_in(packet=str(pkt), **kw)

    def packet_out(self, egress_port, msg):
        pkt = Ether(msg)
        self.log.info('packet out', egress_port=egress_port,
                packet=str(pkt).encode("HEX"))

        if pkt.haslayer(Dot1Q):
            outer_shim = pkt.getlayer(Dot1Q)
            if isinstance(outer_shim.payload, Dot1Q):
                payload = (
                    Ether(src=pkt.src, dst=pkt.dst, type=outer_shim.type) /
                    outer_shim.payload
                )
            else:
                payload = pkt
        else:
            payload = pkt

        self.log.info('sending-packet-to-device', egress_port=egress_port,
                packet=str(payload).encode("HEX"))

        send_pkt = binascii.unhexlify(str(payload).encode("HEX"))

        onu_pkt = openolt_pb2.OnuPacket(intf_id=self.intf_id_from_port_num(egress_port),
                onu_id=self.onu_id_from_port_num(egress_port), pkt=send_pkt)

        self.stub.OnuPacketOut(onu_pkt)

    def send_proxied_message(self, proxy_address, msg):
        omci = openolt_pb2.OmciMsg(intf_id=proxy_address.channel_id, # intf_id
                onu_id=proxy_address.onu_id, pkt=str(msg))
        self.stub.OmciMsgOut(omci)

    def add_onu_device(self, intf_id, port_no, onu_id, serial_number):
        self.log.info("Adding ONU", port_no=port_no, onu_id=onu_id,
                serial_number=serial_number)

        # NOTE - channel_id of onu is set to intf_id
        proxy_address = Device.ProxyAddress(device_id=self.device_id,
                channel_id=intf_id, onu_id=onu_id, onu_session_id=onu_id)

        self.log.info("Adding ONU", proxy_address=proxy_address)

        serial_number_str = ''.join([serial_number.vendor_id,
                self.stringify_vendor_specific(serial_number.vendor_specific)])

        self.adapter_agent.add_onu_device(parent_device_id=self.device_id,
                parent_port_no=port_no, vendor_id=serial_number.vendor_id,
                proxy_address=proxy_address, root=True,
                serial_number=serial_number_str, admin_state=AdminState.ENABLED)

    def intf_id_to_port_no(self, intf_id, intf_type):
        if intf_type is Port.ETHERNET_NNI:
            # FIXME - Remove hardcoded '129'
            return intf_id + 129
        elif intf_type is Port.PON_OLT:
            return 0x2<<28 | intf_id
        else:
	    raise Exception('Invalid port type')


    def port_name(self, port_no, port_type, intf_id=None):
        if port_type is Port.ETHERNET_NNI:
            prefix = "nni"
        elif port_type is Port.PON_OLT:
            return "pon" + str(intf_id)
        elif port_type is Port.ETHERNET_UNI:
            prefix = "uni"
        return prefix + "-" + str(port_no)

    def add_logical_port(self, port_no, intf_id):
        self.log.info('adding-logical-port', port_no=port_no)

        label = self.port_name(port_no, Port.ETHERNET_NNI)

        cap = OFPPF_1GB_FD | OFPPF_FIBER
        curr_speed = OFPPF_1GB_FD
        max_speed = OFPPF_1GB_FD

        ofp = ofp_port(port_no=port_no,
                hw_addr=mac_str_to_tuple('00:00:00:00:00:%02x' % port_no),
                name=label, config=0, state=OFPPS_LIVE, curr=cap,
                advertised=cap, peer=cap, curr_speed=curr_speed,
                max_speed=max_speed)

        logical_port = LogicalPort(id=label, ofp_port=ofp,
                device_id=self.device_id, device_port_no=port_no,
                root_port=True)

        self.adapter_agent.add_logical_port(self.logical_device_id, logical_port)

    def add_port(self, intf_id, port_type, oper_status):
        port_no = self.intf_id_to_port_no(intf_id, port_type)

        label = self.port_name(port_no, port_type, intf_id)

        self.log.info('adding-port', port_no=port_no, label=label,
                port_type=port_type)

        port = Port(port_no=port_no, label=label, type=port_type,
            admin_state=AdminState.ENABLED, oper_status=oper_status)

        self.adapter_agent.add_port(self.device_id, port)

        return port_no, label

    def new_onu_id(self, intf_id):
        onu_id = None
        for i in range(1, 512):
            key = OnuKey(intf_id=intf_id, onu_id=i)
            if key not in self.onus:
                onu_id = i
                break
        return onu_id

    def stringify_vendor_specific(self, vendor_specific):
        return ''.join(str(i) for i in [
                ord(vendor_specific[0])>>4 & 0x0f,
                ord(vendor_specific[0]) & 0x0f,
                ord(vendor_specific[1])>>4 & 0x0f,
                ord(vendor_specific[1]) & 0x0f,
                ord(vendor_specific[2])>>4 & 0x0f,
                ord(vendor_specific[2]) & 0x0f,
                ord(vendor_specific[3])>>4 & 0x0f,
                ord(vendor_specific[3]) & 0x0f])

    def lookup_key(self, serial_number):
        key = None
        for k, r in self.onus.iteritems():
            if r.serial_number.vendor_id == serial_number.vendor_id:
                str1 = self.stringify_vendor_specific(r.serial_number.vendor_specific)
                str2 = self.stringify_vendor_specific(serial_number.vendor_specific)
                if str1 == str2:
                    key = k
                    break
        return key

    def update_flow_table(self, flows):
        device = self.adapter_agent.get_device(self.device_id)
        self.log.debug('update flow table')

        for flow in flows:
            self.log.info('flow-details', device_id=self.device_id, flow=flow)
            classifier_info = dict()
            action_info = dict()
            is_down_stream = None
            _in_port = None
            try:
                _in_port = fd.get_in_port(flow)
                assert _in_port is not None
                # Right now there is only one NNI port. Get the NNI PORT and compare
                # with IN_PUT port number. Need to find better way.
                ports = self.adapter_agent.get_ports(device.id, Port.ETHERNET_NNI)

                for port in ports:
                    if (port.port_no == _in_port):
                        self.log.info('downstream-flow')
                        is_down_stream = True
                        break
                if is_down_stream is None:
                    is_down_stream = False
                    self.log.info('upstream-flow')

                for field in fd.get_ofb_fields(flow):

                    if field.type == fd.ETH_TYPE:
                        classifier_info['eth_type'] = field.eth_type
                        self.log.info('field-type-eth-type',
                                eth_type=classifier_info['eth_type'])

                    elif field.type == fd.IP_PROTO:
                        classifier_info['ip_proto'] = field.ip_proto
                        self.log.info('field-type-ip-proto',
                                ip_proto=classifier_info['ip_proto'])

                    elif field.type == fd.IN_PORT:
                        classifier_info['in_port'] = field.port
                        self.log.info('field-type-in-port',
                                in_port=classifier_info['in_port'])

                    elif field.type == fd.VLAN_VID:
                        classifier_info['vlan_vid'] = field.vlan_vid & 0xfff
                        self.log.info('field-type-vlan-vid',
                                vlan=classifier_info['vlan_vid'])

                    elif field.type == fd.VLAN_PCP:
                        classifier_info['vlan_pcp'] = field.vlan_pcp
                        self.log.info('field-type-vlan-pcp',
                                pcp=classifier_info['vlan_pcp'])

                    elif field.type == fd.UDP_DST:
                        classifier_info['udp_dst'] = field.udp_dst
                        self.log.info('field-type-udp-dst',
                                udp_dst=classifier_info['udp_dst'])

                    elif field.type == fd.UDP_SRC:
                        classifier_info['udp_src'] = field.udp_src
                        self.log.info('field-type-udp-src',
                                udp_src=classifier_info['udp_src'])

                    elif field.type == fd.IPV4_DST:
                        classifier_info['ipv4_dst'] = field.ipv4_dst
                        self.log.info('field-type-ipv4-dst',
                                ipv4_dst=classifier_info['ipv4_dst'])

                    elif field.type == fd.IPV4_SRC:
                        classifier_info['ipv4_src'] = field.ipv4_src
                        self.log.info('field-type-ipv4-src',
                                ipv4_dst=classifier_info['ipv4_src'])

                    elif field.type == fd.METADATA:
                        classifier_info['metadata'] = field.table_metadata
                        self.log.info('field-type-metadata',
                                metadata=classifier_info['metadata'])

                    else:
                        raise NotImplementedError('field.type={}'.format(
                            field.type))

                for action in fd.get_actions(flow):

                    if action.type == fd.OUTPUT:
                        action_info['output'] = action.output.port
                        self.log.info('action-type-output',
                                output=action_info['output'],
                                in_port=classifier_info['in_port'])

                    elif action.type == fd.POP_VLAN:
                        action_info['pop_vlan'] = True
                        self.log.info('action-type-pop-vlan', in_port=_in_port)

                    elif action.type == fd.PUSH_VLAN:
                        action_info['push_vlan'] = True
                        action_info['tpid'] = action.push.ethertype
                        self.log.info('action-type-push-vlan',
                                push_tpid=action_info['tpid'], in_port=_in_port)
                        if action.push.ethertype != 0x8100:
                            self.log.error('unhandled-tpid',
                                   ethertype=action.push.ethertype)

                    elif action.type == fd.SET_FIELD:
                        # action_info['action_type'] = 'set_field'
                        _field = action.set_field.field.ofb_field
                        assert (action.set_field.field.oxm_class ==
                                OFPXMC_OPENFLOW_BASIC)
                        self.log.info('action-type-set-field',
                                field=_field, in_port=_in_port)
                        if _field.type == fd.VLAN_VID:
                            self.log.info('set-field-type-vlan-vid',
                                    vlan_vid=_field.vlan_vid & 0xfff)
                            action_info['vlan_vid'] = (_field.vlan_vid & 0xfff)
                        else:
                            self.log.error('unsupported-action-set-field-type',
                                    field_type=_field.type)
                    else:
                        self.log.error('unsupported-action-type',
                                action_type=action.type, in_port=_in_port)

                # FIXME - Why ignore downstream flows?
                if is_down_stream is False:
                    intf_id = self.intf_id_from_port_num(classifier_info['in_port'])
                    onu_id = self.onu_id_from_port_num(classifier_info['in_port'])
                    self.divide_and_add_flow(intf_id, onu_id, classifier_info, action_info)
                #else:
                #    self.log.info('ignore downstream flow', flow=flow,
                #            classifier_info=classifier_info,
                #            action_info=action_info)

            except Exception as e:
                self.log.exception('failed-to-install-flow', e=e, flow=flow)

    # FIXME - No need for divide_and_add_flow if
    # both upstream and downstream flows
    # are acted upon (not just upstream flows).
    def divide_and_add_flow(self, intf_id, onu_id, classifier, action):
        if 'ip_proto' in classifier:
            if classifier['ip_proto'] == 17:
                self.log.debug('dhcp flow add')
                self.add_dhcp_trap(intf_id, onu_id, classifier, action)
            elif classifier['ip_proto'] == 2:
                self.log.info('igmp flow add ignored')
            else:
                self.log.info("Invalid-Classifier-to-handle", classifier=classifier,
                        action=action)
        elif 'eth_type' in classifier:
            if classifier['eth_type'] == 0x888e:
                self.log.info('eapol flow add')
                self.add_eapol_flow(intf_id, onu_id, classifier, action)
        elif 'push_vlan' in action:
            # FIXME - Is this required?
            #self.prepare_and_add_eapol_flow(intf_id, onu_id, classifier, action)
            #        EAPOL_FLOW_INDEX_DATA_VLAN, EAPOL_DOWNLINK_FLOW_INDEX_DATA_VLAN)
            self.add_data_flow(intf_id, onu_id, classifier, action)
        else:
            self.log.info('Invalid-flow-type-to-handle', classifier=classifier,
                    action=action)

    def add_data_flow(self, intf_id, onu_id, uplink_classifier, uplink_action):

        downlink_classifier = dict(uplink_classifier)
        downlink_action = dict(uplink_action)

        uplink_classifier['pkt_tag_type'] = 'single_tag'

        downlink_classifier['pkt_tag_type'] = 'double_tag'
        downlink_classifier['vlan_vid'] = uplink_action['vlan_vid']
        downlink_classifier['metadata'] = uplink_classifier['vlan_vid']
        del downlink_action['push_vlan']
        downlink_action['pop_vlan'] = True

        # To-Do right now only one GEM port is supported, so below method
        # will take care of handling all the p bits.
        # We need to revisit when mulitple gem port per p bits is needed.
        self.add_hsia_flow(intf_id, onu_id, uplink_classifier, uplink_action,
                downlink_classifier, downlink_action, HSIA_FLOW_INDEX)

    def mk_classifier(self, classifier_info):

        classifier = openolt_pb2.Classifier()

        if 'eth_type' in classifier_info:
            classifier.eth_type = classifier_info['eth_type']
        if 'ip_proto' in classifier_info:
            classifier.ip_proto = classifier_info['ip_proto']
        if 'vlan_vid' in classifier_info:
            classifier.o_vid = classifier_info['vlan_vid']
        if 'metadata' in classifier_info:
            classifier.i_vid = classifier_info['metadata']
        if 'vlan_pcp' in classifier_info:
            classifier.o_pbits = classifier_info['vlan_pcp']
        if 'udp_src' in classifier_info:
            classifier.src_port = classifier_info['udp_src']
        if 'udp_dst' in classifier_info:
            classifier.dst_port = classifier_info['udp_dst']
        if 'ipv4_dst' in classifier_info:
            classifier.dst_ip = classifier_info['ipv4_dst']
        if 'ipv4_src' in classifier_info:
            classifier.src_ip = classifier_info['ipv4_src']
        if 'pkt_tag_type' in classifier_info:
            if classifier_info['pkt_tag_type'] == 'single_tag':
                classifier.pkt_tag_type = 'single_tag'
            elif classifier_info['pkt_tag_type'] == 'double_tag':
                classifier.pkt_tag_type = 'double_tag'
            elif classifier_info['pkt_tag_type'] == 'untagged':
                classifier.pkt_tag_type = 'untagged'
            else:
                classifier.pkt_tag_type = 'none'

        return classifier

    def mk_action(self, action_info):
        action = openolt_pb2.Action()

	if 'pop_vlan' in action_info:
	    action.o_vid = action_info['vlan_vid']
            action.cmd.remove_outer_tag = True
	elif 'push_vlan' in action_info:
	    action.o_vid = action_info['vlan_vid']
            action.cmd.add_outer_tag = True
	elif 'trap_to_host' in action_info:
            action.cmd.trap_to_host = True
	else:
	    self.log.info('Invalid-action-field')
	    return
        return action

    def add_hsia_flow(self, intf_id, onu_id, uplink_classifier, uplink_action,
                downlink_classifier, downlink_action, hsia_id):

        gemport_id = self.mk_gemport_id(onu_id)
        flow_id = self.mk_flow_id(intf_id, onu_id, hsia_id)

        self.log.info('add upstream flow', onu_id=onu_id, classifier=uplink_classifier,
                action=uplink_action, gemport_id=gemport_id, flow_id=flow_id)

        flow = openolt_pb2.Flow(
                onu_id=onu_id, flow_id=flow_id, flow_type="upstream",
                gemport_id=gemport_id, classifier=self.mk_classifier(uplink_classifier),
                action=self.mk_action(uplink_action))

        self.stub.FlowAdd(flow)
        time.sleep(0.1) # FIXME

        self.log.info('add downstream flow', classifier=downlink_classifier,
                action=downlink_action, gemport_id=gemport_id, flow_id=flow_id)

        flow = openolt_pb2.Flow(
                onu_id=onu_id, flow_id=flow_id, flow_type="downstream",
                access_intf_id=intf_id, gemport_id=gemport_id,
                classifier=self.mk_classifier(downlink_classifier),
                action=self.mk_action(downlink_action))

        self.stub.FlowAdd(flow)
        time.sleep(0.1) # FIXME

    def add_dhcp_trap(intf_id, onu_id, self, classifier, action):

        self.log.info('add dhcp trap', classifier=classifier, action=action)

        action.clear()
        action['trap_to_host'] = True
        classifier['pkt_tag_type'] = 'single_tag'
        classifier.pop('vlan_vid', None)

        gemport_id = self.mk_gemport_id(onu_id)
        flow_id = self.mk_flow_id(intf_id, onu_id, DHCP_FLOW_INDEX)

        upstream_flow = openolt_pb2.Flow(
                onu_id=onu_id, flow_id=flow_id, flow_type="upstream",
                gemport_id=gemport_id, classifier=self.mk_classifier(classifier),
                action=self.mk_action(action))

        self.stub.FlowAdd(upstream_flow)

    def add_eapol_flow(self, intf_id, onu_id, uplink_classifier, uplink_action,
            uplink_eapol_id=EAPOL_FLOW_INDEX,
            downlink_eapol_id=EAPOL_DOWNLINK_FLOW_INDEX,
            vlan_id=DEFAULT_MGMT_VLAN):

        self.log.info('add eapol flow', classifier=uplink_classifier, action=uplink_action)

        downlink_classifier = dict(uplink_classifier)
        downlink_action = dict(uplink_action)

        gemport_id = self.mk_gemport_id(onu_id)
        uplink_flow_id = self.mk_flow_id(intf_id, onu_id, uplink_eapol_id)

        # Add Upstream EAPOL Flow.
        uplink_classifier['pkt_tag_type'] = 'single_tag'
        uplink_classifier['vlan_vid'] = vlan_id
        uplink_action.clear()
        uplink_action['trap_to_host'] = True

        upstream_flow = openolt_pb2.Flow(
                onu_id=onu_id, flow_id=uplink_flow_id, flow_type="upstream",
                gemport_id=gemport_id, classifier=self.mk_classifier(uplink_classifier),
                action=self.mk_action(uplink_action))

        self.stub.FlowAdd(upstream_flow)

        # Add Downstream EAPOL Flow.
        downlink_flow_id = self.mk_flow_id(intf_id, onu_id, downlink_eapol_id)
        downlink_classifier['pkt_tag_type'] = 'single_tag'
        downlink_classifier['vlan_vid'] = vlan_id

        downstream_flow = openolt_pb2.Flow(
                onu_id=onu_id, flow_id=downlink_flow_id, flow_type="downstream",
                gemport_id=gemport_id, classifier=self.mk_classifier(downlink_classifier),
                action=self.mk_action(downlink_action))

        self.stub.FlowAdd(downstream_flow)

    def mk_flow_id(self, intf_id, onu_id, idx):
        return intf_id<<11 | onu_id<<4  | idx