#
# 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.

from __future__ import absolute_import
import structlog
from twisted.internet import reactor
from twisted.internet.defer import inlineCallbacks, TimeoutError, failure
from pyvoltha.adapters.extensions.omci.omci_me import Ont2G, OmciNullPointer, PriorityQueueFrame, \
    Ieee8021pMapperServiceProfileFrame
from pyvoltha.adapters.extensions.omci.tasks.task import Task
from pyvoltha.adapters.extensions.omci.omci_defs import EntityOperations, ReasonCodes
from pyvoltha.adapters.extensions.omci.omci_entities import OntG, Tcont, PriorityQueueG
from pon_port import TASK_PRIORITY


OP = EntityOperations
RC = ReasonCodes


class TechProfileDownloadFailure(Exception):
    """
    This error is raised by default when the download fails
    """


class TechProfileResourcesFailure(Exception):
    """
    This error is raised by when one or more resources required is not available
    """


class BrcmTpServiceSpecificTask(Task):
    """
    OpenOMCI Tech-Profile Download Task

    """

    name = "Broadcom Tech-Profile Download Task"

    def __init__(self, omci_agent, handler, uni_id):
        """
        Class initialization

        :param omci_agent: (OmciAdapterAgent) OMCI Adapter agent
        :param handler: (BrcmOpenomciOnuHandler) ONU Device Handler Instance
        :param uni_id: (int) numeric id of the uni port on the onu device, starts at 0
        """
        log = structlog.get_logger(device_id=handler.device_id, uni_id=uni_id)
        log.debug('function-entry')

        super(BrcmTpServiceSpecificTask, self).__init__(BrcmTpServiceSpecificTask.name,
                                                        omci_agent,
                                                        handler.device_id,
                                                        priority=TASK_PRIORITY,
                                                        exclusive=True)

        self.log = log

        self._onu_device = omci_agent.get_device(handler.device_id)
        self._local_deferred = None

        self._uni_port = handler.uni_ports[uni_id]
        assert self._uni_port.uni_id == uni_id

        # Entity IDs. IDs with values can probably be most anything for most ONUs,
        #             IDs set to None are discovered/set

        self._mac_bridge_service_profile_entity_id = \
            handler.mac_bridge_service_profile_entity_id
        self._ieee_mapper_service_profile_entity_id = \
            handler.pon_port.ieee_mapper_service_profile_entity_id
        self._mac_bridge_port_ani_entity_id = \
            handler.pon_port.mac_bridge_port_ani_entity_id
        self._gal_enet_profile_entity_id = \
            handler.gal_enet_profile_entity_id

        # Extract the current set of TCONT and GEM Ports from the Handler's pon_port that are
        # relevant to this task's UNI. It won't change. But, the underlying pon_port may change
        # due to additional tasks on different UNIs. So, it we cannot use the pon_port affter
        # this initializer
        self._tconts = []
        for tcont in list(handler.pon_port.tconts.values()):
            if tcont.uni_id is not None and tcont.uni_id != self._uni_port.uni_id: continue
            self._tconts.append(tcont)

        self._gem_ports = []
        for gem_port in list(handler.pon_port.gem_ports.values()):
            if gem_port.uni_id is not None and gem_port.uni_id != self._uni_port.uni_id: continue
            self._gem_ports.append(gem_port)

        self.tcont_me_to_queue_map = dict()
        self.uni_port_to_queue_map = dict()

    def cancel_deferred(self):
        self.log.debug('function-entry')
        super(BrcmTpServiceSpecificTask, self).cancel_deferred()

        d, self._local_deferred = self._local_deferred, None
        try:
            if d is not None and not d.called:
                d.cancel()
        except:
            pass

    def start(self):
        """
        Start the Tech-Profile Download
        """
        self.log.debug('function-entry')
        super(BrcmTpServiceSpecificTask, self).start()
        self._local_deferred = reactor.callLater(0, self.perform_service_specific_steps)

    def stop(self):
        """
        Shutdown Tech-Profile download tasks
        """
        self.log.debug('function-entry')
        self.log.debug('stopping')

        self.cancel_deferred()
        super(BrcmTpServiceSpecificTask, self).stop()

    def check_status_and_state(self, results, operation=''):
        """
        Check the results of an OMCI response.  An exception is thrown
        if the task was cancelled or an error was detected.

        :param results: (OmciFrame) OMCI Response frame
        :param operation: (str) what operation was being performed
        :return: True if successful, False if the entity existed (already created)
        """
        self.log.debug('function-entry')

        omci_msg = results.fields['omci_message'].fields
        status = omci_msg['success_code']
        error_mask = omci_msg.get('parameter_error_attributes_mask', 'n/a')
        failed_mask = omci_msg.get('failed_attributes_mask', 'n/a')
        unsupported_mask = omci_msg.get('unsupported_attributes_mask', 'n/a')

        self.log.debug("OMCI Result", operation=operation, omci_msg=omci_msg, status=status, error_mask=error_mask,
                       failed_mask=failed_mask, unsupported_mask=unsupported_mask)

        if status == RC.Success:
            self.strobe_watchdog()
            return True

        elif status == RC.InstanceExists:
            return False

        raise TechProfileDownloadFailure(
            '{} failed with a status of {}, error_mask: {}, failed_mask: {}, unsupported_mask: {}'
            .format(operation, status, error_mask, failed_mask, unsupported_mask))

    @inlineCallbacks
    def perform_service_specific_steps(self):
        self.log.debug('function-entry')

        omci_cc = self._onu_device.omci_cc
        gem_pq_associativity = dict()
        pq_to_related_port = dict()
        is_related_ports_configurable = False

        try:
            ################################################################################
            # TCONTS
            #
            #  EntityID will be referenced by:
            #            - GemPortNetworkCtp
            #  References:
            #            - ONU created TCONT (created on ONU startup)

            tcont_idents = self._onu_device.query_mib(Tcont.class_id)
            self.log.debug('tcont-idents', tcont_idents=tcont_idents)

            for tcont in self._tconts:
                self.log.debug('tcont-loop', tcont=tcont)

                if tcont.entity_id is None:
                    free_entity_id = None
                    for k, v in tcont_idents.items():
                        if not isinstance(v, dict):
                            continue
                        alloc_check = v.get('attributes', {}).get('alloc_id', 0)
                        # Some onu report both to indicate an available tcont
                        if alloc_check == 0xFF or alloc_check == 0xFFFF:
                            free_entity_id = k
                            break

                    self.log.debug('tcont-loop-free', free_entity_id=free_entity_id, alloc_id=tcont.alloc_id)

                    if free_entity_id is None:
                        self.log.error('no-available-tconts')
                        break

                    # Also assign entity id within tcont object
                    results = yield tcont.add_to_hardware(omci_cc, free_entity_id)
                    self.check_status_and_state(results, 'new-tcont-added')
                else:
                    # likely already added given entity_id is set, but no harm in doing it again
                    results = yield tcont.add_to_hardware(omci_cc, tcont.entity_id)
                    self.check_status_and_state(results, 'existing-tcont-added')

            ################################################################################
            # GEMS  (GemPortNetworkCtp and GemInterworkingTp)
            #
            #  For both of these MEs, the entity_id is the GEM Port ID. The entity id of the
            #  GemInterworkingTp ME could be different since it has an attribute to specify
            #  the GemPortNetworkCtp entity id.
            #
            #        for the GemPortNetworkCtp ME
            #
            #  GemPortNetworkCtp
            #    EntityID will be referenced by:
            #              - GemInterworkingTp
            #    References:
            #              - TCONT
            #              - Hardcoded upstream TM Entity ID
            #              - (Possibly in Future) Upstream Traffic descriptor profile pointer
            #
            #  GemInterworkingTp
            #    EntityID will be referenced by:
            #              - Ieee8021pMapperServiceProfile
            #    References:
            #              - GemPortNetworkCtp
            #              - Ieee8021pMapperServiceProfile
            #              - GalEthernetProfile
            #

            onu_g = self._onu_device.query_mib(OntG.class_id)
            # If the traffic management option attribute in the ONU-G ME is 0
            # (priority controlled) or 2 (priority and rate controlled), this
            # pointer specifies the priority queue ME serving this GEM port
            # network CTP. If the traffic management option attribute is 1
            # (rate controlled), this attribute redundantly points to the
            # T-CONT serving this GEM port network CTP.
            traffic_mgmt_opt = \
                onu_g.get('attributes', {}).get('traffic_management_options', 0)
            self.log.debug("traffic-mgmt-option", traffic_mgmt_opt=traffic_mgmt_opt)

            prior_q = self._onu_device.query_mib(PriorityQueueG.class_id)
            for k, v in prior_q.items():
                self.log.debug("prior-q", k=k, v=v)

                try:
                    _ = iter(v)
                except TypeError:
                    continue

                if 'instance_id' in v:
                    related_port = v['attributes']['related_port']
                    pq_to_related_port[k] = related_port

                    if v['instance_id'] & 0b1000000000000000:
                        tcont_me = (related_port & 0xffff0000) >> 16
                        if tcont_me not in self.tcont_me_to_queue_map:
                            self.log.debug("prior-q-related-port-and-tcont-me",
                                            related_port=related_port,
                                            tcont_me=tcont_me)
                            self.tcont_me_to_queue_map[tcont_me] = list()

                        self.tcont_me_to_queue_map[tcont_me].append(k)
                    else:
                        uni_port = (related_port & 0xffff0000) >> 16
                        if uni_port ==  self._uni_port.entity_id:
                            if uni_port not in self.uni_port_to_queue_map:
                                self.log.debug("prior-q-related-port-and-uni-port-me",
                                                related_port=related_port,
                                                uni_port_me=uni_port)
                                self.uni_port_to_queue_map[uni_port] = list()

                            self.uni_port_to_queue_map[uni_port].append(k)


            self.log.debug("ul-prior-q", ul_prior_q=self.tcont_me_to_queue_map)
            self.log.debug("dl-prior-q", dl_prior_q=self.uni_port_to_queue_map)

            for gem_port in self._gem_ports:
                # TODO: Traffic descriptor will be available after meter bands are available
                tcont = gem_port.tcont
                if tcont is None:
                    self.log.error('unknown-tcont-reference', gem_id=gem_port.gem_id)
                    continue

                ul_prior_q_entity_id = None
                dl_prior_q_entity_id = None
                if gem_port.direction == "upstream" or \
                        gem_port.direction == "bi-directional":

                    # Sort the priority queue list in order of priority.
                    # 0 is highest priority and 0x0fff is lowest.
                    self.tcont_me_to_queue_map[tcont.entity_id].sort()
                    self.uni_port_to_queue_map[self._uni_port.entity_id].sort()
                    # Get the priority queue by indexing the priority value of the gemport.
                    # The self.tcont_me_to_queue_map and self.uni_port_to_queue_map
                    # have priority queue entities ordered in descending order
                    # of priority

                    ul_prior_q_entity_id = \
                        self.tcont_me_to_queue_map[tcont.entity_id][gem_port.priority_q]
                    dl_prior_q_entity_id = \
                        self.uni_port_to_queue_map[self._uni_port.entity_id][gem_port.priority_q]

                    pq_attributes = dict()
                    pq_attributes["pq_entity_id"] = ul_prior_q_entity_id
                    pq_attributes["weight"] = gem_port.weight
                    pq_attributes["scheduling_policy"] = gem_port.scheduling_policy
                    pq_attributes["priority_q"] = gem_port.priority_q
                    gem_pq_associativity[gem_port.entity_id] = pq_attributes

                    assert ul_prior_q_entity_id is not None and \
                           dl_prior_q_entity_id is not None

                    # TODO: Need to restore on failure.  Need to check status/results
                    results = yield gem_port.add_to_hardware(omci_cc,
                                             tcont.entity_id,
                                             self._ieee_mapper_service_profile_entity_id +
                                                      self._uni_port.mac_bridge_port_num,
                                             self._gal_enet_profile_entity_id,
                                             ul_prior_q_entity_id, dl_prior_q_entity_id)
                    self.check_status_and_state(results, 'assign-gem-port')
                elif gem_port.direction == "downstream":
                    # Downstream is inverse of upstream
                    # TODO: could also be a case of multicast. Not supported for now
                    self.log.debug("skipping-downstream-gem", gem_port=gem_port)
                    pass

            ################################################################################
            # Update the PriorityQeue Attributes for the PQ Associated with Gemport
            #
            # Entityt ID was created prior to this call. This is a set
            #
            #

            ont2g = self._onu_device.query_mib(Ont2G.class_id)
            qos_config_flexibility_ie = ont2g.get(0, {}).get('attributes', {}).\
                                        get('qos_configuration_flexibility', None)
            self.log.debug("qos_config_flexibility",
                            qos_config_flexibility=qos_config_flexibility_ie)

            if qos_config_flexibility_ie & 0b100000:
                is_related_ports_configurable = True

            for k, v in gem_pq_associativity.items():
                if v["scheduling_policy"] == "WRR":
                    self.log.debug("updating-pq-weight")
                    msg = PriorityQueueFrame(v["pq_entity_id"], weight=v["weight"])
                    frame = msg.set()
                    results = yield omci_cc.send(frame)
                    self.check_status_and_state(results, 'set-priority-queues-weight')
                elif v["scheduling_policy"] == "StrictPriority" and \
                        is_related_ports_configurable:
                    self.log.debug("updating-pq-priority")
                    related_port = pq_to_related_port[v["pq_entity_id"]]
                    related_port = related_port & 0xffff0000
                    related_port = related_port | v['priority_q'] # Set priority
                    msg = PriorityQueueFrame(v["pq_entity_id"], related_port=related_port)
                    frame = msg.set()
                    results = yield omci_cc.send(frame)
                    self.check_status_and_state(results, 'set-priority-queues-priority')


            ################################################################################
            # Update the IEEE 802.1p Mapper Service Profile config
            #
            #  EntityID was created prior to this call. This is a set
            #
            #  References:
            #            - Gem Interwork TPs are set here
            #

            gem_entity_ids = [OmciNullPointer] * 8
            for gem_port in self._gem_ports:
                self.log.debug("tp-gem-port", entity_id=gem_port.entity_id, uni_id=gem_port.uni_id)

                if gem_port.direction == "upstream" or \
                        gem_port.direction == "bi-directional":
                    for i, p in enumerate(reversed(gem_port.pbit_map)):
                        if p == '1':
                            gem_entity_ids[i] = gem_port.entity_id
                elif gem_port.direction == "downstream":
                    # Downstream gem port p-bit mapper is inverse of upstream
                    # TODO: Could also be a case of multicast. Not supported for now
                    pass

            msg = Ieee8021pMapperServiceProfileFrame(
                self._ieee_mapper_service_profile_entity_id + self._uni_port.mac_bridge_port_num,  # 802.1p mapper Service Mapper Profile ID
                interwork_tp_pointers=gem_entity_ids  # Interworking TP IDs
            )
            frame = msg.set()
            self.log.debug('openomci-msg', omci_msg=msg)
            results = yield omci_cc.send(frame)
            self.check_status_and_state(results, 'set-8021p-mapper-service-profile-ul')

            self.deferred.callback("tech-profile-download-success")

        except TimeoutError as e:
            self.log.warn('rx-timeout-tech-profile', e=e)
            self.deferred.errback(failure.Failure(e))

        except Exception as e:
            self.log.exception('omci-setup-tech-profile', e=e)
            self.deferred.errback(failure.Failure(e))