# Copyright 2021-2023 H2020 TeraFlow (https://www.teraflow-h2020.eu/)
#
# 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 typing import Dict
import grpc, logging, queue, threading
from common.method_wrappers.ServiceExceptions import ServiceException
from common.proto import monitoring_pb2
from common.proto.context_pb2 import DeviceOperationalStatusEnum, Empty, EventTypeEnum
from common.proto.kpi_sample_types_pb2 import KpiSampleType
from context.client.ContextClient import ContextClient
from monitoring.client.MonitoringClient import MonitoringClient
from monitoring.service.MonitoringServiceServicerImpl import LOGGER
from monitoring.service.NameMapping import NameMapping

LOGGER = logging.getLogger(__name__)

DEVICE_OP_STATUS_UNDEFINED   = DeviceOperationalStatusEnum.DEVICEOPERATIONALSTATUS_UNDEFINED
DEVICE_OP_STATUS_DISABLED    = DeviceOperationalStatusEnum.DEVICEOPERATIONALSTATUS_DISABLED
DEVICE_OP_STATUS_ENABLED     = DeviceOperationalStatusEnum.DEVICEOPERATIONALSTATUS_ENABLED
DEVICE_OP_STATUS_NOT_ENABLED = {DEVICE_OP_STATUS_UNDEFINED, DEVICE_OP_STATUS_DISABLED}
KPISAMPLETYPE_UNKNOWN        = KpiSampleType.KPISAMPLETYPE_UNKNOWN

class EventsDeviceCollector:
    def __init__(self, name_mapping : NameMapping) -> None: # pylint: disable=redefined-outer-name
        self._events_queue = queue.Queue()

        self._context_client_grpc = ContextClient()
        self._device_stream     = self._context_client_grpc.GetDeviceEvents(Empty())
        self._context_client    = self._context_client_grpc
        self._channel           = self._context_client_grpc.channel
        self._monitoring_client = MonitoringClient(host='127.0.0.1')

        self._device_thread   = threading.Thread(target=self._collect, args=(self._device_stream,), daemon=False)

        self._device_to_state : Dict[str, DeviceOperationalStatusEnum] = dict()
        self._name_mapping = name_mapping

    def grpc_server_on(self):
        try:
            grpc.channel_ready_future(self._channel).result(timeout=15)
            return True
        except grpc.FutureTimeoutError:
            return False

    def _collect(self, events_stream):
        try:
            for event in events_stream:
                self._events_queue.put_nowait(event)
        except grpc.RpcError as e:
            if e.code() != grpc.StatusCode.CANCELLED: # pylint: disable=no-member
                raise # pragma: no cover

    def start(self):
        try:
            self._device_thread.start()
        except RuntimeError:
            LOGGER.exception('Start EventTools exception')

    def get_event(self, block : bool = True, timeout : float = 0.1):
        return self._events_queue.get(block=block, timeout=timeout)

    def stop(self):
        self._device_stream.cancel()
        self._device_thread.join()

    def listen_events(self):
        try:
            kpi_id_list = []

            while True:
                # LOGGER.info('getting Kpi by KpiID')
                try:
                    event = self.get_event(block=True, timeout=0.5)

                    event_type = event.event.event_type
                    device_uuid = event.device_id.device_uuid.uuid
                    if event_type in {EventTypeEnum.EVENTTYPE_REMOVE}:
                        self._device_to_state.pop(device_uuid, None)
                        continue

                    if event_type not in {EventTypeEnum.EVENTTYPE_CREATE, EventTypeEnum.EVENTTYPE_UPDATE}:
                        # Unknown event type
                        continue

                    device = self._context_client.GetDevice(event.device_id)
                    self._name_mapping.set_device_name(device_uuid, device.name)

                    old_operational_status = self._device_to_state.get(device_uuid, DEVICE_OP_STATUS_UNDEFINED)
                    device_was_not_enabled = (old_operational_status in DEVICE_OP_STATUS_NOT_ENABLED)

                    new_operational_status = device.device_operational_status
                    device_is_enabled = (new_operational_status == DEVICE_OP_STATUS_ENABLED)
                    self._device_to_state[device_uuid] = new_operational_status

                    activate_monitoring = device_was_not_enabled and device_is_enabled
                    if not activate_monitoring:
                        # device is not ready for monitoring
                        continue

                    for endpoint in device.device_endpoints:
                        endpoint_uuid = endpoint.endpoint_id.endpoint_uuid.uuid
                        self._name_mapping.set_endpoint_name(endpoint_uuid, endpoint.name)

                        for value in endpoint.kpi_sample_types:
                            if value == KPISAMPLETYPE_UNKNOWN: continue

                            kpi_descriptor = monitoring_pb2.KpiDescriptor()
                            kpi_descriptor.kpi_description = device.device_type
                            kpi_descriptor.kpi_sample_type = value
                            kpi_descriptor.device_id.CopyFrom(device.device_id)         # pylint: disable=no-member
                            kpi_descriptor.endpoint_id.CopyFrom(endpoint.endpoint_id)   # pylint: disable=no-member

                            kpi_id = self._monitoring_client.SetKpi(kpi_descriptor)
                            kpi_id_list.append(kpi_id)
                except queue.Empty:
                    break

            return kpi_id_list
        except ServiceException:
            LOGGER.exception('ListenEvents exception')
        except Exception:  # pragma: no cover # pylint: disable=broad-except
            LOGGER.exception('ListenEvents exception')
