# 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.


import asyncio
import logging
import signal
import sys
import threading
import time
from multiprocessing import Manager, Process
from typing import List

from common.Constants import ServiceNameEnum
from common.proto.asyncio.optical_attack_detector_grpc import (
    OpticalAttackDetectorServiceStub,
)
from common.proto.asyncio.optical_attack_detector_pb2 import DetectionRequest
from common.proto.context_pb2 import ContextIdList, Empty, EventTypeEnum, ServiceIdList
from common.proto.kpi_sample_types_pb2 import KpiSampleType
from common.proto.monitoring_pb2 import KpiDescriptor
from common.Settings import (
    ENVVAR_SUFIX_SERVICE_HOST,
    ENVVAR_SUFIX_SERVICE_PORT_GRPC,
    get_env_var_name,
    get_log_level,
    get_metrics_port,
    get_setting,
    wait_for_environment_variables,
)
from common.tools.grpc.Tools import grpc_message_to_json_string
from context.client.ContextClient import ContextClient
from grpclib.client import Channel
from monitoring.client.MonitoringClient import MonitoringClient
from opticalattackmanager.utils.EventsCollector import EventsCollector
from opticalattackmanager.utils.monitor import monitor_services
from prometheus_client import Counter, Histogram, start_http_server

terminate = threading.Event()
LOGGER = None


def signal_handler(signal, frame):  # pylint: disable=redefined-outer-name
    LOGGER.warning("Terminate signal received")
    terminate.set()


def create_kpi(client: MonitoringClient, service_id):
    # create kpi
    kpi_description: KpiDescriptor = KpiDescriptor()
    kpi_description.kpi_description = "Security status of service {}".format(service_id)
    kpi_description.service_id.service_uuid.uuid = service_id
    kpi_description.kpi_sample_type = KpiSampleType.KPISAMPLETYPE_UNKNOWN
    new_kpi = client.SetKpi(kpi_description)
    LOGGER.info("Created KPI {}: ".format(grpc_message_to_json_string(new_kpi)))
    return new_kpi


def get_context_updates(service_list: List):
    # to make sure we are thread safe...
    LOGGER.info("Connecting with context and monitoring components...")
    context_client: ContextClient = ContextClient()
    monitoring_client: MonitoringClient = MonitoringClient()

    events_collector: EventsCollector = EventsCollector(context_client)
    events_collector.start()

    LOGGER.info("Connected successfully... Waiting for events...")

    time.sleep(20)

    while not terminate.wait(timeout=1):
        event = events_collector.get_event(block=True, timeout=1)
        if event is None:
            LOGGER.info("No event received")
            continue  # no event received
        LOGGER.info("Event received: {}".format(grpc_message_to_json_string(event)))
        if event.event.event_type == EventTypeEnum.EVENTTYPE_CREATE:
            LOGGER.info(
                "Service created: {}".format(
                    grpc_message_to_json_string(event.service_id)
                )
            )
            kpi_id = create_kpi(monitoring_client, event.service_id.service_uuid.uuid)
            service_list.append(
                {
                    "context": event.service_id.context_id.context_uuid.uuid,
                    "service": event.service_id.service_uuid.uuid,
                    "kpi": kpi_id.kpi_id.uuid,
                }
            )

        elif event.event.event_type == EventTypeEnum.EVENTTYPE_REMOVE:
            LOGGER.info(
                "Service removed: {}".format(
                    grpc_message_to_json_string(event.service_id)
                )
            )
            # find service and remove it from the list of currently monitored
            for service in service_list:
                if (
                    service["service"] == event.service_id.service_uuid.uuid
                    and service["context"]
                    == event.service_id.context_id.context_uuid.uuid
                ):
                    service_list.remove(service)
                    break

    events_collector.stop()


def main():
    global LOGGER  # pylint: disable=global-statement

    log_level = get_log_level()
    logging.basicConfig(level=log_level)
    LOGGER = logging.getLogger(__name__)

    logging.getLogger("hpack").setLevel(logging.CRITICAL)

    wait_for_environment_variables(
        [
            get_env_var_name(ServiceNameEnum.MONITORING, ENVVAR_SUFIX_SERVICE_HOST),
            get_env_var_name(
                ServiceNameEnum.MONITORING, ENVVAR_SUFIX_SERVICE_PORT_GRPC
            ),
        ]
    )

    wait_for_environment_variables(
        [
            get_env_var_name(ServiceNameEnum.CONTEXT, ENVVAR_SUFIX_SERVICE_HOST),
            get_env_var_name(ServiceNameEnum.CONTEXT, ENVVAR_SUFIX_SERVICE_PORT_GRPC),
        ]
    )

    wait_for_environment_variables(
        [
            get_env_var_name(
                ServiceNameEnum.OPTICALATTACKDETECTOR, ENVVAR_SUFIX_SERVICE_HOST
            ),
            get_env_var_name(
                ServiceNameEnum.OPTICALATTACKDETECTOR, ENVVAR_SUFIX_SERVICE_PORT_GRPC
            ),
        ]
    )

    signal.signal(signal.SIGINT, signal_handler)
    signal.signal(signal.SIGTERM, signal_handler)

    LOGGER.info("Starting...")

    # Start metrics server
    metrics_port = get_metrics_port()
    start_http_server(metrics_port)

    LOGGER.info("Connecting with context component...")
    context_client: ContextClient = ContextClient()
    monitoring_client: MonitoringClient = MonitoringClient()
    LOGGER.info("Connected successfully...")

    # creating a thread-safe list to be shared among threads
    # TODO: comment the lines below to stop monitoring dummy services
    service_list = Manager().list()
    kpi_id = create_kpi(monitoring_client, "1213")
    service_list.append(
        {"context": "admin", "service": "1213", "kpi": kpi_id.kpi_id.uuid}
    )
    kpi_id = create_kpi(monitoring_client, "1456")
    service_list.append(
        {"context": "admin", "service": "1456", "kpi": kpi_id.kpi_id.uuid}
    )

    context_ids: ContextIdList = context_client.ListContextIds(Empty())

    # populate with initial services
    for context_id in context_ids.context_ids:
        context_services: ServiceIdList = context_client.ListServiceIds(context_id)
        for service in context_services.service_ids:
            # in case of a service restart, monitoring component will not duplicate KPIs
            # but rather return the existing KPI if that's the case
            kpi_id = create_kpi(monitoring_client, service.service_uuid.uuid)
            service_list.append(
                {
                    "context": context_id.context_uuid.uuid,
                    "service": service.service_uuid.uuid,
                    "kpi": kpi_id.kpi_id.uuid,
                }
            )

    context_client.close()
    monitoring_client.close()

    # starting background process to monitor service addition/removal
    process_context = Process(target=get_context_updates, args=(service_list,))
    process_context.start()

    time.sleep(5)  # wait for the context updates to startup

    # runs the async loop in the background
    loop = asyncio.get_event_loop()
    loop.run_until_complete(monitor_services(terminate, service_list))
    # asyncio.create_task(monitor_services(service_list))

    # Wait for Ctrl+C or termination signal
    while not terminate.wait(timeout=0.1):
        pass

    LOGGER.info("Terminating...")
    process_context.kill()
    # process_security_loop.kill()

    LOGGER.info("Bye")
    return 0


if __name__ == "__main__":
    sys.exit(main())