import grpc, logging
from concurrent import futures
from queue import Queue
from monitoring.Config import GRPC_SERVICE_PORT, GRPC_MAX_WORKERS, GRPC_GRACE_PERIOD
from monitoring.proto.monitoring_pb2_grpc import  add_MonitoringServiceServicer_to_server
from .MockMonitoringServiceServicerImpl import MockMonitoringServiceServicerImpl

BIND_ADDRESS = '0.0.0.0'
LOGGER = logging.getLogger(__name__)

class MockMonitoringService:
    def __init__(
        self, address=BIND_ADDRESS, port=GRPC_SERVICE_PORT, max_workers=GRPC_MAX_WORKERS,
        grace_period=GRPC_GRACE_PERIOD):

        self.queue_samples = Queue()
        self.address = address
        self.port = port
        self.endpoint = None
        self.max_workers = max_workers
        self.grace_period = grace_period
        self.monitoring_servicer = None
        self.pool = None
        self.server = None

    def start(self):
        self.endpoint = '{:s}:{:s}'.format(str(self.address), str(self.port))
        LOGGER.info('Starting Service (tentative endpoint: {:s}, max_workers: {:s})...'.format(
            str(self.endpoint), str(self.max_workers)))

        self.pool = futures.ThreadPoolExecutor(max_workers=self.max_workers)
        self.server = grpc.server(self.pool) # , interceptors=(tracer_interceptor,))

        self.monitoring_servicer = MockMonitoringServiceServicerImpl(self.queue_samples)
        add_MonitoringServiceServicer_to_server(self.monitoring_servicer, self.server)

        port = self.server.add_insecure_port(self.endpoint)
        self.endpoint = '{:s}:{:s}'.format(str(self.address), str(port))
        LOGGER.info('Listening on {:s}...'.format(str(self.endpoint)))
        self.server.start()

        LOGGER.debug('Service started')

    def stop(self):
        LOGGER.debug('Stopping service (grace period {:s} seconds)...'.format(str(self.grace_period)))
        self.server.stop(self.grace_period)
        LOGGER.debug('Service stopped')