# -*- coding: utf-8 -*-

# Copyright 2018 Whitestack, LLC
# *************************************************************

# This file is part of OSM Monitoring module
# All Rights Reserved to Whitestack, LLC

# 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.
# For those usages not covered by the Apache License, Version 2.0 please
# contact: bdiaz@whitestack.com or glavado@whitestack.com
##

# This version uses a ProcessThreadPoolExecutor to limit the number of processes launched

import logging
from typing import List
import concurrent.futures
import time

from osm_mon.collector.infra_collectors.onos import OnosInfraCollector
from osm_mon.collector.infra_collectors.openstack import OpenstackInfraCollector
from osm_mon.collector.infra_collectors.vio import VIOInfraCollector
from osm_mon.collector.infra_collectors.vmware import VMwareInfraCollector
from osm_mon.collector.metric import Metric
from osm_mon.collector.vnf_collectors.juju import VCACollector
from osm_mon.collector.vnf_collectors.openstack import OpenstackCollector
from osm_mon.collector.vnf_collectors.vio import VIOCollector
from osm_mon.collector.vnf_collectors.vmware import VMwareCollector
from osm_mon.core.common_db import CommonDbClient
from osm_mon.core.config import Config

log = logging.getLogger(__name__)

VIM_COLLECTORS = {
    "openstack": OpenstackCollector,
    "vmware": VMwareCollector,
    "vio": VIOCollector
}
VIM_INFRA_COLLECTORS = {
    "openstack": OpenstackInfraCollector,
    "vmware": VMwareInfraCollector,
    "vio": VIOInfraCollector
}
SDN_INFRA_COLLECTORS = {
    "onosof": OnosInfraCollector,
    "onos_vpls": OnosInfraCollector
}


class CollectorService:

    def __init__(self, config: Config):
        self.conf = config
        self.common_db = CommonDbClient(self.conf)
        return

    # static methods to be executed in the Processes
    @staticmethod
    def _get_vim_type(conf: Config, vim_account_id: str) -> str:
        common_db = CommonDbClient(conf)
        vim_account = common_db.get_vim_account(vim_account_id)
        vim_type = vim_account['vim_type']
        if 'config' in vim_account and 'vim_type' in vim_account['config']:
            vim_type = vim_account['config']['vim_type'].lower()
            if vim_type == 'vio' and 'vrops_site' not in vim_account['config']:
                vim_type = 'openstack'
        return vim_type

    @staticmethod
    def _collect_vim_metrics(conf: Config, vnfr: dict, vim_account_id: str):
        # TODO(diazb) Add support for aws
        metrics = []
        vim_type = CollectorService._get_vim_type(conf, vim_account_id)
        log.debug("vim type.....{}".format(vim_type))
        if vim_type in VIM_COLLECTORS:
            collector = VIM_COLLECTORS[vim_type](conf, vim_account_id)
            metrics = collector.collect(vnfr)
            log.debug("Collecting vim metrics.....{}".format(metrics))
        else:
            log.debug("vimtype %s is not supported.", vim_type)
        return metrics

    @staticmethod
    def _collect_vca_metrics(conf: Config, vnfr: dict):
        metrics = []
        vca_collector = VCACollector(conf)
        metrics = vca_collector.collect(vnfr)
        log.debug("Collecting vca metrics.....{}".format(metrics))
        return metrics

    @staticmethod
    def _collect_vim_infra_metrics(conf: Config, vim_account_id: str):
        log.info("Collecting vim infra metrics")
        metrics = []
        vim_type = CollectorService._get_vim_type(conf, vim_account_id)
        if vim_type in VIM_INFRA_COLLECTORS:
            collector = VIM_INFRA_COLLECTORS[vim_type](conf, vim_account_id)
            metrics = collector.collect()
            log.debug("Collecting vim infra metrics.....{}".format(metrics))
        else:
            log.debug("vimtype %s is not supported.", vim_type)
        return metrics

    @staticmethod
    def _collect_sdnc_infra_metrics(conf: Config, sdnc_id: str):
        log.info("Collecting sdnc metrics")
        metrics = []
        common_db = CommonDbClient(conf)
        sdn_type = common_db.get_sdnc(sdnc_id)['type']
        if sdn_type in SDN_INFRA_COLLECTORS:
            collector = SDN_INFRA_COLLECTORS[sdn_type](conf, sdnc_id)
            metrics = collector.collect()
            log.debug("Collecting sdnc metrics.....{}".format(metrics))
        else:
            log.debug("sdn_type %s is not supported.", sdn_type)
        return metrics

    @staticmethod
    def _stop_process_pool(executor):
        log.info('Shutting down process pool')
        try:
            log.debug('Stopping residual processes in the process pool')
            for pid, process in executor._processes.items():
                if process.is_alive():
                    process.terminate()
        except Exception as e:
            log.info("Exception during process termination")
            log.debug("Exception %s" % (e))

        try:
            # Shutting down executor
            log.debug('Shutting down process pool executor')
            executor.shutdown()
        except RuntimeError as e:
            log.info('RuntimeError in shutting down executer')
            log.debug('RuntimeError %s' % (e))
        return

    def collect_metrics(self) -> List[Metric]:
        vnfrs = self.common_db.get_vnfrs()
        metrics = []

        start_time = time.time()
        # Starting executor pool with pool size process_pool_size. Default process_pool_size is 20
        with concurrent.futures.ProcessPoolExecutor(self.conf.get('collector', 'process_pool_size')) as executor:
            log.info('Started metric collector process pool with pool size %s' % (self.conf.get('collector',
                                                                                                'process_pool_size')))
            futures = []
            for vnfr in vnfrs:
                nsr_id = vnfr['nsr-id-ref']
                vnf_member_index = vnfr['member-vnf-index-ref']
                vim_account_id = self.common_db.get_vim_account_id(nsr_id, vnf_member_index)
                futures.append(executor.submit(CollectorService._collect_vim_metrics, self.conf, vnfr, vim_account_id))
                futures.append(executor.submit(CollectorService._collect_vca_metrics, self.conf, vnfr))

            vims = self.common_db.get_vim_accounts()
            for vim in vims:
                futures.append(executor.submit(CollectorService._collect_vim_infra_metrics, self.conf, vim['_id']))

            sdncs = self.common_db.get_sdncs()
            for sdnc in sdncs:
                futures.append(executor.submit(CollectorService._collect_sdnc_infra_metrics, self.conf, sdnc['_id']))

            try:
                # Wait for future calls to complete till process_execution_timeout. Default is 50 seconds
                for future in concurrent.futures.as_completed(futures, self.conf.get('collector',
                                                                                     'process_execution_timeout')):
                    result = future.result(timeout=int(self.conf.get('collector',
                                                                     'process_execution_timeout')))
                    metrics.extend(result)
                    log.debug('result = %s' % (result))
            except concurrent.futures.TimeoutError as e:
                # Some processes have not completed due to timeout error
                log.info('Some processes have not finished due to TimeoutError exception')
                log.debug('concurrent.futures.TimeoutError exception %s' % (e))

            # Shutting down process pool executor
            CollectorService._stop_process_pool(executor)

        end_time = time.time()
        log.info("Collection completed in %s seconds", end_time - start_time)

        return metrics
