###############################################################################
# Copyright (c) 2017 Koren Lev (Cisco Systems), Yaron Yogev (Cisco Systems)   #
# and others                                                                  #
#                                                                             #
# All rights reserved. This program and the accompanying materials            #
# are made available under the terms of the Apache License, Version 2.0       #
# which accompanies this distribution, and is available at                    #
# http://www.apache.org/licenses/LICENSE-2.0                                  #
###############################################################################
from discover.events.event_base import EventBase, EventResult
from discover.events.event_port_add import EventPortAdd
from discover.events.event_port_delete import EventPortDelete
from discover.events.event_subnet_add import EventSubnetAdd
from discover.fetchers.api.api_access import ApiAccess
from discover.fetchers.api.api_fetch_regions import ApiFetchRegions
from discover.fetchers.db.db_fetch_port import DbFetchPort
from discover.find_links_for_vservice_vnics import FindLinksForVserviceVnics
from discover.scanner import Scanner


class EventSubnetUpdate(EventBase):

    def handle(self, env, notification):
        # check for network document.
        subnet = notification['payload']['subnet']
        project = notification['_context_project_name']
        host_id = notification['publisher_id'].replace('network.', '', 1)
        subnet_id = subnet['id']
        network_id = subnet['network_id']
        network_document = self.inv.get_by_id(env, network_id)
        if not network_document:
            self.log.info('network document does not exist, aborting subnet update')
            return EventResult(result=False, retry=True)

        # update network document.
        subnets = network_document['subnets']
        key = next(filter(lambda k: subnets[k]['id'] == subnet_id, subnets),
                   None)

        if key:
            if subnet['enable_dhcp'] and subnets[key]['enable_dhcp'] is False:
                # scan DHCP namespace to add related document.
                # add dhcp vservice document.
                host = self.inv.get_by_id(env, host_id)
                port_handler = EventPortAdd()
                port_handler.add_dhcp_document(env, host, network_id,
                                               network_document['name'])

                # make sure that self.regions is not empty.
                if len(ApiAccess.regions) == 0:
                    fetcher = ApiFetchRegions()
                    fetcher.set_env(env)
                    fetcher.get(None)

                self.log.info("add port binding to DHCP server.")
                port_id = DbFetchPort(). \
                    get_id_by_field(network_id,
                                    """device_owner LIKE "%dhcp" """)
                port = EventSubnetAdd(). \
                    add_port_document(env, port_id,
                                      network_name=network_document['name'],
                                      project_name=project)
                if port:
                    port_handler. \
                        add_vnic_document(env, host, network_id,
                                          network_name=network_document['name'],
                                          mac_address=port['mac_address'])
                    # add link for vservice - vnic
                    FindLinksForVserviceVnics().add_links(search={"id": "qdhcp-%s" % network_id})
                    scanner = Scanner()
                    scanner.set_env(env)
                    scanner.scan_cliques()
                    FindLinksForVserviceVnics(). \
                        add_links(search={"id": "qdhcp-%s" % network_id})
                    scanner = Scanner()
                    scanner.set_env(env)
                    scanner.scan_cliques()

            if subnet['enable_dhcp'] is False and subnets[key]['enable_dhcp']:
                # delete existed related DHCP documents.
                self.inv.delete("inventory",
                                {'id': "qdhcp-%s" % subnet['network_id']})
                self.log.info("delete DHCP document: qdhcp-%s" %
                              subnet['network_id'])

                port = self.inv.find_items({'network_id': subnet['network_id'],
                                            'device_owner': 'network:dhcp'},
                                           get_single=True)
                if 'id' in port:
                    EventPortDelete().delete_port(env, port['id'])
                    self.log.info("delete port binding to DHCP server.")

            if subnet['name'] == subnets[key]['name']:
                subnets[key] = subnet
            else:
                # TODO: #AskCheng shouldn't we remove the old one?
                subnets[subnet['name']] = subnet

            self.inv.set(network_document)
            return EventResult(result=True,
                               related_object=subnet['id'],
                               display_context=network_id)