# Copyright 2017-present Open Networking Foundation
#
# 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 random

from xos.exceptions import XOSValidationError

from models_decl import VOLTService_decl
from models_decl import VOLTServiceInstance_decl
from models_decl import OLTDevice_decl
from models_decl import PortBase_decl
from models_decl import PONPort_decl
from models_decl import NNIPort_decl
from models_decl import ONUDevice_decl
from models_decl import PONONUPort_decl
from models_decl import UNIPort_decl
from models_decl import TechnologyProfile_decl

import json

class VOLTService(VOLTService_decl):
    class Meta:
        proxy = True

    @staticmethod
    def has_access_device(serial_number):
        try:
            ONUDevice.objects.get(serial_number=serial_number)
            return True
        except IndexError, e:
            return False

class VOLTServiceInstance(VOLTServiceInstance_decl):
    class Meta:
        proxy = True

class OLTDevice(OLTDevice_decl):
    class Meta:
        proxy = True

    def get_volt_si(self):
        return VOLTServiceInstance.objects.all()

    def save(self, *args, **kwargs):

        if (self.host or self.port) and self.mac_address:
            raise XOSValidationError("You can't specify both host/port and mac_address for OLTDevice [host=%s, port=%s, mac_address=%s]" % (self.host, self.port, self.mac_address))

        super(OLTDevice, self).save(*args, **kwargs)

    def delete(self, *args, **kwargs):

        onus = []
        pon_ports = self.pon_ports.all()
        for port in pon_ports:
            onus = onus + list(port.onu_devices.all())


        if len(onus) > 0:
            onus = [o.id for o in onus]

            # find the ONUs used by VOLTServiceInstances
            used_onus = [o.onu_device_id for o in self.get_volt_si()]

            # find the intersection between the onus associated with this OLT and the used one
            used_onus_to_delete = [o for o in onus if o in used_onus]

            if len(used_onus_to_delete) > 0:
                if hasattr(self, "device_id") and self.device_id:
                    item = self.device_id
                elif hasattr(self, "name") and self.name:
                    item = self.name
                else:
                    item = self.id
                raise XOSValidationError('OLT "%s" can\'t be deleted as it has subscribers associated with its ONUs' % item)

        super(OLTDevice, self).delete(*args, **kwargs)

class PortBase(PortBase_decl):
    class Meta:
        proxy = True

class PONPort(PONPort_decl):
    class Meta:
        proxy = True

class NNIPort(NNIPort_decl):
    class Meta:
        proxy = True


class ONUDevice(ONUDevice_decl):
    class Meta:
        proxy = True

    def delete(self, *args, **kwargs):

        if len(self.volt_service_instances.all()) > 0:
            raise XOSValidationError('ONU "%s" can\'t be deleted as it has subscribers associated with it' % self.serial_number)

        super(ONUDevice, self).delete(*args, **kwargs)

class PONONUPort(PONONUPort_decl):
    class Meta:
        proxy = True

class UNIPort(UNIPort_decl):
    class Meta:
        proxy = True

class TechnologyProfile(TechnologyProfile_decl):
    class Meta:
        proxy = True

    def save(self, *args, **kwargs):

        caller_kind = None
        if "caller_kind" in kwargs:
            caller_kind = kwargs.get("caller_kind")

        # only synchronizer is allowed to update the model
        if not self.is_new and caller_kind != "synchronizer":
            if not self.deleted:
                existing = TechnologyProfile.objects.filter(id=self.id)
                raise XOSValidationError('Modification operation is not allowed on Technology Profile [/%s/%s]. Delete it and add again' % (existing[0].technology, existing[0].profile_id))

        # validate if technology profile value is valid JSON format string
        if self.profile_value != None:
            try:
                tp_json_val = json.loads(self.profile_value)
            except ValueError as e:
                raise XOSValidationError('Technology Profile value not in valid JSON format')

        super(TechnologyProfile, self).save(*args, **kwargs)