# Copyright 2012 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
# Copyright 2012 Cisco Systems, Inc.
# Copyright 2012 NEC Corporation
#
#    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.

from __future__ import absolute_import

import collections
import copy
import logging

import netaddr

from django.conf import settings
from django.utils.translation import ugettext_lazy as _
from neutronclient.common import exceptions as neutron_exc
from neutronclient.v2_0 import client as neutron_client
import six

from horizon import exceptions
from horizon import messages
from horizon.utils.memoized import memoized  # noqa
from openstack_dashboard.api import base
from openstack_dashboard.api import network_base
from openstack_dashboard.api import nova
from openstack_dashboard import policy


LOG = logging.getLogger(__name__)

IP_VERSION_DICT = {4: 'IPv4', 6: 'IPv6'}

OFF_STATE = 'OFF'
ON_STATE = 'ON'

ROUTER_INTERFACE_OWNERS = (
    'network:router_interface',
    'network:router_interface_distributed',
    'network:ha_router_replicated_interface'
)


class NeutronAPIDictWrapper(base.APIDictWrapper):

    def __init__(self, apidict):
        if 'admin_state_up' in apidict:
            if apidict['admin_state_up']:
                apidict['admin_state'] = 'UP'
            else:
                apidict['admin_state'] = 'DOWN'

        # Django cannot handle a key name with ':', so use '__'.
        apidict.update({
            key.replace(':', '__'): value
            for key, value in apidict.items()
            if ':' in key
        })
        super(NeutronAPIDictWrapper, self).__init__(apidict)

    def set_id_as_name_if_empty(self, length=8):
        try:
            if not self._apidict['name'].strip():
                id = self._apidict['id']
                if length:
                    id = id[:length]
                self._apidict['name'] = '(%s)' % id
        except KeyError:
            pass

    def items(self):
        return self._apidict.items()

    @property
    def name_or_id(self):
        return (self._apidict.get('name').strip() or
                '(%s)' % self._apidict['id'][:13])


class Agent(NeutronAPIDictWrapper):
    """Wrapper for neutron agents."""


class Network(NeutronAPIDictWrapper):
    """Wrapper for neutron Networks."""

    def to_dict(self):
        d = dict(super(NeutronAPIDictWrapper, self).to_dict())
        d['subnets'] = [s.to_dict() for s in d['subnets']]
        return d


class Subnet(NeutronAPIDictWrapper):
    """Wrapper for neutron subnets."""

    def __init__(self, apidict):
        apidict['ipver_str'] = get_ipver_str(apidict['ip_version'])
        super(Subnet, self).__init__(apidict)


class SubnetPool(NeutronAPIDictWrapper):
    """Wrapper for neutron subnetpools."""


class Port(NeutronAPIDictWrapper):
    """Wrapper for neutron ports."""

    def __init__(self, apidict):
        if 'mac_learning_enabled' in apidict:
            apidict['mac_state'] = \
                ON_STATE if apidict['mac_learning_enabled'] else OFF_STATE
        pairs = apidict.get('allowed_address_pairs')
        if pairs:
            apidict = copy.deepcopy(apidict)
            wrapped_pairs = [PortAllowedAddressPair(pair) for pair in pairs]
            apidict['allowed_address_pairs'] = wrapped_pairs
        super(Port, self).__init__(apidict)


class PortAllowedAddressPair(NeutronAPIDictWrapper):
    """Wrapper for neutron port allowed address pairs."""

    def __init__(self, addr_pair):
        super(PortAllowedAddressPair, self).__init__(addr_pair)
        # Horizon references id property for table operations
        self.id = addr_pair['ip_address']


class Profile(NeutronAPIDictWrapper):
    """Wrapper for neutron profiles."""
    _attrs = ['profile_id', 'name', 'segment_type', 'segment_range',
              'sub_type', 'multicast_ip_index', 'multicast_ip_range']


class Router(NeutronAPIDictWrapper):
    """Wrapper for neutron routers."""


class RouterStaticRoute(NeutronAPIDictWrapper):
    """Wrapper for neutron routes extra route."""

    def __init__(self, route):
        super(RouterStaticRoute, self).__init__(route)
        # Horizon references id property for table operations
        self.id = route['nexthop'] + ":" + route['destination']


class SecurityGroup(NeutronAPIDictWrapper):
    # Required attributes: id, name, description, tenant_id, rules

    def __init__(self, sg, sg_dict=None):
        if sg_dict is None:
            sg_dict = {sg['id']: sg['name']}
        sg['rules'] = [SecurityGroupRule(rule, sg_dict)
                       for rule in sg['security_group_rules']]
        super(SecurityGroup, self).__init__(sg)

    def to_dict(self):
        return {k: self._apidict[k] for k in self._apidict if k != 'rules'}


@six.python_2_unicode_compatible
class SecurityGroupRule(NeutronAPIDictWrapper):
    # Required attributes:
    #   id, parent_group_id
    #   ip_protocol, from_port, to_port, ip_range, group
    #   ethertype, direction (Neutron specific)

    def _get_secgroup_name(self, sg_id, sg_dict):
        if sg_id:
            if sg_dict is None:
                sg_dict = {}
            # If sg name not found in sg_dict,
            # first two parts of UUID is used as sg name.
            return sg_dict.get(sg_id, sg_id[:13])
        else:
            return u''

    def __init__(self, sgr, sg_dict=None):
        # In Neutron, if both remote_ip_prefix and remote_group_id are None,
        # it means all remote IP range is allowed, i.e., 0.0.0.0/0 or ::/0.
        if not sgr['remote_ip_prefix'] and not sgr['remote_group_id']:
            if sgr['ethertype'] == 'IPv6':
                sgr['remote_ip_prefix'] = '::/0'
            else:
                sgr['remote_ip_prefix'] = '0.0.0.0/0'

        rule = {
            'id': sgr['id'],
            'parent_group_id': sgr['security_group_id'],
            'direction': sgr['direction'],
            'ethertype': sgr['ethertype'],
            'ip_protocol': sgr['protocol'],
            'from_port': sgr['port_range_min'],
            'to_port': sgr['port_range_max'],
        }
        cidr = sgr['remote_ip_prefix']
        rule['ip_range'] = {'cidr': cidr} if cidr else {}
        group = self._get_secgroup_name(sgr['remote_group_id'], sg_dict)
        rule['group'] = {'name': group} if group else {}
        super(SecurityGroupRule, self).__init__(rule)

    def __str__(self):
        if 'name' in self.group:
            remote = self.group['name']
        elif 'cidr' in self.ip_range:
            remote = self.ip_range['cidr']
        else:
            remote = 'ANY'
        direction = 'to' if self.direction == 'egress' else 'from'
        if self.from_port:
            if self.from_port == self.to_port:
                proto_port = ("%s/%s" %
                              (self.from_port, self.ip_protocol.lower()))
            else:
                proto_port = ("%s-%s/%s" %
                              (self.from_port, self.to_port,
                               self.ip_protocol.lower()))
        elif self.ip_protocol:
            try:
                ip_proto = int(self.ip_protocol)
                proto_port = "ip_proto=%d" % ip_proto
            except Exception:
                # well-defined IP protocol name like TCP, UDP, ICMP.
                proto_port = self.ip_protocol
        else:
            proto_port = ''

        return (_('ALLOW %(ethertype)s %(proto_port)s '
                  '%(direction)s %(remote)s') %
                {'ethertype': self.ethertype,
                 'proto_port': proto_port,
                 'remote': remote,
                 'direction': direction})


class SecurityGroupManager(network_base.SecurityGroupManager):
    backend = 'neutron'

    def __init__(self, request):
        self.request = request
        self.client = neutronclient(request)

    def _list(self, **filters):
        secgroups = self.client.list_security_groups(**filters)
        return [SecurityGroup(sg) for sg in secgroups.get('security_groups')]

    def list(self):
        tenant_id = self.request.user.tenant_id
        return self._list(tenant_id=tenant_id)

    def _sg_name_dict(self, sg_id, rules):
        """Create a mapping dict from secgroup id to its name."""
        related_ids = set([sg_id])
        related_ids |= set(filter(None, [r['remote_group_id'] for r in rules]))
        related_sgs = self.client.list_security_groups(id=related_ids,
                                                       fields=['id', 'name'])
        related_sgs = related_sgs.get('security_groups')
        return dict((sg['id'], sg['name']) for sg in related_sgs)

    def get(self, sg_id):
        secgroup = self.client.show_security_group(sg_id).get('security_group')
        sg_dict = self._sg_name_dict(sg_id, secgroup['security_group_rules'])
        return SecurityGroup(secgroup, sg_dict)

    def create(self, name, desc):
        body = {'security_group': {'name': name,
                                   'description': desc,
                                   'tenant_id': self.request.user.project_id}}
        secgroup = self.client.create_security_group(body)
        return SecurityGroup(secgroup.get('security_group'))

    def update(self, sg_id, name, desc):
        body = {'security_group': {'name': name,
                                   'description': desc}}
        secgroup = self.client.update_security_group(sg_id, body)
        return SecurityGroup(secgroup.get('security_group'))

    def delete(self, sg_id):
        self.client.delete_security_group(sg_id)

    def rule_create(self, parent_group_id,
                    direction=None, ethertype=None,
                    ip_protocol=None, from_port=None, to_port=None,
                    cidr=None, group_id=None):
        if not cidr:
            cidr = None
        if from_port < 0:
            from_port = None
        if to_port < 0:
            to_port = None
        if isinstance(ip_protocol, int) and ip_protocol < 0:
            ip_protocol = None

        body = {'security_group_rule':
                {'security_group_id': parent_group_id,
                 'direction': direction,
                 'ethertype': ethertype,
                 'protocol': ip_protocol,
                 'port_range_min': from_port,
                 'port_range_max': to_port,
                 'remote_ip_prefix': cidr,
                 'remote_group_id': group_id}}
        try:
            rule = self.client.create_security_group_rule(body)
        except neutron_exc.Conflict:
            raise exceptions.Conflict(_('Security group rule already exists.'))
        rule = rule.get('security_group_rule')
        sg_dict = self._sg_name_dict(parent_group_id, [rule])
        return SecurityGroupRule(rule, sg_dict)

    def rule_delete(self, sgr_id):
        self.client.delete_security_group_rule(sgr_id)

    def list_by_instance(self, instance_id):
        """Gets security groups of an instance."""
        ports = port_list(self.request, device_id=instance_id)
        sg_ids = []
        for p in ports:
            sg_ids += p.security_groups
        return self._list(id=set(sg_ids)) if sg_ids else []

    def update_instance_security_group(self, instance_id,
                                       new_security_group_ids):
        ports = port_list(self.request, device_id=instance_id)
        for p in ports:
            params = {'security_groups': new_security_group_ids}
            port_update(self.request, p.id, **params)


class FloatingIp(base.APIDictWrapper):
    _attrs = ['id', 'ip', 'fixed_ip', 'port_id', 'instance_id',
              'instance_type', 'pool']

    def __init__(self, fip):
        fip['ip'] = fip['floating_ip_address']
        fip['fixed_ip'] = fip['fixed_ip_address']
        fip['pool'] = fip['floating_network_id']
        super(FloatingIp, self).__init__(fip)


class FloatingIpPool(base.APIDictWrapper):
    pass


class FloatingIpTarget(base.APIDictWrapper):
    pass


class FloatingIpManager(network_base.FloatingIpManager):

    device_owner_map = {
        'compute:': 'compute',
        'neutron:LOADBALANCER': 'loadbalancer',
    }

    def __init__(self, request):
        self.request = request
        self.client = neutronclient(request)

    def list_pools(self):
        search_opts = {'router:external': True}
        return [FloatingIpPool(pool) for pool
                in self.client.list_networks(**search_opts).get('networks')]

    def _get_instance_type_from_device_owner(self, device_owner):
        for key, value in self.device_owner_map.items():
            if device_owner.startswith(key):
                return value
        return device_owner

    def _set_instance_info(self, fip, port=None):
        if fip['port_id']:
            if not port:
                port = port_get(self.request, fip['port_id'])
            fip['instance_id'] = port.device_id
            fip['instance_type'] = self._get_instance_type_from_device_owner(
                port.device_owner)
        else:
            fip['instance_id'] = None
            fip['instance_type'] = None

    def list(self, all_tenants=False, **search_opts):
        if not all_tenants:
            tenant_id = self.request.user.tenant_id
            # In Neutron, list_floatingips returns Floating IPs from
            # all tenants when the API is called with admin role, so
            # we need to filter them with tenant_id.
            search_opts['tenant_id'] = tenant_id
            port_search_opts = {'tenant_id': tenant_id}
        else:
            port_search_opts = {}
        fips = self.client.list_floatingips(**search_opts)
        fips = fips.get('floatingips')
        # Get port list to add instance_id to floating IP list
        # instance_id is stored in device_id attribute
        ports = port_list(self.request, **port_search_opts)
        port_dict = collections.OrderedDict([(p['id'], p) for p in ports])
        for fip in fips:
            self._set_instance_info(fip, port_dict.get(fip['port_id']))
        return [FloatingIp(fip) for fip in fips]

    def get(self, floating_ip_id):
        fip = self.client.show_floatingip(floating_ip_id).get('floatingip')
        self._set_instance_info(fip)
        return FloatingIp(fip)

    def allocate(self, pool, tenant_id=None, **params):
        if not tenant_id:
            tenant_id = self.request.user.project_id
        create_dict = {'floating_network_id': pool,
                       'tenant_id': tenant_id}
        if 'floating_ip_address' in params:
            create_dict['floating_ip_address'] = params['floating_ip_address']
        fip = self.client.create_floatingip(
            {'floatingip': create_dict}).get('floatingip')
        self._set_instance_info(fip)
        return FloatingIp(fip)

    def release(self, floating_ip_id):
        self.client.delete_floatingip(floating_ip_id)

    def associate(self, floating_ip_id, port_id):
        # NOTE: In Neutron Horizon floating IP support, port_id is
        # "<port_id>_<ip_address>" format to identify multiple ports.
        pid, ip_address = port_id.split('_', 1)
        update_dict = {'port_id': pid,
                       'fixed_ip_address': ip_address}
        self.client.update_floatingip(floating_ip_id,
                                      {'floatingip': update_dict})

    def disassociate(self, floating_ip_id):
        update_dict = {'port_id': None}
        self.client.update_floatingip(floating_ip_id,
                                      {'floatingip': update_dict})

    def _get_reachable_subnets(self, ports):
        if not is_enabled_by_config('enable_fip_topology_check', True):
            # All subnets are reachable from external network
            return set(
                p.fixed_ips[0]['subnet_id'] for p in ports if p.fixed_ips
            )
        # Retrieve subnet list reachable from external network
        ext_net_ids = [ext_net.id for ext_net in self.list_pools()]
        gw_routers = [r.id for r in router_list(self.request)
                      if (r.external_gateway_info and
                          r.external_gateway_info.get('network_id')
                          in ext_net_ids)]
        reachable_subnets = set([p.fixed_ips[0]['subnet_id'] for p in ports
                                if ((p.device_owner in
                                     ROUTER_INTERFACE_OWNERS)
                                    and (p.device_id in gw_routers))])
        # we have to include any shared subnets as well because we may not
        # have permission to see the router interface to infer connectivity
        shared = set([s.id for n in network_list(self.request, shared=True)
                      for s in n.subnets])
        return reachable_subnets | shared

    def list_targets(self):
        tenant_id = self.request.user.tenant_id
        ports = port_list(self.request, tenant_id=tenant_id)
        servers, has_more = nova.server_list(self.request)
        server_dict = collections.OrderedDict(
            [(s.id, s.name) for s in servers])
        reachable_subnets = self._get_reachable_subnets(ports)
        if is_service_enabled(self.request,
                              config_name='enable_lb',
                              ext_name='lbaas'):
            # Also get the loadbalancer VIPs
            vip_dict = {v['port_id']: v['name']
                        for v in self.client.list_vips().get('vips', [])}
        else:
            vip_dict = {}

        targets = []
        for p in ports:
            # Remove network ports from Floating IP targets
            if p.device_owner.startswith('network:'):
                continue
            port_id = p.id
            server_name = server_dict.get(p.device_id) or vip_dict.get(port_id)

            for ip in p.fixed_ips:
                if ip['subnet_id'] not in reachable_subnets:
                    continue
                target = {'name': '%s: %s' % (server_name, ip['ip_address']),
                          'id': '%s_%s' % (port_id, ip['ip_address']),
                          'port_id': port_id,
                          'instance_id': p.device_id}
                targets.append(FloatingIpTarget(target))
        return targets

    def _target_ports_by_instance(self, instance_id):
        if not instance_id:
            return None
        search_opts = {'device_id': instance_id}
        return port_list(self.request, **search_opts)

    def get_target_id_by_instance(self, instance_id, target_list=None):
        if target_list is not None:
            targets = [target for target in target_list
                       if target['instance_id'] == instance_id]
            if not targets:
                return None
            return targets[0]['id']
        else:
            # In Neutron one port can have multiple ip addresses, so this
            # method picks up the first one and generate target id.
            ports = self._target_ports_by_instance(instance_id)
            if not ports:
                return None
            return '{0}_{1}'.format(ports[0].id,
                                    ports[0].fixed_ips[0]['ip_address'])

    def list_target_id_by_instance(self, instance_id, target_list=None):
        if target_list is not None:
            return [target['id'] for target in target_list
                    if target['instance_id'] == instance_id]
        else:
            ports = self._target_ports_by_instance(instance_id)
            return ['{0}_{1}'.format(p.id, p.fixed_ips[0]['ip_address'])
                    for p in ports]

    def is_simple_associate_supported(self):
        # NOTE: There are two reason that simple association support
        # needs more considerations. (1) Neutron does not support the
        # default floating IP pool at the moment. It can be avoided
        # in case where only one floating IP pool exists.
        # (2) Neutron floating IP is associated with each VIF and
        # we need to check whether such VIF is only one for an instance
        # to enable simple association support.
        return False

    def is_supported(self):
        network_config = getattr(settings, 'OPENSTACK_NEUTRON_NETWORK', {})
        return network_config.get('enable_router', True)


def get_ipver_str(ip_version):
    """Convert an ip version number to a human-friendly string."""
    return IP_VERSION_DICT.get(ip_version, '')


@memoized
def neutronclient(request):
    insecure = getattr(settings, 'OPENSTACK_SSL_NO_VERIFY', False)
    cacert = getattr(settings, 'OPENSTACK_SSL_CACERT', None)
    c = neutron_client.Client(token=request.user.token.id,
                              auth_url=base.url_for(request, 'identity'),
                              endpoint_url=base.url_for(request, 'network'),
                              insecure=insecure, ca_cert=cacert)
    return c


def list_resources_with_long_filters(list_method,
                                     filter_attr, filter_values, **params):
    """List neutron resources with handling RequestURITooLong exception.

    If filter parameters are long, list resources API request leads to
    414 error (URL is too long). For such case, this method split
    list parameters specified by a list_field argument into chunks
    and call the specified list_method repeatedly.

    :param list_method: Method used to retrieve resource list.
    :param filter_attr: attribute name to be filtered. The value corresponding
        to this attribute is specified by "filter_values".
        If you want to specify more attributes for a filter condition,
        pass them as keyword arguments like "attr2=values2".
    :param filter_values: values of "filter_attr" to be filtered.
        If filter_values are too long and the total URI length exceed the
        maximum length supported by the neutron server, filter_values will
        be split into sub lists if filter_values is a list.
    :param params: parameters to pass a specified listing API call
        without any changes. You can specify more filter conditions
        in addition to a pair of filter_attr and filter_values.
    """
    try:
        params[filter_attr] = filter_values
        return list_method(**params)
    except neutron_exc.RequestURITooLong as uri_len_exc:
        # The URI is too long because of too many filter values.
        # Use the excess attribute of the exception to know how many
        # filter values can be inserted into a single request.

        # We consider only the filter condition from (filter_attr,
        # filter_values) and do not consider other filter conditions
        # which may be specified in **params.
        if type(filter_values) != list:
            filter_values = [filter_values]

        # Length of each query filter is:
        # <key>=<value>& (e.g., id=<uuid>)
        # The length will be key_len + value_maxlen + 2
        all_filter_len = sum(len(filter_attr) + len(val) + 2
                             for val in filter_values)
        allowed_filter_len = all_filter_len - uri_len_exc.excess

        val_maxlen = max(len(val) for val in filter_values)
        filter_maxlen = len(filter_attr) + val_maxlen + 2
        chunk_size = allowed_filter_len // filter_maxlen

        resources = []
        for i in range(0, len(filter_values), chunk_size):
            params[filter_attr] = filter_values[i:i + chunk_size]
            resources.extend(list_method(**params))
        return resources


def network_list(request, **params):
    LOG.debug("network_list(): params=%s", params)
    networks = neutronclient(request).list_networks(**params).get('networks')
    # Get subnet list to expand subnet info in network list.
    subnets = subnet_list(request)
    subnet_dict = dict([(s['id'], s) for s in subnets])
    # Expand subnet list from subnet_id to values.
    for n in networks:
        # Due to potential timing issues, we can't assume the subnet_dict data
        # is in sync with the network data.
        n['subnets'] = [subnet_dict[s] for s in n.get('subnets', []) if
                        s in subnet_dict]
    return [Network(n) for n in networks]


def network_list_for_tenant(request, tenant_id, include_external=False,
                            **params):
    """Return a network list available for the tenant.

    The list contains networks owned by the tenant and public networks.
    If requested_networks specified, it searches requested_networks only.
    """
    LOG.debug("network_list_for_tenant(): tenant_id=%s, params=%s"
              % (tenant_id, params))

    networks = []
    shared = params.get('shared')
    if shared is not None:
        del params['shared']

    if shared in (None, False):
        # If a user has admin role, network list returned by Neutron API
        # contains networks that do not belong to that tenant.
        # So we need to specify tenant_id when calling network_list().
        networks += network_list(request, tenant_id=tenant_id,
                                 shared=False, **params)

    if shared in (None, True):
        # In the current Neutron API, there is no way to retrieve
        # both owner networks and public networks in a single API call.
        networks += network_list(request, shared=True, **params)
    params['router:external'] = params.get('router:external', True)
    if params['router:external'] and include_external:
        if shared is not None:
            params['shared'] = shared
        fetched_net_ids = [n.id for n in networks]
        # Retrieves external networks when router:external is not specified
        # in (filtering) params or router:external=True filter is specified.
        # When router:external=False is specified there is no need to query
        # networking API because apparently nothing will match the filter.
        ext_nets = network_list(request, **params)
        networks += [n for n in ext_nets if
                     n.id not in fetched_net_ids]

    return networks


def network_get(request, network_id, expand_subnet=True, **params):
    LOG.debug("network_get(): netid=%s, params=%s" % (network_id, params))
    network = neutronclient(request).show_network(network_id,
                                                  **params).get('network')
    if expand_subnet:
        if request.user.tenant_id == network['tenant_id'] or network['shared']:
            # Since the number of subnets per network must be small,
            # call subnet_get() for each subnet instead of calling
            # subnet_list() once.
            network['subnets'] = [subnet_get(request, sid)
                                  for sid in network['subnets']]
    return Network(network)


def network_create(request, **kwargs):
    """Create a  network object.

    :param request: request context
    :param tenant_id: (optional) tenant id of the network created
    :param name: (optional) name of the network created
    :returns: Network object
    """
    LOG.debug("network_create(): kwargs = %s" % kwargs)
    # In the case network profiles are being used, profile id is needed.
    if 'net_profile_id' in kwargs:
        kwargs['n1kv:profile'] = kwargs.pop('net_profile_id')
    if 'tenant_id' not in kwargs:
        kwargs['tenant_id'] = request.user.project_id
    body = {'network': kwargs}
    network = neutronclient(request).create_network(body=body).get('network')
    return Network(network)


def network_update(request, network_id, **kwargs):
    LOG.debug("network_update(): netid=%s, params=%s" % (network_id, kwargs))
    body = {'network': kwargs}
    network = neutronclient(request).update_network(network_id,
                                                    body=body).get('network')
    return Network(network)


def network_delete(request, network_id):
    LOG.debug("network_delete(): netid=%s" % network_id)
    neutronclient(request).delete_network(network_id)


def subnet_list(request, **params):
    LOG.debug("subnet_list(): params=%s" % (params))
    subnets = neutronclient(request).list_subnets(**params).get('subnets')
    return [Subnet(s) for s in subnets]


def subnet_get(request, subnet_id, **params):
    LOG.debug("subnet_get(): subnetid=%s, params=%s" % (subnet_id, params))
    subnet = neutronclient(request).show_subnet(subnet_id,
                                                **params).get('subnet')
    return Subnet(subnet)


def subnet_create(request, network_id, **kwargs):
    """Create a subnet on a specified network.

    :param request: request context
    :param network_id: network id a subnet is created on
    :param cidr: (optional) subnet IP address range
    :param ip_version: (optional) IP version (4 or 6)
    :param gateway_ip: (optional) IP address of gateway
    :param tenant_id: (optional) tenant id of the subnet created
    :param name: (optional) name of the subnet created
    :param subnetpool_id: (optional) subnetpool to allocate prefix from
    :param prefixlen: (optional) length of prefix to allocate
    :returns: Subnet object

    Although both cidr+ip_version and subnetpool_id+preifxlen is listed as
    optional you MUST pass along one of the combinations to get a successful
    result.
    """
    LOG.debug("subnet_create(): netid=%s, kwargs=%s"
              % (network_id, kwargs))
    body = {'subnet': {'network_id': network_id}}
    if 'tenant_id' not in kwargs:
        kwargs['tenant_id'] = request.user.project_id
    body['subnet'].update(kwargs)
    subnet = neutronclient(request).create_subnet(body=body).get('subnet')
    return Subnet(subnet)


def subnet_update(request, subnet_id, **kwargs):
    LOG.debug("subnet_update(): subnetid=%s, kwargs=%s" % (subnet_id, kwargs))
    body = {'subnet': kwargs}
    subnet = neutronclient(request).update_subnet(subnet_id,
                                                  body=body).get('subnet')
    return Subnet(subnet)


def subnet_delete(request, subnet_id):
    LOG.debug("subnet_delete(): subnetid=%s" % subnet_id)
    neutronclient(request).delete_subnet(subnet_id)


def subnetpool_list(request, **params):
    LOG.debug("subnetpool_list(): params=%s" % (params))
    subnetpools = \
        neutronclient(request).list_subnetpools(**params).get('subnetpools')
    return [SubnetPool(s) for s in subnetpools]


def subnetpool_get(request, subnetpool_id, **params):
    LOG.debug("subnetpool_get(): subnetpoolid=%s, params=%s" %
              (subnetpool_id, params))
    subnetpool = \
        neutronclient(request).show_subnetpool(subnetpool_id,
                                               **params).get('subnetpool')
    return SubnetPool(subnetpool)


def subnetpool_create(request, name, prefixes, **kwargs):
    """Create a subnetpool.

    ip_version is auto-detected in back-end.

    Parameters:
    request           -- Request context
    name              -- Name for subnetpool
    prefixes          -- List of prefixes for pool

    Keyword Arguments (optional):
    min_prefixlen     -- Minimum prefix length for allocations from pool
    max_prefixlen     -- Maximum prefix length for allocations from pool
    default_prefixlen -- Default prefix length for allocations from pool
    default_quota     -- Default quota for allocations from pool
    shared            -- Subnetpool should be shared (Admin-only)
    tenant_id         -- Owner of subnetpool

    Returns:
    SubnetPool object
    """
    LOG.debug("subnetpool_create(): name=%s, prefixes=%s, kwargs=%s"
              % (name, prefixes, kwargs))
    body = {'subnetpool':
            {'name': name,
             'prefixes': prefixes,
             }
            }
    if 'tenant_id' not in kwargs:
        kwargs['tenant_id'] = request.user.project_id
    body['subnetpool'].update(kwargs)
    subnetpool = \
        neutronclient(request).create_subnetpool(body=body).get('subnetpool')
    return SubnetPool(subnetpool)


def subnetpool_update(request, subnetpool_id, **kwargs):
    LOG.debug("subnetpool_update(): subnetpoolid=%s, kwargs=%s" %
              (subnetpool_id, kwargs))
    body = {'subnetpool': kwargs}
    subnetpool = \
        neutronclient(request).update_subnetpool(subnetpool_id,
                                                 body=body).get('subnetpool')
    return SubnetPool(subnetpool)


def subnetpool_delete(request, subnetpool_id):
    LOG.debug("subnetpool_delete(): subnetpoolid=%s" % subnetpool_id)
    return neutronclient(request).delete_subnetpool(subnetpool_id)


def port_list(request, **params):
    LOG.debug("port_list(): params=%s" % (params))
    ports = neutronclient(request).list_ports(**params).get('ports')
    return [Port(p) for p in ports]


def port_get(request, port_id, **params):
    LOG.debug("port_get(): portid=%s, params=%s" % (port_id, params))
    port = neutronclient(request).show_port(port_id, **params).get('port')
    return Port(port)


def unescape_port_kwargs(**kwargs):
    for key in kwargs:
        if '__' in key:
            kwargs[':'.join(key.split('__'))] = kwargs.pop(key)
    return kwargs


def port_create(request, network_id, **kwargs):
    """Create a port on a specified network.

    :param request: request context
    :param network_id: network id a subnet is created on
    :param device_id: (optional) device id attached to the port
    :param tenant_id: (optional) tenant id of the port created
    :param name: (optional) name of the port created
    :returns: Port object
    """
    LOG.debug("port_create(): netid=%s, kwargs=%s" % (network_id, kwargs))
    # In the case policy profiles are being used, profile id is needed.
    if 'policy_profile_id' in kwargs:
        kwargs['n1kv:profile'] = kwargs.pop('policy_profile_id')
    kwargs = unescape_port_kwargs(**kwargs)
    body = {'port': {'network_id': network_id}}
    if 'tenant_id' not in kwargs:
        kwargs['tenant_id'] = request.user.project_id
    body['port'].update(kwargs)
    port = neutronclient(request).create_port(body=body).get('port')
    return Port(port)


def port_delete(request, port_id):
    LOG.debug("port_delete(): portid=%s" % port_id)
    neutronclient(request).delete_port(port_id)


def port_update(request, port_id, **kwargs):
    LOG.debug("port_update(): portid=%s, kwargs=%s" % (port_id, kwargs))
    kwargs = unescape_port_kwargs(**kwargs)
    body = {'port': kwargs}
    port = neutronclient(request).update_port(port_id, body=body).get('port')
    return Port(port)


def profile_list(request, type_p, **params):
    LOG.debug("profile_list(): "
              "profile_type=%(profile_type)s, params=%(params)s",
              {'profile_type': type_p, 'params': params})
    if type_p == 'network':
        profiles = neutronclient(request).list_network_profiles(
            **params).get('network_profiles')
    elif type_p == 'policy':
        profiles = neutronclient(request).list_policy_profiles(
            **params).get('policy_profiles')
    return [Profile(n) for n in profiles]


def profile_get(request, profile_id, **params):
    LOG.debug("profile_get(): "
              "profileid=%(profileid)s, params=%(params)s",
              {'profileid': profile_id, 'params': params})
    profile = neutronclient(request).show_network_profile(
        profile_id, **params).get('network_profile')
    return Profile(profile)


def profile_create(request, **kwargs):
    LOG.debug("profile_create(): kwargs=%s", kwargs)
    body = {'network_profile': {}}
    body['network_profile'].update(kwargs)
    profile = neutronclient(request).create_network_profile(
        body=body).get('network_profile')
    return Profile(profile)


def profile_delete(request, profile_id):
    LOG.debug("profile_delete(): profile_id=%s", profile_id)
    neutronclient(request).delete_network_profile(profile_id)


def profile_update(request, profile_id, **kwargs):
    LOG.debug("profile_update(): "
              "profileid=%(profileid)s, kwargs=%(kwargs)s",
              {'profileid': profile_id, 'kwargs': kwargs})
    body = {'network_profile': kwargs}
    profile = neutronclient(request).update_network_profile(
        profile_id, body=body).get('network_profile')
    return Profile(profile)


def profile_bindings_list(request, type_p, **params):
    LOG.debug("profile_bindings_list(): "
              "profile_type=%(profile_type)s params=%(params)s",
              {'profile_type': type_p, 'params': params})
    if type_p == 'network':
        bindings = neutronclient(request).list_network_profile_bindings(
            **params).get('network_profile_bindings')
    elif type_p == 'policy':
        bindings = neutronclient(request).list_policy_profile_bindings(
            **params).get('policy_profile_bindings')
    return [Profile(n) for n in bindings]


def router_create(request, **kwargs):
    LOG.debug("router_create():, kwargs=%s" % kwargs)
    body = {'router': {}}
    if 'tenant_id' not in kwargs:
        kwargs['tenant_id'] = request.user.project_id
    body['router'].update(kwargs)
    router = neutronclient(request).create_router(body=body).get('router')
    return Router(router)


def router_update(request, r_id, **kwargs):
    LOG.debug("router_update(): router_id=%s, kwargs=%s" % (r_id, kwargs))
    body = {'router': {}}
    body['router'].update(kwargs)
    router = neutronclient(request).update_router(r_id, body=body)
    return Router(router['router'])


def router_get(request, router_id, **params):
    router = neutronclient(request).show_router(router_id,
                                                **params).get('router')
    return Router(router)


def router_list(request, **params):
    routers = neutronclient(request).list_routers(**params).get('routers')
    return [Router(r) for r in routers]


def router_list_on_l3_agent(request, l3_agent_id, **params):
    routers = neutronclient(request).\
        list_routers_on_l3_agent(l3_agent_id,
                                 **params).get('routers')
    return [Router(r) for r in routers]


def router_delete(request, router_id):
    neutronclient(request).delete_router(router_id)


def router_add_interface(request, router_id, subnet_id=None, port_id=None):
    body = {}
    if subnet_id:
        body['subnet_id'] = subnet_id
    if port_id:
        body['port_id'] = port_id
    client = neutronclient(request)
    return client.add_interface_router(router_id, body)


def router_remove_interface(request, router_id, subnet_id=None, port_id=None):
    body = {}
    if subnet_id:
        body['subnet_id'] = subnet_id
    if port_id:
        body['port_id'] = port_id
    neutronclient(request).remove_interface_router(router_id, body)


def router_add_gateway(request, router_id, network_id):
    body = {'network_id': network_id}
    neutronclient(request).add_gateway_router(router_id, body)


def router_remove_gateway(request, router_id):
    neutronclient(request).remove_gateway_router(router_id)


def router_static_route_list(request, router_id=None):
    router = router_get(request, router_id)
    try:
        routes = [RouterStaticRoute(r) for r in router.routes]
    except AttributeError:
        LOG.debug("router_static_route_list(): router_id=%s, "
                  "router=%s", (router_id, router))
        return []
    return routes


def router_static_route_remove(request, router_id, route_ids):
    currentroutes = router_static_route_list(request, router_id=router_id)
    newroutes = []
    for oldroute in currentroutes:
        if oldroute.id not in route_ids:
            newroutes.append({'nexthop': oldroute.nexthop,
                              'destination': oldroute.destination})
    body = {'routes': newroutes}
    new = router_update(request, router_id, **body)
    return new


def router_static_route_add(request, router_id, newroute):
    body = {}
    currentroutes = router_static_route_list(request, router_id=router_id)
    body['routes'] = [newroute] + [{'nexthop': r.nexthop,
                                    'destination': r.destination}
                                   for r in currentroutes]
    new = router_update(request, router_id, **body)
    return new


def tenant_quota_get(request, tenant_id):
    return base.QuotaSet(neutronclient(request).show_quota(tenant_id)['quota'])


def tenant_quota_update(request, tenant_id, **kwargs):
    quotas = {'quota': kwargs}
    return neutronclient(request).update_quota(tenant_id, quotas)


def agent_list(request, **params):
    agents = neutronclient(request).list_agents(**params)
    return [Agent(a) for a in agents['agents']]


def list_dhcp_agent_hosting_networks(request, network, **params):
    agents = neutronclient(request).list_dhcp_agent_hosting_networks(network,
                                                                     **params)
    return [Agent(a) for a in agents['agents']]


def list_l3_agent_hosting_router(request, router, **params):
    agents = neutronclient(request).list_l3_agent_hosting_routers(router,
                                                                  **params)
    return [Agent(a) for a in agents['agents']]


def show_network_ip_availability(request, network_id):
    ip_availability = neutronclient(request).show_network_ip_availability(
        network_id)
    return ip_availability


def add_network_to_dhcp_agent(request, dhcp_agent, network_id):
    body = {'network_id': network_id}
    return neutronclient(request).add_network_to_dhcp_agent(dhcp_agent, body)


def remove_network_from_dhcp_agent(request, dhcp_agent, network_id):
    return neutronclient(request).remove_network_from_dhcp_agent(dhcp_agent,
                                                                 network_id)


def provider_list(request):
    providers = neutronclient(request).list_service_providers()
    return providers['service_providers']


def servers_update_addresses(request, servers, all_tenants=False):
    """Retrieve servers networking information from Neutron if enabled.

       Should be used when up to date networking information is required,
       and Nova's networking info caching mechanism is not fast enough.
    """

    # Get all (filtered for relevant servers) information from Neutron
    try:
        ports = list_resources_with_long_filters(
            port_list, 'device_id', [instance.id for instance in servers],
            request=request)
        fips = FloatingIpManager(request)
        if fips.is_supported():
            floating_ips = list_resources_with_long_filters(
                fips.list, 'port_id', [port.id for port in ports],
                all_tenants=all_tenants)
        else:
            floating_ips = []
        networks = list_resources_with_long_filters(
            network_list, 'id', set([port.network_id for port in ports]),
            request=request)
    except Exception:
        error_message = _('Unable to connect to Neutron.')
        LOG.error(error_message)
        messages.error(request, error_message)
        return

    # Map instance to its ports
    instances_ports = collections.defaultdict(list)
    for port in ports:
        instances_ports[port.device_id].append(port)

    # Map port to its floating ips
    ports_floating_ips = collections.defaultdict(list)
    for fip in floating_ips:
        ports_floating_ips[fip.port_id].append(fip)

    # Map network id to its name
    network_names = dict(((network.id, network.name) for network in networks))

    for server in servers:
        try:
            addresses = _server_get_addresses(
                request,
                server,
                instances_ports,
                ports_floating_ips,
                network_names)
        except Exception as e:
            LOG.error(six.text_type(e))
        else:
            server.addresses = addresses


def _server_get_addresses(request, server, ports, floating_ips, network_names):
    def _format_address(mac, ip, type):
        try:
            version = netaddr.IPAddress(ip).version
        except Exception:
            error_message = _('Unable to parse IP address %s.') % ip
            LOG.error(error_message)
            messages.error(request, error_message)
            raise
        return {u'OS-EXT-IPS-MAC:mac_addr': mac,
                u'version': version,
                u'addr': ip,
                u'OS-EXT-IPS:type': type}

    addresses = collections.defaultdict(list)
    instance_ports = ports.get(server.id, [])
    for port in instance_ports:
        network_name = network_names.get(port.network_id)
        if network_name is not None:
            for fixed_ip in port.fixed_ips:
                addresses[network_name].append(
                    _format_address(port.mac_address,
                                    fixed_ip['ip_address'],
                                    u'fixed'))
            port_fips = floating_ips.get(port.id, [])
            for fip in port_fips:
                addresses[network_name].append(
                    _format_address(port.mac_address,
                                    fip.floating_ip_address,
                                    u'floating'))

    return dict(addresses)


@memoized
def list_extensions(request):
    extensions_list = neutronclient(request).list_extensions()
    if 'extensions' in extensions_list:
        return tuple(extensions_list['extensions'])
    else:
        return ()


@memoized
def is_extension_supported(request, extension_alias):
    extensions = list_extensions(request)

    for extension in extensions:
        if extension['alias'] == extension_alias:
            return True
    else:
        return False


def is_enabled_by_config(name, default=True):
    network_config = getattr(settings, 'OPENSTACK_NEUTRON_NETWORK', {})
    return network_config.get(name, default)


@memoized
def is_service_enabled(request, config_name, ext_name):
    return (is_enabled_by_config(config_name) and
            is_extension_supported(request, ext_name))


@memoized
def is_quotas_extension_supported(request):
    return (is_enabled_by_config('enable_quotas', False) and
            is_extension_supported(request, 'quotas'))


# Using this mechanism till a better plugin/sub-plugin detection
# mechanism is available.
# When using specific plugins the profile_support can be
# turned on if needed to configure and/or use profiles.
# Since this is a temporary mechanism used to detect profile_support
# @memorize is not being used.
# TODO(absubram): Change this config variable check with
# subplugin/plugin detection API when it becomes available.
def is_port_profiles_supported():
    network_config = getattr(settings, 'OPENSTACK_NEUTRON_NETWORK', {})
    # Can be used to check for vendor specific plugin
    profile_support = network_config.get('profile_support', None)
    if str(profile_support).lower() == 'cisco':
        return True


# FEATURE_MAP is used to define:
# - related neutron extension name (key: "extension")
# - corresponding dashboard config (key: "config")
# - RBAC policies (key: "poclies")
# If a key is not contained, the corresponding permission check is skipped.
FEATURE_MAP = {
    'dvr': {
        'extension': 'dvr',
        'config': {
            'name': 'enable_distributed_router',
            'default': False,
        },
        'policies': {
            'get': 'get_router:distributed',
            'create': 'create_router:distributed',
            'update': 'update_router:distributed',
        }
    },
    'l3-ha': {
        'extension': 'l3-ha',
        'config': {'name': 'enable_ha_router',
                   'default': False},
        'policies': {
            'get': 'get_router:ha',
            'create': 'create_router:ha',
            'update': 'update_router:ha',
        }
    },
}


def get_feature_permission(request, feature, operation=None):
    """Check if a feature-specific field can be displayed.

    This method check a permission for a feature-specific field.
    Such field is usually provided through Neutron extension.

    :param request: Request Object
    :param feature: feature name defined in FEATURE_MAP
    :param operation (optional): Operation type. The valid value should be
        defined in FEATURE_MAP[feature]['policies']
        It must be specified if FEATURE_MAP[feature] has 'policies'.
    """
    network_config = getattr(settings, 'OPENSTACK_NEUTRON_NETWORK', {})
    feature_info = FEATURE_MAP.get(feature)
    if not feature_info:
        # Translators: Only used inside Horizon code and invisible to users
        raise ValueError(_("The requested feature '%(feature)s' is unknown. "
                           "Please make sure to specify a feature defined "
                           "in FEATURE_MAP."))

    # Check dashboard settings
    feature_config = feature_info.get('config')
    if feature_config:
        if not network_config.get(feature_config['name'],
                                  feature_config['default']):
            return False

    # Check policy
    feature_policies = feature_info.get('policies')
    if feature_policies:
        policy_name = feature_policies.get(operation)
        if not policy_name:
            # Translators: Only used inside Horizon code and invisible to users
            raise ValueError(_("The 'operation' parameter for "
                               "get_feature_permission '%(feature)s' "
                               "is invalid. It should be one of %(allowed)s")
                             % {'feature': feature,
                                'allowed': ' '.join(feature_policies.keys())})
        role = (('network', policy_name),)
        if not policy.check(role, request):
            return False

    # Check if a required extension is enabled
    feature_extension = feature_info.get('extension')
    if feature_extension:
        try:
            return is_extension_supported(request, feature_extension)
        except Exception:
            msg = (_("Failed to check Neutron '%s' extension is not supported")
                   % feature_extension)
            LOG.info(msg)
            return False

    # If all checks are passed, now a given feature is allowed.
    return True
