# Copyright 2014 Juniper Networks.  All rights reserved.
#
#    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 oslo.config import cfg
import requests

from neutron.api.v2 import attributes as attr
from neutron.common import exceptions as exc
from neutron.db import portbindings_base
from neutron.extensions import external_net
from neutron.extensions import portbindings
from neutron.extensions import securitygroup
from neutron import neutron_plugin_base_v2
from neutron.openstack.common import jsonutils
from neutron.openstack.common import log as logging
from neutron.plugins.opencontrail.common import exceptions as c_exc


LOG = logging.getLogger(__name__)

opencontrail_opts = [
    cfg.StrOpt('api_server_ip', default='127.0.0.1',
               help='IP address to connect to opencontrail controller'),
    cfg.IntOpt('api_server_port', default=8082,
               help='Port to connect to opencontrail controller'),
]

cfg.CONF.register_opts(opencontrail_opts, 'CONTRAIL')

CONTRAIL_EXCEPTION_MAP = {
    requests.codes.not_found: c_exc.ContrailNotFoundError,
    requests.codes.conflict: c_exc.ContrailConflictError,
    requests.codes.bad_request: c_exc.ContrailBadRequestError,
    requests.codes.service_unavailable: c_exc.ContrailServiceUnavailableError,
    requests.codes.unauthorized: c_exc.ContrailNotAuthorizedError,
    requests.codes.internal_server_error: c_exc.ContrailError,
}


class NeutronPluginContrailCoreV2(neutron_plugin_base_v2.NeutronPluginBaseV2,
                                  securitygroup.SecurityGroupPluginBase,
                                  portbindings_base.PortBindingBaseMixin,
                                  external_net.External_net):

    supported_extension_aliases = ["security-group", "router",
                                   "port-security", "binding", "agent",
                                   "quotas", "external-net"]
    PLUGIN_URL_PREFIX = '/neutron'
    __native_bulk_support = False

    def __init__(self):
        """Initialize the plugin class."""

        super(NeutronPluginContrailCoreV2, self).__init__()
        portbindings_base.register_port_dict_function()
        self.base_binding_dict = self._get_base_binding_dict()

    def _get_base_binding_dict(self):
        """return VIF type and details."""

        binding = {
            portbindings.VIF_TYPE: portbindings.VIF_TYPE_VROUTER,
            portbindings.VIF_DETAILS: {
                # TODO(praneetb): Replace with new VIF security details
                portbindings.CAP_PORT_FILTER:
                'security-group' in self.supported_extension_aliases
            }
        }
        return binding

    def _request_api_server(self, url, data=None, headers=None):
        """Send received request to api server."""

        return requests.post(url, data=data, headers=headers)

    def _relay_request(self, url_path, data=None):
        """Send received request to api server."""

        url = "http://%s:%d%s" % (cfg.CONF.CONTRAIL.api_server_ip,
                                  cfg.CONF.CONTRAIL.api_server_port,
                                  url_path)

        return self._request_api_server(
            url, data=data, headers={'Content-type': 'application/json'})

    def _request_backend(self, context, data_dict, obj_name, action):
        """Relays request to the controller."""

        context_dict = self._encode_context(context, action, obj_name)
        data = jsonutils.dumps({'context': context_dict, 'data': data_dict})

        url_path = "%s/%s" % (self.PLUGIN_URL_PREFIX, obj_name)
        response = self._relay_request(url_path, data=data)
        if response.content:
            return response.status_code, response.json()
        else:
            return response.status_code, response.content

    def _encode_context(self, context, operation, apitype):
        """Encode the context to be sent to the controller."""

        cdict = {'user_id': getattr(context, 'user_id', ''),
                 'is_admin': getattr(context, 'is_admin', False),
                 'operation': operation,
                 'type': apitype,
                 'tenant_id': getattr(context, 'tenant_id', None)}
        if context.roles:
            cdict['roles'] = context.roles
        if context.tenant:
            cdict['tenant'] = context.tenant
        return cdict

    def _encode_resource(self, resource_id=None, resource=None, fields=None,
                         filters=None):
        """Encode a resource to be sent to the controller."""

        resource_dict = {}
        if resource_id:
            resource_dict['id'] = resource_id
        if resource:
            resource_dict['resource'] = resource
        resource_dict['filters'] = filters
        resource_dict['fields'] = fields
        return resource_dict

    def _prune(self, resource_dict, fields):
        """Prune the resource dictionary based in the fields."""

        if fields:
            return dict(((key, item) for key, item in resource_dict.items()
                         if key in fields))
        return resource_dict

    def _transform_response(self, status_code, info=None, obj_name=None,
                            fields=None):
        """Transform the response for a Resource API."""

        if status_code == requests.codes.ok:
            if not isinstance(info, list):
                return self._prune(info, fields)
            else:
                return [self._prune(items, fields) for items in info]
        self._raise_contrail_error(status_code, info, obj_name)

    def _raise_contrail_error(self, status_code, info, obj_name):
        """Raises an error in handling of a Resource.

        This method converts return error code into neutron exception.
        """

        if status_code == requests.codes.bad_request:
            raise c_exc.ContrailBadRequestError(
                msg=info['message'], resource=obj_name)
        error_class = CONTRAIL_EXCEPTION_MAP.get(status_code,
                                                 c_exc.ContrailError)
        raise error_class(msg=info['message'])

    def _create_resource(self, res_type, context, res_data):
        """Create a resource in API server.

        This method encodes neutron model, and sends it to the
        contrail api server.
        """

        for key, value in res_data[res_type].items():
            if value == attr.ATTR_NOT_SPECIFIED:
                res_data[res_type][key] = None

        res_dict = self._encode_resource(resource=res_data[res_type])
        status_code, res_info = self._request_backend(context, res_dict,
                                                      res_type, 'CREATE')
        res_dicts = self._transform_response(status_code, info=res_info,
                                             obj_name=res_type)
        LOG.debug("create_%(res_type)s(): %(res_dicts)s",
                  {'res_type': res_type, 'res_dicts': res_dicts})

        return res_dicts

    def _get_resource(self, res_type, context, res_id, fields):
        """Get a resource from API server.

        This method gets a resource from the contrail api server
        """

        res_dict = self._encode_resource(resource_id=res_id, fields=fields)
        status_code, res_info = self._request_backend(context, res_dict,
                                                      res_type, 'READ')
        res_dicts = self._transform_response(status_code, info=res_info,
                                             fields=fields, obj_name=res_type)
        LOG.debug("get_%(res_type)s(): %(res_dicts)s",
                  {'res_type': res_type, 'res_dicts': res_dicts})

        return res_dicts

    def _update_resource(self, res_type, context, res_id, res_data):
        """Update a resource in API server.

        This method updates a resource in the contrail api server
        """

        res_dict = self._encode_resource(resource_id=res_id,
                                         resource=res_data[res_type])
        status_code, res_info = self._request_backend(context, res_dict,
                                                      res_type, 'UPDATE')
        res_dicts = self._transform_response(status_code, info=res_info,
                                             obj_name=res_type)
        LOG.debug("update_%(res_type)s(): %(res_dicts)s",
                  {'res_type': res_type, 'res_dicts': res_dicts})

        return res_dicts

    def _delete_resource(self, res_type, context, res_id):
        """Delete a resource in API server

        This method deletes a resource in the contrail api server
        """

        res_dict = self._encode_resource(resource_id=res_id)
        LOG.debug("delete_%(res_type)s(): %(res_id)s",
                  {'res_type': res_type, 'res_id': res_id})
        status_code, res_info = self._request_backend(context, res_dict,
                                                      res_type, 'DELETE')
        if status_code != requests.codes.ok:
            self._raise_contrail_error(status_code, info=res_info,
                                       obj_name=res_type)

    def _list_resource(self, res_type, context, filters, fields):
        """Get the list of a Resource."""

        res_dict = self._encode_resource(filters=filters, fields=fields)
        status_code, res_info = self._request_backend(context, res_dict,
                                                      res_type, 'READALL')
        res_dicts = self._transform_response(status_code, info=res_info,
                                             fields=fields, obj_name=res_type)
        LOG.debug(
            "get_%(res_type)s(): filters: %(filters)r data: %(res_dicts)r",
            {'res_type': res_type, 'filters': filters,
             'res_dicts': res_dicts})

        return res_dicts

    def _count_resource(self, res_type, context, filters):
        """Get the count of a Resource."""

        res_dict = self._encode_resource(filters=filters)
        _, res_count = self._request_backend(context, res_dict, res_type,
                                             'READCOUNT')
        LOG.debug("get_%(res_type)s_count(): %(res_count)r",
                  {'res_type': res_type, 'res_count': res_count})
        return res_count

    def _get_network(self, context, res_id, fields=None):
        """Get the attributes of a Virtual Network."""

        return self._get_resource('network', context, res_id, fields)

    def create_network(self, context, network):
        """Creates a new Virtual Network."""

        return self._create_resource('network', context, network)

    def get_network(self, context, network_id, fields=None):
        """Get the attributes of a particular Virtual Network."""

        return self._get_network(context, network_id, fields)

    def update_network(self, context, network_id, network):
        """Updates the attributes of a particular Virtual Network."""

        return self._update_resource('network', context, network_id,
                                     network)

    def delete_network(self, context, network_id):
        """Deletes the network with the specified network identifier."""

        self._delete_resource('network', context, network_id)

    def get_networks(self, context, filters=None, fields=None):
        """Get the list of Virtual Networks."""

        return self._list_resource('network', context, filters,
                                   fields)

    def get_networks_count(self, context, filters=None):
        """Get the count of Virtual Network."""

        networks_count = self._count_resource('network', context, filters)
        return networks_count['count']

    def create_subnet(self, context, subnet):
        """Creates a new subnet, and assigns it a symbolic name."""

        if subnet['subnet']['gateway_ip'] is None:
            subnet['subnet']['gateway_ip'] = '0.0.0.0'

        if subnet['subnet']['host_routes'] != attr.ATTR_NOT_SPECIFIED:
            if (len(subnet['subnet']['host_routes']) >
                    cfg.CONF.max_subnet_host_routes):
                raise exc.HostRoutesExhausted(subnet_id=subnet[
                    'subnet'].get('id', _('new subnet')),
                    quota=cfg.CONF.max_subnet_host_routes)

        subnet_created = self._create_resource('subnet', context, subnet)
        return self._make_subnet_dict(subnet_created)

    def _make_subnet_dict(self, subnet):
        """Fixes subnet attributes."""

        if subnet.get('gateway_ip') == '0.0.0.0':
            subnet['gateway_ip'] = None
        return subnet

    def _get_subnet(self, context, subnet_id, fields=None):
        """Get the attributes of a subnet."""

        subnet = self._get_resource('subnet', context, subnet_id, fields)
        return self._make_subnet_dict(subnet)

    def get_subnet(self, context, subnet_id, fields=None):
        """Get the attributes of a particular subnet."""

        return self._get_subnet(context, subnet_id, fields)

    def update_subnet(self, context, subnet_id, subnet):
        """Updates the attributes of a particular subnet."""

        subnet = self._update_resource('subnet', context, subnet_id, subnet)
        return self._make_subnet_dict(subnet)

    def delete_subnet(self, context, subnet_id):
        """
        Deletes the subnet with the specified subnet identifier
        belonging to the specified tenant.
        """

        self._delete_resource('subnet', context, subnet_id)

    def get_subnets(self, context, filters=None, fields=None):
        """Get the list of subnets."""

        return [self._make_subnet_dict(s)
                for s in self._list_resource(
                    'subnet', context, filters, fields)]

    def get_subnets_count(self, context, filters=None):
        """Get the count of subnets."""

        subnets_count = self._count_resource('subnet', context, filters)
        return subnets_count['count']

    def _make_port_dict(self, port, fields=None):
        """filters attributes of a port based on fields."""

        if not fields:
            port.update(self.base_binding_dict)
        else:
            for key in self.base_binding_dict:
                if key in fields:
                    port.update(self.base_binding_dict[key])
        return port

    def _get_port(self, context, res_id, fields=None):
        """Get the attributes of a port."""

        port = self._get_resource('port', context, res_id, fields)
        return self._make_port_dict(port, fields)

    def _update_ips_for_port(self, context, original_ips, new_ips):
        """Add or remove IPs from the port."""

        # These ips are still on the port and haven't been removed
        prev_ips = []

        # the new_ips contain all of the fixed_ips that are to be updated
        if len(new_ips) > cfg.CONF.max_fixed_ips_per_port:
            msg = _('Exceeded maximim amount of fixed ips per port')
            raise exc.InvalidInput(error_message=msg)

        # Remove all of the intersecting elements
        for original_ip in original_ips[:]:
            for new_ip in new_ips[:]:
                if ('ip_address' in new_ip and
                        original_ip['ip_address'] == new_ip['ip_address']):
                    original_ips.remove(original_ip)
                    new_ips.remove(new_ip)
                    prev_ips.append(original_ip)

        return new_ips, prev_ips

    def create_port(self, context, port):
        """Creates a port on the specified Virtual Network."""

        port = self._create_resource('port', context, port)
        return self._make_port_dict(port)

    def get_port(self, context, port_id, fields=None):
        """Get the attributes of a particular port."""

        return self._get_port(context, port_id, fields)

    def update_port(self, context, port_id, port):
        """Updates a port.

        Updates the attributes of a port on the specified Virtual
        Network.
        """

        if 'fixed_ips' in port['port']:
            original = self._get_port(context, port_id)
            added_ips, prev_ips = self._update_ips_for_port(
                context, original['fixed_ips'], port['port']['fixed_ips'])
            port['port']['fixed_ips'] = prev_ips + added_ips

        port = self._update_resource('port', context, port_id, port)
        return self._make_port_dict(port)

    def delete_port(self, context, port_id):
        """Deletes a port.

        Deletes a port on a specified Virtual Network,
        if the port contains a remote interface attachment,
        the remote interface is first un-plugged and then the port
        is deleted.
        """

        self._delete_resource('port', context, port_id)

    def get_ports(self, context, filters=None, fields=None):
        """Get all ports.

        Retrieves all port identifiers belonging to the
        specified Virtual Network with the specfied filter.
        """

        return [self._make_port_dict(p, fields)
                for p in self._list_resource('port', context, filters, fields)]

    def get_ports_count(self, context, filters=None):
        """Get the count of ports."""

        ports_count = self._count_resource('port', context, filters)
        return ports_count['count']

    # Router API handlers
    def create_router(self, context, router):
        """Creates a router.

        Creates a new Logical Router, and assigns it
        a symbolic name.
        """

        return self._create_resource('router', context, router)

    def get_router(self, context, router_id, fields=None):
        """Get the attributes of a router."""

        return self._get_resource('router', context, router_id, fields)

    def update_router(self, context, router_id, router):
        """Updates the attributes of a router."""

        return self._update_resource('router', context, router_id,
                                     router)

    def delete_router(self, context, router_id):
        """Deletes a router."""

        self._delete_resource('router', context, router_id)

    def get_routers(self, context, filters=None, fields=None):
        """Retrieves all router identifiers."""

        return self._list_resource('router', context, filters, fields)

    def get_routers_count(self, context, filters=None):
        """Get the count of routers."""

        routers_count = self._count_resource('router', context, filters)
        return routers_count['count']

    def _validate_router_interface_request(self, interface_info):
        """Validates parameters to the router interface requests."""

        port_id_specified = interface_info and 'port_id' in interface_info
        subnet_id_specified = interface_info and 'subnet_id' in interface_info
        if not (port_id_specified or subnet_id_specified):
            msg = _("Either subnet_id or port_id must be specified")
            raise exc.BadRequest(resource='router', msg=msg)

    def add_router_interface(self, context, router_id, interface_info):
        """Add interface to a router."""

        self._validate_router_interface_request(interface_info)

        if 'port_id' in interface_info:
            if 'subnet_id' in interface_info:
                msg = _("Cannot specify both subnet-id and port-id")
                raise exc.BadRequest(resource='router', msg=msg)

        res_dict = self._encode_resource(resource_id=router_id,
                                         resource=interface_info)
        status_code, res_info = self._request_backend(context, res_dict,
                                                      'router', 'ADDINTERFACE')
        if status_code != requests.codes.ok:
            self._raise_contrail_error(status_code, info=res_info,
                                       obj_name='add_router_interface')
        return res_info

    def remove_router_interface(self, context, router_id, interface_info):
        """Delete interface from a router."""

        self._validate_router_interface_request(interface_info)

        res_dict = self._encode_resource(resource_id=router_id,
                                         resource=interface_info)
        status_code, res_info = self._request_backend(context, res_dict,
                                                      'router', 'DELINTERFACE')
        if status_code != requests.codes.ok:
            self._raise_contrail_error(status_code, info=res_info,
                                       obj_name='remove_router_interface')
        return res_info

    # Floating IP API handlers
    def create_floatingip(self, context, floatingip):
        """Creates a floating IP."""

        return self._create_resource('floatingip', context, floatingip)

    def update_floatingip(self, context, fip_id, floatingip):
        """Updates the attributes of a floating IP."""

        return self._update_resource('floatingip', context, fip_id,
                                     floatingip)

    def get_floatingip(self, context, fip_id, fields=None):
        """Get the attributes of a floating ip."""

        return self._get_resource('floatingip', context, fip_id, fields)

    def delete_floatingip(self, context, fip_id):
        """Deletes a floating IP."""

        self._delete_resource('floatingip', context, fip_id)

    def get_floatingips(self, context, filters=None, fields=None):
        """Retrieves all floating ips identifiers."""

        return self._list_resource('floatingip', context, filters, fields)

    def get_floatingips_count(self, context, filters=None):
        """Get the count of floating IPs."""

        fips_count = self._count_resource('floatingip', context, filters)
        return fips_count['count']

    # Security Group handlers
    def create_security_group(self, context, security_group):
        """Creates a Security Group."""

        return self._create_resource('security_group', context,
                                     security_group)

    def get_security_group(self, context, sg_id, fields=None, tenant_id=None):
        """Get the attributes of a security group."""

        return self._get_resource('security_group', context, sg_id, fields)

    def update_security_group(self, context, sg_id, security_group):
        """Updates the attributes of a security group."""

        return self._update_resource('security_group', context, sg_id,
                                     security_group)

    def delete_security_group(self, context, sg_id):
        """Deletes a security group."""

        self._delete_resource('security_group', context, sg_id)

    def get_security_groups(self, context, filters=None, fields=None,
                            sorts=None, limit=None, marker=None,
                            page_reverse=False):
        """Retrieves all security group identifiers."""

        return self._list_resource('security_group', context,
                                   filters, fields)

    def create_security_group_rule(self, context, security_group_rule):
        """Creates a security group rule."""

        return self._create_resource('security_group_rule', context,
                                     security_group_rule)

    def delete_security_group_rule(self, context, sg_rule_id):
        """Deletes a security group rule."""

        self._delete_resource('security_group_rule', context, sg_rule_id)

    def get_security_group_rule(self, context, sg_rule_id, fields=None):
        """Get the attributes of a security group rule."""

        return self._get_resource('security_group_rule', context,
                                  sg_rule_id, fields)

    def get_security_group_rules(self, context, filters=None, fields=None,
                                 sorts=None, limit=None, marker=None,
                                 page_reverse=False):
        """Retrieves all security group rules."""

        return self._list_resource('security_group_rule', context,
                                   filters, fields)
