# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2011 OpenStack LLC.
# Copyright (c) 2011 X.commerce, a business unit of eBay Inc.
# Copyright 2011 Grid Dynamics
# Copyright 2011 Eldar Nugaev, Kirill Shileev, Ilya Alekseyev
#
#    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 webob

from nova.api.openstack import extensions
from nova.api.openstack import wsgi
from nova.api.openstack import xmlutil
from nova import compute
from nova.compute import utils as compute_utils
from nova import exception
from nova import network
from nova.openstack.common import log as logging


LOG = logging.getLogger(__name__)
authorize = extensions.extension_authorizer('compute', 'floating_ips')


def make_float_ip(elem):
    elem.set('id')
    elem.set('ip')
    elem.set('pool')
    elem.set('fixed_ip')
    elem.set('instance_id')


class FloatingIPTemplate(xmlutil.TemplateBuilder):
    def construct(self):
        root = xmlutil.TemplateElement('floating_ip',
                                       selector='floating_ip')
        make_float_ip(root)
        return xmlutil.MasterTemplate(root, 1)


class FloatingIPsTemplate(xmlutil.TemplateBuilder):
    def construct(self):
        root = xmlutil.TemplateElement('floating_ips')
        elem = xmlutil.SubTemplateElement(root, 'floating_ip',
                                          selector='floating_ips')
        make_float_ip(elem)
        return xmlutil.MasterTemplate(root, 1)


def _translate_floating_ip_view(floating_ip):
    result = {
        'id': floating_ip['id'],
        'ip': floating_ip['address'],
        'pool': floating_ip['pool'],
    }
    try:
        result['fixed_ip'] = floating_ip['fixed_ip']['address']
    except (TypeError, KeyError):
        result['fixed_ip'] = None
    try:
        result['instance_id'] = floating_ip['instance']['uuid']
    except (TypeError, KeyError):
        result['instance_id'] = None
    return {'floating_ip': result}


def _translate_floating_ips_view(floating_ips):
    return {'floating_ips': [_translate_floating_ip_view(ip)['floating_ip']
                             for ip in floating_ips]}


def get_instance_by_floating_ip_addr(self, context, address):
    snagiibfa = self.network_api.get_instance_id_by_floating_address
    instance_id = snagiibfa(context, address)
    if instance_id:
        return self.compute_api.get(context, instance_id)


def disassociate_floating_ip(self, context, instance, address):
    try:
        self.network_api.disassociate_floating_ip(context, instance, address)
    except exception.NotAuthorized:
        raise webob.exc.HTTPUnauthorized()
    except exception.FloatingIpNotAssociated:
        msg = _('Floating ip is not associated')
        raise webob.exc.HTTPBadRequest(explanation=msg)


class FloatingIPController(object):
    """The Floating IPs API controller for the OpenStack API."""

    def __init__(self):
        self.compute_api = compute.API()
        self.network_api = network.API()
        super(FloatingIPController, self).__init__()

    def _get_fixed_ip(self, context, fixed_ip_id):
        if fixed_ip_id is None:
            return None
        try:
            return self.network_api.get_fixed_ip(context, fixed_ip_id)
        except exception.FixedIpNotFound:
            return None

    def _get_instance(self, context, instance_id):
        return self.compute_api.get(context, instance_id)

    def _set_metadata(self, context, floating_ip):
        fixed_ip_id = floating_ip['fixed_ip_id']
        floating_ip['fixed_ip'] = self._get_fixed_ip(context,
                                                     fixed_ip_id)
        instance_id = None
        if floating_ip['fixed_ip']:
            instance_id = floating_ip['fixed_ip']['instance_id']

        if instance_id:
            floating_ip['instance'] = self._get_instance(context,
                                                         instance_id)
        else:
            floating_ip['instance'] = None

    @wsgi.serializers(xml=FloatingIPTemplate)
    def show(self, req, id):
        """Return data about the given floating ip."""
        context = req.environ['nova.context']
        authorize(context)

        try:
            floating_ip = self.network_api.get_floating_ip(context, id)
        except exception.NotFound:
            raise webob.exc.HTTPNotFound()

        self._set_metadata(context, floating_ip)

        return _translate_floating_ip_view(floating_ip)

    @wsgi.serializers(xml=FloatingIPsTemplate)
    def index(self, req):
        """Return a list of floating ips allocated to a project."""
        context = req.environ['nova.context']
        authorize(context)

        floating_ips = self.network_api.get_floating_ips_by_project(context)

        for floating_ip in floating_ips:
            self._set_metadata(context, floating_ip)

        return _translate_floating_ips_view(floating_ips)

    @wsgi.serializers(xml=FloatingIPTemplate)
    def create(self, req, body=None):
        context = req.environ['nova.context']
        authorize(context)

        pool = None
        if body and 'pool' in body:
            pool = body['pool']
        try:
            address = self.network_api.allocate_floating_ip(context, pool)
            ip = self.network_api.get_floating_ip_by_address(context, address)
        except exception.NoMoreFloatingIps:
            if pool:
                msg = _("No more floating ips in pool %s.") % pool
            else:
                msg = _("No more floating ips available.")
            raise webob.exc.HTTPRequestEntityTooLarge(explanation=msg)

        return _translate_floating_ip_view(ip)

    def delete(self, req, id):
        context = req.environ['nova.context']
        authorize(context)

        # get the floating ip object
        floating_ip = self.network_api.get_floating_ip(context, id)
        address = floating_ip['address']

        # get the associated instance object (if any)
        instance = get_instance_by_floating_ip_addr(self, context, address)

        # disassociate if associated
        if floating_ip.get('fixed_ip_id'):
            disassociate_floating_ip(self, context, instance, address)

        # release ip from project
        self.network_api.release_floating_ip(context, address)
        return webob.Response(status_int=202)

    def _get_ip_by_id(self, context, value):
        """Checks that value is id and then returns its address."""
        return self.network_api.get_floating_ip(context, value)['address']


class FloatingIPActionController(wsgi.Controller):
    def __init__(self, *args, **kwargs):
        super(FloatingIPActionController, self).__init__(*args, **kwargs)
        self.compute_api = compute.API()
        self.network_api = network.API()

    @wsgi.action('addFloatingIp')
    def _add_floating_ip(self, req, id, body):
        """Associate floating_ip to an instance."""
        context = req.environ['nova.context']
        authorize(context)

        try:
            address = body['addFloatingIp']['address']
        except TypeError:
            msg = _("Missing parameter dict")
            raise webob.exc.HTTPBadRequest(explanation=msg)
        except KeyError:
            msg = _("Address not specified")
            raise webob.exc.HTTPBadRequest(explanation=msg)

        instance = self.compute_api.get(context, id)

        cached_nwinfo = compute_utils.get_nw_info_for_instance(instance)
        if not cached_nwinfo:
            msg = _('No nw_info cache associated with instance')
            raise webob.exc.HTTPBadRequest(explanation=msg)

        fixed_ips = cached_nwinfo.fixed_ips()
        if not fixed_ips:
            msg = _('No fixed ips associated to instance')
            raise webob.exc.HTTPBadRequest(explanation=msg)

        # TODO(tr3buchet): this will associate the floating IP with the
        # first fixed_ip an instance has. This should be
        # changed to support specifying a particular fixed_ip if
        # multiple exist.
        if len(fixed_ips) > 1:
            msg = _('multiple fixed_ips exist, using the first: %s')
            LOG.warning(msg, fixed_ips[0]['address'])

        try:
            self.network_api.associate_floating_ip(context, instance,
                                  floating_address=address,
                                  fixed_address=fixed_ips[0]['address'])
        except exception.FloatingIpAssociated:
            msg = _('floating ip is already associated')
            raise webob.exc.HTTPBadRequest(explanation=msg)
        except exception.NoFloatingIpInterface:
            msg = _('l3driver call to add floating ip failed')
            raise webob.exc.HTTPBadRequest(explanation=msg)
        except Exception:
            msg = _('Error. Unable to associate floating ip')
            LOG.exception(msg)
            raise webob.exc.HTTPBadRequest(explanation=msg)

        return webob.Response(status_int=202)

    @wsgi.action('removeFloatingIp')
    def _remove_floating_ip(self, req, id, body):
        """Dissociate floating_ip from an instance."""
        context = req.environ['nova.context']
        authorize(context)

        try:
            address = body['removeFloatingIp']['address']
        except TypeError:
            msg = _("Missing parameter dict")
            raise webob.exc.HTTPBadRequest(explanation=msg)
        except KeyError:
            msg = _("Address not specified")
            raise webob.exc.HTTPBadRequest(explanation=msg)

        # get the floating ip object
        floating_ip = self.network_api.get_floating_ip_by_address(context,
                                                                  address)
        # get the associated instance object (if any)
        instance = get_instance_by_floating_ip_addr(self, context, address)

        # disassociate if associated
        if floating_ip.get('fixed_ip_id'):
            disassociate_floating_ip(self, context, instance, address)

        return webob.Response(status_int=202)


class Floating_ips(extensions.ExtensionDescriptor):
    """Floating IPs support"""

    name = "Floating_ips"
    alias = "os-floating-ips"
    namespace = "http://docs.openstack.org/compute/ext/floating_ips/api/v1.1"
    updated = "2011-06-16T00:00:00+00:00"

    def get_resources(self):
        resources = []

        res = extensions.ResourceExtension('os-floating-ips',
                         FloatingIPController(),
                         member_actions={})
        resources.append(res)

        return resources

    def get_controller_extensions(self):
        controller = FloatingIPActionController()
        extension = extensions.ControllerExtension(self, 'servers', controller)
        return [extension]
