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

# Copyright 2011 Andrew Bogott for the Wikimedia 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 urllib

import webob

from nova.api.openstack import extensions
from nova.api.openstack import wsgi
from nova.api.openstack import xmlutil
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_ip_dns')


def make_dns_entry(elem):
    elem.set('id')
    elem.set('ip')
    elem.set('type')
    elem.set('domain')
    elem.set('name')


def make_domain_entry(elem):
    elem.set('domain')
    elem.set('scope')
    elem.set('project')
    elem.set('availability_zone')


class FloatingIPDNSTemplate(xmlutil.TemplateBuilder):
    def construct(self):
        root = xmlutil.TemplateElement('dns_entry',
                                       selector='dns_entry')
        make_dns_entry(root)
        return xmlutil.MasterTemplate(root, 1)


class FloatingIPDNSsTemplate(xmlutil.TemplateBuilder):
    def construct(self):
        root = xmlutil.TemplateElement('dns_entries')
        elem = xmlutil.SubTemplateElement(root, 'dns_entry',
                                          selector='dns_entries')
        make_dns_entry(elem)
        return xmlutil.MasterTemplate(root, 1)


class DomainTemplate(xmlutil.TemplateBuilder):
    def construct(self):
        root = xmlutil.TemplateElement('domain_entry',
                                       selector='domain_entry')
        make_domain_entry(root)
        return xmlutil.MasterTemplate(root, 1)


class DomainsTemplate(xmlutil.TemplateBuilder):
    def construct(self):
        root = xmlutil.TemplateElement('domain_entries')
        elem = xmlutil.SubTemplateElement(root, 'domain_entry',
                                          selector='domain_entries')
        make_domain_entry(elem)
        return xmlutil.MasterTemplate(root, 1)


def _translate_dns_entry_view(dns_entry):
    result = {}
    result['ip'] = dns_entry.get('ip')
    result['id'] = dns_entry.get('id')
    result['type'] = dns_entry.get('type')
    result['domain'] = dns_entry.get('domain')
    result['name'] = dns_entry.get('name')
    return {'dns_entry': result}


def _translate_dns_entries_view(dns_entries):
    return {'dns_entries': [_translate_dns_entry_view(entry)['dns_entry']
                            for entry in dns_entries]}


def _translate_domain_entry_view(domain_entry):
    result = {}
    result['domain'] = domain_entry.get('domain')
    result['scope'] = domain_entry.get('scope')
    result['project'] = domain_entry.get('project')
    result['availability_zone'] = domain_entry.get('availability_zone')
    return {'domain_entry': result}


def _translate_domain_entries_view(domain_entries):
    return {'domain_entries':
            [_translate_domain_entry_view(entry)['domain_entry']
                             for entry in domain_entries]}


def _unquote_domain(domain):
    """Unquoting function for receiving a domain name in a URL.

    Domain names tend to have .'s in them.  Urllib doesn't quote dots,
    but Routes tends to choke on them, so we need an extra level of
    by-hand quoting here.
    """
    return urllib.unquote(domain).replace('%2E', '.')


def _create_dns_entry(ip, name, domain):
    return {'ip': ip, 'name': name, 'domain': domain}


def _create_domain_entry(domain, scope=None, project=None, av_zone=None):
    return {'domain': domain, 'scope': scope, 'project': project,
            'availability_zone': av_zone}


class FloatingIPDNSDomainController(object):
    """DNS domain controller for OpenStack API"""

    def __init__(self):
        self.network_api = network.API()
        super(FloatingIPDNSDomainController, self).__init__()

    @wsgi.serializers(xml=DomainsTemplate)
    def index(self, req):
        """Return a list of available DNS domains."""
        context = req.environ['nova.context']
        authorize(context)
        domains = self.network_api.get_dns_domains(context)
        domainlist = [_create_domain_entry(domain['domain'],
                                         domain.get('scope'),
                                         domain.get('project'),
                                         domain.get('availability_zone'))
                    for domain in domains]

        return _translate_domain_entries_view(domainlist)

    @wsgi.serializers(xml=DomainTemplate)
    def update(self, req, id, body):
        """Add or modify domain entry"""
        context = req.environ['nova.context']
        authorize(context)
        fqdomain = _unquote_domain(id)
        try:
            entry = body['domain_entry']
            scope = entry['scope']
        except (TypeError, KeyError):
            raise webob.exc.HTTPUnprocessableEntity()
        project = entry.get('project', None)
        av_zone = entry.get('availability_zone', None)
        if (scope not in ('private', 'public') or
            project and av_zone or
            scope == 'private' and project or
            scope == 'public' and av_zone):
            raise webob.exc.HTTPUnprocessableEntity()
        if scope == 'private':
            create_dns_domain = self.network_api.create_private_dns_domain
            area_name, area = 'availability_zone', av_zone
        else:
            create_dns_domain = self.network_api.create_public_dns_domain
            area_name, area = 'project', project
        create_dns_domain(context, fqdomain, area)
        return _translate_domain_entry_view({'domain': fqdomain,
                                             'scope': scope,
                                             area_name: area})

    def delete(self, req, id):
        """Delete the domain identified by id. """
        context = req.environ['nova.context']
        authorize(context)
        domain = _unquote_domain(id)

        # Delete the whole domain
        try:
            self.network_api.delete_dns_domain(context, domain)
        except exception.NotFound as e:
            raise webob.exc.HTTPNotFound(explanation=unicode(e))

        return webob.Response(status_int=202)


class FloatingIPDNSEntryController(object):
    """DNS Entry controller for OpenStack API"""

    def __init__(self):
        self.network_api = network.API()
        super(FloatingIPDNSEntryController, self).__init__()

    @wsgi.serializers(xml=FloatingIPDNSTemplate)
    def show(self, req, domain_id, id):
        """Return the DNS entry that corresponds to domain_id and id."""
        context = req.environ['nova.context']
        authorize(context)
        domain = _unquote_domain(domain_id)
        name = id

        entries = self.network_api.get_dns_entries_by_name(context,
                                                           name, domain)
        entry = _create_dns_entry(entries[0], name, domain)
        return _translate_dns_entry_view(entry)

    @wsgi.serializers(xml=FloatingIPDNSsTemplate)
    def index(self, req, domain_id):
        """Return a list of dns entries for the specified domain and ip."""
        context = req.environ['nova.context']
        authorize(context)
        params = req.GET
        floating_ip = params.get('ip')
        domain = _unquote_domain(domain_id)

        if not floating_ip:
            raise webob.exc.HTTPUnprocessableEntity()

        entries = self.network_api.get_dns_entries_by_address(context,
                                                              floating_ip,
                                                              domain)
        entrylist = [_create_dns_entry(floating_ip, entry, domain)
                     for entry in entries]

        return _translate_dns_entries_view(entrylist)

    @wsgi.serializers(xml=FloatingIPDNSTemplate)
    def update(self, req, domain_id, id, body):
        """Add or modify dns entry"""
        context = req.environ['nova.context']
        authorize(context)
        domain = _unquote_domain(domain_id)
        name = id
        try:
            entry = body['dns_entry']
            address = entry['ip']
            dns_type = entry['dns_type']
        except (TypeError, KeyError):
            raise webob.exc.HTTPUnprocessableEntity()

        entries = self.network_api.get_dns_entries_by_name(context,
                                                           name, domain)
        if not entries:
            # create!
            self.network_api.add_dns_entry(context, address, name,
                                           dns_type, domain)
        else:
            # modify!
            self.network_api.modify_dns_entry(context, name, address, domain)

        return _translate_dns_entry_view({'ip': address,
                                          'name': name,
                                          'type': dns_type,
                                          'domain': domain})

    def delete(self, req, domain_id, id):
        """Delete the entry identified by req and id. """
        context = req.environ['nova.context']
        authorize(context)
        domain = _unquote_domain(domain_id)
        name = id

        try:
            self.network_api.delete_dns_entry(context, name, domain)
        except exception.NotFound as e:
            raise webob.exc.HTTPNotFound(explanation=unicode(e))

        return webob.Response(status_int=202)


class Floating_ip_dns(extensions.ExtensionDescriptor):
    """Floating IP DNS support"""

    name = "Floating_ip_dns"
    alias = "os-floating-ip-dns"
    namespace = "http://docs.openstack.org/ext/floating_ip_dns/api/v1.1"
    updated = "2011-12-23T00:00:00+00:00"

    def __init__(self, ext_mgr):
        self.network_api = network.API()
        super(Floating_ip_dns, self).__init__(ext_mgr)

    def get_resources(self):
        resources = []

        res = extensions.ResourceExtension('os-floating-ip-dns',
                         FloatingIPDNSDomainController())
        resources.append(res)

        res = extensions.ResourceExtension('entries',
                         FloatingIPDNSEntryController(),
                         parent={'member_name': 'domain',
                                 'collection_name': 'os-floating-ip-dns'})
        resources.append(res)

        return resources
