# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.
"""
NFSN DNS Driver
"""
import re
import sys

from libcloud.common.exceptions import BaseHTTPError
from libcloud.common.nfsn import NFSNConnection
from libcloud.dns.base import DNSDriver, Zone, Record
from libcloud.dns.types import ZoneDoesNotExistError, RecordDoesNotExistError
from libcloud.dns.types import RecordAlreadyExistsError
from libcloud.dns.types import Provider, RecordType
from libcloud.utils.py3 import httplib

__all__ = [
    'NFSNDNSDriver',
]

# The NFSN API does not return any internal "ID" strings for any DNS records.
# This means that we must set all returned Record objects' id properties to
# None. It also means that we cannot implement libcloud APIs that rely on
# record_id, such as get_record(). Instead, the NFSN-specific
# ex_get_records_by() method will return the desired Record objects.
#
# Additionally, the NFSN API does not provide ways to create, delete, or list
# all zones, so create_zone(), delete_zone(), and list_zones() are not
# implemented.


class NFSNDNSDriver(DNSDriver):
    type = Provider.NFSN
    name = 'NFSN DNS'
    website = 'https://www.nearlyfreespeech.net'
    connectionCls = NFSNConnection

    RECORD_TYPE_MAP = {
        RecordType.A: 'A',
        RecordType.AAAA: 'AAAA',
        RecordType.CNAME: 'CNAME',
        RecordType.MX: 'MX',
        RecordType.NS: 'NS',
        RecordType.SRV: 'SRV',
        RecordType.TXT: 'TXT',
        RecordType.PTR: 'PTR',
    }

    def list_records(self, zone):
        """
        Return a list of all records for the provided zone.

        :param zone: Zone to list records for.
        :type zone: :class:`Zone`

        :return: ``list`` of :class:`Record`
        """
        # Just use ex_get_records_by() with no name or type filters.
        return self.ex_get_records_by(zone)

    def get_zone(self, zone_id):
        """
        Return a Zone instance.

        :param zone_id: name of the required zone, for example "example.com".
        :type  zone_id: ``str``

        :rtype: :class:`Zone`
        :raises: ZoneDoesNotExistError: If no zone could be found.
        """
        # We will check if there is a serial property for this zone. If so,
        # then the zone exists.
        try:
            self.connection.request(action='/dns/%s/serial' % zone_id)
        except BaseHTTPError:
            e = sys.exc_info()[1]
            if e.code == httplib.NOT_FOUND:
                raise ZoneDoesNotExistError(zone_id=None, driver=self,
                                            value=e.message)
            raise e
        return Zone(id=None, domain=zone_id, type='master', ttl=3600,
                    driver=self)

    def ex_get_records_by(self, zone, name=None, type=None):
        """
        Return a list of records for the provided zone, filtered by name and/or
        type.

        :param zone: Zone to list records for.
        :type zone: :class:`Zone`

        :param zone: Zone where the requested records are found.
        :type  zone: :class:`Zone`

        :param name: name of the records, for example "www". (optional)
        :type  name: ``str``

        :param type: DNS record type (A, MX, TXT). (optional)
        :type  type: :class:`RecordType`

        :return: ``list`` of :class:`Record`
        """
        payload = {}
        if name is not None:
            payload['name'] = name
        if type is not None:
            payload['type'] = type

        action = '/dns/%s/listRRs' % zone.domain
        response = self.connection.request(action=action, data=payload,
                                           method='POST')
        return self._to_records(response, zone)

    def create_record(self, name, zone, type, data, extra=None):
        """
        Create a new record.

        :param name: Record name without the domain name (e.g. www).
                     Note: If you want to create a record for a base domain
                     name, you should specify empty string ('') for this
                     argument.
        :type  name: ``str``

        :param zone: Zone where the requested record is created.
        :type  zone: :class:`Zone`

        :param type: DNS record type (A, MX, TXT).
        :type  type: :class:`RecordType`

        :param data: Data for the record (depends on the record type).
        :type  data: ``str``

        :param extra: Extra attributes (driver specific, e.g. 'ttl').
                      (optional)
        :type extra: ``dict``

        :rtype: :class:`Record`
        """
        action = '/dns/%s/addRR' % zone.domain
        payload = {'name': name, 'data': data, 'type': type}
        if extra is not None and extra.get('ttl', None) is not None:
            payload['ttl'] = extra['ttl']
        try:
            self.connection.request(action=action, data=payload, method='POST')
        except BaseHTTPError:
            e = sys.exc_info()[1]
            exists_re = re.compile(r'That RR already exists on the domain')
            if e.code == httplib.BAD_REQUEST and \
               re.search(exists_re, e.message) is not None:
                value = '"%s" already exists in %s' % (name, zone.domain)
                raise RecordAlreadyExistsError(value=value, driver=self,
                                               record_id=None)
            raise e
        return self.ex_get_records_by(zone=zone, name=name, type=type)[0]

    def delete_record(self, record):
        """
        Use this method to delete a record.

        :param record: record to delete
        :type record: `Record`

        :rtype: Bool
        """
        action = '/dns/%s/removeRR' % record.zone.domain
        payload = {'name': record.name, 'data': record.data,
                   'type': record.type}
        try:
            self.connection.request(action=action, data=payload, method='POST')
        except BaseHTTPError:
            e = sys.exc_info()[1]
            if e.code == httplib.NOT_FOUND:
                raise RecordDoesNotExistError(value=e.message, driver=self,
                                              record_id=None)
            raise e
        return True

    def _to_record(self, item, zone):
        ttl = int(item['ttl'])
        return Record(id=None, name=item['name'], data=item['data'],
                      type=item['type'], zone=zone, driver=self, ttl=ttl)

    def _to_records(self, items, zone):
        records = []
        for item in items.object:
            records.append(self._to_record(item, zone))
        return records
