#
#
#

import base64
import binascii
import logging
from collections import defaultdict

import ovh
from ovh import ResourceNotFoundError

from octodns.record import Record
from octodns.provider.base import BaseProvider

__VERSION__ = '0.0.2'


class OvhProvider(BaseProvider):
    SUPPORTS_GEO = False
    SUPPORTS_DYNAMIC = False
    ZONE_NOT_FOUND_MESSAGE = 'This service does not exist'

    # This variable is also used in populate method to filter which OVH record
    # types are supported by octodns
    SUPPORTS = set(
        (
            'A',
            'AAAA',
            'CAA',
            'CNAME',
            'DKIM',
            'MX',
            'NAPTR',
            'NS',
            'PTR',
            'SPF',
            'SRV',
            'SSHFP',
            'TXT',
        )
    )

    def __init__(
        self,
        id,
        endpoint,
        application_key,
        application_secret,
        consumer_key,
        *args,
        **kwargs,
    ):
        self.log = logging.getLogger(f'OvhProvider[{id}]')
        self.log.debug(
            '__init__: id=%s, endpoint=%s, application_key=%s, '
            'application_secret=***, consumer_key=%s',
            id,
            endpoint,
            application_key,
            consumer_key,
        )
        super().__init__(id, *args, **kwargs)
        self._client = ovh.Client(
            endpoint=endpoint,
            application_key=application_key,
            application_secret=application_secret,
            consumer_key=consumer_key,
        )

    def populate(self, zone, target=False, lenient=False):
        self.log.debug(
            'populate: name=%s, target=%s, lenient=%s',
            zone.name,
            target,
            lenient,
        )
        zone_name = zone.name[:-1]
        try:
            records = self.get_records(zone_name=zone_name)
            exists = True
        except ResourceNotFoundError as e:
            if str(e) != self.ZONE_NOT_FOUND_MESSAGE:
                raise
            exists = False
            records = []

        values = defaultdict(lambda: defaultdict(list))
        for record in records:
            values[record['subDomain']][record['fieldType']].append(record)

        before = len(zone.records)
        for name, types in values.items():
            for _type, records in types.items():
                if _type not in self.SUPPORTS:
                    self.log.warning(
                        'Not managed record of type %s, skip', _type
                    )
                    continue
                data_for = getattr(self, f'_data_for_{_type}')
                record = Record.new(
                    zone,
                    name,
                    data_for(_type, records),
                    source=self,
                    lenient=lenient,
                )
                zone.add_record(record, lenient=lenient)

        self.log.info(
            'populate:   found %s records, exists=%s',
            len(zone.records) - before,
            exists,
        )
        return exists

    def _apply(self, plan):
        desired = plan.desired
        changes = plan.changes
        zone_name = desired.name[:-1]
        self.log.info(
            '_apply: zone=%s, len(changes)=%d', desired.name, len(changes)
        )
        for change in changes:
            class_name = change.__class__.__name__
            getattr(self, f'_apply_{class_name}'.lower())(zone_name, change)

        # We need to refresh the zone to really apply the changes
        self._client.post(f'/domain/zone/{zone_name}/refresh')

    def _apply_create(self, zone_name, change):
        new = change.new
        params_for = getattr(self, f'_params_for_{new._type}')
        for params in params_for(new):
            self.create_record(zone_name, params)

    def _apply_update(self, zone_name, change):
        self._apply_delete(zone_name, change)
        self._apply_create(zone_name, change)

    def _apply_delete(self, zone_name, change):
        existing = change.existing
        record_type = existing._type
        if record_type == "TXT":
            if self._is_valid_dkim(existing.values[0]):
                record_type = 'DKIM'
        self.delete_records(zone_name, record_type, existing.name)

    @staticmethod
    def _data_for_multiple(_type, records):
        return {
            'ttl': records[0]['ttl'],
            'type': _type,
            'values': [record['target'] for record in records],
        }

    @staticmethod
    def _data_for_single(_type, records):
        record = records[0]
        return {'ttl': record['ttl'], 'type': _type, 'value': record['target']}

    @staticmethod
    def _data_for_CAA(_type, records):
        values = []
        for record in records:
            flags, tag, value = record['target'].split(' ', 2)
            values.append({'flags': flags, 'tag': tag, 'value': value[1:-1]})
        return {'ttl': records[0]['ttl'], 'type': _type, 'values': values}

    @staticmethod
    def _data_for_MX(_type, records):
        values = []
        for record in records:
            preference, exchange = record['target'].split(' ', 1)
            values.append({'preference': preference, 'exchange': exchange})
        return {'ttl': records[0]['ttl'], 'type': _type, 'values': values}

    @staticmethod
    def _data_for_NAPTR(_type, records):
        values = []
        for record in records:
            order, preference, flags, service, regexp, replacement = record[
                'target'
            ].split(' ', 5)
            values.append(
                {
                    'flags': flags[1:-1],
                    'order': order,
                    'preference': preference,
                    'regexp': regexp[1:-1],
                    'replacement': replacement,
                    'service': service[1:-1],
                }
            )
        return {'type': _type, 'ttl': records[0]['ttl'], 'values': values}

    @staticmethod
    def _data_for_SRV(_type, records):
        values = []
        for record in records:
            priority, weight, port, target = record['target'].split(' ', 3)
            values.append(
                {
                    'port': port,
                    'priority': priority,
                    'target': f'{target}',
                    'weight': weight,
                }
            )
        return {'type': _type, 'ttl': records[0]['ttl'], 'values': values}

    @staticmethod
    def _data_for_SSHFP(_type, records):
        values = []
        for record in records:
            algorithm, fingerprint_type, fingerprint = record['target'].split(
                ' ', 2
            )
            values.append(
                {
                    'algorithm': algorithm,
                    'fingerprint': fingerprint,
                    'fingerprint_type': fingerprint_type,
                }
            )
        return {'type': _type, 'ttl': records[0]['ttl'], 'values': values}

    @staticmethod
    def _data_for_DKIM(_type, records):
        return {
            'ttl': records[0]['ttl'],
            'type': "TXT",
            'values': [
                record['target'].replace(';', '\\;') for record in records
            ],
        }

    _data_for_A = _data_for_multiple
    _data_for_AAAA = _data_for_multiple
    _data_for_NS = _data_for_multiple
    _data_for_TXT = _data_for_multiple
    _data_for_SPF = _data_for_multiple
    _data_for_PTR = _data_for_single
    _data_for_CNAME = _data_for_single

    @staticmethod
    def _params_for_multiple(record):
        for value in record.values:
            yield {
                'target': value,
                'subDomain': record.name,
                'ttl': record.ttl,
                'fieldType': record._type,
            }

    @staticmethod
    def _params_for_single(record):
        yield {
            'target': record.value,
            'subDomain': record.name,
            'ttl': record.ttl,
            'fieldType': record._type,
        }

    @staticmethod
    def _params_for_CAA(record):
        for value in record.values:
            yield {
                'target': f'{value.flags} {value.tag} "{value.value}"',
                'subDomain': record.name,
                'ttl': record.ttl,
                'fieldType': record._type,
            }

    @staticmethod
    def _params_for_MX(record):
        for value in record.values:
            yield {
                'target': f'{value.preference:d} {value.exchange}',
                'subDomain': record.name,
                'ttl': record.ttl,
                'fieldType': record._type,
            }

    @staticmethod
    def _params_for_NAPTR(record):
        for value in record.values:
            content = (
                f'{value.order} {value.preference} "{value.flags}" '
                f'"{value.service}" "{value.regexp}" {value.replacement}'
            )
            yield {
                'target': content,
                'subDomain': record.name,
                'ttl': record.ttl,
                'fieldType': record._type,
            }

    @staticmethod
    def _params_for_SRV(record):
        for value in record.values:
            yield {
                'target': f'{value.priority} {value.weight} {value.port} '
                f'{value.target}',
                'subDomain': record.name,
                'ttl': record.ttl,
                'fieldType': record._type,
            }

    @staticmethod
    def _params_for_SSHFP(record):
        for value in record.values:
            yield {
                'target': f'{value.algorithm} {value.fingerprint_type} '
                f'{value.fingerprint}',
                'subDomain': record.name,
                'ttl': record.ttl,
                'fieldType': record._type,
            }

    def _params_for_TXT(self, record):
        for value in record.values:
            field_type = 'TXT'
            if self._is_valid_dkim(value):
                field_type = 'DKIM'
                value = value.replace("\\;", ";")
            yield {
                'target': value,
                'subDomain': record.name,
                'ttl': record.ttl,
                'fieldType': field_type,
            }

    _params_for_A = _params_for_multiple
    _params_for_AAAA = _params_for_multiple
    _params_for_NS = _params_for_multiple
    _params_for_SPF = _params_for_multiple

    _params_for_CNAME = _params_for_single
    _params_for_PTR = _params_for_single

    def _is_valid_dkim(self, value):
        """Check if value is a valid DKIM"""
        validator_dict = {
            'h': lambda val: val in ['sha1', 'sha256'],
            's': lambda val: val in ['*', 'email'],
            't': lambda val: val in ['y', 's'],
            'v': lambda val: val == 'DKIM1',
            'k': lambda val: val == 'rsa',
            'n': lambda _: True,
            'g': lambda _: True,
        }

        splitted = [v for v in value.split('\\;') if v]
        found_key = False
        for splitted_value in splitted:
            sub_split = [x.strip() for x in splitted_value.split("=", 1)]
            if len(sub_split) < 2:
                return False
            key, value = sub_split[0], sub_split[1]
            if key == "p":
                is_valid_key = self._is_valid_dkim_key(value)
                if not is_valid_key:
                    return False
                found_key = True
            else:
                is_valid_key = validator_dict.get(key, lambda _: False)(value)
                if not is_valid_key:
                    return False
        return found_key

    @staticmethod
    def _is_valid_dkim_key(key):
        result = True
        base64_decode = getattr(base64, 'decodestring', None)
        base64_decode = getattr(base64, 'decodebytes', base64_decode)

        try:
            result = base64_decode(bytearray(key, 'utf-8'))
        except binascii.Error:
            result = False
        return result

    def get_records(self, zone_name):
        """
        List all records of a DNS zone
        :param zone_name: Name of zone
        :return: list of id's records
        """
        records = self._client.get(f'/domain/zone/{zone_name}/record')
        return [self.get_record(zone_name, record_id) for record_id in records]

    def get_record(self, zone_name, record_id):
        """
        Get record with given id
        :param zone_name: Name of the zone
        :param record_id: Id of the record
        :return: Value of the record
        """
        return self._client.get(f'/domain/zone/{zone_name}/record/{record_id}')

    def delete_records(self, zone_name, record_type, subdomain):
        """
        Delete record from have fieldType=type and subDomain=subdomain
        :param zone_name: Name of the zone
        :param record_type: fieldType
        :param subdomain: subDomain
        """
        records = self._client.get(
            f'/domain/zone/{zone_name}/record',
            fieldType=record_type,
            subDomain=subdomain,
        )
        for record in records:
            self.delete_record(zone_name, record)

    def delete_record(self, zone_name, record_id):
        """
        Delete record with a given id
        :param zone_name: Name of the zone
        :param record_id: Id of the record
        """
        self.log.debug('Delete record: zone: %s, id %s', zone_name, record_id)
        self._client.delete(f'/domain/zone/{zone_name}/record/{record_id}')

    def create_record(self, zone_name, params):
        """
        Create a record
        :param zone_name: Name of the zone
        :param params: {'fieldType': 'A', 'ttl': 60, 'subDomain': 'www',
        'target': '1.2.3.4'
        """
        self.log.debug('Create record: zone: %s, id %s', zone_name, params)
        return self._client.post(f'/domain/zone/{zone_name}/record', **params)
