#
#
#

from __future__ import absolute_import, division, print_function, \
    unicode_literals

from collections import defaultdict
from requests import Session
import logging

from ..record import Record
from .base import BaseProvider


class DnsimpleClientException(Exception):
    pass


class DnsimpleClientNotFound(DnsimpleClientException):

    def __init__(self):
        super(DnsimpleClientNotFound, self).__init__('Not found')


class DnsimpleClientUnauthorized(DnsimpleClientException):

    def __init__(self):
        super(DnsimpleClientUnauthorized, self).__init__('Unauthorized')


class DnsimpleClient(object):

    def __init__(self, token, account, sandbox):
        self.account = account
        sess = Session()
        sess.headers.update({'Authorization': 'Bearer {}'.format(token)})
        self._sess = sess
        if sandbox:
            self.base = 'https://api.sandbox.dnsimple.com/v2/'
        else:
            self.base = 'https://api.dnsimple.com/v2/'

    def _request(self, method, path, params=None, data=None):
        url = '{}{}{}'.format(self.base, self.account, path)
        resp = self._sess.request(method, url, params=params, json=data)
        if resp.status_code == 401:
            raise DnsimpleClientUnauthorized()
        if resp.status_code == 404:
            raise DnsimpleClientNotFound()
        resp.raise_for_status()
        return resp

    def domain(self, name):
        path = '/domains/{}'.format(name)
        return self._request('GET', path).json()

    def domain_create(self, name):
        return self._request('POST', '/domains', data={'name': name})

    def records(self, zone_name):
        ret = []

        page = 1
        while True:
            data = self._request('GET', '/zones/{}/records'.format(zone_name),
                                 {'page': page}).json()
            ret += data['data']
            pagination = data['pagination']
            if page >= pagination['total_pages']:
                break
            page += 1

        return ret

    def record_create(self, zone_name, params):
        path = '/zones/{}/records'.format(zone_name)
        self._request('POST', path, data=params)

    def record_delete(self, zone_name, record_id):
        path = '/zones/{}/records/{}'.format(zone_name, record_id)
        self._request('DELETE', path)


class DnsimpleProvider(BaseProvider):
    '''
    Dnsimple provider using API v2

    dnsimple:
        class: octodns.provider.dnsimple.DnsimpleProvider
        # API v2 account access token (required)
        token: letmein
        # Your account number (required)
        account: 42
        # Use sandbox (optional)
        sandbox: true
    '''
    SUPPORTS_GEO = False
    SUPPORTS_DYNAMIC = False
    SUPPORTS = set(('A', 'AAAA', 'ALIAS', 'CAA', 'CNAME', 'MX', 'NAPTR', 'NS',
                    'PTR', 'SPF', 'SRV', 'SSHFP', 'TXT'))

    def __init__(self, id, token, account, sandbox=False, *args, **kwargs):
        self.log = logging.getLogger('DnsimpleProvider[{}]'.format(id))
        self.log.debug('__init__: id=%s, token=***, account=%s', id, account)
        super(DnsimpleProvider, self).__init__(id, *args, **kwargs)
        self._client = DnsimpleClient(token, account, sandbox)

        self._zone_records = {}

    def _data_for_multiple(self, _type, records):
        return {
            'ttl': records[0]['ttl'],
            'type': _type,
            'values': [r['content'] for r in records]
        }

    _data_for_A = _data_for_multiple
    _data_for_AAAA = _data_for_multiple
    _data_for_SPF = _data_for_multiple

    def _data_for_TXT(self, _type, records):
        return {
            'ttl': records[0]['ttl'],
            'type': _type,
            # escape semicolons
            'values': [r['content'].replace(';', '\\;') for r in records]
        }

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

    def _data_for_CNAME(self, _type, records):
        record = records[0]
        return {
            'ttl': record['ttl'],
            'type': _type,
            'value': '{}.'.format(record['content'])
        }

    _data_for_ALIAS = _data_for_CNAME

    def _data_for_MX(self, _type, records):
        values = []
        for record in records:
            values.append({
                'preference': record['priority'],
                'exchange': '{}.'.format(record['content'])
            })
        return {
            'ttl': records[0]['ttl'],
            'type': _type,
            'values': values
        }

    def _data_for_NAPTR(self, _type, records):
        values = []
        for record in records:
            try:
                order, preference, flags, service, regexp, replacement = \
                    record['content'].split(' ', 5)
            except ValueError:
                # their api will let you create invalid records, this
                # essentially handles that by ignoring them for values
                # purposes. That will cause updates to happen to delete them if
                # they shouldn't exist or update them if they're wrong
                continue
            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
        }

    def _data_for_NS(self, _type, records):
        values = []
        for record in records:
            content = record['content']
            if content[-1] != '.':
                content = '{}.'.format(content)
            values.append(content)
        return {
            'ttl': records[0]['ttl'],
            'type': _type,
            'values': values,
        }

    def _data_for_PTR(self, _type, records):
        record = records[0]
        return {
            'ttl': record['ttl'],
            'type': _type,
            'value': record['content']
        }

    def _data_for_SRV(self, _type, records):
        values = []
        for record in records:
            try:
                weight, port, target = record['content'].split(' ', 2)
            except ValueError:
                # see _data_for_NAPTR's continue
                continue
            values.append({
                'port': port,
                'priority': record['priority'],
                'target': '{}.'.format(target),
                'weight': weight
            })
        return {
            'type': _type,
            'ttl': records[0]['ttl'],
            'values': values
        }

    def _data_for_SSHFP(self, _type, records):
        values = []
        for record in records:
            try:
                algorithm, fingerprint_type, fingerprint = \
                    record['content'].split(' ', 2)
            except ValueError:
                # see _data_for_NAPTR's continue
                continue
            values.append({
                'algorithm': algorithm,
                'fingerprint': fingerprint,
                'fingerprint_type': fingerprint_type
            })
        return {
            'type': _type,
            'ttl': records[0]['ttl'],
            'values': values
        }

    def zone_records(self, zone):
        if zone.name not in self._zone_records:
            try:
                self._zone_records[zone.name] = \
                    self._client.records(zone.name[:-1])
            except DnsimpleClientNotFound:
                return []

        return self._zone_records[zone.name]

    def populate(self, zone, target=False, lenient=False):
        self.log.debug('populate: name=%s, target=%s, lenient=%s', zone.name,
                       target, lenient)

        values = defaultdict(lambda: defaultdict(list))
        for record in self.zone_records(zone):
            _type = record['type']
            if _type not in self.SUPPORTS:
                continue
            elif _type == 'TXT' and record['content'].startswith('ALIAS for'):
                # ALIAS has a "ride along" TXT record with 'ALIAS for XXXX',
                # we're ignoring it
                continue
            values[record['name']][record['type']].append(record)

        before = len(zone.records)
        for name, types in values.items():
            for _type, records in types.items():
                data_for = getattr(self, '_data_for_{}'.format(_type))
                record = Record.new(zone, name, data_for(_type, records),
                                    source=self, lenient=lenient)
                zone.add_record(record, lenient=lenient)

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

    def _params_for_multiple(self, record):
        for value in record.values:
            yield {
                'content': value,
                'name': record.name,
                'ttl': record.ttl,
                'type': record._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

    def _params_for_TXT(self, record):
        for value in record.values:
            yield {
                # un-escape semicolons
                'content': value.replace('\\', ''),
                'name': record.name,
                'ttl': record.ttl,
                'type': record._type,
            }

    def _params_for_CAA(self, record):
        for value in record.values:
            yield {
                'content': '{} {} "{}"'.format(value.flags, value.tag,
                                               value.value),
                'name': record.name,
                'ttl': record.ttl,
                'type': record._type
            }

    def _params_for_single(self, record):
        yield {
            'content': record.value,
            'name': record.name,
            'ttl': record.ttl,
            'type': record._type
        }

    _params_for_ALIAS = _params_for_single
    _params_for_CNAME = _params_for_single
    _params_for_PTR = _params_for_single

    def _params_for_MX(self, record):
        for value in record.values:
            yield {
                'content': value.exchange,
                'name': record.name,
                'priority': value.preference,
                'ttl': record.ttl,
                'type': record._type
            }

    def _params_for_NAPTR(self, record):
        for value in record.values:
            content = '{} {} "{}" "{}" "{}" {}' \
                .format(value.order, value.preference, value.flags,
                        value.service, value.regexp, value.replacement)
            yield {
                'content': content,
                'name': record.name,
                'ttl': record.ttl,
                'type': record._type
            }

    def _params_for_SRV(self, record):
        for value in record.values:
            yield {
                'content': '{} {} {}'.format(value.weight, value.port,
                                             value.target),
                'name': record.name,
                'priority': value.priority,
                'ttl': record.ttl,
                'type': record._type
            }

    def _params_for_SSHFP(self, record):
        for value in record.values:
            yield {
                'content': '{} {} {}'.format(value.algorithm,
                                             value.fingerprint_type,
                                             value.fingerprint),
                'name': record.name,
                'ttl': record.ttl,
                'type': record._type
            }

    def _apply_Create(self, change):
        new = change.new
        params_for = getattr(self, '_params_for_{}'.format(new._type))
        for params in params_for(new):
            self._client.record_create(new.zone.name[:-1], params)

    def _apply_Update(self, change):
        self._apply_Delete(change)
        self._apply_Create(change)

    def _apply_Delete(self, change):
        existing = change.existing
        zone = existing.zone
        for record in self.zone_records(zone):
            if existing.name == record['name'] and \
               existing._type == record['type']:
                self._client.record_delete(zone.name[:-1], record['id'])

    def _apply(self, plan):
        desired = plan.desired
        changes = plan.changes
        self.log.debug('_apply: zone=%s, len(changes)=%d', desired.name,
                       len(changes))

        domain_name = desired.name[:-1]
        try:
            self._client.domain(domain_name)
        except DnsimpleClientNotFound:
            self.log.debug('_apply:   no matching zone, creating domain')
            self._client.domain_create(domain_name)

        for change in changes:
            class_name = change.__class__.__name__
            getattr(self, '_apply_{}'.format(class_name))(change)

        # Clear out the cache if any
        self._zone_records.pop(desired.name, None)