# -*- coding: utf-8 -*-
# copyright 2016 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr -- mailto:contact@logilab.fr
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

"""cubicweb-elasticsearch specific hooks and operations"""

import logging

from elasticsearch.exceptions import ConnectionError, NotFoundError
from urllib3.exceptions import ProtocolError

from cubicweb.server import hook
from cubicweb.predicates import score_entity
from cubicweb_elasticsearch.es import indexable_types, fulltext_indexable_rql, CUSTOM_ATTRIBUTES

log = logging.getLogger(__name__)


def entity_indexable(entity):
    return entity.cw_etype in indexable_types(entity._cw.vreg.schema) or \
        entity.cw_etype in CUSTOM_ATTRIBUTES


class ContentUpdateIndexES(hook.Hook):
    """detect content change and updates ES indexing"""

    __regid__ = 'elasticsearch.contentupdatetoes'
    __select__ = hook.Hook.__select__ & score_entity(entity_indexable)
    events = ('after_update_entity', 'after_add_entity', 'after_delete_entity')
    category = 'es'

    def __call__(self):
        IndexEsOperation.get_instance(self._cw).add_data(self.entity)


class RelationsUpdateIndexES(hook.Hook):
    """detect relations changes and updates ES indexing"""

    __regid__ = 'elasticsearch.relationsupdatetoes'
    events = ('after_add_relation', 'before_delete_relation')
    category = 'es'

    def __call__(self):
        # XXX add a selector for object and subject
        for entity in (self._cw.entity_from_eid(self.eidfrom),
                       self._cw.entity_from_eid(self.eidto)):
            cw_etype = entity.cw_etype
            if (cw_etype in indexable_types(entity._cw.vreg.schema) or
                    cw_etype in CUSTOM_ATTRIBUTES):
                IndexEsOperation.get_instance(self._cw).add_data(entity)


class IndexEsOperation(hook.DataOperationMixIn, hook.Operation):

    @staticmethod
    def delete_doc(self, es, **kwargs):
        try:
            # TODO option for async ?
            es.delete(**kwargs)
        except (ConnectionError, ProtocolError):
            log.warning('Failed to delete in hook, could not connect to ES')
        except NotFoundError:
            log.info('Failed to delete es document in hook (%s)', repr(kwargs))

    def postcommit_event(self):
        indexer = self.cnx.vreg['es'].select('indexer', self.cnx)
        es = indexer.get_connection()
        if es is None or not indexer.index_name:
            log.error('no connection to ES (not configured) skip ES indexing')
            return
        for entity in self.get_data():
            kwargs = dict(index=indexer.index_name,
                          id=entity.eid,
                          doc_type=entity.cw_etype)
            if self.cnx.deleted_in_transaction(entity.eid):
                self.delete_doc(es, **kwargs)
                continue
            rql = fulltext_indexable_rql(entity.cw_etype,
                                         entity._cw.vreg.schema,
                                         eid=entity.eid)
            indexable_entity = self.cnx.execute(rql).one()
            serializer = indexable_entity.cw_adapt_to('IFullTextIndexSerializable')
            json = serializer.serialize(complete=True)
            if not json:
                # if en entity has been already indexed, we still
                # keep the first indexation
                # which is wrong. We should remove the existing es entry.
                continue
            kwargs['body'] = json
            # Entities with fulltext_containers relations return their container
            # IFullTextIndex serializer, therefore the "id" and "doc_type" in
            # kwargs below must be container data.
            kwargs['id'] = json['eid']
            kwargs['doc_type'] = getattr(serializer, 'doc_type', json['cw_etype'])
            try:
                # TODO option for async ?
                es.index(**kwargs)
            except (ConnectionError, ProtocolError):
                log.warning('Failed to index in hook, could not connect to ES')
            except Exception as exc:
                log.exception('Failed to index in hook')
                raise