# -*- coding: utf-8 -*-

'''

Created on Jul 30, 2012

@author: ymh

'''

from haystack.backends import BaseEngine, elasticsearch_backend

from haystack.exceptions import MissingDependency

from haystack.utils import get_identifier

import collections

try:

    import requests

except ImportError:

    raise MissingDependency("The 'elasticsearch' backend requires the installation of 'requests'.")

try:

    import pyelasticsearch

except ImportError:

    raise MissingDependency("The 'elasticsearch' backend requires the installation of 'pyelasticsearch'. Please refer to the documentation.")

class ElasticsearchSearchBackend(elasticsearch_backend.ElasticsearchSearchBackend):

    def build_search_kwargs(self, query_string, sort_by=None, start_offset=0, end_offset=None,

                        fields='', highlight=False, facets=None,

                        date_facets=None, query_facets=None,

                        narrow_queries=None, spelling_query=None,

                        within=None, dwithin=None, distance_point=None,

                        models=None, limit_to_registered_models=None,

                        result_class=None):

        kwargs = super(ElasticsearchSearchBackend, self).build_search_kwargs(query_string, sort_by=sort_by, start_offset=start_offset, end_offset=end_offset,

                        fields=fields, highlight=highlight, facets=facets,

                        date_facets=date_facets, query_facets=query_facets,

                        narrow_queries=narrow_queries, spelling_query=spelling_query,

                        within=within, dwithin=dwithin, distance_point=distance_point,

                        models=models, limit_to_registered_models=limit_to_registered_models,

                        result_class=result_class)

        #TODO : try to make list of field dynamic

        #TODO : How to handle multiple 

        if highlight:

            fields_def = { }

                fields_def['tags'] = {}

                fields_def['title'] = {}

                fields_def['abstract'] = {}

            kwargs['highlight'] = {

                'pre_tags' : ["<span class='highlight'>"],

                'post_tags' : ["</span>"],

                "number_of_fragments" : 0,

                'fields': fields_def                

            }

        return kwargs

    def remove(self, obj_or_string, commit=True):

        if not self.setup_complete:

            try:

                self.setup()

            except (requests.RequestException, pyelasticsearch.ElasticHttpError), e:

                if not self.silently_fail:

                    raise

                self.log.error("Failed to remove document '%s' from Elasticsearch: %s", repr(obj_or_string), e)

                return

        if isinstance(obj_or_string, collections.Iterable) and not isinstance(obj_or_string, basestring):

            ids = [get_identifier(elt) for elt in obj_or_string]

            if not ids:

                return

            q = {'ids' : {'values' : ids}}

            self.conn.delete_by_query(self.index_name, 'modelresult', q)

        else: 

            return super(ElasticsearchSearchBackend, self).remove(obj_or_string, commit=commit) 

class ElasticsearchSearchEngine(BaseEngine):

    backend = ElasticsearchSearchBackend

    query = elasticsearch_backend.ElasticsearchSearchQuery