From 9c84842c111fd5a65a970369f36ad34ed2d6344c Mon Sep 17 00:00:00 2001
From: Kuroshini <o.hayatov@id-east.ru>
Date: Tue, 3 Dec 2019 22:35:38 +0300
Subject: [PATCH] tags dynamic filters #3

---
 apps/search_indexes/filters.py | 37 ++++++++++++----------------------
 1 file changed, 13 insertions(+), 24 deletions(-)

diff --git a/apps/search_indexes/filters.py b/apps/search_indexes/filters.py
index a12c37f7..ec67fe7a 100644
--- a/apps/search_indexes/filters.py
+++ b/apps/search_indexes/filters.py
@@ -4,7 +4,7 @@ from django_elasticsearch_dsl_drf.filter_backends import SearchFilterBackend, \
     FacetedSearchFilterBackend, GeoSpatialFilteringFilterBackend
 from search_indexes.utils import OBJECT_FIELD_PROPERTIES
 from six import iteritems
-from functools import reduce
+from tag.models import TagCategory
 
 
 class CustomGeoSpatialFilteringFilterBackend(GeoSpatialFilteringFilterBackend):
@@ -92,7 +92,7 @@ class CustomFacetedSearchFilterBackend(FacetedSearchFilterBackend):
                     'global'
                 ).bucket(__field, agg)
             else:
-                if __field != 'tag' or not request.query_params.getlist('tags_id__in'):
+                if __field != 'tag':
                     qs = queryset.__copy__()
                     qs.query = queryset.query._clone()
                     filterer = make_filter(__facet)
@@ -116,9 +116,11 @@ class CustomFacetedSearchFilterBackend(FacetedSearchFilterBackend):
                     view.paginator.facets_computed.update({facet_name: qs.execute().aggregations[facet_name]})
                 else:
                     tag_facets = []
+                    preserve_ids = []
                     facet_name = '_filter_' + __field
-                    for category_tags_ids in request.query_params.getlist('tags_id__in'):
-                        tags_to_remove = category_tags_ids.split('__')
+                    for category in TagCategory.objects.prefetch_related('tags').filter(public=True,
+                                                                                        value_type=TagCategory.LIST):
+                        tags_to_remove = list(map(lambda t: t.id, category.tags.all()))
                         qs = queryset.__copy__()
                         qs.query = queryset.query._clone()
                         filterer = make_tags_filter(__facet, tags_to_remove)
@@ -140,32 +142,19 @@ class CustomFacetedSearchFilterBackend(FacetedSearchFilterBackend):
                             filter=agg_filter
                         ).bucket(__field, agg)
                         tag_facets.append(qs.execute().aggregations[facet_name])
-                    view.paginator.facets_computed.update({facet_name: self.merge_buckets(tag_facets)})
+                        preserve_ids.append(tags_to_remove)
+                    view.paginator.facets_computed.update({facet_name: self.merge_buckets(tag_facets, preserve_ids)})
         return queryset
 
     @staticmethod
-    def merge_buckets(buckets: list):
+    def merge_buckets(buckets: list, presrve_ids: list):
         """Reduces all buckets preserving class"""
         result_bucket = buckets[0]
-        for bucket in buckets[1:]:
+        result_bucket.tag.buckets = list(filter(lambda x: x in presrve_ids[0], result_bucket.tag.buckets._l_))
+        for bucket, ids in list(zip(buckets, presrve_ids))[1:]:
             for tag in bucket.tag.buckets._l_:
-                result_bucket.tag.buckets.append(tag)
-
-        def reducer(prev, cur):
-            """Unique by key"""
-            if not len(list(filter(lambda x: x['key'] == cur['key'], prev))):
-                prev.append(cur)
-            return prev
-
-        buckets_count = len(buckets)
-        result_bucket.tag.buckets = list(filter(lambda t: t is not None, [
-            tag if len(list(filter(lambda t: t['key'] == tag['key'], result_bucket.tag.buckets._l_))) == buckets_count else None
-            for tag in result_bucket.tag.buckets._l_])) # here we remove tags which don't present in any bucket
-        result_bucket.tag.buckets = list(reduce(
-            reducer,
-            result_bucket.tag.buckets._l_,
-            []
-        ))
+                if tag['key'] in ids:
+                    result_bucket.tag.buckets.append(tag)
         return result_bucket