From 63aedd7d614f5ab2026fafb46a3f28b6d80d1469 Mon Sep 17 00:00:00 2001
From: etj <etj@geo-solutions.it>
Date: Thu, 29 Jun 2023 15:48:22 +0200
Subject: [PATCH] [Fixes #11102] Faceting: prefiltering

---
 geonode/base/api/filters.py | 15 ++++++++++-----
 geonode/facets/tests.py     | 23 +++++++++++++++++++++++
 geonode/facets/views.py     | 13 +++++++++++--
 3 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/geonode/base/api/filters.py b/geonode/base/api/filters.py
index f8691e0178d..a2428bfdc65 100644
--- a/geonode/base/api/filters.py
+++ b/geonode/base/api/filters.py
@@ -56,11 +56,16 @@ class TKeywordsFilter(BaseFilterBackend):
     """
 
     def filter_queryset(self, request, queryset, view):
-        return (
-            self.filter_queryset_GROUP(request, queryset, view)
-            if "force_and" not in request.GET
-            else self.filter_queryset_AND(request, queryset, view)
-        )
+        # we must make the GET mutable since in the filters, some queryparams are popped
+        request.GET._mutable = True
+        try:
+            return (
+                self.filter_queryset_GROUP(request, queryset, view)
+                if "force_and" not in request.GET
+                else self.filter_queryset_AND(request, queryset, view)
+            )
+        finally:
+            request.GET._mutable = False
 
     def filter_queryset_AND(self, request, queryset, view):
         """
diff --git a/geonode/facets/tests.py b/geonode/facets/tests.py
index d582f4e2041..b5ae7f7541f 100644
--- a/geonode/facets/tests.py
+++ b/geonode/facets/tests.py
@@ -28,6 +28,8 @@
 from django.urls import reverse
 
 from geonode.base.models import Thesaurus, ThesaurusLabel, ThesaurusKeyword, ThesaurusKeywordLabel, ResourceBase, Region
+from geonode.facets.models import facet_registry
+from geonode.facets.providers.region import RegionFacetProvider
 from geonode.tests.base import GeoNodeBaseTestSupport
 import geonode.facets.views as views
 
@@ -294,6 +296,27 @@ def test_topics(self):
             obj = json.loads(res.content)
             self.assertEqual(exp, len(obj["topics"]["items"]), f"Unexpected topic count {exp} for facet {facet}")
 
+    def test_prefiltering(self):
+        reginfo = RegionFacetProvider().get_info()
+        t0info = facet_registry.get_provider("t_0").get_info()
+        t1info = facet_registry.get_provider("t_1").get_info()
+
+        for facet, filters, totals, count0 in (
+            ("t_0", {}, 2, 10),
+            ("t_0", {reginfo["key"]: "R0"}, 1, 1),
+            ("t_1", {}, 2, 10),
+            ("t_1", {reginfo["key"]: "R0"}, 1, 2),
+            ("t_1", {reginfo["key"]: "R1"}, 2, 3),
+            (reginfo["name"], {}, 2, 4),
+            (reginfo["name"], {t0info["key"]: self.thesauri_k["0_0"].id}, 2, 1),
+            (reginfo["name"], {t1info["key"]: self.thesauri_k["1_0"].id}, 2, 3),
+        ):
+            req = self.rf.get(reverse("get_facet", args=[facet]), data=filters)
+            res: JsonResponse = views.get_facet(req, facet)
+            obj = json.loads(res.content)
+            self.assertEqual(totals, obj["topics"]["total"], f"Bad totals for facet '{facet} and filter {filters}")
+            self.assertEqual(count0, obj["topics"]["items"][0]["count"], f"Bad count0 for facet '{facet}")
+
     def test_user_auth(self):
         # make sure the user authorization pre-filters the visible resources
         # TODO test
diff --git a/geonode/facets/views.py b/geonode/facets/views.py
index 8aa18439f83..717eabfc57a 100644
--- a/geonode/facets/views.py
+++ b/geonode/facets/views.py
@@ -27,6 +27,8 @@
 from django.urls import reverse
 
 from django.conf import settings
+
+from geonode.base.api.views import ResourceBaseViewSet
 from geonode.base.models import ResourceBase
 from geonode.facets.models import FacetProvider, DEFAULT_FACET_PAGE_SIZE, facet_registry
 from geonode.security.utils import get_visible_resources
@@ -160,8 +162,15 @@ def _prefilter_topics(request):
     :return: a QuerySet on ResourceBase
     """
     logger.debug("Filtering by user '%s'", request.user)
-    # return ResourceBase.objects
-    return get_visible_resources(ResourceBase.objects, request.user)
+    filters = {k: vlist for k, vlist in request.query_params.lists() if k.startswith("filter{")}
+
+    if filters:
+        viewset = ResourceBaseViewSet(request=request, format_kwarg={}, kwargs=filters)
+        viewset.initial(request)
+        return get_visible_resources(queryset=viewset.filter_queryset(viewset.get_queryset()), user=request.user)
+    else:
+        # return ResourceBase.objects
+        return get_visible_resources(ResourceBase.objects, request.user)
 
 
 def _resolve_language(request) -> (str, bool):