Filter accommodations around a given center point and a radius.

accommodation/filters.py

@@ -1,4 +1,5 @@
-from django.contrib.gis.geos import Polygon
+from django.contrib.gis.geos import Point, Polygon
+from django.contrib.gis.measure import Distance
 from django_filters.rest_framework import FilterSet, filters
 from rest_framework.exceptions import ValidationError
 
@@ -8,6 +9,7 @@
 class AccommodationFilter(FilterSet):
     bbox = filters.CharFilter(method="filter_bbox", label="Bounding box")
     is_accessible = filters.BooleanFilter(method="filter_is_accessible", label="Only accessible accommodations")
+    center = filters.CharFilter(method="filter_center", label="Center point for radius filtering (lon,lat)")
 
     def filter_bbox(self, queryset, name, value):
         try:
@@ -25,6 +27,16 @@ def filter_is_accessible(self, queryset, name, value):
             return queryset.filter(nb_accessible_apartments__gt=0)
         return queryset
 
+    def filter_center(self, queryset, name, value):
+        try:
+            lon, lat = map(float, value.split(","))
+            point = Point(lon, lat)
+            radius = float(self.data.get("radius") or 10)
+            distance = Distance(km=radius)
+            return queryset.filter(geom__distance_lte=(point, distance))
+        except (ValueError, TypeError):
+            raise ValidationError("Invalid center format. Should be 'longitude,latitude'. Radius must be a number.")
+
     class Meta:
         model = Accommodation
         fields = []

accommodation/views.py

@@ -30,6 +30,18 @@ class AccommodationDetailView(generics.RetrieveAPIView):
             description="Filter to return only accommodations with accessible apartments (nb_accessible_apartments > 0).",
             required=False,
         ),
+        OpenApiParameter(
+            "center",
+            OpenApiTypes.STR,
+            description="Center point for radius filtering. Format: longitude,latitude.",
+            required=False,
+        ),
+        OpenApiParameter(
+            "radius",
+            OpenApiTypes.NUMBER,
+            description="Radius in kilometers for filtering accommodations around the center point.",
+            required=False,
+        ),
     ],
     responses=AccommodationGeoSerializer,
 )

tests/accommodation/test_api.py

@@ -85,3 +85,37 @@ def test_accommodation_list_view_filters(self):
         returned_ids = [feature["id"] for feature in results["results"]["features"]]
         assert self.accommodation_nantes_accessible.id in returned_ids
         assert self.accommodation_nantes_non_accessible.id not in returned_ids
+
+    def test_accommodation_list_center_radius(self):
+        center = "-1.5536,47.2184"  # Nantes (near the accessible accommodation)
+
+        response = self.client.get(reverse("accommodation-list"), {"center": center, "radius": 0.2})
+        results = response.json()
+
+        assert len(results["results"]["features"]) == 1
+
+        returned_ids = [feature["id"] for feature in results["results"]["features"]]
+        assert self.accommodation_nantes_accessible.id in returned_ids
+        assert self.accommodation_nantes_non_accessible.id not in returned_ids
+
+        response = self.client.get(reverse("accommodation-list"), {"center": center, "radius": 2})
+        results = response.json()
+
+        assert len(results["results"]["features"]) == 2
+
+        returned_ids = [feature["id"] for feature in results["results"]["features"]]
+        assert self.accommodation_nantes_accessible.id in returned_ids
+        assert self.accommodation_nantes_non_accessible.id in returned_ids
+
+        center_paris = "2.35,48.85"  # Paris
+
+        response = self.client.get(reverse("accommodation-list"), {"center": center_paris, "radius": 10})
+        results = response.json()
+
+        assert len(results["results"]["features"]) == 1
+
+        returned_ids = [feature["id"] for feature in results["results"]["features"]]
+        assert self.accommodation_paris.id in returned_ids
+        assert self.accommodation_lyon.id not in returned_ids
+        assert self.accommodation_nantes_accessible.id not in returned_ids
+        assert self.accommodation_nantes_non_accessible.id not in returned_ids