Offloaded study group radius calculation to backend and fixed study groups serializer

stude/study_groups/serializers.py

@@ -14,6 +14,7 @@ class CustomUserKeyRelatedField(serializers.PrimaryKeyRelatedField):
 
 
 class StudyGroupSerializer(serializers.ModelSerializer):
+    name = serializers.CharField()
     users = CustomUserKeyRelatedField(
         queryset=CustomUser.objects.all(), many=True)
     subject = serializers.SlugRelatedField(
@@ -21,6 +22,7 @@ class StudyGroupSerializer(serializers.ModelSerializer):
     location = PointField()
     landmark = serializers.SlugRelatedField(
         queryset=Landmark.objects.all(), many=False, slug_field='name', required=False, allow_null=True)
+    radius = serializers.FloatField()
 
     def create(self, validated_data):
         user = self.context['request'].user
@@ -40,7 +42,7 @@ class StudyGroupSerializer(serializers.ModelSerializer):
     class Meta:
         model = StudyGroup
         fields = '__all__'
-        read_only_fields = ['landmark']
+        read_only_fields = ['landmark', 'radius']
 
 
 class StudyGroupMembershipSerializer(serializers.ModelSerializer):

stude/study_groups/views.py

@@ -4,11 +4,12 @@ from rest_framework.exceptions import PermissionDenied
 from rest_framework.permissions import IsAuthenticated
 from .serializers import StudyGroupSerializer
 from .models import StudyGroup
-from subjects.models import Subject
+from subjects.models import Subject, SubjectInstance
 from student_status.models import StudentStatus
 from rest_framework import generics, viewsets, exceptions
 from django.contrib.gis.geos import fromstr
 from django.contrib.gis.db.models.functions import Distance
+
 # Create your views here.
 
 
@@ -20,6 +21,11 @@ class StudyGroupListView(generics.ListAPIView):
     def get_queryset(self):
         user = self.request.user
 
+        if not user.is_student:
+            raise PermissionDenied(
+                "You must be a student to view study groups"
+            )
+
         if not user.is_student:
             raise PermissionDenied(
                 "You must be a student to view study groups"
@@ -29,15 +35,14 @@ class StudyGroupListView(generics.ListAPIView):
         user_course = user.course
         print(user_course)
 
-        # Get subject names related to the user's course
+        # Get the subject name of the student's subjects from SubjectInstance
-        subject_names = Subject.objects.filter(
+        user_subject_names = user.subjects.values_list('subject', flat=True)
-            course=user_course
+        print('user subjects:', user_subject_names)
-        ).values_list('subject', flat=True)
+        # Get the corresponding Subject models
+        user_subjects = Subject.objects.filter(name__in=user_subject_names)
+        # Now fetch the StudyGroups with the matching Subject models
+        studygroups = StudyGroup.objects.filter(subject__in=user_subjects)
 
-        print(subject_names)
-
-        # Now fetch the StudyGroups with the matching subject names
-        studygroups = StudyGroup.objects.filter(subject_name__in=subject_names)
         return studygroups
 
 
@@ -64,16 +69,30 @@ class StudyGroupListNearView(generics.ListAPIView):
         user_course = user.course
         print(user_course)
 
-        # Get subject names related to the user's course
+        # Get the subject name of the student's subjects from SubjectInstance
-        subject_names = Subject.objects.filter(
+        user_subject_names = user.subjects.values_list('subject', flat=True)
-            course=user_course
+        # Get the corresponding Subject models
-        ).values_list('subject', flat=True)
+        user_subjects = Subject.objects.filter(name__in=user_subject_names)
 
-        print(subject_names)
+        # Now fetch the StudyGroups with the matching Subject models that are within 100m
+        studygroups = StudyGroup.objects.filter(subject__in=user_subjects).annotate(
+            distance=Distance('location', user_location)).filter(distance__lte=100)
+
+        for group in studygroups:
+            # Get all StudentStatus locations of the group
+            group_locations = group.users.values_list('location', flat=True)
+            # Convert string locations to GEOSGeometry objects
+            point_locations = [fromstr(loc, srid=4326)
+                               for loc in group_locations]
+            # Calculate distances between every pair of locations
+            distances = [(loc1.distance(
+                loc2)*100000)for loc1 in point_locations for loc2 in point_locations]
+            # Get the maximum distance
+            group_radius = max(distances) if distances else 0
+            group_radius = max(group_radius, 15)
+            # Annotate the group with the radius
+            group.radius = group_radius
 
-        # Now fetch the StudyGroups with the matching subject names that are within 50m
-        studygroups = StudyGroup.objects.filter(subject_name__in=subject_names).annotate(
-            distance=Distance('location', user_location)).filter(distance__lte=50)
         return studygroups