From f9a3e7a440c83a779155ce41525d5bd2ea4a974a Mon Sep 17 00:00:00 2001
From: Keannu Bernasol <noehbernasol0@gmail.com>
Date: Sun, 24 Sep 2023 21:54:14 +0800
Subject: [PATCH] Added initial study group creation, joining, and deletion
 functionality

---
 stude/study_groups/views.py | 45 ++++++++++++++++++++++++++++++++++---
 1 file changed, 42 insertions(+), 3 deletions(-)

diff --git a/stude/study_groups/views.py b/stude/study_groups/views.py
index 4f92cab..e517e58 100644
--- a/stude/study_groups/views.py
+++ b/stude/study_groups/views.py
@@ -9,15 +9,55 @@ 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
-
+from rest_framework import status
+from rest_framework.response import Response
 # Create your views here.
 
 
-class StudyGroupListView(generics.ListAPIView):
+class StudyGroupListView(generics.ListCreateAPIView, generics.UpdateAPIView, generics.DestroyAPIView):
     permission_classes = [IsAuthenticated]
     serializer_class = StudyGroupSerializer
     queryset = StudyGroup.objects.all()
 
+    def partial_update(self, instance, request, *args, **kwargs):
+        # Ensure only "users" field is being updated
+        if set(request.data.keys()) != {"users"}:
+            return Response({"detail": "Only the 'users' field can be updated."}, status=status.HTTP_400_BAD_REQUEST)
+
+        # Get the current list of users
+        instance = self.get_object()
+        current_users = set(instance.users.values_list('id', flat=True))
+
+        # Get the new list of users from the request
+        new_users = set(request.data['users'])
+
+        # Check if the only difference between the two sets is the current user
+        diff = current_users.symmetric_difference(new_users)
+        if len(diff) > 1 or (len(diff) == 1 and request.user.id not in diff):
+            return Response({"detail": "You can only add or remove yourself from the study group."}, status=status.HTTP_400_BAD_REQUEST)
+
+        # Delete the study group if there are no users left
+        instance = self.get_object()
+        if not instance.users.exists():
+            instance.delete()
+
+        return super().partial_update(request, *args, **kwargs)
+
+    def destroy(self, request, *args, **kwargs):
+        instance = self.get_object()
+
+        # Check if the current user is the creator of the study group
+        # Assuming 'date_joined' is a field in your User model
+        creator = instance.users.all().first()
+        if request.user != creator:
+            return Response({"detail": "Only the creator can delete the study group."}, status=status.HTTP_400_BAD_REQUEST)
+
+        # Check if the current user is the only one in the study group
+        if instance.users.count() > 1:
+            return Response({"detail": "The study group cannot be deleted if there are other users in it."}, status=status.HTTP_400_BAD_REQUEST)
+
+        return super().destroy(request, *args, **kwargs)
+
     def get_queryset(self):
         user = self.request.user
 
@@ -52,7 +92,6 @@ class StudyGroupListView(generics.ListAPIView):
             group_radius = max(group_radius, 15)
             # Annotate the group with the radius
             group.radius = group_radius
-        print('test', studygroups)
         return studygroups