refactor: include exists action in quibletviewset for checkin

Author: stabldev

backend/apps/quiblet/api/v1/serializers.py

@@ -21,3 +21,8 @@ class QuibletSlimSerializer(serializers.ModelSerializer):
     class Meta:
         model = QuibletModel
         fields = ('name', 'avatar')
+
+
+class QuibletExistsSerializer(serializers.Serializer):
+    exists = serializers.BooleanField()
+    name = serializers.CharField()

backend/apps/quiblet/api/v1/viewsets.py

@@ -1,16 +1,50 @@
+from http import HTTPMethod
 from typing import cast
 
-from rest_framework.viewsets import ModelViewSet
+from django.db.models import QuerySet
+from rest_framework import exceptions, response, viewsets
+from rest_framework.decorators import action
 
 from common.patches.request import PatchedHttpRequest
 
 from ...models import QuibletModel
-from .serializers import QuibletSerializer
+from .serializers import QuibletExistsSerializer, QuibletSerializer
 
 
-class QuibletModelViewSet(ModelViewSet):
+class QuibletModelViewSet(viewsets.ModelViewSet):
     queryset = QuibletModel.objects.all()
     serializer_class = QuibletSerializer
+    lookup_field = 'name'
+
+    def get_queryset(self) -> QuerySet[QuibletModel]:  # pyright: ignore
+        return super().get_queryset()
+
+    def get_object(self) -> QuibletModel:  # pyright: ignore
+        qs = self.get_queryset()
+        filter_kwargs = {f'{self.lookup_field}': self.kwargs[self.lookup_field]}
+        obj = qs.filter(**filter_kwargs).first()
+
+        if not obj:
+            raise exceptions.NotFound(
+                f'Quiblet with name {self.kwargs[self.lookup_field]} not found.'
+            )
+        return obj
+
+    def get_serializer_class(self):  # pyright: ignore
+        if self.action == 'exists':
+            return QuibletExistsSerializer
+        return super().get_serializer_class()
+
+    @action(detail=True, methods=[HTTPMethod.GET])
+    def exists(self, request, name=None):
+        res = dict(exists=False, name=name)
+
+        quiblet = self.get_queryset().filter(name__iexact=name).first()
+        if quiblet is not None:
+            res['exists'] = True
+            res['name'] = quiblet.name
+
+        return response.Response(res)
 
     def perform_create(self, serializer):
         patched_request = cast(PatchedHttpRequest, self.request)

backend/apps/quiblet/models.py

@@ -13,7 +13,12 @@
 
 
 class QuibletModel(AvatarMixin, CreatedAtMixin, IsPublicMixin):
-    name = models.CharField(_('name'), unique=True, max_length=25)
+    name = models.CharField(
+        _('name'),
+        unique=True,
+        max_length=25,
+        error_messages={'unique': 'Quiblet with this name already exists.'},
+    )
     description = models.TextField(_('description'))
     cover = models.ImageField(
         _('cover'),