feat: implement encrypted metadata support and fix public_id handling in letter serialization

backend/letters/serializers.py

@@ -30,7 +30,7 @@ class LetterSerializer(serializers.ModelSerializer):
             "updated_at",
             "images",
         ]  # user to be fetched from request
-        read_only_fields = ["public_id", "created_at", "updated_at"]
+        read_only_fields = ["created_at", "updated_at"]
 
     def validate(self, data):
         if (data.get("encrypted_content") or data.get("encrypted_metadata")) and not data.get("encrypted_dek"):

backend/letters/views.py

@@ -16,7 +16,11 @@ class LetterView(generics.ListCreateAPIView):
         return Letter.objects.filter(user=self.request.user)
 
     def put(self, request, public_id):
-        serializer = self.get_serializer(data=request.data)
+        data = request.data.copy()
+        # remove public_id from data to avoid UniqueValidator firing
+        # since we use it from the URL for update_or_create anyway
+        data.pop("public_id", None)
+        serializer = self.get_serializer(data=data)
 
         serializer.is_valid(raise_exception=True)