feat(v2): add multiple extra features from the pdf slides

backend/processing/views.py

@@ -3,8 +3,18 @@ from rest_framework.response import Response
 from rest_framework.views import APIView
 
 from .algorithms import ProcessingError
-from .selectors import image_session_get, processing_job_get
-from .services import batch_job_create, image_session_create, image_session_process, processing_job_payload
+from .registry import operation_metadata
+from .selectors import image_session_get, image_state_get, image_states_list, processing_job_get
+from .services import (
+    batch_job_create,
+    combine_states,
+    image_session_create,
+    image_session_process,
+    image_state_apply_operation,
+    image_state_payload,
+    image_states_payload,
+    processing_job_payload,
+)
 
 
 def error_response(message, code=status.HTTP_400_BAD_REQUEST):
@@ -59,6 +69,73 @@ class ProcessView(APIView):
             return error_response(str(exc), code)
 
 
+class OperationsView(APIView):
+    def get(self, request):
+        return Response({"operations": operation_metadata()})
+
+
+class SessionStatesView(APIView):
+    def get(self, request, session_id):
+        session = image_session_get(session_id=session_id)
+        if session is None:
+            return error_response("Image session does not exist.", status.HTTP_404_NOT_FOUND)
+        return Response({"session_id": str(session.id), "states": image_states_payload(states=image_states_list(session_id=session.id))})
+
+
+class StateOperationView(APIView):
+    class InputSerializer(serializers.Serializer):
+        operation = serializers.CharField()
+        params = serializers.DictField(required=False, default=dict)
+
+    def post(self, request, state_id):
+        serializer = self.InputSerializer(data=request.data)
+        serializer.is_valid(raise_exception=True)
+        state = image_state_get(state_id=state_id)
+        if state is None:
+            return error_response("Image state does not exist.", status.HTTP_404_NOT_FOUND)
+        try:
+            payload = image_state_apply_operation(
+                state=state,
+                operation=serializer.validated_data["operation"],
+                params=serializer.validated_data.get("params", {}),
+            )
+            return Response(payload, status=status.HTTP_201_CREATED)
+        except ProcessingError as exc:
+            code = status.HTTP_410_GONE if str(exc) == "Image session has expired." else status.HTTP_400_BAD_REQUEST
+            return error_response(str(exc), code)
+
+
+class StateCombineView(APIView):
+    class InputSerializer(serializers.Serializer):
+        operation = serializers.ChoiceField(choices=["add", "subtract", "dot_product", "average", "and", "or"])
+        state_ids = serializers.ListField(child=serializers.UUIDField(), min_length=2)
+        params = serializers.DictField(required=False, default=dict)
+
+    def post(self, request):
+        serializer = self.InputSerializer(data=request.data)
+        serializer.is_valid(raise_exception=True)
+        states = [image_state_get(state_id=state_id) for state_id in serializer.validated_data["state_ids"]]
+        if any(state is None for state in states):
+            return error_response("One or more image states do not exist.", status.HTTP_404_NOT_FOUND)
+        try:
+            payload = combine_states(
+                states=states,
+                operation=serializer.validated_data["operation"],
+                params=serializer.validated_data.get("params", {}),
+            )
+            return Response(payload, status=status.HTTP_201_CREATED)
+        except ProcessingError as exc:
+            return error_response(str(exc))
+
+
+class StateHistogramView(APIView):
+    def get(self, request, state_id):
+        state = image_state_get(state_id=state_id)
+        if state is None:
+            return error_response("Image state does not exist.", status.HTTP_404_NOT_FOUND)
+        return Response({"state_id": str(state.id), "histogram": state.histogram, "state": image_state_payload(state=state, include_image=False)})
+
+
 class BatchView(APIView):
     class InputSerializer(serializers.Serializer):
         operation = serializers.ChoiceField(choices=["average", "subtract"])