Add bulk assignment API

backend/examples/assignment/strategies.py

@@ -1,5 +1,6 @@
 import abc
 import dataclasses
+import enum
 import random
 from typing import List
 
@@ -12,6 +13,23 @@ class Assignment:
     example: int
 
 
+class StrategyName(enum.Enum):
+    weighted_sequential = enum.auto()
+    weighted_random = enum.auto()
+    sampling_without_replacement = enum.auto()
+
+
+def create_assignment_strategy(strategy_name: StrategyName, dataset_size: int, weights: List[int]) -> "BaseStrategy":
+    if strategy_name == StrategyName.weighted_sequential:
+        return WeightedSequentialStrategy(dataset_size, weights)
+    elif strategy_name == StrategyName.weighted_random:
+        return WeightedRandomStrategy(dataset_size, weights)
+    elif strategy_name == StrategyName.sampling_without_replacement:
+        return SamplingWithoutReplacementStrategy(dataset_size, weights)
+    else:
+        raise ValueError(f"Unknown strategy name: {strategy_name}")
+
+
 class BaseStrategy(abc.ABC):
     @abc.abstractmethod
     def assign(self) -> List[Assignment]:

backend/examples/assignment/workload.py

@@ -0,0 +1,20 @@
+from typing import List
+
+from pydantic import BaseModel, NonNegativeInt
+
+
+class Workload(BaseModel):
+    weight: NonNegativeInt
+    member_id: int
+
+
+class WorkloadAllocation(BaseModel):
+    workloads: List[Workload]
+
+    @property
+    def member_ids(self):
+        return [w.member_id for w in self.workloads]
+
+    @property
+    def weights(self):
+        return [w.weight for w in self.workloads]

backend/examples/urls.py

@@ -1,6 +1,11 @@
 from django.urls import path
 
-from .views.assignment import AssignmentDetail, AssignmentList, ResetAssignment
+from .views.assignment import (
+    AssignmentDetail,
+    AssignmentList,
+    BulkAssignment,
+    ResetAssignment,
+)
 from .views.comment import CommentDetail, CommentList
 from .views.example import ExampleDetail, ExampleList
 from .views.example_state import ExampleStateList
@@ -9,6 +14,7 @@ urlpatterns = [
     path(route="assignments", view=AssignmentList.as_view(), name="assignment_list"),
     path(route="assignments/<uuid:assignment_id>", view=AssignmentDetail.as_view(), name="assignment_detail"),
     path(route="assignments/reset", view=ResetAssignment.as_view(), name="assignment_reset"),
+    path(route="assignments/bulk_assign", view=BulkAssignment.as_view(), name="bulk_assignment"),
     path(route="examples", view=ExampleList.as_view(), name="example_list"),
     path(route="examples/<int:example_id>", view=ExampleDetail.as_view(), name="example_detail"),
     path(route="comments", view=CommentList.as_view(), name="comment_list"),

backend/examples/views/assignment.py

@@ -1,12 +1,15 @@
 from django.shortcuts import get_object_or_404
 from django_filters.rest_framework import DjangoFilterBackend
+from pydantic import ValidationError
 from rest_framework import filters, generics, status
 from rest_framework.permissions import IsAuthenticated
 from rest_framework.views import APIView, Response
 
+from examples.assignment.strategies import StrategyName, create_assignment_strategy
+from examples.assignment.workload import WorkloadAllocation
 from examples.models import Assignment
 from examples.serializers import AssignmentSerializer
-from projects.models import Project
+from projects.models import Member, Project
 from projects.permissions import IsProjectAdmin, IsProjectStaffAndReadOnly
 
 
@@ -46,3 +49,50 @@ class ResetAssignment(APIView):
     def delete(self, *args, **kwargs):
         Assignment.objects.filter(project=self.project).delete()
         return Response(status=status.HTTP_204_NO_CONTENT)
+
+
+class BulkAssignment(APIView):
+    serializer_class = AssignmentSerializer
+    permission_classes = [IsAuthenticated & IsProjectAdmin]
+
+    def post(self, *args, **kwargs):
+        try:
+            strategy_name = StrategyName[self.request.data["strategy_name"]]
+        except KeyError:
+            return Response(
+                {"detail": "Invalid strategy name"},
+                status=status.HTTP_400_BAD_REQUEST,
+            )
+
+        try:
+            workload_allocation = WorkloadAllocation(workloads=self.request.data["workloads"])
+        except ValidationError as e:
+            return Response(
+                {"detail": e.errors()},
+                status=status.HTTP_400_BAD_REQUEST,
+            )
+
+        project = get_object_or_404(Project, pk=self.kwargs["project_id"])
+        members = Member.objects.filter(project=project, pk__in=workload_allocation.member_ids)
+        if len(members) != len(workload_allocation.member_ids):
+            return Response(
+                {"detail": "Invalid member ids"},
+                status=status.HTTP_400_BAD_REQUEST,
+            )
+        # Sort members by workload_allocation.member_ids
+        members = sorted(members, key=lambda m: workload_allocation.member_ids.index(m.id))
+
+        dataset_size = project.examples.count()  # Todo: unassigned examples
+        strategy = create_assignment_strategy(strategy_name, dataset_size, workload_allocation.weights)
+        assignments = strategy.assign()
+        example_ids = project.examples.values_list("pk", flat=True)
+        assignments = [
+            Assignment(
+                project=project,
+                example=example_ids[assignment.example],
+                assignee=members[assignment.user].user,
+            )
+            for assignment in assignments
+        ]
+        Assignment.objects.bulk_create(assignments)
+        return Response(status=status.HTTP_201_CREATED)