feat: backfill modality on existing public content nodes

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: rtibblesbot

Makefile

@@ -41,6 +41,8 @@ migrate:
 deploy-migrate:
 	# studio#5974: remove at cutover.
 	python contentcuration/manage.py backfill_column --model contentcuration.File --source-field file_size --target-field file_size_bigint
+	# studio#6171: remove after release.
+	python contentcuration/manage.py backfill_public_contentnode_modality
 
 contentnodegc:
 	python contentcuration/manage.py garbage_collect

contentcuration/kolibri_public/management/commands/backfill_public_contentnode_modality.py

@@ -0,0 +1,44 @@
+from django.core.management.base import BaseCommand
+from django.core.management.base import CommandError
+from django.db import transaction
+from kolibri_public.models import ContentNode
+from kolibri_public.search import annotate_modality
+
+
+class Command(BaseCommand):
+    help = "Set kolibri_public ContentNode.modality from options.modality, in batches."
+
+    def add_arguments(self, parser):
+        parser.add_argument("--batch-size", type=int, default=10000)
+
+    def handle(self, *args, **options):
+        batch_size = options["batch_size"]
+        if batch_size < 1:
+            raise CommandError("--batch-size must be >= 1")
+
+        # Only unfilled rows, so re-runs resume past what is already done.
+        unfilled = ContentNode.objects.filter(
+            modality__isnull=True, options__contains='"modality":'
+        )
+        unfilled_pks = unfilled.order_by("pk").values_list("pk", flat=True)
+
+        # Keyset paging by pk: rows whose modality value is unrecognised stay
+        # NULL, so the window must advance past them rather than re-query.
+        batch_start = unfilled_pks.first()
+        while batch_start is not None:
+            batch_end = unfilled_pks.filter(pk__gte=batch_start)[
+                batch_size - 1 : batch_size
+            ].first()
+            window = unfilled.filter(pk__gte=batch_start)
+            if batch_end is not None:
+                window = window.filter(pk__lte=batch_end)
+            with transaction.atomic():
+                annotate_modality(window)
+            self.stdout.write(
+                "backfilled through pk={}".format(
+                    batch_start if batch_end is None else batch_end
+                )
+            )
+            if batch_end is None:
+                break
+            batch_start = unfilled_pks.filter(pk__gt=batch_end).first()

contentcuration/kolibri_public/tests/test_backfill_public_contentnode_modality.py

@@ -0,0 +1,42 @@
+import uuid
+
+from django.core.management import call_command
+from django.test import TestCase
+from kolibri_public import models
+from le_utils.constants import content_kinds
+from le_utils.constants import modalities
+
+
+class BackfillPublicContentNodeModalityTestCase(TestCase):
+    def _create_node(self, options):
+        return models.ContentNode.objects.create(
+            pk=uuid.uuid4().hex,
+            channel_id=uuid.uuid4().hex,
+            content_id=uuid.uuid4().hex,
+            kind=content_kinds.TOPIC,
+            title="node",
+            options=options,
+        )
+
+    def test_sets_modality_from_options(self):
+        quiz = self._create_node({"modality": modalities.QUIZ})
+        course = self._create_node({"modality": modalities.COURSE})
+        plain = self._create_node({})
+
+        call_command("backfill_public_contentnode_modality")
+
+        self.assertEqual(
+            dict(models.ContentNode.objects.values_list("id", "modality")),
+            {quiz.id: modalities.QUIZ, course.id: modalities.COURSE, plain.id: None},
+        )
+
+    def test_backfills_across_batches_past_unrecognised_values(self):
+        unknown = self._create_node({"modality": "NOT_A_MODALITY"})
+        quizzes = [self._create_node({"modality": modalities.QUIZ}) for _ in range(4)]
+
+        call_command("backfill_public_contentnode_modality", batch_size=2)
+
+        self.assertEqual(
+            dict(models.ContentNode.objects.values_list("id", "modality")),
+            {unknown.id: None, **{q.id: modalities.QUIZ for q in quizzes}},
+        )