# Generated by Django 5.1.3 on 2025-12-21 05:53

from django.db import migrations
from django.db.models import F


def backfill_activity_at(apps, schema_editor):
    """Backfill activity_at from updated_at for existing Threads."""
    Thread = apps.get_model("core_messages", "Thread")
    Thread.objects.filter(activity_at__isnull=True).update(activity_at=F("updated_at"))


def reverse_backfill(apps, schema_editor):
    """Reverse the backfill by setting activity_at to null."""
    Thread = apps.get_model("core_messages", "Thread")
    Thread.objects.update(activity_at=None)


class Migration(migrations.Migration):
    dependencies = [
        (
            "core_messages",
            "0002_message_metadata_thread_activity_at_thread_metadata_and_more",
        ),
    ]

    operations = [
        migrations.RunPython(backfill_activity_at, reverse_backfill),
    ]