from django.db import migrations

from locations.seed import seed


def seed_locations(apps, schema_editor):
    seed(apps.get_model("locations", "Atoll"), apps.get_model("locations", "Island"))


def unseed_locations(apps, schema_editor):
    """Only removes rows nothing references."""
    Atoll = apps.get_model("locations", "Atoll")
    Island = apps.get_model("locations", "Island")
    from locations.seed import ATOLLS

    for entry in ATOLLS:
        Island.objects.filter(
            atoll__name=entry["name"], name__in=entry["islands"], users__isnull=True
        ).delete()
        Atoll.objects.filter(
            name=entry["name"], islands__isnull=True, users__isnull=True
        ).delete()


class Migration(migrations.Migration):
    dependencies = [
        ("locations", "0001_initial"),
        # Islands/atolls are referenced by users; keep the tables in step.
        ("users", "0001_initial"),
    ]

    operations = [migrations.RunPython(seed_locations, unseed_locations)]