from django.db import migrations, models


class Migration(migrations.Migration):
    """
    Add slug to DeliveryArea as nullable/non-unique first.
    The unique constraint and NOT NULL are applied in 0003 AFTER the data
    migration has populated every slug — this avoids the duplicate-empty-string
    IntegrityError that occurs when ALTER TABLE sets default='' on existing rows.
    """

    dependencies = [
        ("store", "0001_initial"),
    ]

    operations = [
        # nullable + no unique constraint so existing rows don't conflict
        migrations.AddField(
            model_name="deliveryarea",
            name="slug",
            field=models.SlugField(max_length=100, null=True, blank=True),
        ),
        migrations.AlterField(
            model_name="deliveryarea",
            name="county",
            field=models.CharField(
                max_length=100,
                help_text="Region / province name, e.g. Nairobi, Central, Coast",
            ),
        ),
    ]