from pathlib import Path

from django.db import migrations, models
from django.template.defaultfilters import slugify


def rename_photos(apps, schema_editor):
    Photo = apps.get_model("photologue", "Photo")
    taken_slugs = set(Photo.objects.values_list("slug", flat=True))

    for photo in Photo.objects.order_by("pk"):
        new_title = Path(photo.image.name).stem
        base_slug = slugify(new_title)

        taken_slugs.discard(photo.slug)

        if base_slug in taken_slugs:
            counter = 2
            while f"{base_slug}-{counter}" in taken_slugs:
                counter += 1
            new_slug = f"{base_slug}-{counter}"
        else:
            new_slug = base_slug

        taken_slugs.add(new_slug)
        photo.title = new_title
        photo.slug = new_slug
        photo.save()


class Migration(migrations.Migration):

    dependencies = [
        ('photologue', '0006_allow_duplicate_gallery_titles'),
    ]

    operations = [
        migrations.AlterField(
            model_name='photo',
            name='title',
            field=models.CharField(max_length=250, verbose_name='title'),
        ),
        migrations.RunPython(rename_photos, migrations.RunPython.noop),
    ]