from django.db import migrations


def add_image_permissions_to_admin_groups(apps, schema_editor):
    ContentType = apps.get_model("contenttypes.ContentType")
    Permission = apps.get_model("auth.Permission")
    Group = apps.get_model("auth.Group")

    # Get image permissions
    image_content_type, _created = ContentType.objects.get_or_create(
        model="image", app_label="wagtailimages"
    )

    add_image_permission, _created = Permission.objects.get_or_create(
        content_type=image_content_type,
        codename="add_image",
        defaults={"name": "Can add image"},
    )
    change_image_permission, _created = Permission.objects.get_or_create(
        content_type=image_content_type,
        codename="change_image",
        defaults={"name": "Can change image"},
    )
    delete_image_permission, _created = Permission.objects.get_or_create(
        content_type=image_content_type,
        codename="delete_image",
        defaults={"name": "Can delete image"},
    )

    # Assign it to Editors and Moderators groups
    for group in Group.objects.filter(name__in=["Editors", "Moderators"]):
        group.permissions.add(
            add_image_permission, change_image_permission, delete_image_permission
        )


def remove_image_permissions(apps, schema_editor):
    """Reverse the above additions of permissions."""
    ContentType = apps.get_model("contenttypes.ContentType")
    Permission = apps.get_model("auth.Permission")
    image_content_type = ContentType.objects.get(
        model="image",
        app_label="wagtailimages",
    )
    # This cascades to Group
    Permission.objects.filter(
        content_type=image_content_type,
        codename__in=("add_image", "change_image", "delete_image"),
    ).delete()


class Migration(migrations.Migration):

    dependencies = [
        ("wagtailimages", "0001_initial"),
        # Need to run wagtailcores initial data migration to make sure the groups are created
        ("wagtailcore", "0002_initial_data"),
    ]

    operations = [
        migrations.RunPython(
            add_image_permissions_to_admin_groups, remove_image_permissions
        ),
    ]