from django.db import models


class Article(models.Model):
    author = models.ForeignKey(
        "auth.User", null=True, blank=True, on_delete=models.CASCADE
    )
    title = models.CharField(max_length=30)
    body = models.TextField()
    slug = models.SlugField(blank=True)


class CanonicalArticle(models.Model):
    author = models.ForeignKey(
        "auth.User", null=True, blank=True, on_delete=models.CASCADE
    )
    title = models.CharField(max_length=30)
    body = models.TextField()
    slug = models.SlugField(blank=True)

    def get_canonical_slug(self):
        if self.author:
            return "{0.author.username}-{0.slug}".format(self)
        return "unauthored-{0.slug}".format(self)