from django.db import models

from django.db.models import QuerySet

from django.db.models.manager import BaseManager

from django.urls import reverse

class Artist(models.Model):

    name = models.CharField(max_length=100)

    class Meta:

        ordering = ["name"]

        verbose_name = "professional artist"

        verbose_name_plural = "professional artists"

    def __str__(self):

        return self.name

    def get_absolute_url(self):

        return reverse("artist_detail", kwargs={"pk": self.id})

class Author(models.Model):

    name = models.CharField(max_length=100)

    slug = models.SlugField()

    class Meta:

        ordering = ["name"]

    def __str__(self):

        return self.name

class DoesNotExistQuerySet(QuerySet):

    def get(self, *args, **kwargs):

        raise Author.DoesNotExist

DoesNotExistBookManager = BaseManager.from_queryset(DoesNotExistQuerySet)

class Book(models.Model):

    name = models.CharField(max_length=255)

    slug = models.SlugField()

    pages = models.IntegerField()

    authors = models.ManyToManyField(Author)

    pubdate = models.DateField()

    objects = models.Manager()

    does_not_exist = DoesNotExistBookManager()

    class Meta:

        ordering = ["-pubdate"]

    def __str__(self):

        return self.name

class Page(models.Model):

    content = models.TextField()

    template = models.CharField(max_length=255)

class BookSigning(models.Model):

    event_date = models.DateTimeField()