text: from django.db import models
  from django.contrib.auth.models import AbstractBaseUser, BaseUserManager, \
                                          PermissionsMixin
  from django.conf import settings
  
  # Create your models here.
  class UserManager(BaseUserManager):
  
    def create_user(self, email, password=None, **extra_fields):
      """Creates and saves a new user"""
      if not email:
        raise ValueError('Users must have an email address')
      user = self.model(email=self.normalize_email(email), **extra_fields)
      user.set_password(password)
      user.save(using=self._db)
  
      return user
  
    def create_superuser(self, email, password):
      """Creates and saves a new super user"""
      user = self.create_user(email, password)
      user.is_staff = True
      user.is_superuser = True
      user.save(using=self._db)
  
      return user
  
  class User(AbstractBaseUser, PermissionsMixin):
    """Custom user model that supports using email instead of username"""
    email = models.EmailField(max_length=255, unique=True)
    name = models.CharField(max_length=255)
    is_active = models.BooleanField(default=True)
    is_staff = models.BooleanField(default=False)
  
    objects = UserManager()
  
    USERNAME_FIELD = 'email'
  
  class Tag(models.Model):
    """Tag to be used for a recipe"""
    name = models.CharField(max_length=255)
    user = models.ForeignKey(
      settings.AUTH_USER_MODEL,
      on_delete=models.CASCADE,
    )
  
    def __str__(self):
      return self.name
  
  class Ingredient(models.Model):
    """Ingredient to be used in a recipe"""
    name = models.CharField(max_length=255)
    user = models.ForeignKey(
      settings.AUTH_USER_MODEL,
      on_delete=models.CASCADE
    )
  
    def __str__(self):
      return self.name
  
  class Recipe(models.Model):
    """Recipe object"""
    user = models.ForeignKey(
      settings.AUTH_USER_MODEL,
      on_delete=models.CASCADE
    )
    title = models.CharField(max_length=255)
    time_minutes = models.IntegerField()
    price = models.DecimalField(max_digits=5, decimal_places=2)
    link = models.CharField(max_length=255, blank=True)
    ingredients = models.ManyToManyField('Ingredient')
    tags = models.ManyToManyField('Tag')
  
    def __str__(self):
      return self.title