from django.db import models
from django.contrib.auth.models import User


class ClassAtSchool(models.Model):
    name = models.CharField(max_length=30, unique=True, blank=False)

    def __str__(self):
        return self.name


class Teacher(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    class_at_school = models.ManyToManyField(ClassAtSchool)

    def __str__(self):
        return self.user.username


class Student(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    class_at_school = models.ForeignKey(ClassAtSchool, on_delete=models.CASCADE)

    class Meta:
        ordering = ['user']

    def __str__(self):
        return self.user.username