from django.db import models
from mptt.managers import TreeManager
from mptt.models import MPTTModel, TreeForeignKey


class Specialization(MPTTModel):
    name = models.CharField(max_length=500)
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children', db_index=True)
    order = models.PositiveIntegerField()
    selectable = models.BooleanField(default=True)

    objects = TreeManager()

    def __str__(self):
        return self.name

    class Meta:
        get_latest_by = 'order'
        ordering = ['order']
        verbose_name = 'Специализация'
        verbose_name_plural = 'Специализации'

    class MPTTMeta:
        order_insertion_by = ['order', 'name']