from django.db import models
from django.core.exceptions import ValidationError
from django.utils.translation import ugettext as _

from model_utils.models import TimeStampedModel


class Group(TimeStampedModel, models.Model):
    groupname = models.CharField(max_length=16, unique=True)
    gid = models.PositiveSmallIntegerField(unique=True, primary_key=True)
    descr = models.TextField(blank=True)
    passwd = models.CharField(max_length=128, blank=True)


class User(TimeStampedModel, models.Model):
    username = models.CharField(max_length=64, unique=True)
    uid = models.PositiveSmallIntegerField(unique=True, primary_key=True)
    group = models.ForeignKey(Group)
    gecos = models.CharField(max_length=128, blank=True)
    homedir = models.CharField(max_length=256)
    shell = models.CharField(max_length=64)


class Shadow(TimeStampedModel, models.Model):
    user = models.OneToOneField(User, primary_key=True)
    passwd = models.CharField(max_length=128)
    changedays = models.PositiveSmallIntegerField(blank=True, null=True)
    minage = models.PositiveSmallIntegerField(blank=True, null=True)
    maxage = models.PositiveSmallIntegerField(blank=True, null=True)
    gracedays = models.PositiveSmallIntegerField(blank=True, null=True)
    inactdays = models.PositiveSmallIntegerField(blank=True, null=True)
    expiredays = models.PositiveSmallIntegerField(blank=True, null=True,
                                                  default=None)


class AdditionalGroup(TimeStampedModel, models.Model):
    user = models.ForeignKey(User)
    group = models.ForeignKey(Group)

    class Meta:
        unique_together = ('user', 'group')

    def clean(self):
        if self.user.group == self.group:
            raise ValidationError(_(
                "You can not use a user's primary group."))