from django.core.exceptions import ValidationError
from django.db import models
from django.test import TestCase

from .models import GenericIPAddress


class GenericIPAddressFieldTests(TestCase):

    def test_genericipaddressfield_formfield_protocol(self):
        """
        GenericIPAddressField with a specified protocol does not generate a
        formfield without a protocol.
        """
        model_field = models.GenericIPAddressField(protocol='IPv4')
        form_field = model_field.formfield()
        with self.assertRaises(ValidationError):
            form_field.clean('::1')
        model_field = models.GenericIPAddressField(protocol='IPv6')
        form_field = model_field.formfield()
        with self.assertRaises(ValidationError):
            form_field.clean('127.0.0.1')

    def test_null_value(self):
        """
        Null values should be resolved to None.
        """
        GenericIPAddress.objects.create()
        o = GenericIPAddress.objects.get()
        self.assertIsNone(o.ip)

    def test_blank_string_saved_as_null(self):
        o = GenericIPAddress.objects.create(ip='')
        o.refresh_from_db()
        self.assertIsNone(o.ip)
        GenericIPAddress.objects.update(ip='')
        o.refresh_from_db()
        self.assertIsNone(o.ip)

    def test_save_load(self):
        instance = GenericIPAddress.objects.create(ip='::1')
        loaded = GenericIPAddress.objects.get()
        self.assertEqual(loaded.ip, instance.ip)