from django.contrib.admin.sites import AdminSite
from django.db import IntegrityError
from django.test import TestCase

from .admin import BoxAdmin, BoxTypeAdmin
from .models import Box, BoxType


class BoxTypeModelTests(TestCase):
    """Tests for the BoxType model."""

    def setUp(self):
        """Set up test fixtures."""
        self.box_type = BoxType.objects.create(
            name='Small Box',
            width=100,
            height=50,
            length=150
        )

    def test_box_type_str_returns_name(self):
        """BoxType __str__ should return the name."""
        self.assertEqual(str(self.box_type), 'Small Box')

    def test_box_type_creation(self):
        """BoxType should be created with correct attributes."""
        self.assertEqual(self.box_type.name, 'Small Box')
        self.assertEqual(self.box_type.width, 100)
        self.assertEqual(self.box_type.height, 50)
        self.assertEqual(self.box_type.length, 150)

    def test_box_type_ordering(self):
        """BoxTypes should be ordered by name."""
        BoxType.objects.create(name='Alpha Box', width=10, height=10, length=10)
        BoxType.objects.create(name='Zeta Box', width=20, height=20, length=20)
        box_types = list(BoxType.objects.values_list('name', flat=True))
        self.assertEqual(box_types, ['Alpha Box', 'Small Box', 'Zeta Box'])


class BoxModelTests(TestCase):
    """Tests for the Box model."""

    def setUp(self):
        """Set up test fixtures."""
        self.box_type = BoxType.objects.create(
            name='Standard Box',
            width=200,
            height=100,
            length=300
        )
        self.box = Box.objects.create(
            id='BOX001',
            box_type=self.box_type
        )

    def test_box_str_returns_id(self):
        """Box __str__ should return the box ID."""
        self.assertEqual(str(self.box), 'BOX001')

    def test_box_creation(self):
        """Box should be created with correct attributes."""
        self.assertEqual(self.box.id, 'BOX001')
        self.assertEqual(self.box.box_type, self.box_type)

    def test_box_type_relationship(self):
        """Box should be accessible from BoxType via related_name."""
        self.assertIn(self.box, self.box_type.boxes.all())

    def test_box_id_max_length(self):
        """Box ID should accept up to 10 characters."""
        box = Box.objects.create(id='ABCD123456', box_type=self.box_type)
        self.assertEqual(len(box.id), 10)

    def test_box_type_protect_on_delete(self):
        """Deleting a BoxType with boxes should raise IntegrityError."""
        with self.assertRaises(IntegrityError):
            self.box_type.delete()

    def test_box_type_delete_when_no_boxes(self):
        """Deleting a BoxType without boxes should succeed."""
        empty_type = BoxType.objects.create(
            name='Empty Type',
            width=10,
            height=10,
            length=10
        )
        empty_type_id = empty_type.id
        empty_type.delete()
        self.assertFalse(BoxType.objects.filter(id=empty_type_id).exists())


class BoxTypeAdminTests(TestCase):
    """Tests for the BoxType admin configuration."""

    def setUp(self):
        """Set up test fixtures."""
        self.site = AdminSite()
        self.admin = BoxTypeAdmin(BoxType, self.site)

    def test_list_display(self):
        """BoxTypeAdmin should display correct fields."""
        self.assertEqual(
            self.admin.list_display,
            ('name', 'width', 'height', 'length')
        )

    def test_search_fields(self):
        """BoxTypeAdmin should search by name."""
        self.assertEqual(self.admin.search_fields, ('name',))


class BoxAdminTests(TestCase):
    """Tests for the Box admin configuration."""

    def setUp(self):
        """Set up test fixtures."""
        self.site = AdminSite()
        self.admin = BoxAdmin(Box, self.site)

    def test_list_display(self):
        """BoxAdmin should display correct fields."""
        self.assertEqual(self.admin.list_display, ('id', 'box_type'))

    def test_list_filter(self):
        """BoxAdmin should filter by box_type."""
        self.assertEqual(self.admin.list_filter, ('box_type',))

    def test_search_fields(self):
        """BoxAdmin should search by id."""
        self.assertEqual(self.admin.search_fields, ('id',))