import datetime
import pytz

from decimal import Decimal
from django.contrib.auth.models import User
from django.core.exceptions import ObjectDoesNotExist
from django.core.exceptions import ValidationError
from django.core.management import call_command
from django.test import TestCase

from registrasion.models import commerce
from registrasion.models import conditions
from registrasion.models import inventory
from registrasion.models import people
from registrasion.controllers.product import ProductController

from controller_helpers import TestingCartController
from patch_datetime import SetTimeMixin

UTC = pytz.timezone('UTC')


class RegistrationCartTestCase(SetTimeMixin, TestCase):

    def setUp(self):
        super(RegistrationCartTestCase, self).setUp()

    def tearDown(self):
        if True:
            # If you're seeing segfaults in tests, enable this.
            call_command(
                'flush',
                verbosity=0,
                interactive=False,
                reset_sequences=False,
                allow_cascade=False,
                inhibit_post_migrate=False
            )

        super(RegistrationCartTestCase, self).tearDown()

    @classmethod
    def setUpTestData(cls):

        super(RegistrationCartTestCase, cls).setUpTestData()

        cls.USER_1 = User.objects.create_user(
            username='testuser',
            email='test@example.com',
            password='top_secret')

        cls.USER_2 = User.objects.create_user(
            username='testuser2',
            email='test2@example.com',
            password='top_secret')

        attendee1 = people.Attendee.get_instance(cls.USER_1)
        people.AttendeeProfileBase.objects.create(
            attendee=attendee1,
        )
        attendee2 = people.Attendee.get_instance(cls.USER_2)
        people.AttendeeProfileBase.objects.create(
            attendee=attendee2,
        )

        cls.RESERVATION = datetime.timedelta(hours=1)

        cls.categories = []
        for i in xrange(2):
            cat = inventory.Category.objects.create(
                name="Category " + str(i + 1),
                description="This is a test category",
                order=i,
                render_type=inventory.Category.RENDER_TYPE_RADIO,
                required=False,
            )
            cls.categories.append(cat)

        cls.CAT_1 = cls.categories[0]
        cls.CAT_2 = cls.categories[1]

        cls.products = []
        for i in xrange(4):
            prod = inventory.Product.objects.create(
                name="Product " + str(i + 1),
                description="This is a test product.",
                category=cls.categories[i / 2],  # 2 products per category
                price=Decimal("10.00"),
                reservation_duration=cls.RESERVATION,
                limit_per_user=10,
                order=1,
            )
            cls.products.append(prod)

        cls.PROD_1 = cls.products[0]
        cls.PROD_2 = cls.products[1]
        cls.PROD_3 = cls.products[2]
        cls.PROD_4 = cls.products[3]

        cls.PROD_4.price = Decimal("5.00")
        cls.PROD_4.save()

        # Burn through some carts -- this made some past flag tests fail
        current_cart = TestingCartController.for_user(cls.USER_1)

        current_cart.next_cart()

        current_cart = TestingCartController.for_user(cls.USER_2)

        current_cart.next_cart()

    @classmethod
    def make_ceiling(cls, name, limit=None, start_time=None, end_time=None):
        limit_ceiling = conditions.TimeOrStockLimitFlag.objects.create(
            description=name,
            condition=conditions.FlagBase.DISABLE_IF_FALSE,
            limit=limit,
            start_time=start_time,
            end_time=end_time
        )
        limit_ceiling.products.add(cls.PROD_1, cls.PROD_2)

    @classmethod
    def make_category_ceiling(
            cls, name, limit=None, start_time=None, end_time=None):
        limit_ceiling = conditions.TimeOrStockLimitFlag.objects.create(
            description=name,
            condition=conditions.FlagBase.DISABLE_IF_FALSE,
            limit=limit,
            start_time=start_time,
            end_time=end_time
        )
        limit_ceiling.categories.add(cls.CAT_1)

    @classmethod
    def make_discount_ceiling(
            cls, name, limit=None, start_time=None, end_time=None,
            percentage=100):
        limit_ceiling = conditions.TimeOrStockLimitDiscount.objects.create(
            description=name,
            start_time=start_time,
            end_time=end_time,
            limit=limit,
        )
        conditions.DiscountForProduct.objects.create(
            discount=limit_ceiling,
            product=cls.PROD_1,
            percentage=percentage,
            quantity=10,
        )

    @classmethod
    def new_voucher(self, code="VOUCHER", limit=1):
        voucher = inventory.Voucher.objects.create(
            recipient="Voucher recipient",
            code=code,
            limit=limit,
        )
        return voucher

    @classmethod
    def reget(cls, object):
        return type(object).objects.get(id=object.id)


class BasicCartTests(RegistrationCartTestCase):

    def test_get_cart(self):
        current_cart = TestingCartController.for_user(self.USER_1)

        current_cart.next_cart()

        old_cart = current_cart

        current_cart = TestingCartController.for_user(self.USER_1)
        self.assertNotEqual(old_cart.cart, current_cart.cart)

        current_cart2 = TestingCartController.for_user(self.USER_1)
        self.assertEqual(current_cart.cart, current_cart2.cart)

    def test_add_to_cart_collapses_product_items(self):
        current_cart = TestingCartController.for_user(self.USER_1)

        # Add a product twice
        current_cart.add_to_cart(self.PROD_1, 1)
        current_cart.add_to_cart(self.PROD_1, 1)

        # Count of products for a given user should be collapsed.
        items = commerce.ProductItem.objects.filter(
            cart=current_cart.cart,
            product=self.PROD_1)
        self.assertEqual(1, len(items))
        item = items[0]
        self.assertEquals(2, item.quantity)

    def test_set_quantity(self):
        current_cart = TestingCartController.for_user(self.USER_1)

        def get_item():
            return commerce.ProductItem.objects.get(
                cart=current_cart.cart,
                product=self.PROD_1)

        current_cart.set_quantity(self.PROD_1, 1)
        self.assertEqual(1, get_item().quantity)

        # Setting the quantity to zero should remove the entry from the cart.
        current_cart.set_quantity(self.PROD_1, 0)
        with self.assertRaises(ObjectDoesNotExist):
            get_item()

        current_cart.set_quantity(self.PROD_1, 9)
        self.assertEqual(9, get_item().quantity)

        with self.assertRaises(ValidationError):
            current_cart.set_quantity(self.PROD_1, 11)

        self.assertEqual(9, get_item().quantity)

        with self.assertRaises(ValidationError):
            current_cart.set_quantity(self.PROD_1, -1)

        self.assertEqual(9, get_item().quantity)

        current_cart.set_quantity(self.PROD_1, 2)
        self.assertEqual(2, get_item().quantity)

    def test_add_to_cart_product_per_user_limit(self):
        current_cart = TestingCartController.for_user(self.USER_1)

        # User should be able to add 1 of PROD_1 to the current cart.
        current_cart.add_to_cart(self.PROD_1, 1)

        # User should be able to add 1 of PROD_1 to the current cart.
        current_cart.add_to_cart(self.PROD_1, 1)

        # User should not be able to add 10 of PROD_1 to the current cart now,
        # because they have a limit of 10.
        with self.assertRaises(ValidationError):
            current_cart.add_to_cart(self.PROD_1, 10)

        current_cart.next_cart()

        current_cart = TestingCartController.for_user(self.USER_1)
        # User should not be able to add 10 of PROD_1 to the current cart now,
        # even though it's a new cart.
        with self.assertRaises(ValidationError):
            current_cart.add_to_cart(self.PROD_1, 10)

        # Second user should not be affected by first user's limits
        second_user_cart = TestingCartController.for_user(self.USER_2)
        second_user_cart.add_to_cart(self.PROD_1, 10)

    def set_limits(self):
        self.CAT_2.limit_per_user = 10
        self.PROD_2.limit_per_user = None
        self.PROD_3.limit_per_user = None
        self.PROD_4.limit_per_user = 6

        self.CAT_2.save()
        self.PROD_2.save()
        self.PROD_3.save()
        self.PROD_4.save()

    def test_per_user_product_limit_ignored_if_blank(self):
        self.set_limits()

        current_cart = TestingCartController.for_user(self.USER_1)
        # There is no product limit on PROD_2, and there is no cat limit
        current_cart.add_to_cart(self.PROD_2, 1)
        # There is no product limit on PROD_3, but there is a cat limit
        current_cart.add_to_cart(self.PROD_3, 1)

    def test_per_user_category_limit_ignored_if_blank(self):
        self.set_limits()
        current_cart = TestingCartController.for_user(self.USER_1)
        # There is no product limit on PROD_2, and there is no cat limit
        current_cart.add_to_cart(self.PROD_2, 1)
        # There is no cat limit on PROD_1, but there is a prod limit
        current_cart.add_to_cart(self.PROD_1, 1)

    def test_per_user_category_limit_only(self):
        self.set_limits()

        current_cart = TestingCartController.for_user(self.USER_1)

        # Cannot add to cart if category limit is filled by one product.
        current_cart.set_quantity(self.PROD_3, 10)
        with self.assertRaises(ValidationError):
            current_cart.set_quantity(self.PROD_4, 1)

        # Can add to cart if category limit is not filled by one product
        current_cart.set_quantity(self.PROD_3, 5)
        current_cart.set_quantity(self.PROD_4, 5)
        # Cannot add to cart if category limit is filled by two products
        with self.assertRaises(ValidationError):
            current_cart.add_to_cart(self.PROD_3, 1)

        current_cart.next_cart()

        current_cart = TestingCartController.for_user(self.USER_1)
        # The category limit should extend across carts
        with self.assertRaises(ValidationError):
            current_cart.add_to_cart(self.PROD_3, 10)

    def test_per_user_category_and_product_limits(self):
        self.set_limits()

        current_cart = TestingCartController.for_user(self.USER_1)

        # Hit both the product and category edges:
        current_cart.set_quantity(self.PROD_3, 4)
        current_cart.set_quantity(self.PROD_4, 6)
        with self.assertRaises(ValidationError):
            # There's unlimited PROD_3, but limited in the category
            current_cart.add_to_cart(self.PROD_3, 1)

        current_cart.set_quantity(self.PROD_3, 0)
        with self.assertRaises(ValidationError):
            # There's only 6 allowed of PROD_4
            current_cart.add_to_cart(self.PROD_4, 1)

        # The limits should extend across carts...

        current_cart.next_cart()

        current_cart = TestingCartController.for_user(self.USER_1)
        current_cart.set_quantity(self.PROD_3, 4)

        with self.assertRaises(ValidationError):
            current_cart.set_quantity(self.PROD_3, 5)

        with self.assertRaises(ValidationError):
            current_cart.set_quantity(self.PROD_4, 1)

    def __available_products_test(self, item, quantity):
        self.set_limits()

        def get_prods():
            return ProductController.available_products(
                self.USER_1,
                products=[self.PROD_2, self.PROD_3, self.PROD_4],
            )

        current_cart = TestingCartController.for_user(self.USER_1)
        prods = get_prods()
        self.assertTrue(item in prods)
        current_cart.add_to_cart(item, quantity)
        self.assertTrue(item in prods)

        current_cart.next_cart()

        current_cart = TestingCartController.for_user(self.USER_1)

        prods = get_prods()
        self.assertTrue(item not in prods)

    def test_available_products_respects_category_limits(self):
        self.__available_products_test(self.PROD_3, 10)

    def test_available_products_respects_product_limits(self):
        self.__available_products_test(self.PROD_4, 6)