from registrasion.controllers.cart import CartController
from registrasion import models as rego

from django.core.exceptions import ObjectDoesNotExist


class TestingCartController(CartController):

    def set_quantity(self, product, quantity, batched=False):
        ''' Sets the _quantity_ of the given _product_ in the cart to the given
        _quantity_. '''

        self.set_quantities(((product, quantity),))

    def add_to_cart(self, product, quantity):
        ''' Adds _quantity_ of the given _product_ to the cart. Raises
        ValidationError if constraints are violated.'''

        try:
            product_item = rego.ProductItem.objects.get(
                cart=self.cart,
                product=product)
            old_quantity = product_item.quantity
        except ObjectDoesNotExist:
            old_quantity = 0
        self.set_quantity(product, old_quantity + quantity)