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

from django.core.exceptions import ObjectDoesNotExist
from django.core.exceptions import ValidationError


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)

    def next_cart(self):
        self.cart.active = False
        self.cart.save()


class TestingInvoiceController(InvoiceController):

    def pay(self, reference, amount):
        ''' Testing method for simulating an invoice paymenht by the given
        amount. '''

        self.validate_allowed_to_pay()

        ''' Adds a payment '''
        payment = rego.ManualPayment.objects.create(
            invoice=self.invoice,
            reference=reference,
            amount=amount,
        )

        self.update_status()