edan_f0/oscar/apps/shipping/repository.py

from decimal import Decimal as D

from django.core.exceptions import ImproperlyConfigured
from django.utils.translation import ugettext_lazy as _

from oscar.apps.shipping import methods


class Repository(object):
    """
    Repository class responsible for returning ShippingMethod
    objects for a given user, basket etc
    """
    methods = (methods.Free(),)

    def get_shipping_methods(self, user, basket, shipping_addr=None,
                             request=None, **kwargs):
        """
        Return a list of all applicable shipping method objects
        for a given basket, address etc.

        We default to returning the ``Method`` models that have been defined
        but this behaviour can easily be overridden by subclassing this class
        and overriding this method.
        """
        return self.prime_methods(basket, self.methods)

    def get_default_shipping_method(self, user, basket, shipping_addr=None,
                                    request=None, **kwargs):
        """
        Return a 'default' shipping method to show on the basket page to give
        the customer an indication of what their order will cost.
        """
        shipping_methods = self.get_shipping_methods(
            user, basket, shipping_addr, request, **kwargs)
        if len(shipping_methods) == 0:
            raise ImproperlyConfigured(
                _("You need to define some shipping methods"))

        # Choose the cheapest method by default
        return min(shipping_methods, key=lambda method: method.charge_excl_tax)

    def prime_methods(self, basket, methods):
        """
        Prime a list of shipping method instances

        This involves injecting the basket instance into each and adding any
        discount wrappers.
        """
        return [self.prime_method(basket, method) for
                method in methods]

    def prime_method(self, basket, method):
        """
        Prime an individual method instance
        """
        method.set_basket(basket)
        # If the basket has a shipping offer, wrap the shipping method with a
        # decorating class that applies the offer discount to the shipping
        # charge.
        if basket.offer_applications.shipping_discounts:
            # We assume there is only one shipping discount available
            discount = basket.offer_applications.shipping_discounts[0]
            if method.charge_incl_tax > D('0.00'):
                return methods.OfferDiscount(method, discount['offer'])
        return method

    def find_by_code(self, code, basket):
        """
        Return the appropriate Method object for the given code
        """
        for method in self.methods:
            if method.code == code:
                return self.prime_method(basket, method)

        # Check for NoShippingRequired as that is a special case
        if code == methods.NoShippingRequired.code:
            return self.prime_method(basket, methods.NoShippingRequired())