106 lines
3.2 KiB
Python
106 lines
3.2 KiB
Python
import itertools
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from collections import namedtuple
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from django.db.models import Q
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from registrasion import models as rego
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from conditions import ConditionController
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DiscountEnabler = namedtuple(
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"DiscountEnabler", (
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"discount",
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"condition",
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"value"))
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class ProductController(object):
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def __init__(self, product):
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self.product = product
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def user_can_add_within_limit(self, user, quantity):
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''' Return true if the user is able to add _quantity_ to their count of
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this Product without exceeding _limit_per_user_.'''
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carts = rego.Cart.objects.filter(user=user)
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items = rego.ProductItem.objects.filter(
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product=self.product,
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cart=carts)
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count = 0
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for item in items:
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count += item.quantity
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if quantity + count > self.product.limit_per_user:
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return False
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else:
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return True
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def can_add_with_enabling_conditions(self, user, quantity):
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''' Returns true if the user is able to add _quantity_ to their count
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of this Product without exceeding the ceilings the product is attached
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to. '''
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conditions = rego.EnablingConditionBase.objects.filter(
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Q(products=self.product) | Q(categories=self.product.category)
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).select_subclasses()
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mandatory_violated = False
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non_mandatory_met = False
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for condition in conditions:
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cond = ConditionController.for_condition(condition)
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met = cond.is_met(user, quantity)
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if condition.mandatory and not met:
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mandatory_violated = True
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break
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if met:
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non_mandatory_met = True
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if mandatory_violated:
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# All mandatory conditions must be met
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return False
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if len(conditions) > 0 and not non_mandatory_met:
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# If there's any non-mandatory conditions, one must be met
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return False
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return True
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def get_enabler(self, condition):
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if condition.percentage is not None:
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value = condition.percentage * self.product.price
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else:
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value = condition.price
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return DiscountEnabler(
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discount=condition.discount,
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condition=condition,
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value=value
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)
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def available_discounts(self, user):
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''' Returns the set of available discounts for this user, for this
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product. '''
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product_discounts = rego.DiscountForProduct.objects.filter(
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product=self.product)
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category_discounts = rego.DiscountForCategory.objects.filter(
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category=self.product.category
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)
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potential_discounts = set(itertools.chain(
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(self.get_enabler(i) for i in product_discounts),
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(self.get_enabler(i) for i in category_discounts),
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))
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discounts = []
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for discount in potential_discounts:
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real_discount = rego.DiscountBase.objects.get_subclass(
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pk=discount.discount.pk)
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cond = ConditionController.for_condition(real_discount)
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if cond.is_met(user, 0):
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discounts.append(discount)
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return discounts
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