98 lines
3.1 KiB
Python
98 lines
3.1 KiB
Python
import itertools
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from django.db.models import Q
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from django.db.models import Sum
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from registrasion import models as rego
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from category import CategoryController
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from conditions import ConditionController
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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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@classmethod
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def available_products(cls, user, category=None, products=None):
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''' Returns a list of all of the products that are available per
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enabling conditions from the given categories.
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TODO: refactor so that all conditions are tested here and
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can_add_with_enabling_conditions calls this method. '''
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if category is None and products is None:
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raise ValueError("You must provide products or a category")
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if category is not None:
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all_products = rego.Product.objects.filter(category=category)
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else:
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all_products = []
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if products is not None:
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all_products = itertools.chain(all_products, products)
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out = [
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product
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for product in all_products
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if CategoryController(product.category).user_quantity_remaining(user) > 0
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if cls(product).user_quantity_remaining(user) > 0
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if cls(product).can_add_with_enabling_conditions(user, 0)
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]
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out.sort(key=lambda product: product.order)
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return out
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def user_quantity_remaining(self, user):
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''' Returns the quantity of this product that the user add in the
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current cart. '''
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prod_limit = self.product.limit_per_user
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if prod_limit is None:
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# Don't need to run the remaining queries
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return 999999 # We can do better
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carts = rego.Cart.objects.filter(
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user=user,
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active=False,
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released=False,
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)
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items = rego.ProductItem.objects.filter(
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cart__in=carts,
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product=self.product,
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)
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prod_count = items.aggregate(Sum("quantity"))["quantity__sum"] or 0
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return prod_limit - prod_count
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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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