Replaces user_can_add_within_limit with user_quantity_remaining

registrasion/controllers/cart.py

@@ -70,6 +70,7 @@ class CartController(object):
         self.cart.revision += 1
         self.cart.save()
 
+
     @transaction.atomic
     def set_quantities(self, product_quantities):
 
@@ -104,6 +105,17 @@ class CartController(object):
                 )
 
         # Test each product limit here
+        for product, quantity in product_quantities:
+            prod = ProductController(product)
+            limit = prod.user_quantity_remaining(self.cart.user)
+
+            if quantity > limit:
+                # TODO: batch errors
+                raise ValidationError(
+                    "You may only have %d of product: %s" % (
+                        limit, cat.name,
+                    )
+                )
 
         # Test each enabling condition here
 
@@ -154,9 +166,6 @@ class CartController(object):
                 self.cart.user, adjustment):
             raise ValidationError("Not enough of that product left (ec)")
 
-        if not prod.user_can_add_within_limit(self.cart.user, adjustment):
-            raise ValidationError("Not enough of that product left (user)")
-
         product_item.quantity = quantity
         product_item.save()
 

registrasion/controllers/product.py

@@ -34,39 +34,36 @@ class ProductController(object):
             product
             for product in all_products
             if CategoryController(product.category).user_quantity_remaining(user) > 0
-            if cls(product).user_can_add_within_limit(user, 1, past_carts=True)
+            if cls(product).user_quantity_remaining(user) > 0
             if cls(product).can_add_with_enabling_conditions(user, 0)
         ]
         out.sort(key=lambda product: product.order)
         return out
 
-    def user_can_add_within_limit(self, user, quantity, past_carts=False):
+    def user_quantity_remaining(self, user):
-        ''' Return true if the user is able to add _quantity_ to their count of
+        ''' Returns the quantity of this product that the user add in the
-        this Product without exceeding _limit_per_user_.'''
+        current cart. '''
+
+        prod_limit = self.product.limit_per_user
+
+        if prod_limit is None:
+            # Don't need to run the remaining queries
+            return 999999  # We can do better
 
         carts = rego.Cart.objects.filter(
             user=user,
+            active=False,
             released=False,
         )
-        if past_carts:
-            carts = carts.filter(active=False)
 
         items = rego.ProductItem.objects.filter(
             cart__in=carts,
+            product=self.product,
         )
 
-        prod_items = items.filter(product=self.product)
+        prod_count = items.aggregate(Sum("quantity"))["quantity__sum"] or 0
 
-        prod_count = prod_items.aggregate(Sum("quantity"))["quantity__sum"]
+        return prod_limit - prod_count
-        prod_count = prod_count or 0
-
-        prod_limit = self.product.limit_per_user
-        prod_met = prod_limit is None or quantity + prod_count <= prod_limit
-
-        if prod_met:
-            return True
-        else:
-            return False
 
     def can_add_with_enabling_conditions(self, user, quantity):
         ''' Returns true if the user is able to add _quantity_ to their count