Split bills between orders of the same billing address

uncloud_django_based/uncloud/uncloud_pay/models.py

@@ -9,10 +9,10 @@ from django.core.exceptions import ObjectDoesNotExist
 import uuid
 import logging
 from functools import reduce
+import itertools
 from math import ceil
 from datetime import timedelta
 from calendar import monthrange
-
 from decimal import Decimal
 
 import uncloud_pay.stripe
@@ -525,10 +525,12 @@ class Bill(models.Model):
 
     @property
     def billing_address(self):
-        # FIXME: make sure all the orders of a bill match the same billing address.
         orders = Order.objects.filter(bill=self)
+        # The genrate_for method makes sure all the orders of a bill share the
+        # same billing address. TODO: It would be nice to enforce that somehow...
         return orders[0].billing_address
 
+    # TODO: split this huuuge method!
     @staticmethod
     def generate_for(year, month, user):
         # /!\ We exclusively work on the specified year and month.
@@ -587,6 +589,13 @@ class Bill(models.Model):
             prepaid_due_date = min(creation_date, starting_date) + BILL_PAYMENT_DELAY
             postpaid_due_date = max(creation_date, ending_date) + BILL_PAYMENT_DELAY
 
+            # There should not be any bill linked to orders with different
+            # billing addresses.
+            per_address_orders = itertools.groupby(
+                    unpaid_orders['monthly_or_less'],
+                    lambda o: o.billing_address)
+
+            for addr, bill_orders in per_address_orders:
                 next_monthly_bill = Bill.objects.create(owner=user,
                     creation_date=creation_date,
                     starting_date=starting_date, # FIXME: this is a hack!
@@ -595,7 +604,7 @@ class Bill(models.Model):
 
                 # It is not possible to register many-to-many relationship before
                 # the two end-objects are saved in database.
-            for order in unpaid_orders['monthly_or_less']:
+                for order in bill_orders:
                     order.bill.add(next_monthly_bill)
 
                 logger.info("Generated monthly bill {} (amount: {}) for user {}."
@@ -614,6 +623,13 @@ class Bill(models.Model):
                 ending_date = next_yearly_bill_start_on.replace(
                         year=next_yearly_bill_start_on.year+1) - timedelta(days=1)
 
+                # There should not be any bill linked to orders with different
+                # billing addresses.
+                per_address_orders = itertools.groupby(
+                        unpaid_orders['yearly'][next_yearly_bill_start_on],
+                        lambda o: o.billing_address)
+
+                for addr, bill_orders in per_address_orders:
                     next_yearly_bill = Bill.objects.create(owner=user,
                             creation_date=creation_date,
                             starting_date=next_yearly_bill_start_on,
@@ -622,7 +638,7 @@ class Bill(models.Model):
 
                     # It is not possible to register many-to-many relationship before
                     # the two end-objects are saved in database.
-                for order in unpaid_orders['yearly'][next_yearly_bill_start_on]:
+                    for order in bill_orders:
                         order.bill.add(next_yearly_bill)
 
                     logger.info("Generated yearly bill {} (amount: {}) for user {}."

uncloud_django_based/uncloud/uncloud_pay/tests.py

@@ -143,7 +143,6 @@ class ProductActivationTestCase(TestCase):
                 starting_date=starting_date,
                 recurring_period=RecurringPeriod.PER_MONTH,
                 billing_address=self.billing_address)
-        order.save()
 
         product = GenericServiceProduct(
                 custom_description="Test product",
@@ -154,7 +153,7 @@ class ProductActivationTestCase(TestCase):
         product.save()
 
         # XXX: to be automated.
-        order.add_record(product.one_time_price, product.recurring_price(), product.description)
+        order.add_record(product.one_time_price, product.recurring_price, product.description)
 
         # Validate initial state: must be awaiting payment.
         self.assertEqual(product.status, UncloudStatus.AWAITING_PAYMENT)
@@ -167,3 +166,63 @@ class ProductActivationTestCase(TestCase):
                 GenericServiceProduct.objects.get(uuid=product.uuid).status,
                 UncloudStatus.PENDING
                 )
+
+class BillingAddressTestCase(TestCase):
+    def setUp(self):
+        self.user = get_user_model().objects.create(
+                username='jdoe',
+                email='john.doe@domain.tld')
+
+        self.billing_address_01 = BillingAddress.objects.create(
+                owner=self.user,
+                street="unknown1",
+                city="unknown1",
+                postal_code="unknown1",
+                country="CH")
+
+        self.billing_address_02 = BillingAddress.objects.create(
+                owner=self.user,
+                street="unknown2",
+                city="unknown2",
+                postal_code="unknown2",
+                country="CH")
+
+    def test_billing_with_single_address(self):
+        # Create new orders somewhere in the past so that we do not encounter
+        # auto-created initial bills.
+        starting_date = datetime.fromisoformat('2020-03-01')
+
+        order_01 = Order.objects.create(
+                owner=self.user,
+                starting_date=starting_date,
+                recurring_period=RecurringPeriod.PER_MONTH,
+                billing_address=self.billing_address_01)
+        order_02 = Order.objects.create(
+                owner=self.user,
+                starting_date=starting_date,
+                recurring_period=RecurringPeriod.PER_MONTH,
+                billing_address=self.billing_address_01)
+
+        # We need a single bill since we work with a single address.
+        bills = Bill.generate_for(2020, 4, self.user)
+        self.assertEqual(len(bills), 1)
+
+    def test_billing_with_multiple_addresses(self):
+        # Create new orders somewhere in the past so that we do not encounter
+        # auto-created initial bills.
+        starting_date = datetime.fromisoformat('2020-03-01')
+
+        order_01 = Order.objects.create(
+                owner=self.user,
+                starting_date=starting_date,
+                recurring_period=RecurringPeriod.PER_MONTH,
+                billing_address=self.billing_address_01)
+        order_02 = Order.objects.create(
+                owner=self.user,
+                starting_date=starting_date,
+                recurring_period=RecurringPeriod.PER_MONTH,
+                billing_address=self.billing_address_02)
+
+        # We need different bills since we work with different addresses.
+        bills = Bill.generate_for(2020, 4, self.user)
+        self.assertEqual(len(bills), 2)