remove big mistake: orders from product

Signed-off-by: Nico Schottelius <nico@nico-notebook.schottelius.org>

doc/uncloud-manual-2020-08-01.org

@@ -84,6 +84,14 @@ python manage.py migrate
 * URLs
   - api/ - the rest API
 * uncloud Products
+** Product features
+   - Dependencies on other products
+   - Minimum parameters (min cpu, min ram, etc).
+   - Can also realise the dcl vm
+     - dualstack vm = VM + IPv4 + SSD
+   - Need to have a non-misguiding name for the "bare VM"
+   - Should support network boot (?)
+
 ** VPN
 *** How to add a new VPN Host
 **** Install wireguard to the host
@@ -219,7 +227,85 @@ VPNNetworks can be managed by all authenticated users.
      - Product
 ***** TODO Recurring product support
 ****** TODO Support replacing orders for updates
-****** TODO [#A] Finish split of bill creation
-****** TODO [#A] Test the new functions in the Order class
+****** DONE [#A] Finish split of bill creation
+       CLOSED: [2020-09-11 Fri 23:19]
+****** TODO Test the new functions in the Order class
+****** Define the correct order replacement logic
+       Assumption:
+       - recurringperiods are 30days
+******* Case 1: downgrading
+        - User commits to 10 CHF for 30 days
+        - Wants to downgrade after 15 days to 5 CHF product
+        - Expected result:
+          - order 1: 10 CHF until +30days
+          - order 2: 5 CHF starting 30days + 1s
+          - Sum of the two orders is 15 CHF
+        - Question is
+          - when is the VM shutdown?
+            - a) instantly
+            - b) at the end of the cycle
+          - best solution
+            - user can choose between a ... b any time
+******* Duration
+        - You cannot cancel the duration
+        - You can upgrade and with that cancel the duration
+        - The idea of a duration is that you commit for it
+        - If you want to commit lower (daily basis for instance) you
+          have higher per period prices
+******* Case X
+        - User has VM with 2 Core / 2 GB RAM
+        - User modifies with to 1 core / 3 GB RAM
+        - We treat it as down/upgrade independent of the modifications
+
+******* Case 2: upgrading after 1 day
+        - committed for 30 days
+        - upgrade after 1 day
+        - so first order will be charged for 1/30ths
+
+******* Case 2: upgrading
+        - User commits to 10 CHF for 30 days
+        - Wants to upgrade after 15 days to 20 CHF product
+        - Order 1 : 1 VM with 2 Core / 2 GB / 10 SSD -- 10 CHF
+          - 30days period, stopped after 15, so quantity is 0.5 = 5 CHF
+        - Order 2 : 1 VM with 2 Core / 6 GB / 10 SSD -- 20 CHF
+          - after 15 days
+          - VM is upgraded instantly
+          - Expected result:
+            - order 1: 10 CHF until +15days = 0.5 units = 5 CHF
+            - order 2: 20 CHF starting 15days + 1s ... +30 days after
+              the 15 days -> 45 days = 1 unit = 20 CHF
+            - Total on bill: 25 CHF
+
+******* Case 2: upgrading
+        - User commits to 10 CHF for 30 days
+        - Wants to upgrade after 15 days to 20 CHF product
+        - Expected result:
+          - order 1: 10 CHF until +30days = 1 units = 10 CHF
+
+          - order 2: 20 CHF starting 15days + 1s = 1 unit = 20 CHF
+          - Total on bill: 30 CHF
+
+
+****** TODO Note: ending date not set if replaced by default (implicit!)
+       - Should the new order modify the old order on save()?
+****** DONE Fix totally wrong bill dates in our test case
+       CLOSED: [2020-09-09 Wed 01:00]
+       - 2020 used instead of 2019
+       - Was due to existing test data ...
+***** TODO Bill logic is still wrong
+      - Bill starting_date is the date of the first order
+      - However first encountered order does not have to be the
+        earliest in the bill!
+      - Bills should not have a duration
+      - Bills should only have a (unique) issue date
+      - We charge based on bill_records
+        - Last time charged issue date of the bill OR earliest date
+          after that
+        - Every bill generation checks all (relevant) orders
+          - add a flag "not_for_billing" or "closed"
+          - query on that flag
+          - verify it every time
+
+
 ***** TODO Generating bill for admins/staff
       -

opennebula/migrations/0005_remove_vm_orders.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.1 on 2020-09-28 18:44
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('opennebula', '0004_auto_20200809_1237'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='vm',
+            name='orders',
+        ),
+    ]

uncloud_net/migrations/0005_remove_vpnnetwork_orders.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.1 on 2020-09-28 18:44
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('uncloud_net', '0004_auto_20200809_1237'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='vpnnetwork',
+            name='orders',
+        ),
+    ]

uncloud_pay/migrations/0015_auto_20200928_1844.py

@@ -0,0 +1,25 @@
+# Generated by Django 3.1 on 2020-09-28 18:44
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('uncloud_pay', '0014_auto_20200825_1915'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='sampleonetimeproduct',
+            name='orders',
+        ),
+        migrations.RemoveField(
+            model_name='samplerecurringproduct',
+            name='orders',
+        ),
+        migrations.RemoveField(
+            model_name='samplerecurringproductonetimefee',
+            name='orders',
+        ),
+    ]

uncloud_pay/models.py

@@ -354,17 +354,18 @@ class Order(models.Model):
         return self.starting_date + datetime.timedelta(seconds=self.recurring_period)
 
     @property
-    def next_ending_date(self):
+    def next_cancel_or_downgrade_date(self):
         """
         Return the next proper ending date after n times the
-        recurring_period, where n is an integer.
+        recurring_period, where n is an integer that applies for downgrading
+        or cancelling.
         """
 
         if self.recurring_period > 0:
             now = timezone.now()
             delta = now - self.starting_date
 
-            num_times = math.ceil(delta.total_seconds() / self.recurring_period)
+            num_times = ceil(delta.total_seconds() / self.recurring_period)
 
             next_date = self.starting_date + datetime.timedelta(seconds= num_times * self.recurring_period)
         else:
@@ -452,8 +453,9 @@ class Order(models.Model):
         if self.ending_date and self.ending_date < self.starting_date:
             raise ValidationError("End date cannot be before starting date")
 
-        if self.ending_date and self.ending_date < self.earliest_ending_date:
-            raise ValidationError("Ending date is before minimum duration (starting_date + recurring period)")
+        # do not check this if we upgrade
+        # if self.ending_date and self.ending_date < self.earliest_ending_date:
+        #     raise ValidationError("Ending date is before minimum duration (starting_date + recurring period)")
 
         super().save(*args, **kwargs)
 
@@ -853,11 +855,9 @@ class BillRecord(models.Model):
 
 class Product(UncloudModel):
     """
-    A product is something a user orders. To record the pricing, we
+    A product is something a user can order. To record the pricing, we
     create order that define a state in time.
 
-    A product can *depend* on other products.
-
     A product can have *one* one_time_order and/or *one*
     recurring_order.
 
@@ -872,12 +872,12 @@ class Product(UncloudModel):
 
     description = "Generic Product"
 
-    orders = models.ManyToManyField(Order)
-
     status = models.CharField(max_length=32,
             choices=UncloudStatus.choices,
             default=UncloudStatus.AWAITING_PAYMENT)
 
+#    config = models.JSONField()
+
     # Default period for all products
     default_recurring_period = RecurringPeriod.PER_30D
 
@@ -941,6 +941,7 @@ class Product(UncloudModel):
             self.orders.add(recurring_order)
 
 
+    # FIXME: this could/should be part of Order (?)
     def create_or_update_recurring_order(self, when_to_start=None, recurring_period=None):
         if not self.recurring_price:
             return
@@ -954,8 +955,8 @@ class Product(UncloudModel):
         if self.last_recurring_order:
             if self.recurring_price < self.last_recurring_order.price:
 
-                if when_to_start < self.last_recurring_order.next_ending_date:
-                    when_to_start = start_after(self.last_recurring_order.next_ending_date)
+                if when_to_start < self.last_recurring_order.next_cancel_or_downgrade_date:
+                    when_to_start = start_after(self.last_recurring_order.next_cancel_or_downgrade_date)
 
             when_to_end = end_before(when_to_start)
 
@@ -967,10 +968,9 @@ class Product(UncloudModel):
                                              description=str(self),
                                              replaces=self.last_recurring_order)
 
-            self.last_recurring_order.end_date = when_to_end
+            self.last_recurring_order.replace_with(new_order)
             self.orders.add(new_order)
         else:
-            # This might be a bug as it might (re-)create the one time order
             self.create_order(when_to_start, recurring_period)
 
     @property

uncloud_pay/tests.py

@@ -1,6 +1,7 @@
 from django.test import TestCase
 from django.contrib.auth import get_user_model
 from datetime import datetime, date, timedelta
+from django.utils import timezone
 
 from .models import *
 from uncloud_service.models import GenericServiceProduct
@@ -93,7 +94,9 @@ class ProductTestCase(TestCase):
         p = SampleRecurringProduct.objects.create(owner=self.user)
         p.create_order(timezone.make_aware(datetime.datetime(2020,3,3)))
 
-        p.create_or_update_recurring_order(timezone.make_aware(datetime.datetime(2020,3,3)))
+        p.create_or_update_recurring_order(timezone.make_aware(datetime.datetime(2020,3,4)))
+
+        # FIXME: where is the assert?
 
 
 class BillingAddressTestCase(TestCase):
@@ -413,38 +416,96 @@ class ModifyProductTestCase(TestCase):
         self.assertNotEqual(bills[0].sum, pro_rata_amount * price)
         self.assertEqual(bills[0].sum, price)
 
-    def test_bill_for_increasing_product_easy(self):
+
+    def test_downgrade_product(self):
         """
-        Modify product, check general logi
+        Test downgrading behaviour:
+
+        We create a recurring product (recurring time: 30 days) and downgrade after 15 days.
+
+        We create the bill right AFTER the end of the first order.
+
+        Expected result:
+
+        - First bill record for 30 days
+        - Second bill record starting after 30 days
+        - Bill contains two bill records
+
         """
 
-        # Create product
-        starting_date = timezone.make_aware(datetime.datetime(2019,3,3))
+        user = self.user
+
+
+
         starting_price = 10
-        product = SampleRecurringProduct.objects.create(owner=self.user,
-                                                        rc_price=starting_price)
+        downgrade_price = 5
+
+
+        starting_date = timezone.make_aware(datetime.datetime(2019,3,3))
+        first_order_should_end_at = starting_date + datetime.timedelta(days=30)
+        change1_date  = start_after(starting_date + datetime.timedelta(days=15))
+        bill_ending_date = change1_date + datetime.timedelta(days=1)
+
+
+        product = SampleRecurringProduct.objects.create(owner=user, rc_price=starting_price)
         product.create_order(starting_date)
 
-        change1_date  = timezone.make_aware(datetime.datetime(2019,4,17))
-        product.rc_price = 20
+        product.rc_price = downgrade_price
         product.save()
         product.create_or_update_recurring_order(when_to_start=change1_date)
 
-        bill_ending_date = timezone.make_aware(datetime.datetime(2019,6,30))
-        bills = Bill.create_next_bills_for_user(self.user,
-                                                ending_date=bill_ending_date)
+        bills = Bill.create_next_bills_for_user(user, ending_date=bill_ending_date)
 
         bill = bills[0]
         bill_records = BillRecord.objects.filter(bill=bill)
 
-        self.assertEqual(len(bill_records), 3)
-        self.assertEqual(int(bill.sum), 35)
+        self.assertEqual(len(bill_records), 2)
+
+        self.assertEqual(bill_records[0].starting_date, starting_date)
+
+        self.assertEqual(bill_records[0].order.ending_date, first_order_should_end_at)
+
+        # self.assertEqual(bill_records[0].ending_date, first_order_should_end_at)
+
+        # self.assertEqual(bill_records[0].quantity, 1)
+
+        # self.assertEqual(bill_records[1].quantity, 1)
+        # self.assertEqual(int(bill.sum), 15)
+
+    def test_upgrade_product(self):
+        """
+        Test upgrading behaviour
+        """
+
+        user = self.user
+
+        # Create product
+        starting_date = timezone.make_aware(datetime.datetime(2019,3,3))
+        starting_price = 10
+        product = SampleRecurringProduct.objects.create(owner=user, rc_price=starting_price)
+        product.create_order(starting_date)
+
+        change1_date  = start_after(starting_date + datetime.timedelta(days=15))
+        product.rc_price = 20
+        product.save()
+        product.create_or_update_recurring_order(when_to_start=change1_date)
+
+        bill_ending_date = change1_date + datetime.timedelta(days=1)
+        bills = Bill.create_next_bills_for_user(user, ending_date=bill_ending_date)
+
+        bill = bills[0]
+        bill_records = BillRecord.objects.filter(bill=bill)
+
+        self.assertEqual(len(bill_records), 2)
+        self.assertEqual(bill_records[0].quantity, .5)
+
+        self.assertEqual(bill_records[0].ending_date, end_before(change1_date))
+
+        self.assertEqual(bill_records[1].quantity, 1)
+        self.assertEqual(bill_records[1].starting_date, change1_date)
+
+        self.assertEqual(int(bill.sum), 25)
 
-        # Expected bill sum & records:
-        # 2019-03-03 - 2019-04-02  +30d: 10
-        # 2019-04-02 - 2019-04-17: +15d: 5
-        # 2019-04-17 - 2019-05-17: +30d: 20
-        # total: 35
 
 
     # def test_bill_for_increasing_product(self):

uncloud_service/migrations/0005_auto_20200928_1844.py

@@ -0,0 +1,21 @@
+# Generated by Django 3.1 on 2020-09-28 18:44
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('uncloud_service', '0004_auto_20200809_1237'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='genericserviceproduct',
+            name='orders',
+        ),
+        migrations.RemoveField(
+            model_name='matrixserviceproduct',
+            name='orders',
+        ),
+    ]

uncloud_vm/migrations/0005_auto_20200928_1844.py

@@ -0,0 +1,25 @@
+# Generated by Django 3.1 on 2020-09-28 18:44
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('uncloud_vm', '0004_auto_20200809_1237'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='vmdiskproduct',
+            name='orders',
+        ),
+        migrations.RemoveField(
+            model_name='vmproduct',
+            name='orders',
+        ),
+        migrations.RemoveField(
+            model_name='vmsnapshotproduct',
+            name='orders',
+        ),
+    ]