One step furter to allow saving of orders w/o explicit recurringperiod

uncloud_pay/migrations/0031_auto_20201006_1655.py

@@ -0,0 +1,17 @@
+# Generated by Django 3.1 on 2020-10-06 16:55
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('uncloud_pay', '0030_auto_20201006_1640'),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name='producttorecurringperiod',
+            constraint=models.UniqueConstraint(fields=('product', 'recurring_period'), name='recurring_period_once_per_product'),
+        ),
+    ]

uncloud_pay/models.py

@@ -252,7 +252,6 @@ class RecurringPeriod(models.Model):
                                                      defaults={ 'duration_seconds': seconds })
 
 
-
     @staticmethod
     def secs_to_name(secs):
         name = ""
@@ -358,8 +357,10 @@ class Product(UncloudModel):
 
     @property
     def default_recurring_period(self):
-        return RecurringPeriod.objects.get(product=self,
-                                           is_default=True)
+        """
+        Return the default recurring Period
+        """
+        return self.recurring_periods.get(producttorecurringperiod__is_default=True)
 
     @classmethod
     def populate_db_defaults(cls):
@@ -907,7 +908,7 @@ class Order(models.Model):
         if self._state.adding:
             (self.one_time_price, self.recurring_price) = self.prices
 
-            if not self.recurring_period:
+            if self.recurring_period_id is None:
                 self.recurring_period = self.product.default_recurring_period
 
         # FIXME: ensure the recurring period is defined in the product
@@ -916,7 +917,7 @@ class Order(models.Model):
 
 
     def __str__(self):
-        return f"{self.description} (order={self.id})"
+        return f"Order {self.id} from {self.owner}: {self.product}"
 
 class Bill(models.Model):
     """
@@ -1263,7 +1264,9 @@ class ProductToRecurringPeriod(models.Model):
         constraints = [
             models.UniqueConstraint(fields=['product'],
                                     condition=Q(is_default=True),
-                                    name='one_default_recurring_period_per_product')
+                                    name='one_default_recurring_period_per_product'),
+            models.UniqueConstraint(fields=['product', 'recurring_period'],
+                                    name='recurring_period_once_per_product')
         ]
 
     def __str__(self):