LIL-271. Fix balance calc & add balance to user serializer

api/v1/serializers/user.py

@@ -35,6 +35,7 @@ class UserSerializer(serializers.ModelSerializer):
             'fb_data',
             'is_email_proved',
             'photo',
+            'balance',
         )
 
         read_only_fields = (
@@ -44,6 +45,7 @@ class UserSerializer(serializers.ModelSerializer):
             'is_staff',
             'fb_id',
             'fb_data',
+            'balance',
         )
 
 

apps/payment/models.py

@@ -2,6 +2,7 @@ from django.db import models
 from django.contrib.auth import get_user_model
 from django.contrib.postgres.fields import ArrayField, JSONField
 
+from constance import config
 from paymentwall import Pingback
 from polymorphic.models import PolymorphicModel
 
@@ -21,7 +22,8 @@ class AuthorBalance(models.Model):
         (1, 'Accepted'),
         (2, 'Declined'),
     )
-    author = models.ForeignKey(User, on_delete=models.CASCADE, verbose_name='Автор', null=True, blank=True, related_name='balances')
+    author = models.ForeignKey(User, on_delete=models.CASCADE, verbose_name='Автор',
+                               null=True, blank=True, related_name='balances')
     type = models.PositiveSmallIntegerField('Тип', choices=TYPE_CHOICES, default=0)
     amount = models.DecimalField('Итого', max_digits=8, decimal_places=2, default=0)
     commission = models.DecimalField('Комиссия', max_digits=8, decimal_places=2, default=0)
@@ -55,6 +57,9 @@ class Payment(PolymorphicModel):
         verbose_name = 'Платеж'
         verbose_name_plural = 'Платежи'
 
+    def calc_commission(self):
+        return self.amount * config.SERVICE_COMMISSION / 100
+
 
 class CoursePayment(Payment):
     course = models.ForeignKey(Course, on_delete=models.CASCADE, verbose_name='Курс')
@@ -72,9 +77,11 @@ class CoursePayment(Payment):
                 author=self.course.author,
                 amount=self.amount,
                 payment=self,
+                commission=self.calc_commission(),
             )
         else:
             author_balance.amount = self.amount
+            author_balance.commission = self.calc_commission()
             author_balance.save()
 
 
@@ -96,11 +103,3 @@ class SchoolPayment(Payment):
         self.amount = month_price_sum
         super().save(*args, **kwargs)
         author_balance = getattr(self, 'authorbalance', None)
-        if not author_balance:
-            AuthorBalance.objects.create(
-                amount=month_price_sum,
-                payment=self,
-            )
-        else:
-            author_balance.amount = self.amount
-            author_balance.save()

apps/user/models.py

@@ -61,8 +61,15 @@ class User(AbstractUser):
         user_data = dumps(user_data, ensure_ascii=False)
         return user_data
 
+    @property
     def balance(self):
-        return self.balances.aggregate(models.Sum('amount')).get('amount__sum', 0)
+        aggregate = self.balances.aggregate(
+            models.Sum('amount'),
+            models.Sum('commission'),
+        )
+        amount = aggregate.get('amount__sum', 0)
+        commission = aggregate.get('commission__sum', 0)
+        return amount - commission
 
 
 @receiver(post_save, sender=User)