Make balance a user attribute + decimalfield

uncloud/uncloud/__init__.py

@@ -0,0 +1,4 @@
+# Define DecimalField properties, used to represent amounts of money.
+# Used in pay and auth
+AMOUNT_MAX_DIGITS=10
+AMOUNT_DECIMALS=2

uncloud/uncloud_auth/migrations/0002_auto_20200318_1343.py

@@ -0,0 +1,25 @@
+# Generated by Django 3.0.3 on 2020-03-18 13:43
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('uncloud_auth', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='user',
+            name='amount',
+            field=models.DecimalField(decimal_places=2, default=0.0, max_digits=10, validators=[django.core.validators.MinValueValidator(0)]),
+        ),
+        migrations.AddField(
+            model_name='user',
+            name='maximum_credit',
+            field=models.FloatField(default=0),
+            preserve_default=False,
+        ),
+    ]

uncloud/uncloud_auth/migrations/0003_auto_20200318_1345.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.0.3 on 2020-03-18 13:45
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('uncloud_auth', '0002_auto_20200318_1343'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='user',
+            name='amount',
+        ),
+        migrations.AlterField(
+            model_name='user',
+            name='maximum_credit',
+            field=models.DecimalField(decimal_places=2, default=0.0, max_digits=10, validators=[django.core.validators.MinValueValidator(0)]),
+        ),
+    ]

uncloud/uncloud_auth/models.py

@@ -1,5 +1,23 @@
 from django.contrib.auth.models import AbstractUser
+from django.db import models
+from django.core.validators import MinValueValidator
 
+from uncloud import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
+
+from uncloud_pay.models import get_balance_for_user
 
 class User(AbstractUser):
-    pass
+    """
+    We use the standard user and add a maximum negative credit that is allowed
+    to be accumulated
+    """
+
+    maximum_credit = models.DecimalField(
+            default=0.0,
+            max_digits=AMOUNT_MAX_DIGITS,
+            decimal_places=AMOUNT_DECIMALS,
+            validators=[MinValueValidator(0)])
+
+    @property
+    def balance(self):
+        return get_balance_for_user(self)

uncloud/uncloud_auth/serializers.py

@@ -1,14 +1,13 @@
 from django.contrib.auth import get_user_model
 from rest_framework import serializers
-from uncloud_pay.models import get_balance_for_user
+
+from uncloud import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
 
 class UserSerializer(serializers.ModelSerializer):
+
     class Meta:
         model = get_user_model()
-        fields = ['username', 'email', 'balance']
+        fields = ['username', 'email', 'balance', 'maximum_credit' ]
 
-    # Display current 'balance'
-    balance = serializers.SerializerMethodField('get_balance')
-
-    def get_balance(self, user):
-        return get_balance_for_user(user)
+    balance = serializers.DecimalField(max_digits=AMOUNT_MAX_DIGITS,
+                                       decimal_places=AMOUNT_DECIMALS)

uncloud/uncloud_auth/views.py

@@ -10,7 +10,8 @@ class UserViewSet(viewsets.ReadOnlyModelViewSet):
             obj = get_user_model().objects.all()
         else:
             # This is a bit stupid: we have a user, we create a queryset by
-            # matching on the username.
+            # matching on the username. But I don't know a "nicer" way.
+            # Nico, 2020-03-18
             obj = get_user_model().objects.filter(username=self.request.user.username)
 
         return obj

uncloud/uncloud_pay/models.py

@@ -14,14 +14,14 @@ from math import ceil
 from datetime import timedelta
 from calendar import monthrange
 
-import uncloud_pay.stripe
-from uncloud_pay.helpers import beginning_of_month, end_of_month
-
 from decimal import Decimal
 
-# Define DecimalField properties, used to represent amounts of money.
-AMOUNT_MAX_DIGITS=10
-AMOUNT_DECIMALS=2
+import uncloud_pay.stripe
+from uncloud_pay.helpers import beginning_of_month, end_of_month
+from uncloud import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
+
+
+
 
 # Used to generate bill due dates.
 BILL_PAYMENT_DELAY=timedelta(days=10)