Merge remote-tracking branch 'origin/fnux-hacks'

uncloud/uncloud_pay/helpers.py

@@ -2,32 +2,9 @@ from functools import reduce
 from datetime import datetime
 from rest_framework import mixins
 from rest_framework.viewsets import GenericViewSet
-from django.db.models import Q
-from .models import Bill, Payment, PaymentMethod, Order
 from django.utils import timezone
-from django.core.exceptions import ObjectDoesNotExist
 from calendar import monthrange
 
-def get_balance_for(user):
-    bills = reduce(
-            lambda acc, entry: acc + entry.total,
-            Bill.objects.filter(owner=user),
-            0)
-    payments = reduce(
-            lambda acc, entry: acc + entry.amount,
-            Payment.objects.filter(owner=user),
-            0)
-    return payments - bills
-
-def get_payment_method_for(user):
-    methods = PaymentMethod.objects.filter(owner=user)
-    for method in methods:
-        # Do we want to do something with non-primary method?
-        if method.primary:
-            return method
-
-    return None
-
 def beginning_of_month(year, month):
     tz = timezone.get_current_timezone()
     return datetime(year=year, month=month, day=1, tzinfo=tz)
@@ -38,53 +15,6 @@ def end_of_month(year, month):
     return datetime(year=year, month=month, day=days,
             hour=23, minute=59, second=59, tzinfo=tz)
 
-def generate_bills_for(year, month, user, allowed_delay):
-    # /!\ We exclusively work on the specified year and month.
-
-    # Default values for next bill (if any). Only saved at the end of
-    # this method, if relevant.
-    next_bill = Bill(owner=user,
-            starting_date=beginning_of_month(year, month),
-            ending_date=end_of_month(year, month),
-            creation_date=timezone.now(),
-            due_date=timezone.now() + allowed_delay)
-
-    # Select all orders active on the request period.
-    orders = Order.objects.filter(
-            Q(ending_date__gt=next_bill.starting_date) | Q(ending_date__isnull=True),
-            owner=user)
-
-    # Check if there is already a bill covering the order and period pair:
-    #   * Get latest bill by ending_date: previous_bill.ending_date
-    #   * If previous_bill.ending_date is before next_bill.ending_date, a new
-    #   bill has to be generated.
-    unpaid_orders = []
-    for order in orders:
-        try:
-            previous_bill = order.bill.latest('ending_date')
-        except ObjectDoesNotExist:
-            previous_bill = None
-
-        if previous_bill == None or previous_bill.ending_date < next_bill.ending_date:
-            unpaid_orders.append(order)
-
-    # Commit next_bill if it there are 'unpaid' orders.
-    if len(unpaid_orders) > 0:
-        next_bill.save()
-
-        # It is not possible to register many-to-many relationship before
-        # the two end-objects are saved in database.
-        for order in unpaid_orders:
-            order.bill.add(next_bill)
-
-        # TODO: use logger.
-        print("Generated bill {} (amount: {}) for user {}."
-                .format(next_bill.uuid, next_bill.total, user))
-
-        return next_bill
-
-    # Return None if no bill was created.
-
 class ProductViewSet(mixins.CreateModelMixin,
                    mixins.RetrieveModelMixin,
                    mixins.ListModelMixin,

uncloud/uncloud_pay/management/commands/charge-negative-balance.py

@@ -1,7 +1,6 @@
 from django.core.management.base import BaseCommand
 from uncloud_auth.models import User
-from uncloud_pay.models import Order, Bill
+from uncloud_pay.models import Order, Bill, PaymentMethod, get_balance_for
-from uncloud_pay.helpers import get_balance_for, get_payment_method_for
 
 from datetime import timedelta
 from django.utils import timezone
@@ -19,7 +18,7 @@ class Command(BaseCommand):
             balance = get_balance_for(user)
             if balance < 0:
                 print("User {} has negative balance ({}), charging.".format(user.username, balance))
-                payment_method = get_payment_method_for(user)
+                payment_method = PaymentMethod.get_primary_for(user)
                 if payment_method != None:
                     amount_to_be_charged = abs(balance)
                     charge_ok = payment_method.charge(amount_to_be_charged)

uncloud/uncloud_pay/management/commands/generate-bills.py

@@ -7,7 +7,7 @@ from django.core.exceptions import ObjectDoesNotExist
 
 from datetime import timedelta, date
 from django.utils import timezone
-from uncloud_pay.helpers import generate_bills_for
+from uncloud_pay.models import Bill
 
 BILL_PAYMENT_DELAY=timedelta(days=10)
 
@@ -28,7 +28,7 @@ class Command(BaseCommand):
 
         for user in users:
             now = timezone.now()
-            generate_bills_for(
+            Bill.generate_for(
                     year=now.year,
                     month=now.month,
                     user=user,

uncloud/uncloud_pay/management/commands/handle-overdue-bills.py

@@ -1,13 +1,12 @@
 from django.core.management.base import BaseCommand
 from uncloud_auth.models import User
-from uncloud_pay.models import Order, Bill
+from uncloud_pay.models import Bill
-from uncloud_pay.helpers import get_balance_for, get_payment_method_for
 
 from datetime import timedelta
 from django.utils import timezone
 
 class Command(BaseCommand):
-    help = 'Generate bills and charge customers if necessary.'
+    help = 'Take action on overdue bills.'
 
     def add_arguments(self, parser):
         pass
@@ -16,28 +15,9 @@ class Command(BaseCommand):
         users = User.objects.all()
         print("Processing {} users.".format(users.count()))
         for user in users:
-            balance = get_balance_for(user)
+            for bill in Bill.get_overdue_for(user):
-            if balance < 0:
+                print("/!\ Overdue bill for {}, {} with amount {}"
-                print("User {} has negative balance ({}), checking for overdue bills."
+                        .format(user.username, bill.uuid, bill.amount))
-                        .format(user.username, balance))
+                # TODO: take action?
-
-                # Get bills DESCENDING by creation date (= latest at top).
-                bills = Bill.objects.filter(
-                        owner=user,
-                        due_date__lt=timezone.now()
-                        ).order_by('-creation_date')
-                overdue_balance = abs(balance)
-                overdue_bills = []
-                for bill in bills:
-                    if  overdue_balance < 0:
-                        break # XXX: I'm (fnux) not fond of breaks!
-
-                    overdue_balance -= bill.amount
-                    overdue_bills.append(bill)
-
-                for bill in overdue_bills:
-                    print("/!\ Overdue bill for {}, {} with amount {}"
-                            .format(user.username, bill.uuid, bill.amount))
-                    # TODO: take action?
 
         print("=> Done.")

uncloud/uncloud_pay/migrations/0014_auto_20200303_1027.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.0.3 on 2020-03-03 10:27
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('uncloud_pay', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.RenameField(
+            model_name='orderrecord',
+            old_name='setup_fee',
+            new_name='one_time_price',
+        ),
+    ]

uncloud/uncloud_pay/migrations/0015_stripecustomer.py

@@ -0,0 +1,24 @@
+# Generated by Django 3.0.3 on 2020-03-03 13:56
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('uncloud_pay', '0014_auto_20200303_1027'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='StripeCustomer',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('stripe_id', models.CharField(max_length=32)),
+                ('owner', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+    ]

uncloud/uncloud_pay/migrations/0016_auto_20200303_1552.py

@@ -0,0 +1,25 @@
+# Generated by Django 3.0.3 on 2020-03-03 15:52
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('uncloud_pay', '0015_stripecustomer'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='stripecustomer',
+            name='id',
+        ),
+        migrations.AlterField(
+            model_name='stripecustomer',
+            name='owner',
+            field=models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, primary_key=True, serialize=False, to=settings.AUTH_USER_MODEL),
+        ),
+    ]

uncloud/uncloud_pay/models.py

@@ -1,19 +1,31 @@
 from django.db import models
-from functools import reduce
+from django.db.models import Q
 from django.contrib.auth import get_user_model
 from django.core.validators import MinValueValidator
 from django.utils.translation import gettext_lazy as _
 from django.utils import timezone
+from django.dispatch import receiver
+from django.core.exceptions import ObjectDoesNotExist
+import django.db.models.signals as signals
+
+import uuid
+from functools import reduce
 from math import ceil
 from datetime import timedelta
 from calendar import monthrange
 
-import uuid
+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
 
+# Used to generate bill due dates.
+BILL_PAYMENT_DELAY=timedelta(days=10)
+
 # See https://docs.djangoproject.com/en/dev/ref/models/fields/#field-choices-enum-types
 class RecurringPeriod(models.TextChoices):
     ONE_TIME   = 'ONCE', _('Onetime')
@@ -24,6 +36,34 @@ class RecurringPeriod(models.TextChoices):
     PER_HOUR   = 'HOUR', _('Per Hour')
     PER_SECOND = 'SECOND', _('Per Second')
 
+# See https://docs.djangoproject.com/en/dev/ref/models/fields/#field-choices-enum-types
+class ProductStatus(models.TextChoices):
+    PENDING          = 'PENDING', _('Pending')
+    AWAITING_PAYMENT = 'AWAITING_PAYMENT', _('Awaiting payment')
+    BEING_CREATED    = 'BEING_CREATED', _('Being created')
+    ACTIVE           = 'ACTIVE', _('Active')
+    DELETED          = 'DELETED', _('Deleted')
+
+###
+# Users.
+
+def get_balance_for(user):
+    bills = reduce(
+            lambda acc, entry: acc + entry.total,
+            Bill.objects.filter(owner=user),
+            0)
+    payments = reduce(
+            lambda acc, entry: acc + entry.amount,
+            Payment.objects.filter(owner=user),
+            0)
+    return payments - bills
+
+class StripeCustomer(models.Model):
+    owner = models.OneToOneField( get_user_model(),
+            primary_key=True,
+            on_delete=models.CASCADE)
+    stripe_id = models.CharField(max_length=32)
+
 ###
 # Payments and Payment Methods.
 
@@ -50,6 +90,20 @@ class Payment(models.Model):
                               default='unknown')
     timestamp = models.DateTimeField(editable=False, auto_now_add=True)
 
+    # WIP prepaid and service activation logic by fnux.
+    ## We override save() in order to active products awaiting payment.
+    #def save(self, *args, **kwargs):
+    #    # TODO: only run activation logic on creation, not on update.
+    #    unpaid_bills_before_payment = Bill.get_unpaid_for(self.owner)
+    #    super(Payment, self).save(*args, **kwargs) # Save payment in DB.
+    #    unpaid_bills_after_payment = Bill.get_unpaid_for(self.owner)
+
+    #    newly_paid_bills = list(
+    #            set(unpaid_bills_before_payment) - set(unpaid_bills_after_payment))
+    #    for bill in newly_paid_bills:
+    #        bill.activate_orders()
+
+
 class PaymentMethod(models.Model):
     uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
     owner = models.ForeignKey(get_user_model(),
@@ -67,24 +121,50 @@ class PaymentMethod(models.Model):
     # Only used for "Stripe" source
     stripe_card_id = models.CharField(max_length=32, blank=True, null=True)
 
+    @property
+    def stripe_card_last4(self):
+        if self.source == 'stripe':
+            card_request = uncloud_pay.stripe.get_card(
+                    StripeCustomer.objects.get(owner=self.owner).stripe_id,
+                    self.stripe_card_id)
+            if card_request['error'] == None:
+                return card_request['response_object']['last4']
+            else:
+                return None
+        else:
+            return None
+
+
     def charge(self, amount):
         if amount > 0: # Make sure we don't charge negative amount by errors...
             if self.source == 'stripe':
-                # TODO: wire to stripe, see meooow-payv1/strip_utils.py
+                stripe_customer = StripeCustomer.objects.get(owner=self.owner).stripe_id
-                payment = Payment(owner=self.owner, source=self.source, amount=amount)
+                charge_request = uncloud_pay.stripe.charge_customer(amount, stripe_customer, self.stripe_card_id)
-                payment.save() # TODO: Check return status
+                if charge_request['error'] == None:
+                    payment = Payment(owner=self.owner, source=self.source, amount=amount)
+                    payment.save() # TODO: Check return status
 
-                return True
+                    return payment
+                else:
+                    raise Exception('Stripe error: {}'.format(charge_request['error']))
             else:
-                # We do not handle that source yet.
+                raise Exception('This payment method is unsupported/cannot be charged.')
-                return False
         else:
-            return False
+            raise Exception('Cannot charge negative amount.')
+
+
+    def get_primary_for(user):
+        methods = PaymentMethod.objects.filter(owner=user)
+        for method in methods:
+            # Do we want to do something with non-primary method?
+            if method.primary:
+                return method
+
+        return None
 
     class Meta:
         unique_together = [['owner', 'primary']]
 
-
 ###
 # Bills & Payments.
 
@@ -113,13 +193,91 @@ class Bill(models.Model):
 
     @property
     def total(self):
-        return reduce(lambda acc, record: acc + record.amount(), self.records, 0)
+        return reduce(lambda acc, record: acc + record.amount, self.records, 0)
 
     @property
     def final(self):
         # A bill is final when its ending date is passed.
         return self.ending_date < timezone.now()
 
+    @staticmethod
+    def generate_for(year, month, user):
+        # /!\ We exclusively work on the specified year and month.
+
+        # Default values for next bill (if any). Only saved at the end of
+        # this method, if relevant.
+        next_bill = Bill(owner=user,
+                starting_date=beginning_of_month(year, month),
+                ending_date=end_of_month(year, month),
+                creation_date=timezone.now(),
+                due_date=timezone.now() + BILL_PAYMENT_DELAY)
+
+        # Select all orders active on the request period.
+        orders = Order.objects.filter(
+                Q(ending_date__gt=next_bill.starting_date) | Q(ending_date__isnull=True),
+                owner=user)
+
+        # Check if there is already a bill covering the order and period pair:
+        #   * Get latest bill by ending_date: previous_bill.ending_date
+        #   * If previous_bill.ending_date is before next_bill.ending_date, a new
+        #   bill has to be generated.
+        unpaid_orders = []
+        for order in orders:
+            try:
+                previous_bill = order.bill.latest('ending_date')
+            except ObjectDoesNotExist:
+                previous_bill = None
+
+            if previous_bill == None or previous_bill.ending_date < next_bill.ending_date:
+                unpaid_orders.append(order)
+
+        # Commit next_bill if it there are 'unpaid' orders.
+        if len(unpaid_orders) > 0:
+            next_bill.save()
+
+            # It is not possible to register many-to-many relationship before
+            # the two end-objects are saved in database.
+            for order in unpaid_orders:
+                order.bill.add(next_bill)
+
+            # TODO: use logger.
+            print("Generated bill {} (amount: {}) for user {}."
+                    .format(next_bill.uuid, next_bill.total, user))
+
+            return next_bill
+
+        # Return None if no bill was created.
+        return None
+
+    @staticmethod
+    def get_unpaid_for(user):
+        balance = get_balance_for(user)
+        unpaid_bills = []
+        # No unpaid bill if balance is positive.
+        if balance >= 0:
+            return []
+        else:
+            bills = Bill.objects.filter(
+                    owner=user,
+                    due_date__lt=timezone.now()
+                    ).order_by('-creation_date')
+
+            # Amount to be paid by the customer.
+            unpaid_balance = abs(balance)
+            for bill in bills:
+                if  unpaid_balance < 0:
+                    break
+
+                    unpaid_balance -= bill.amount
+                    unpaid_bills.append(bill)
+
+            return unpaid_bills
+
+    @staticmethod
+    def get_overdue_for(user):
+        unpaid_bills = Bill.get_unpaid_for(user)
+        return list(filter(lambda bill: bill.due_date > timezone.now(), unpaid_bills))
+
 class BillRecord():
     """
     Entry of a bill, dynamically generated from order records.
@@ -128,12 +286,17 @@ class BillRecord():
     def __init__(self, bill, order_record):
         self.bill = bill
         self.order = order_record.order
-        self.setup_fee = order_record.setup_fee
         self.recurring_price = order_record.recurring_price
         self.recurring_period = order_record.recurring_period
         self.description = order_record.description
 
-    def amount(self):
+        if self.order.starting_date > self.bill.starting_date:
+            self.one_time_price = order_record.one_time_price
+        else:
+            self.one_time_price = 0
+
+    @property
+    def recurring_count(self):
         # Compute billing delta.
         billed_until = self.bill.ending_date
         if self.order.ending_date != None and self.order.ending_date < self.order.ending_date:
@@ -166,39 +329,31 @@ class BillRecord():
             (_, days_in_month) = monthrange(
                     self.bill.starting_date.year,
                     self.bill.starting_date.month)
-            adjusted_recurring_price = self.recurring_price / days_in_month
+            return Decimal(days / days_in_month)
-            recurring_price = adjusted_recurring_price * days
-
-            return self.recurring_price # TODO
         elif self.recurring_period == RecurringPeriod.PER_DAY:
             days = ceil(billed_delta / timedelta(days=1))
-            return self.recurring_price * days
+            return Decimal(days)
         elif self.recurring_period == RecurringPeriod.PER_HOUR:
             hours = ceil(billed_delta / timedelta(hours=1))
-            return self.recurring_price * hours
+            return Decimal(hours)
         elif self.recurring_period == RecurringPeriod.PER_SECOND:
             seconds = ceil(billed_delta / timedelta(seconds=1))
-            return self.recurring_price * seconds
+            return Decimal(seconds)
+        elif self.recurring_period == RecurringPeriod.ONE_TIME:
+            return Decimal(0)
         else:
             raise Exception('Unsupported recurring period: {}.'.
                     format(record.recurring_period))
 
+    @property
+    def amount(self):
+        return self.recurring_price * self.recurring_count + self.one_time_price
+
 ###
 # Orders.
 
-# /!\ BIG FAT WARNING /!\ #
-#
 # Order are assumed IMMUTABLE and used as SOURCE OF TRUST for generating
 # bills. Do **NOT** mutate then!
-#
-# Why? We need to store the state somewhere since product are mutable (e.g.
-# adding RAM to VM, changing price of 1GB of RAM, ...). An alternative could
-# have been to only store the state in bills but would have been more
-# confusing: the order is a 'contract' with the customer, were both parts
-# agree on deal => That's what we want to keep archived.
-#
-# /!\ BIG FAT WARNING /!\ #
-
 class Order(models.Model):
     uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
     owner = models.ForeignKey(get_user_model(),
@@ -224,22 +379,31 @@ class Order(models.Model):
         return OrderRecord.objects.filter(order=self)
 
     @property
-    def setup_fee(self):
+    def one_time_price(self):
-        return reduce(lambda acc, record: acc + record.setup_fee, self.records, 0)
+        return reduce(lambda acc, record: acc + record.one_time_price, self.records, 0)
 
     @property
     def recurring_price(self):
         return reduce(lambda acc, record: acc + record.recurring_price, self.records, 0)
 
-    def add_record(self, setup_fee, recurring_price, description):
+    def add_record(self, one_time_price, recurring_price, description):
         OrderRecord.objects.create(order=self,
-                setup_fee=setup_fee,
+                one_time_price=one_time_price,
                 recurring_price=recurring_price,
                 description=description)
 
+
 class OrderRecord(models.Model):
+    """
+    Order records store billing informations for products: the actual product
+    might be mutated and/or moved to another order but we do not want to loose
+    the details of old orders.
+
+    Used as source of trust to dynamically generate bill entries.
+    """
+
     order = models.ForeignKey(Order, on_delete=models.CASCADE)
-    setup_fee = models.DecimalField(default=0.0,
+    one_time_price = models.DecimalField(default=0.0,
             max_digits=AMOUNT_MAX_DIGITS,
             decimal_places=AMOUNT_DECIMALS,
             validators=[MinValueValidator(0)])
@@ -276,15 +440,9 @@ class Product(models.Model):
 
     description = ""
 
-    status = models.CharField(max_length=256,
+    status = models.CharField(max_length=32,
-                              choices = (
+            choices=ProductStatus.choices,
-                                  ('pending', 'Pending'),
+            default=ProductStatus.PENDING)
-                                  ('being_created', 'Being created'),
-                                  ('active', 'Active'),
-                                  ('deleted', 'Deleted')
-                              ),
-                              default='pending'
-    )
 
     order = models.ForeignKey(Order,
                               on_delete=models.CASCADE,
@@ -296,7 +454,7 @@ class Product(models.Model):
         pass # To be implemented in child.
 
     @property
-    def setup_fee(self):
+    def one_time_price(self):
         return 0
 
     @property

uncloud/uncloud_pay/serializers.py

@@ -1,13 +1,6 @@
 from django.contrib.auth import get_user_model
 from rest_framework import serializers
 from .models import *
-from .helpers import get_balance_for
-
-from functools import reduce
-from uncloud_vm.serializers import VMProductSerializer
-from uncloud_vm.models import VMProduct
-
-import uncloud_pay.stripe as stripe
 
 ###
 # Users.
@@ -19,8 +12,6 @@ class UserSerializer(serializers.ModelSerializer):
 
     # Display current 'balance'
     balance = serializers.SerializerMethodField('get_balance')
-    def __sum_balance(self, entries):
-        return reduce(lambda acc, entry: acc + entry.amount, entries, 0)
 
     def get_balance(self, user):
         return get_balance_for(user)
@@ -34,9 +25,14 @@ class PaymentSerializer(serializers.ModelSerializer):
         fields = ['owner', 'amount', 'source', 'timestamp']
 
 class PaymentMethodSerializer(serializers.ModelSerializer):
+    stripe_card_last4 = serializers.IntegerField()
+
     class Meta:
         model = PaymentMethod
-        fields = ['source', 'description', 'primary']
+        fields = ['uuid', 'source', 'description', 'primary', 'stripe_card_last4']
+
+class ChargePaymentMethodSerializer(serializers.Serializer):
+    amount = serializers.DecimalField(max_digits=10, decimal_places=2)
 
 class CreditCardSerializer(serializers.Serializer):
     number = serializers.IntegerField()
@@ -51,41 +47,6 @@ class CreatePaymentMethodSerializer(serializers.ModelSerializer):
         model = PaymentMethod
         fields = ['source', 'description', 'primary', 'credit_card']
 
-    def create(self, validated_data):
-        credit_card = stripe.CreditCard(**validated_data.pop('credit_card'))
-        user = self.context['request'].user
-        customer = stripe.create_customer(user.username, user.email)
-        # TODO check customer error
-        customer_id = customer['response_object']['id']
-        stripe_card = stripe.create_card(customer_id, credit_card)
-        # TODO: check credit card error
-        validated_data['stripe_card_id'] = stripe_card['response_object']['id']
-class CreditCardSerializer(serializers.Serializer):
-    number = serializers.IntegerField()
-    exp_month = serializers.IntegerField()
-    exp_year = serializers.IntegerField()
-    cvc = serializers.IntegerField()
-
-class CreatePaymentMethodSerializer(serializers.ModelSerializer):
-    credit_card = CreditCardSerializer()
-
-    class Meta:
-        model = PaymentMethod
-        fields = ['source', 'description', 'primary', 'credit_card']
-
-    def create(self, validated_data):
-        credit_card = stripe.CreditCard(**validated_data.pop('credit_card'))
-        user = self.context['request'].user
-        customer = stripe.create_customer(user.username, user.email)
-        # TODO check customer error
-        customer_id = customer['response_object']['id']
-        stripe_card = stripe.create_card(customer_id, credit_card)
-        # TODO: check credit card error
-        validated_data['stripe_card_id'] = stripe_card['response_object']['id']
-        payment_method = PaymentMethod.objects.create(**validated_data)
-        return payment_method
-        payment_method = PaymentMethod.objects.create(**validated_data)
-        return payment_method
 
 ###
 # Bills
@@ -96,6 +57,8 @@ class BillRecordSerializer(serializers.Serializer):
     description = serializers.CharField()
     recurring_period = serializers.CharField()
     recurring_price = serializers.DecimalField(max_digits=10, decimal_places=2)
+    recurring_count = serializers.DecimalField(max_digits=10, decimal_places=2)
+    one_time_price = serializers.DecimalField(max_digits=10, decimal_places=2)
     amount = serializers.DecimalField(max_digits=10, decimal_places=2)
 
 class BillSerializer(serializers.ModelSerializer):
@@ -111,7 +74,7 @@ class BillSerializer(serializers.ModelSerializer):
 class OrderRecordSerializer(serializers.ModelSerializer):
     class Meta:
         model = OrderRecord
-        fields  = ['setup_fee', 'recurring_price', 'description']
+        fields  = ['one_time_price', 'recurring_price', 'description']
 
 
 class OrderSerializer(serializers.ModelSerializer):
@@ -119,7 +82,4 @@ class OrderSerializer(serializers.ModelSerializer):
     class Meta:
         model = Order
         fields = ['uuid', 'creation_date', 'starting_date', 'ending_date',
-                'bill', 'recurring_period', 'records', 'recurring_price', 'setup_fee']
+                'bill', 'recurring_period', 'records', 'recurring_price', 'one_time_price']
-
-class ProductSerializer(serializers.Serializer):
-    vms = VMProductSerializer(many=True, read_only=True)

uncloud/uncloud_pay/stripe.py

@@ -2,6 +2,9 @@ import stripe
 import stripe.error
 import logging
 
+from django.core.exceptions import ObjectDoesNotExist
+import uncloud_pay.models
+
 import uncloud.secrets
 
 # Static stripe configuration used below.
@@ -18,7 +21,7 @@ def handle_stripe_error(f):
             'error': None
         }
 
-        common_message = "Currently it's not possible to make payments."
+        common_message = "Currently it is not possible to make payments."
         try:
             response_object = f(*args, **kwargs)
             response = {
@@ -79,11 +82,24 @@ class CreditCard():
 
 # Actual Stripe logic.
 
+def get_customer_id_for(user):
+    try:
+        # .get() raise if there is no matching entry.
+        return uncloud_pay.models.StripeCustomer.objects.get(owner=user).stripe_id
+    except ObjectDoesNotExist:
+        # No entry yet - making a new one.
+        customer_request = create_customer(user.username, user.email)
+        if customer_request['error'] == None:
+            mapping = uncloud_pay.models.StripeCustomer.objects.create(
+                    owner=user,
+                    stripe_id=customer_request['response_object']['id']
+                    )
+            return mapping.stripe_id
+        else:
+            return None
+
 @handle_stripe_error
 def create_card(customer_id, credit_card):
-    # Test settings
-    credit_card.number = "5555555555554444"
-
     return stripe.Customer.create_source(
             customer_id,
             card={
@@ -95,14 +111,18 @@ def create_card(customer_id, credit_card):
 
 @handle_stripe_error
 def get_card(customer_id, card_id):
-    return stripe.Card.retrieve_source(customer_id, card_id)
+    return stripe.Customer.retrieve_source(customer_id, card_id)
 
 @handle_stripe_error
-def charge_customer(amount, source):
+def charge_customer(amount, customer_id, card_id):
+    # Amount is in CHF but stripes requires smallest possible unit.
+    # See https://stripe.com/docs/api/charges/create
+    adjusted_amount = int(amount * 100)
     return stripe.Charge.create(
-            amount=amount,
+            amount=adjusted_amount,
-            currenty=CURRENCY,
+            currency=CURRENCY,
-            source=source)
+            customer=customer_id,
+            source=card_id)
 
 @handle_stripe_error
 def create_customer(name, email):

uncloud/uncloud_pay/views.py

@@ -1,4 +1,5 @@
 from django.shortcuts import render
+from django.db import transaction
 from django.contrib.auth import get_user_model
 from rest_framework import viewsets, permissions, status
 from rest_framework.response import Response
@@ -9,6 +10,7 @@ import json
 from .models import *
 from .serializers import *
 from datetime import datetime
+import uncloud_pay.stripe as uncloud_stripe
 
 ###
 # Standard user views:
@@ -62,6 +64,8 @@ class PaymentMethodViewSet(viewsets.ModelViewSet):
     def get_serializer_class(self):
         if self.action == 'create':
             return CreatePaymentMethodSerializer
+        elif self.action == 'charge':
+            return ChargePaymentMethodSerializer
         else:
             return PaymentMethodSerializer
 
@@ -69,26 +73,47 @@ class PaymentMethodViewSet(viewsets.ModelViewSet):
     def get_queryset(self):
         return PaymentMethod.objects.filter(owner=self.request.user)
 
+    # XXX: Handling of errors is far from great down there.
+    @transaction.atomic
     def create(self, request):
         serializer = self.get_serializer(data=request.data)
         serializer.is_valid(raise_exception=True)
-        serializer.save(owner=request.user)
 
-        headers = self.get_success_headers(serializer.data)
+        # Retrieve Stripe customer ID for user.
-        return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)
+        customer_id  = uncloud_stripe.get_customer_id_for(request.user)
+        if customer_id == None:
+            return Response(
+                    {'error': 'Could not resolve customer stripe ID.'},
+                    status=status.HTTP_500_INTERNAL_SERVER_ERROR)
+
+        # Register card under stripe customer.
+        credit_card = uncloud_stripe.CreditCard(**serializer.validated_data.pop('credit_card'))
+        card_request = uncloud_stripe.create_card(customer_id, credit_card)
+        if card_request['error']:
+            return Response({'stripe_error': card_request['error']}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
+        card_id = card_request['response_object']['id']
+
+        # Save payment method locally.
+        serializer.validated_data['stripe_card_id'] = card_request['response_object']['id']
+        payment_method = PaymentMethod.objects.create(owner=request.user, **serializer.validated_data)
+
+        # We do not want to return the credit card details sent with the POST
+        # request.
+        output_serializer = PaymentMethodSerializer(payment_method)
+        return Response(output_serializer.data)
 
-    # TODO: find a way to customize serializer for actions.
-    # drf-action-serializer module seems to do that.
     @action(detail=True, methods=['post'])
     def charge(self, request, pk=None):
         payment_method = self.get_object()
         serializer = self.get_serializer(data=request.data)
         serializer.is_valid(raise_exception=True)
-        amount = serializer.data['amount']
+        amount = serializer.validated_data['amount']
-        if payment_method.charge(amount):
+        try:
-            return Response({'charged', amount})
+            payment = payment_method.charge(amount)
-        else:
+            output_serializer = PaymentSerializer(payment)
-            return Response(status=status.HTTP_500_INTERNAL_ERROR)
+            return Response(output_serializer.data)
+        except Exception as e:
+            return Response({'error': str(e)}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
 
 ###
 # Admin views.

uncloud/uncloud_vm/views.py

@@ -106,7 +106,7 @@ class VMProductViewSet(ProductViewSet):
 
         # Add Product record to order (VM is mutable, allows to keep history in order).
         # XXX: Move this to some kind of on_create hook in parent Product class?
-        order.add_record(vm.setup_fee,
+        order.add_record(vm.one_time_price,
                 vm.recurring_price(order.recurring_period), vm.description)
 
         return Response(serializer.data)

uncloud/ungleich_service/models.py

@@ -28,5 +28,5 @@ class MatrixServiceProduct(Product):
             RecurringPeriod.choices))
 
     @property
-    def setup_fee(self):
+    def one_time_price(self):
         return 30

uncloud/ungleich_service/views.py

@@ -41,7 +41,7 @@ class MatrixServiceProductViewSet(ProductViewSet):
         # XXX: Move this to some kind of on_create hook in parent
         # Product class?
         order.add_record(
-                vm.setup_fee,
+                vm.one_time_price,
                 vm.recurring_price(order.recurring_period),
                 vm.description)
 
@@ -54,7 +54,7 @@ class MatrixServiceProductViewSet(ProductViewSet):
         # XXX: Move this to some kind of on_create hook in parent
         # Product class?
         order.add_record(
-                service.setup_fee,
+                service.one_time_price,
                 service.recurring_price(order.recurring_period),
                 service.description)