import logging
import itertools
import datetime
from math import ceil
from calendar import monthrange
from decimal import Decimal
from functools import reduce
from django.db import models
from django.db.models import Q
from django.contrib.auth import get_user_model
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType
from django.utils.translation import gettext_lazy as _
from django.core.validators import MinValueValidator
from django.utils import timezone
from django.core.exceptions import ObjectDoesNotExist, ValidationError
from django.conf import settings
import uncloud_pay.stripe
from uncloud import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
from uncloud.models import UncloudAddress
# Used to generate bill due dates.
BILL_PAYMENT_DELAY=datetime.timedelta(days=10)
# Initialize logger.
logger = logging.getLogger(__name__)
def start_of_month(a_day):
""" Returns first of the month of a given datetime object"""
return a_day.replace(day=1,hour=0,minute=0,second=0, microsecond=0)
def end_of_month(a_day):
""" Returns first of the month of a given datetime object"""
_, last_day = monthrange(a_day.year, a_day.month)
return a_day.replace(day=last_day,hour=23,minute=59,second=59, microsecond=0)
def start_of_this_month():
""" Returns first of this month"""
a_day = timezone.now()
return a_day.replace(day=1,hour=0,minute=0,second=0, microsecond=0)
def end_of_this_month():
""" Returns first of this month"""
a_day = timezone.now()
_, last_day = monthrange(a_day.year, a_day.month)
return a_day.replace(day=last_day,hour=23,minute=59,second=59, microsecond=0)
def end_before(a_date):
""" Return suitable datetimefield for ending just before a_date """
return a_date - datetime.timedelta(seconds=1)
def start_after(a_date):
""" Return suitable datetimefield for starting just after a_date """
return a_date + datetime.timedelta(seconds=1)
def default_payment_delay():
return timezone.now() + BILL_PAYMENT_DELAY
class Currency(models.TextChoices):
"""
Possible currencies to be billed
"""
CHF = 'CHF', _('Swiss Franc')
EUR = 'EUR', _('Euro')
USD = 'USD', _('US Dollar')
def get_balance_for_user(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
###
# Stripe
class StripeCustomer(models.Model):
owner = models.OneToOneField( get_user_model(),
primary_key=True,
on_delete=models.CASCADE)
stripe_id = models.CharField(max_length=32)
def __str__(self):
return self.owner.username
###
# Payments and Payment Methods.
class Payment(models.Model):
owner = models.ForeignKey(get_user_model(),
on_delete=models.CASCADE)
amount = models.DecimalField(
default=0.0,
max_digits=AMOUNT_MAX_DIGITS,
decimal_places=AMOUNT_DECIMALS,
validators=[MinValueValidator(0)])
source = models.CharField(max_length=256,
choices = (
('wire', 'Wire Transfer'),
('stripe', 'Stripe'),
('voucher', 'Voucher'),
('referral', 'Referral'),
('unknown', 'Unknown')
),
default='unknown')
timestamp = models.DateTimeField(editable=False, auto_now_add=True)
# We override save() in order to active products awaiting payment.
def save(self, *args, **kwargs):
# _state.adding is switched to false after super(...) call.
being_created = self._state.adding
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_products()
class PaymentMethod(models.Model):
owner = models.ForeignKey(get_user_model(),
on_delete=models.CASCADE,
editable=False)
source = models.CharField(max_length=256,
choices = (
('stripe', 'Stripe'),
('unknown', 'Unknown'),
),
default='stripe')
description = models.TextField()
primary = models.BooleanField(default=False, editable=False)
# Only used for "Stripe" source
stripe_payment_method_id = models.CharField(max_length=32, blank=True, null=True)
stripe_setup_intent_id = models.CharField(max_length=32, blank=True, null=True)
@property
def stripe_card_last4(self):
if self.source == 'stripe' and self.active:
payment_method = uncloud_pay.stripe.get_payment_method(
self.stripe_payment_method_id)
return payment_method.card.last4
else:
return None
@property
def active(self):
if self.source == 'stripe' and self.stripe_payment_method_id != None:
return True
else:
return False
def charge(self, amount):
if not self.active:
raise Exception('This payment method is inactive.')
if amount < 0: # Make sure we don't charge negative amount by errors...
raise Exception('Cannot charge negative amount.')
if self.source == 'stripe':
stripe_customer = StripeCustomer.objects.get(owner=self.owner).stripe_id
stripe_payment = uncloud_pay.stripe.charge_customer(
amount, stripe_customer, self.stripe_payment_method_id)
if 'paid' in stripe_payment and stripe_payment['paid'] == False:
raise Exception(stripe_payment['error'])
else:
payment = Payment.objects.create(
owner=self.owner, source=self.source, amount=amount)
return payment
else:
raise Exception('This payment method is unsupported/cannot be charged.')
def set_as_primary_for(self, user):
methods = PaymentMethod.objects.filter(owner=user, primary=True)
for method in methods:
print(method)
method.primary = False
method.save()
self.primary = True
self.save()
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.active and method.primary:
return method
return None
class Meta:
# TODO: limit to one primary method per user.
# unique_together is no good since it won't allow more than one
# non-primary method.
pass
# See https://docs.djangoproject.com/en/dev/ref/models/fields/#field-choices-enum-types
class RecurringPeriodDefaultChoices(models.IntegerChoices):
"""
This is an old class and being superseeded by the database model below
"""
PER_365D = 365*24*3600, _('Per 365 days')
PER_30D = 30*24*3600, _('Per 30 days')
PER_WEEK = 7*24*3600, _('Per Week')
PER_DAY = 24*3600, _('Per Day')
PER_HOUR = 3600, _('Per Hour')
PER_MINUTE = 60, _('Per Minute')
PER_SECOND = 1, _('Per Second')
ONE_TIME = 0, _('Onetime')
# RecurringPeriods
class RecurringPeriod(models.Model):
"""
Available recurring periods.
By default seeded from RecurringPeriodChoices
"""
name = models.CharField(max_length=100, unique=True)
duration_seconds = models.IntegerField(unique=True)
@classmethod
def populate_db_defaults(cls):
for (seconds, name) in RecurringPeriodDefaultChoices.choices:
obj, created = cls.objects.get_or_create(name=name,
defaults={ 'duration_seconds': seconds })
@staticmethod
def secs_to_name(secs):
name = ""
days = 0
hours = 0
if secs > 24*3600:
days = secs // (24*3600)
secs -= (days*24*3600)
if secs > 3600:
hours = secs // 3600
secs -= hours*3600
return f"{days} days {hours} hours {secs} seconds"
def __str__(self):
duration = self.secs_to_name(self.duration_seconds)
return f"{self.name} ({duration})"
###
# Bills.
class BillingAddress(UncloudAddress):
owner = models.ForeignKey(get_user_model(), on_delete=models.CASCADE)
vat_number = models.CharField(max_length=100, default="", blank=True)
active = models.BooleanField(default=False)
class Meta:
constraints = [
models.UniqueConstraint(fields=['owner'],
condition=Q(active=True),
name='one_active_billing_address_per_user')
]
@classmethod
def populate_db_defaults(cls):
"""
Ensure we have at least one billing address that is associated with the uncloud-admin.
This way we are sure that an UncloudProvider can be created.
Cannot use get_or_create as that looks for exactly one.
"""
owner = get_user_model().objects.get(username=settings.UNCLOUD_ADMIN_NAME)
billing_address = cls.objects.filter(owner=owner).first()
if not billing_address:
billing_address = cls.objects.create(owner=owner,
organization="uncloud admins",
name="Uncloud Admin",
street="Uncloudstreet. 42",
city="Luchsingen",
postal_code="8775",
country="CH",
active=True)
@staticmethod
def get_address_for(user):
return BillingAddress.objects.get(owner=user, active=True)
def __str__(self):
return "{} - {}, {}, {} {}, {}".format(
self.owner,
self.full_name, self.street, self.postal_code, self.city,
self.country)
###
# VAT
class VATRate(models.Model):
starting_date = models.DateField(blank=True, null=True)
ending_date = models.DateField(blank=True, null=True)
territory_codes = models.TextField(blank=True, default='')
currency_code = models.CharField(max_length=10)
rate = models.FloatField()
rate_type = models.TextField(blank=True, default='')
description = models.TextField(blank=True, default='')
@staticmethod
def get_for_country(country_code):
vat_rate = None
try:
vat_rate = VATRate.objects.get(
territory_codes=country_code, start_date__isnull=False, stop_date=None
)
return vat_rate.rate
except VATRate.DoesNotExist as dne:
logger.debug(str(dne))
logger.debug("Did not find VAT rate for %s, returning 0" % country_code)
return 0
def __str__(self):
return f"{self.territory_codes}: {self.starting_date} - {self.ending_date}: {self.rate_type}"
###
# Products
class Product(models.Model):
"""
A product is something a user can order. To record the pricing, we
create order that define a state in time.
A product can have *one* one_time_order and/or *one*
recurring_order.
If either of them needs to be updated, a new order of the same
type will be created and links to the previous order.
"""
name = models.CharField(max_length=256, unique=True)
description = models.CharField(max_length=1024)
config = models.JSONField()
recurring_periods = models.ManyToManyField(RecurringPeriod, through='ProductToRecurringPeriod')
currency = models.CharField(max_length=32, choices=Currency.choices, default=Currency.CHF)
@property
def default_recurring_period(self):
"""
Return the default recurring Period
"""
return self.recurring_periods.get(producttorecurringperiod__is_default=True)
@classmethod
def populate_db_defaults(cls):
recurring_period = RecurringPeriod.objects.get(name="Per 30 days")
obj, created = cls.objects.get_or_create(name="Dual Stack Virtual Machine v1",
description="A standard virtual machine",
currency=Currency.CHF,
config={
'features': {
'cores':
{ 'min': 1,
'max': 48,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 3
},
'ram_gb':
{ 'min': 1,
'max': 256,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 4
},
'ssd_gb':
{ 'min': 10,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 0.35
},
'hdd_gb':
{ 'min': 0,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 15/1000
},
'additional_ipv4_address':
{ 'min': 0,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 8
},
}
}
)
obj.recurring_periods.add(recurring_period, through_defaults= { 'is_default': True })
obj, created = cls.objects.get_or_create(name="Dual Stack Virtual Machine v2",
description="A standard virtual machine",
currency=Currency.CHF,
config={
'features': {
'base':
{ 'min': 1,
'max': 1,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 1
},
'cores':
{ 'min': 1,
'max': 48,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 3
},
'ram_gb':
{ 'min': 1,
'max': 256,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 4
},
'ssd_gb':
{ 'min': 10,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 0.35
},
'hdd_gb':
{ 'min': 0,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 15/1000
},
'additional_ipv4_address':
{ 'min': 0,
'one_time_price_per_unit': 0,
'recurring_price_per_unit': 9
},
}
}
)
obj.recurring_periods.add(recurring_period, through_defaults= { 'is_default': True })
obj, created = cls.objects.get_or_create(name="reverse DNS",
description="Reverse DNS network",
currency=Currency.CHF,
config={
'parameters': [
'network'
]
})
obj.recurring_periods.add(recurring_period, through_defaults= { 'is_default': True })
def __str__(self):
return f"{self.name} - {self.description}"
@property
def recurring_orders(self):
return self.orders.order_by('id').exclude(recurring_period=RecurringPeriod.objects.get(name="ONE_TIME"))
@property
def last_recurring_order(self):
return self.recurring_orders.last()
@property
def one_time_orders(self):
return self.orders.order_by('id').filter(recurring_period=RecurringPeriod.objects.get(name="ONE_TIME"))
@property
def last_one_time_order(self):
return self.one_time_orders.last()
def create_order(self, when_to_start=None, recurring_period=None):
billing_address = BillingAddress.get_address_for(self.owner)
if not billing_address:
raise ValidationError("Cannot order without a billing address")
if not when_to_start:
when_to_start = timezone.now()
if not recurring_period:
recurring_period = self.default_recurring_period
# Create one time order if we did not create one already
if self.one_time_price > 0 and not self.last_one_time_order:
one_time_order = Order.objects.create(owner=self.owner,
billing_address=billing_address,
starting_date=when_to_start,
price=self.one_time_price,
recurring_period=RecurringPeriod.objects.get(name="ONE_TIME"),
description=str(self))
self.orders.add(one_time_order)
else:
one_time_order = None
if recurring_period != RecurringPeriod.objects.get(name="ONE_TIME"):
if one_time_order:
recurring_order = Order.objects.create(owner=self.owner,
billing_address=billing_address,
starting_date=when_to_start,
price=self.recurring_price,
recurring_period=recurring_period,
depends_on=one_time_order,
description=str(self))
else:
recurring_order = Order.objects.create(owner=self.owner,
billing_address=billing_address,
starting_date=when_to_start,
price=self.recurring_price,
recurring_period=recurring_period,
description=str(self))
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
if not recurring_period:
recurring_period = self.default_recurring_period
if not when_to_start:
when_to_start = timezone.now()
if self.last_recurring_order:
if self.recurring_price < self.last_recurring_order.price:
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)
new_order = Order.objects.create(owner=self.owner,
billing_address=self.last_recurring_order.billing_address,
starting_date=when_to_start,
price=self.recurring_price,
recurring_period=recurring_period,
description=str(self),
replaces=self.last_recurring_order)
self.last_recurring_order.replace_with(new_order)
self.orders.add(new_order)
else:
self.create_order(when_to_start, recurring_period)
@property
def is_recurring(self):
return self.recurring_price > 0
@property
def billing_address(self):
return self.order.billing_address
def discounted_price_by_period(self, requested_period):
"""
Each product has a standard recurring period for which
we define a pricing. I.e. VPN is usually year, VM is usually monthly.
The user can opt-in to use a different period, which influences the price:
The longer a user commits, the higher the discount.
Products can also be limited in the available periods. For instance
a VPN only makes sense to be bought for at least one day.
Rules are as follows:
given a standard recurring period of ..., changing to ... modifies price ...
# One month for free if buying / year, compared to a month: about 8.33% discount
per_year -> per_month -> /11
per_month -> per_year -> *11
# Month has 30.42 days on average. About 7.9% discount to go monthly
per_month -> per_day -> /28
per_day -> per_month -> *28
# Day has 24h, give one for free
per_day -> per_hour -> /23
per_hour -> per_day -> /23
Examples
VPN @ 120CHF/y becomes
- 10.91 CHF/month (130.91 CHF/year)
- 0.39 CHF/day (142.21 CHF/year)
VM @ 15 CHF/month becomes
- 165 CHF/month (13.75 CHF/month)
- 0.54 CHF/day (16.30 CHF/month)
"""
# FIXME: This logic needs to be phased out / replaced by product specific (?)
# proportions. Maybe using the RecurringPeriod table to link the possible discounts/add ups
if self.default_recurring_period == RecurringPeriod.PER_365D:
if requested_period == RecurringPeriod.PER_365D:
return self.recurring_price
if requested_period == RecurringPeriod.PER_30D:
return self.recurring_price/11.
if requested_period == RecurringPeriod.PER_DAY:
return self.recurring_price/11./28.
elif self.default_recurring_period == RecurringPeriod.PER_30D:
if requested_period == RecurringPeriod.PER_365D:
return self.recurring_price*11
if requested_period == RecurringPeriod.PER_30D:
return self.recurring_price
if requested_period == RecurringPeriod.PER_DAY:
return self.recurring_price/28.
elif self.default_recurring_period == RecurringPeriod.PER_DAY:
if requested_period == RecurringPeriod.PER_365D:
return self.recurring_price*11*28
if requested_period == RecurringPeriod.PER_30D:
return self.recurring_price*28
if requested_period == RecurringPeriod.PER_DAY:
return self.recurring_price
else:
# FIXME: use the right type of exception here!
raise Exception("Did not implement the discounter for this case")
def save(self, *args, **kwargs):
# try:
# ba = BillingAddress.get_address_for(self.owner)
# except BillingAddress.DoesNotExist:
# raise ValidationError("User does not have a billing address")
# if not ba.active:
# raise ValidationError("User does not have an active billing address")
# Verify the required JSON fields
super().save(*args, **kwargs)
###
# Orders.
class Order(models.Model):
"""
Order are assumed IMMUTABLE and used as SOURCE OF TRUST for generating
bills. Do **NOT** mutate then!
An one time order is "closed" (does not need to be billed anymore)
if it has one bill record. Having more than one is a programming
error.
A recurring order is closed if it has been replaced
(replaces__isnull=False) AND the ending_date is set AND it was
billed the last time it needed to be billed (how to check the last
item?)
BOTH are closed, if they are ended/closed AND have been fully
charged.
Fully charged == fully billed: sum_of_order_usage == sum_of_bill_records
"""
owner = models.ForeignKey(get_user_model(),
on_delete=models.CASCADE,
editable=True)
billing_address = models.ForeignKey(BillingAddress,
on_delete=models.CASCADE)
description = models.TextField()
product = models.ForeignKey(Product, blank=False, null=False, on_delete=models.CASCADE)
config = models.JSONField()
creation_date = models.DateTimeField(auto_now_add=True)
starting_date = models.DateTimeField(default=timezone.now)
ending_date = models.DateTimeField(blank=True, null=True)
recurring_period = models.ForeignKey(RecurringPeriod,
on_delete=models.CASCADE,
editable=True)
one_time_price = models.DecimalField(default=0.0,
max_digits=AMOUNT_MAX_DIGITS,
decimal_places=AMOUNT_DECIMALS,
validators=[MinValueValidator(0)])
recurring_price = models.DecimalField(default=0.0,
max_digits=AMOUNT_MAX_DIGITS,
decimal_places=AMOUNT_DECIMALS,
validators=[MinValueValidator(0)])
currency = models.CharField(max_length=32, choices=Currency.choices, default=Currency.CHF)
replaces = models.ForeignKey('self',
related_name='replaced_by',
on_delete=models.CASCADE,
blank=True,
null=True)
depends_on = models.ForeignKey('self',
related_name='parent_of',
on_delete=models.CASCADE,
blank=True,
null=True)
should_be_billed = models.BooleanField(default=True)
@property
def earliest_ending_date(self):
"""
Recurring orders cannot end before finishing at least one recurring period.
One time orders have a recurring period of 0, so this work universally
"""
return self.starting_date + datetime.timedelta(seconds=self.recurring_period.duration_seconds)
def next_cancel_or_downgrade_date(self, until_when=None):
"""
Return the next proper ending date after n times the
recurring_period, where n is an integer that applies for downgrading
or cancelling.
"""
if not until_when:
until_when = timezone.now()
if until_when < self.starting_date:
raise ValidationError("Cannot end before start of start of order")
if self.recurring_period.duration_seconds > 0:
delta = until_when - self.starting_date
num_times = ceil(delta.total_seconds() / self.recurring_period.duration_seconds)
next_date = self.starting_date + datetime.timedelta(seconds=num_times * self.recurring_period.duration_seconds)
else:
next_date = self.starting_date
return next_date
def get_ending_date_for_bill(self, bill):
"""
Determine the ending date given a specific bill
"""
# If the order is quit, charge the final amount / finish (????)
# Probably not a good idea -- FIXME :continue until usual
if self.ending_date:
this_ending_date = self.ending_date
else:
if self.next_cancel_or_downgrade_date(bill.ending_date) > bill.ending_date:
this_ending_date = self.next_cancel_or_downgrade_date(bill.ending_date)
else:
this_ending_date = bill.ending_date
return this_ending_date
@property
def count_billed(self):
"""
How many times this order was billed so far.
This logic is mainly thought to be for recurring bills, but also works for one time bills
"""
return sum([ br.quantity for br in self.bill_records.all() ])
def count_used(self, when=None):
"""
How many times this order was billed so far.
This logic is mainly thought to be for recurring bills, but also works for one time bills
"""
if self.is_one_time:
return 1
if not when:
when = timezone.now()
# Cannot be used after it ended
if self.ending_date and when > self.ending_date:
when = self.ending_date
return (when - self.starting_date) / self.default_recurring_period
@property
def all_usage_billed(self, when=None):
"""
Returns true if this order does not need any further billing
ever. In other words: is this order "closed"?
"""
if self.count_billed == self.count_used(when):
return True
else:
return False
@property
def is_closed(self):
if self.all_usage_billed and self.ending_date:
return True
else:
return False
@property
def is_recurring(self):
return not self.recurring_period == RecurringPeriod.objects.get(name="ONE_TIME")
@property
def is_one_time(self):
return not self.is_recurring
def replace_with(self, new_order):
new_order.replaces = self
self.ending_date = end_before(new_order.starting_date)
self.save()
def update_order(self, config, starting_date=None):
"""
Updating an order means creating a new order and reference the previous order
"""
if not starting_date:
starting_date = timezone.now()
new_order = self.__class__(owner=self.owner,
billing_address=self.billing_address,
description=self.description,
product=self.product,
config=config,
starting_date=starting_date,
currency=self.currency
)
(new_order.one_time_price, new_order.recurring_price, new_order.config) = new_order.calculate_prices_and_config()
new_order.replaces = self
new_order.save()
self.ending_date = end_before(new_order.starting_date)
self.save()
return new_order
def create_bill_record(self, bill):
br = None
# Note: check for != 0 not > 0, as we allow discounts to be expressed with < 0
if self.one_time_price != 0 and self.billrecord_set.count() == 0:
br = BillRecord.objects.create(bill=bill,
order=self,
starting_date=self.starting_date,
ending_date=self.starting_date,
is_recurring_record=False)
if self.recurring_price != 0:
br = BillRecord.objects.filter(bill=bill, order=self, is_recurring_record=True).first()
if br:
self.update_bill_record_for_recurring_order(br, bill)
else:
br = self.create_new_bill_record_for_recurring_order(bill)
return br
def update_bill_record_for_recurring_order(self,
bill_record,
bill):
"""
Possibly update a bill record according to the information in the bill
"""
# If the order has an ending date set, we might need to adjust the bill_record
if self.ending_date:
if bill_record_for_this_bill.ending_date != self.ending_date:
bill_record_for_this_bill.ending_date = self.ending_date
else:
# recurring, not terminated, should go until at least end of bill
if bill_record_for_this_bill.ending_date < bill.ending_date:
bill_record_for_this_bill.ending_date = bill.ending_date
bill_record_for_this_bill.save()
def create_new_bill_record_for_recurring_order(self, bill):
"""
Create a new bill record
"""
last_bill_record = BillRecord.objects.filter(order=self, is_recurring_record=True).order_by('id').last()
starting_date=self.starting_date
if last_bill_record:
# We already charged beyond the end of this bill's period
if last_bill_record.ending_date >= bill.ending_date:
return
# This order is terminated or replaced
if self.ending_date:
# And the last bill record already covered us -> nothing to be done anymore
if last_bill_record.ending_date == self.ending_date:
return
starting_date = start_after(last_bill_record.ending_date)
ending_date = self.get_ending_date_for_bill(bill)
return BillRecord.objects.create(bill=bill,
order=self,
starting_date=starting_date,
ending_date=ending_date,
is_recurring_record=True)
def calculate_prices_and_config(self):
one_time_price = 0
recurring_price = 0
if self.config:
config = self.config
if 'features' not in self.config:
self.config['features'] = {}
else:
config = {
'features': {}
}
# FIXME: adjust prices to the selected recurring_period to the
if 'features' in self.product.config:
for feature in self.product.config['features']:
# Set min to 0 if not specified
min_val = self.product.config['features'][feature].get('min', 0)
# We might not even have 'features' cannot use .get() on it
try:
value = self.config['features'][feature]
except (KeyError, TypeError):
value = self.product.config['features'][feature]['min']
# Set max to current value if not specified
max_val = self.product.config['features'][feature].get('max', value)
if value < min_val or value > max_val:
raise ValidationError(f"Feature '{feature}' must be at least {min_val} and at maximum {max_val}. Value is: {value}")
one_time_price += self.product.config['features'][feature]['one_time_price_per_unit'] * value
recurring_price += self.product.config['features'][feature]['recurring_price_per_unit'] * value
config['features'][feature] = value
return (one_time_price, recurring_price, config)
def check_parameters(self):
if 'parameters' in self.product.config:
for parameter in self.product.config['parameters']:
if not parameter in self.config['parameters']:
raise ValidationError(f"Required parameter '{parameter}' is missing.")
def save(self, *args, **kwargs):
# Calculate the price of the order when we create it
# IMMUTABLE fields -- need to create new order to modify them
# However this is not enforced here...
if self._state.adding:
(self.one_time_price, self.recurring_price, self.config) = self.calculate_prices_and_config()
if self.recurring_period_id is None:
self.recurring_period = self.product.default_recurring_period
try:
prod_period = self.product.recurring_periods.get(producttorecurringperiod__recurring_period=self.recurring_period)
except ObjectDoesNotExist:
raise ValidationError(f"Recurring Period {self.recurring_period} not allowed for product {self.product}")
self.check_parameters()
if self.ending_date and self.ending_date < self.starting_date:
raise ValidationError("End date cannot be before starting date")
super().save(*args, **kwargs)
def __str__(self):
try:
conf = " ".join([ f"{key}:{val}" for key,val in self.config['features'].items() if val != 0 ])
except KeyError:
conf = ""
return f"Order {self.id}: {self.description} {conf}"
class Bill(models.Model):
"""
A bill is a representation of usage at a specific time
"""
owner = models.ForeignKey(get_user_model(),
on_delete=models.CASCADE)
creation_date = models.DateTimeField(auto_now_add=True)
starting_date = models.DateTimeField(default=start_of_this_month)
ending_date = models.DateTimeField()
due_date = models.DateField(default=default_payment_delay)
billing_address = models.ForeignKey(BillingAddress,
on_delete=models.CASCADE,
editable=True,
null=False)
# FIXME: editable=True -> is in the admin, but also editable in DRF
# Maybe filter fields in the serializer?
is_final = models.BooleanField(default=False)
class Meta:
constraints = [
models.UniqueConstraint(fields=['owner',
'starting_date',
'ending_date' ],
name='one_bill_per_month_per_user')
]
def close(self):
"""
Close/finish a bill
"""
self.is_final = True
self.save()
@property
def sum(self):
bill_records = BillRecord.objects.filter(bill=self)
return sum([ br.sum for br in bill_records ])
@property
def vat_rate(self):
"""
Handling VAT is a tricky business - thus we only implement the cases
that we clearly now and leave it open to fellow developers to implement
correct handling for other cases.
Case CH:
- If the customer is in .ch -> apply standard rate
- If the customer is in EU AND private -> apply country specific rate
- If the customer is in EU AND business -> do not apply VAT
- If the customer is outside EU and outside CH -> do not apply VAT
"""
provider = UncloudProvider.objects.get()
# Assume always VAT inside the country
if provider.country == self.billing_address.country:
vat_rate = VATRate.objects.get(country=provider.country,
when=self.ending_date)
elif self.billing_address.country in EU:
# FIXME: need to check for validated vat number
if self.billing_address.vat_number:
return 0
else:
return VATRate.objects.get(country=self.biling_address.country,
when=self.ending_date)
else: # non-EU, non-national
return 0
@classmethod
def create_bills_for_all_users(cls):
"""
Create next bill for each user
"""
for owner in get_user_model().objects.all():
cls.create_next_bills_for_user(owner)
@classmethod
def create_next_bills_for_user(cls, owner, ending_date=None):
"""
Create one bill per billing address, as the VAT rates might be different
for each address
"""
bills = []
for billing_address in BillingAddress.objects.filter(owner=owner):
bills.append(cls.create_next_bill_for_user_address(billing_address, ending_date))
return bills
@classmethod
def create_next_bill_for_user_address(cls, billing_address, ending_date=None):
"""
Create the next bill for a specific billing address of a user
"""
owner = billing_address.owner
all_orders = Order.objects.filter(owner=owner,
billing_address=billing_address).order_by('id')
bill = cls.get_or_create_bill(billing_address, ending_date=ending_date)
for order in all_orders:
order.create_bill_record(bill)
return bill
@classmethod
def get_or_create_bill(cls, billing_address, ending_date=None):
"""
Get / reuse last bill if it is not yet closed
Create bill, if there is no bill or if bill is closed.
"""
last_bill = cls.objects.filter(billing_address=billing_address).order_by('id').last()
all_orders = Order.objects.filter(billing_address=billing_address).order_by('id')
first_order = all_orders.first()
bill = None
# Get date & bill from previous bill, if it exists
if last_bill:
if not last_bill.is_final:
bill = last_bill
starting_date = last_bill.starting_date
ending_date = bill.ending_date
else:
starting_date = last_bill.ending_date + datetime.timedelta(seconds=1)
else:
# Might be an idea to make this the start of the month, too
if first_order:
starting_date = first_order.starting_date
else:
starting_date = timezone.now()
if not ending_date:
ending_date = end_of_month(starting_date)
if not bill:
bill = cls.objects.create(
owner=billing_address.owner,
starting_date=starting_date,
ending_date=ending_date,
billing_address=billing_address)
return bill
def __str__(self):
return f"Bill {self.owner}-{self.id}"
class BillRecord(models.Model):
"""
Entry of a bill, dynamically generated from an order.
"""
bill = models.ForeignKey(Bill, on_delete=models.CASCADE)
order = models.ForeignKey(Order, on_delete=models.CASCADE)
creation_date = models.DateTimeField(auto_now_add=True)
starting_date = models.DateTimeField()
ending_date = models.DateTimeField()
is_recurring_record = models.BooleanField(blank=False, null=False)
@property
def quantity(self):
""" Determine the quantity by the duration"""
if not self.is_recurring_record:
return 1
record_delta = self.ending_date - self.starting_date
return record_delta.total_seconds()/self.order.recurring_period.duration_seconds
@property
def sum(self):
if self.is_recurring_record:
return self.order.recurring_price * Decimal(self.quantity)
else:
return self.order.one_time_price
@property
def price(self):
if self.is_recurring_record:
return self.order.recurring_price
else:
return self.order.one_time_price
def __str__(self):
if self.is_recurring_record:
bill_line = f"{self.starting_date} - {self.ending_date}: {self.quantity} x {self.order}"
else:
bill_line = f"{self.starting_date}: {self.order}"
return bill_line
def save(self, *args, **kwargs):
if self.ending_date < self.starting_date:
raise ValidationError("End date cannot be before starting date")
super().save(*args, **kwargs)
class ProductToRecurringPeriod(models.Model):
"""
Intermediate manytomany mapping class that allows storing the default recurring period
for a product
"""
recurring_period = models.ForeignKey(RecurringPeriod, on_delete=models.CASCADE)
product = models.ForeignKey(Product, on_delete=models.CASCADE)
is_default = models.BooleanField(default=False)
class Meta:
constraints = [
models.UniqueConstraint(fields=['product'],
condition=Q(is_default=True),
name='one_default_recurring_period_per_product'),
models.UniqueConstraint(fields=['product', 'recurring_period'],
name='recurring_period_once_per_product')
]
def __str__(self):
return f"{self.product} - {self.recurring_period} (default: {self.is_default})"