549 lines
19 KiB
Python
549 lines
19 KiB
Python
from django.db import models
|
|
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.core.exceptions import ObjectDoesNotExist
|
|
|
|
import uuid
|
|
from functools import reduce
|
|
from math import ceil
|
|
from datetime import timedelta
|
|
from calendar import monthrange
|
|
|
|
from decimal import Decimal
|
|
|
|
import uncloud_pay.stripe
|
|
from uncloud_pay.helpers import beginning_of_month, end_of_month
|
|
from uncloud import AMOUNT_DECIMALS, AMOUNT_MAX_DIGITS
|
|
from uncloud.models import UncloudModel, UncloudStatus
|
|
|
|
|
|
# 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')
|
|
PER_YEAR = 'YEAR', _('Per Year')
|
|
PER_MONTH = 'MONTH', _('Per Month')
|
|
PER_DAY = 'DAY', _('Per Day')
|
|
PER_HOUR = 'HOUR', _('Per Hour')
|
|
PER_MINUTE = 'MINUTE', _('Per Minute')
|
|
PER_SECOND = 'SECOND', _('Per Second')
|
|
|
|
|
|
|
|
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
|
|
|
|
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.
|
|
|
|
class Payment(models.Model):
|
|
uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
|
|
|
|
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)
|
|
|
|
# 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(),
|
|
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:
|
|
if method.primary:
|
|
return method
|
|
|
|
return None
|
|
|
|
###
|
|
# Bills.
|
|
|
|
class Bill(models.Model):
|
|
uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
|
|
owner = models.ForeignKey(get_user_model(),
|
|
on_delete=models.CASCADE)
|
|
|
|
creation_date = models.DateTimeField(auto_now_add=True)
|
|
starting_date = models.DateTimeField()
|
|
ending_date = models.DateTimeField()
|
|
due_date = models.DateField()
|
|
|
|
valid = models.BooleanField(default=True)
|
|
|
|
@property
|
|
def reference(self):
|
|
return "{}-{}".format(
|
|
self.owner.username,
|
|
self.creation_date.strftime("%Y-%m-%d-%H%M"))
|
|
|
|
@property
|
|
def records(self):
|
|
bill_records = []
|
|
orders = Order.objects.filter(bill=self)
|
|
for order in orders:
|
|
for order_record in order.records:
|
|
bill_record = BillRecord(self, order_record)
|
|
bill_records.append(bill_record)
|
|
|
|
return bill_records
|
|
|
|
@property
|
|
def total(self):
|
|
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.
|
|
"""
|
|
|
|
def __init__(self, bill, order_record):
|
|
self.bill = bill
|
|
self.order = order_record.order
|
|
self.recurring_price = order_record.recurring_price
|
|
self.recurring_period = order_record.recurring_period
|
|
self.description = order_record.description
|
|
|
|
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:
|
|
billed_until = self.order.ending_date
|
|
|
|
billed_from = self.bill.starting_date
|
|
if self.order.starting_date > self.bill.starting_date:
|
|
billed_from = self.order.starting_date
|
|
|
|
if billed_from > billed_until:
|
|
# TODO: think about and check edges cases. This should not be
|
|
# possible.
|
|
raise Exception('Impossible billing delta!')
|
|
|
|
billed_delta = billed_until - billed_from
|
|
|
|
# TODO: refactor this thing?
|
|
# TODO: weekly
|
|
# TODO: yearly
|
|
if self.recurring_period == RecurringPeriod.PER_MONTH:
|
|
days = ceil(billed_delta / timedelta(days=1))
|
|
|
|
# XXX: we assume monthly bills for now.
|
|
if (self.bill.starting_date.year != self.bill.starting_date.year or
|
|
self.bill.starting_date.month != self.bill.ending_date.month):
|
|
raise Exception('Bill {} covers more than one month. Cannot bill PER_MONTH.'.
|
|
format(self.bill.uuid))
|
|
|
|
# XXX: minumal length of monthly order is to be enforced somewhere else.
|
|
(_, days_in_month) = monthrange(
|
|
self.bill.starting_date.year,
|
|
self.bill.starting_date.month)
|
|
return Decimal(days / days_in_month)
|
|
elif self.recurring_period == RecurringPeriod.PER_DAY:
|
|
days = ceil(billed_delta / timedelta(days=1))
|
|
return Decimal(days)
|
|
elif self.recurring_period == RecurringPeriod.PER_HOUR:
|
|
hours = ceil(billed_delta / timedelta(hours=1))
|
|
return Decimal(hours)
|
|
elif self.recurring_period == RecurringPeriod.PER_SECOND:
|
|
seconds = ceil(billed_delta / timedelta(seconds=1))
|
|
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.
|
|
|
|
# Order are assumed IMMUTABLE and used as SOURCE OF TRUST for generating
|
|
# bills. Do **NOT** mutate then!
|
|
class Order(models.Model):
|
|
uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
|
|
owner = models.ForeignKey(get_user_model(),
|
|
on_delete=models.CASCADE,
|
|
editable=False)
|
|
|
|
# TODO: enforce ending_date - starting_date to be larger than recurring_period.
|
|
creation_date = models.DateTimeField(auto_now_add=True)
|
|
starting_date = models.DateTimeField(auto_now_add=True)
|
|
ending_date = models.DateTimeField(blank=True,
|
|
null=True)
|
|
|
|
bill = models.ManyToManyField(Bill,
|
|
editable=False,
|
|
blank=True)
|
|
|
|
recurring_period = models.CharField(max_length=32,
|
|
choices = RecurringPeriod.choices,
|
|
default = RecurringPeriod.PER_MONTH)
|
|
|
|
@property
|
|
def records(self):
|
|
return OrderRecord.objects.filter(order=self)
|
|
|
|
@property
|
|
def one_time_price(self):
|
|
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, one_time_price, recurring_price, description):
|
|
OrderRecord.objects.create(order=self,
|
|
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)
|
|
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)])
|
|
|
|
description = models.TextField()
|
|
|
|
|
|
@property
|
|
def recurring_period(self):
|
|
return self.order.recurring_period
|
|
|
|
@property
|
|
def starting_date(self):
|
|
return self.order.starting_date
|
|
|
|
@property
|
|
def ending_date(self):
|
|
return self.order.ending_date
|
|
|
|
|
|
###
|
|
# Products
|
|
|
|
# Abstract (= no database representation) class used as parent for products
|
|
# (e.g. uncloud_vm.models.VMProduct).
|
|
class Product(UncloudModel):
|
|
uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
|
|
owner = models.ForeignKey(get_user_model(),
|
|
on_delete=models.CASCADE,
|
|
editable=False)
|
|
|
|
description = ""
|
|
|
|
status = models.CharField(max_length=32,
|
|
choices=UncloudStatus.choices,
|
|
default=UncloudStatus.PENDING)
|
|
|
|
order = models.ForeignKey(Order,
|
|
on_delete=models.CASCADE,
|
|
editable=False,
|
|
null=True)
|
|
|
|
# Default period for all products
|
|
default_recurring_period = RecurringPeriod.PER_MONTH
|
|
|
|
|
|
@property
|
|
def recurring_price(self, recurring_period=RecurringPeriod.PER_MONTH):
|
|
pass # To be implemented in child.
|
|
|
|
@property
|
|
def one_time_price(self):
|
|
return 0
|
|
|
|
@property
|
|
def recurring_period(self):
|
|
return self.order.recurring_period
|
|
|
|
@staticmethod
|
|
def allowed_recurring_periods():
|
|
return RecurringPeriod.choices
|
|
|
|
class Meta:
|
|
abstract = True
|
|
|
|
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)
|
|
|
|
"""
|
|
|
|
|
|
if self.default_recurring_period == RecurringPeriod.PER_YEAR:
|
|
if requested_period == RecurringPeriod.PER_YEAR:
|
|
return self.recurring_price
|
|
if requested_period == RecurringPeriod.PER_MONTH:
|
|
return self.recurring_price/11.
|
|
if requested_period == RecurringPeriod.PER_DAY:
|
|
return self.recurring_price/11./28.
|
|
|
|
elif self.default_recurring_period == RecurringPeriod.PER_MONTH:
|
|
if requested_period == RecurringPeriod.PER_YEAR:
|
|
return self.recurring_price*11
|
|
if requested_period == RecurringPeriod.PER_MONTH:
|
|
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_YEAR:
|
|
return self.recurring_price*11*28
|
|
if requested_period == RecurringPeriod.PER_MONTH:
|
|
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")
|