symposion_app/registrasion/controllers/invoice.py
2016-08-21 17:14:19 +10:00

367 lines
12 KiB
Python

from decimal import Decimal
from django.core.exceptions import ObjectDoesNotExist
from django.core.exceptions import ValidationError
from django.db import transaction
from django.db.models import Sum
from django.utils import timezone
from registrasion.contrib.mail import send_email
from registrasion.models import commerce
from registrasion.models import conditions
from registrasion.models import people
from cart import CartController
from credit_note import CreditNoteController
from for_id import ForId
class InvoiceController(ForId, object):
__MODEL__ = commerce.Invoice
def __init__(self, invoice):
self.invoice = invoice
self.update_status()
self.update_validity() # Make sure this invoice is up-to-date
@classmethod
def for_cart(cls, cart):
''' Returns an invoice object for a given cart at its current revision.
If such an invoice does not exist, the cart is validated, and if valid,
an invoice is generated.'''
cart.refresh_from_db()
try:
invoice = commerce.Invoice.objects.exclude(
status=commerce.Invoice.STATUS_VOID,
).get(
cart=cart,
cart_revision=cart.revision,
)
except ObjectDoesNotExist:
cart_controller = CartController(cart)
cart_controller.validate_cart() # Raises ValidationError on fail.
cls.void_all_invoices(cart)
invoice = cls._generate(cart)
return cls(invoice)
@classmethod
def void_all_invoices(cls, cart):
invoices = commerce.Invoice.objects.filter(cart=cart).all()
for invoice in invoices:
cls(invoice).void()
@classmethod
def resolve_discount_value(cls, item):
try:
condition = conditions.DiscountForProduct.objects.get(
discount=item.discount,
product=item.product
)
except ObjectDoesNotExist:
condition = conditions.DiscountForCategory.objects.get(
discount=item.discount,
category=item.product.category
)
if condition.percentage is not None:
value = item.product.price * (condition.percentage / 100)
else:
value = condition.price
return value
@classmethod
@transaction.atomic
def _generate(cls, cart):
''' Generates an invoice for the given cart. '''
cart.refresh_from_db()
issued = timezone.now()
reservation_limit = cart.reservation_duration + cart.time_last_updated
# Never generate a due time that is before the issue time
due = max(issued, reservation_limit)
# Get the invoice recipient
profile = people.AttendeeProfileBase.objects.get_subclass(
id=cart.user.attendee.attendeeprofilebase.id,
)
recipient = profile.invoice_recipient()
invoice = commerce.Invoice.objects.create(
user=cart.user,
cart=cart,
cart_revision=cart.revision,
status=commerce.Invoice.STATUS_UNPAID,
value=Decimal(),
issue_time=issued,
due_time=due,
recipient=recipient,
)
product_items = commerce.ProductItem.objects.filter(cart=cart)
product_items = product_items.select_related(
"product",
"product__category",
)
if len(product_items) == 0:
raise ValidationError("Your cart is empty.")
product_items = product_items.order_by(
"product__category__order", "product__order"
)
discount_items = commerce.DiscountItem.objects.filter(cart=cart)
discount_items = discount_items.select_related(
"discount",
"product",
"product__category",
)
line_items = []
invoice_value = Decimal()
for item in product_items:
product = item.product
line_item = commerce.LineItem(
invoice=invoice,
description="%s - %s" % (product.category.name, product.name),
quantity=item.quantity,
price=product.price,
product=product,
)
line_items.append(line_item)
invoice_value += line_item.quantity * line_item.price
for item in discount_items:
line_item = commerce.LineItem(
invoice=invoice,
description=item.discount.description,
quantity=item.quantity,
price=cls.resolve_discount_value(item) * -1,
product=item.product,
)
line_items.append(line_item)
invoice_value += line_item.quantity * line_item.price
commerce.LineItem.objects.bulk_create(line_items)
invoice.value = invoice_value
invoice.save()
cls.email_on_invoice_creation(invoice)
return invoice
def can_view(self, user=None, access_code=None):
''' Returns true if the accessing user is allowed to view this invoice,
or if the given access code matches this invoice's user's access code.
'''
if user == self.invoice.user:
return True
if user.is_staff:
return True
if self.invoice.user.attendee.access_code == access_code:
return True
return False
def _refresh(self):
''' Refreshes the underlying invoice and cart objects. '''
self.invoice.refresh_from_db()
if self.invoice.cart:
self.invoice.cart.refresh_from_db()
def validate_allowed_to_pay(self):
''' Passes cleanly if we're allowed to pay, otherwise raise
a ValidationError. '''
self._refresh()
if not self.invoice.is_unpaid:
raise ValidationError("You can only pay for unpaid invoices.")
if not self.invoice.cart:
return
if not self._invoice_matches_cart():
raise ValidationError("The registration has been amended since "
"generating this invoice.")
CartController(self.invoice.cart).validate_cart()
def total_payments(self):
''' Returns the total amount paid towards this invoice. '''
payments = commerce.PaymentBase.objects.filter(invoice=self.invoice)
total_paid = payments.aggregate(Sum("amount"))["amount__sum"] or 0
return total_paid
def update_status(self):
''' Updates the status of this invoice based upon the total
payments.'''
old_status = self.invoice.status
total_paid = self.total_payments()
num_payments = commerce.PaymentBase.objects.filter(
invoice=self.invoice,
).count()
remainder = self.invoice.value - total_paid
if old_status == commerce.Invoice.STATUS_UNPAID:
# Invoice had an amount owing
if remainder <= 0:
# Invoice no longer has amount owing
self._mark_paid()
elif total_paid == 0 and num_payments > 0:
# Invoice has multiple payments totalling zero
self._mark_void()
elif old_status == commerce.Invoice.STATUS_PAID:
if remainder > 0:
# Invoice went from having a remainder of zero or less
# to having a positive remainder -- must be a refund
self._mark_refunded()
elif old_status == commerce.Invoice.STATUS_REFUNDED:
# Should not ever change from here
pass
elif old_status == commerce.Invoice.STATUS_VOID:
# Should not ever change from here
pass
# Generate credit notes from residual payments
residual = 0
if self.invoice.is_paid:
if remainder < 0:
residual = 0 - remainder
elif self.invoice.is_void or self.invoice.is_refunded:
residual = total_paid
if residual != 0:
CreditNoteController.generate_from_invoice(self.invoice, residual)
self.email_on_invoice_change(
self.invoice,
old_status,
self.invoice.status,
)
def _mark_paid(self):
''' Marks the invoice as paid, and updates the attached cart if
necessary. '''
cart = self.invoice.cart
if cart:
cart.status = commerce.Cart.STATUS_PAID
cart.save()
self.invoice.status = commerce.Invoice.STATUS_PAID
self.invoice.save()
def _mark_refunded(self):
''' Marks the invoice as refunded, and updates the attached cart if
necessary. '''
cart = self.invoice.cart
if cart:
cart.status = commerce.Cart.STATUS_RELEASED
cart.save()
self.invoice.status = commerce.Invoice.STATUS_REFUNDED
self.invoice.save()
def _mark_void(self):
''' Marks the invoice as refunded, and updates the attached cart if
necessary. '''
self.invoice.status = commerce.Invoice.STATUS_VOID
self.invoice.save()
def _invoice_matches_cart(self):
''' Returns true if there is no cart, or if the revision of this
invoice matches the current revision of the cart. '''
self._refresh()
cart = self.invoice.cart
if not cart:
return True
return cart.revision == self.invoice.cart_revision
def update_validity(self):
''' Voids this invoice if the cart it is attached to has updated. '''
if not self._invoice_matches_cart():
self.void()
def void(self):
''' Voids the invoice if it is valid to do so. '''
if self.total_payments() > 0:
raise ValidationError("Invoices with payments must be refunded.")
elif self.invoice.is_refunded:
raise ValidationError("Refunded invoices may not be voided.")
self._mark_void()
@transaction.atomic
def refund(self):
''' Refunds the invoice by generating a CreditNote for the value of
all of the payments against the cart.
The invoice is marked as refunded, and the underlying cart is marked
as released.
'''
if self.invoice.is_void:
raise ValidationError("Void invoices cannot be refunded")
# Raises a credit note fot the value of the invoice.
amount = self.total_payments()
if amount == 0:
self.void()
return
CreditNoteController.generate_from_invoice(self.invoice, amount)
self.update_status()
@classmethod
def email(cls, invoice, kind):
''' Sends out an e-mail notifying the user about something to do
with that invoice. '''
context = {
"invoice": invoice,
}
send_email(invoice.user.email, kind, context=context)
@classmethod
def email_on_invoice_creation(cls, invoice):
''' Sends out an e-mail notifying the user that an invoice has been
created. '''
cls.email(invoice, "invoice_created")
@classmethod
def email_on_invoice_change(cls, invoice, old_status, new_status):
''' Sends out all of the necessary notifications that the status of the
invoice has changed to:
- Invoice is now paid
- Invoice is now refunded
'''
# The statuses that we don't care about.
silent_status = [
commerce.Invoice.STATUS_VOID,
commerce.Invoice.STATUS_UNPAID,
]
if old_status == new_status:
return
if False and new_status in silent_status:
pass
cls.email(invoice, "invoice_updated")