185 lines
5.9 KiB
Python
185 lines
5.9 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 registrasion import models as rego
|
|
|
|
from cart import CartController
|
|
|
|
|
|
class InvoiceController(object):
|
|
|
|
def __init__(self, invoice):
|
|
self.invoice = invoice
|
|
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.'''
|
|
|
|
try:
|
|
invoice = rego.Invoice.objects.get(
|
|
cart=cart,
|
|
cart_revision=cart.revision,
|
|
void=False,
|
|
)
|
|
except ObjectDoesNotExist:
|
|
cart_controller = CartController(cart)
|
|
cart_controller.validate_cart() # Raises ValidationError on fail.
|
|
|
|
# Void past invoices for this cart
|
|
rego.Invoice.objects.filter(cart=cart).update(void=True)
|
|
|
|
invoice = cls._generate(cart)
|
|
|
|
return InvoiceController(invoice)
|
|
|
|
@classmethod
|
|
def resolve_discount_value(cls, item):
|
|
try:
|
|
condition = rego.DiscountForProduct.objects.get(
|
|
discount=item.discount,
|
|
product=item.product
|
|
)
|
|
except ObjectDoesNotExist:
|
|
condition = rego.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
|
|
def _generate(cls, cart):
|
|
''' Generates an invoice for the given cart. '''
|
|
invoice = rego.Invoice.objects.create(
|
|
user=cart.user,
|
|
cart=cart,
|
|
cart_revision=cart.revision,
|
|
value=Decimal()
|
|
)
|
|
invoice.save()
|
|
|
|
product_items = rego.ProductItem.objects.filter(cart=cart)
|
|
|
|
if len(product_items) == 0:
|
|
raise ValidationError("Your cart is empty.")
|
|
|
|
product_items = product_items.order_by(
|
|
"product__category__order", "product__order"
|
|
)
|
|
discount_items = rego.DiscountItem.objects.filter(cart=cart)
|
|
invoice_value = Decimal()
|
|
for item in product_items:
|
|
product = item.product
|
|
line_item = rego.LineItem.objects.create(
|
|
invoice=invoice,
|
|
description="%s - %s" % (product.category.name, product.name),
|
|
quantity=item.quantity,
|
|
price=product.price,
|
|
)
|
|
line_item.save()
|
|
invoice_value += line_item.quantity * line_item.price
|
|
|
|
for item in discount_items:
|
|
line_item = rego.LineItem.objects.create(
|
|
invoice=invoice,
|
|
description=item.discount.description,
|
|
quantity=item.quantity,
|
|
price=cls.resolve_discount_value(item) * -1,
|
|
)
|
|
line_item.save()
|
|
invoice_value += line_item.quantity * line_item.price
|
|
|
|
# TODO: calculate line items from discounts
|
|
invoice.value = invoice_value
|
|
invoice.save()
|
|
|
|
return invoice
|
|
|
|
def update_validity(self):
|
|
''' Updates the validity of this invoice if the cart it is attached to
|
|
has updated. '''
|
|
if self.invoice.cart is not None:
|
|
if self.invoice.cart.revision != self.invoice.cart_revision:
|
|
self.void()
|
|
|
|
def void(self):
|
|
''' Voids the invoice if it is valid to do so. '''
|
|
if self.invoice.paid:
|
|
raise ValidationError("Paid invoices cannot be voided, "
|
|
"only refunded.")
|
|
self.invoice.void = True
|
|
self.invoice.save()
|
|
|
|
@transaction.atomic
|
|
def pay(self, reference, amount):
|
|
''' Pays the invoice by the given amount. If the payment
|
|
equals the total on the invoice, finalise the invoice.
|
|
(NB should be transactional.)
|
|
'''
|
|
if self.invoice.cart:
|
|
cart = CartController(self.invoice.cart)
|
|
cart.validate_cart() # Raises ValidationError if invalid
|
|
|
|
if self.invoice.void:
|
|
raise ValidationError("Void invoices cannot be paid")
|
|
|
|
if self.invoice.paid:
|
|
raise ValidationError("Paid invoices cannot be paid again")
|
|
|
|
''' Adds a payment '''
|
|
payment = rego.Payment.objects.create(
|
|
invoice=self.invoice,
|
|
reference=reference,
|
|
amount=amount,
|
|
)
|
|
payment.save()
|
|
|
|
payments = rego.Payment.objects.filter(invoice=self.invoice)
|
|
agg = payments.aggregate(Sum("amount"))
|
|
total = agg["amount__sum"]
|
|
|
|
if total == self.invoice.value:
|
|
self.invoice.paid = True
|
|
|
|
if self.invoice.cart:
|
|
cart = self.invoice.cart
|
|
cart.active = False
|
|
cart.save()
|
|
|
|
self.invoice.save()
|
|
|
|
@transaction.atomic
|
|
def refund(self, reference, amount):
|
|
''' Refunds the invoice by the given amount. The invoice is
|
|
marked as unpaid, and the underlying cart is marked as released.
|
|
'''
|
|
|
|
if self.invoice.void:
|
|
raise ValidationError("Void invoices cannot be refunded")
|
|
|
|
''' Adds a payment '''
|
|
payment = rego.Payment.objects.create(
|
|
invoice=self.invoice,
|
|
reference=reference,
|
|
amount=0 - amount,
|
|
)
|
|
payment.save()
|
|
|
|
self.invoice.paid = False
|
|
self.invoice.void = True
|
|
|
|
if self.invoice.cart:
|
|
cart = self.invoice.cart
|
|
cart.released = True
|
|
cart.save()
|
|
|
|
self.invoice.save()
|