Moves total_payments() to Invoice model; adds balance_due()

registrasion/controllers/invoice.py

@@ -269,19 +269,12 @@ class InvoiceController(ForId, object):
 
         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()
+        total_paid = self.invoice.total_payments()
         num_payments = commerce.PaymentBase.objects.filter(
             invoice=self.invoice,
         ).count()
@@ -366,7 +359,7 @@ class InvoiceController(ForId, object):
     def update_validity(self):
         ''' Voids this invoice if the cart it is attached to has updated. '''
         if not self._invoice_matches_cart():
-            if self.total_payments() > 0:
+            if self.invoice.total_payments() > 0:
                 # Free up the payments made to this invoice
                 self.refund()
             else:
@@ -374,7 +367,7 @@ class InvoiceController(ForId, object):
 
     def void(self):
         ''' Voids the invoice if it is valid to do so. '''
-        if self.total_payments() > 0:
+        if self.invoice.total_payments() > 0:
             raise ValidationError("Invoices with payments must be refunded.")
         elif self.invoice.is_refunded:
             raise ValidationError("Refunded invoices may not be voided.")
@@ -394,7 +387,7 @@ class InvoiceController(ForId, object):
             raise ValidationError("Void invoices cannot be refunded")
 
         # Raises a credit note fot the value of the invoice.
-        amount = self.total_payments()
+        amount = self.invoice.total_payments()
 
         if amount == 0:
             self.void()

registrasion/models/commerce.py

@@ -4,7 +4,7 @@ from . import inventory
 from django.contrib.auth.models import User
 from django.core.exceptions import ValidationError
 from django.db import models
-from django.db.models import F, Q
+from django.db.models import F, Q, Sum
 from django.utils import timezone
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
@@ -175,6 +175,17 @@ class Invoice(models.Model):
     def is_refunded(self):
         return self.status == self.STATUS_REFUNDED
 
+    def total_payments(self):
+        ''' Returns the total amount paid towards this invoice. '''
+
+        payments = PaymentBase.objects.filter(invoice=self)
+        total_paid = payments.aggregate(Sum("amount"))["amount__sum"] or 0
+        return total_paid
+
+    def balance_due(self):
+        ''' Returns the total balance remaining towards this invoice. '''
+        return self.value - self.total_payments()
+
     # Invoice Number
     user = models.ForeignKey(User)
     cart = models.ForeignKey(Cart, null=True)
@@ -224,6 +235,11 @@ class LineItem(models.Model):
         return "Line: %s * %d @ %s" % (
             self.description, self.quantity, self.price)
 
+    @property
+    def total_price(self):
+        ''' price * quantity '''
+        return self.price * self.quantity
+
     invoice = models.ForeignKey(Invoice)
     description = models.CharField(max_length=255)
     quantity = models.PositiveIntegerField()

registrasion/templatetags/registrasion_tags.py

@@ -74,24 +74,3 @@ def items_purchased(context, category=None):
     return ItemController(context.request.user).items_purchased(
         category=category
     )
-
-
-@register.filter
-def multiply(value, arg):
-    ''' Multiplies value by arg.
-
-    This is useful when displaying invoices, as it lets you multiply the
-    quantity by the unit value.
-
-    Arguments:
-
-        value (number)
-
-        arg (number)
-
-    Returns:
-        number: value * arg
-
-    '''
-
-    return value * arg

registrasion/tests/test_credit_note.py

@@ -29,7 +29,9 @@ class CreditNoteTestCase(TestHelperMixin, RegistrationCartTestCase):
         invoice.pay("Reference", to_pay)
 
         # The total paid should be equal to the value of the invoice only
-        self.assertEqual(invoice.invoice.value, invoice.total_payments())
+        self.assertEqual(
+            invoice.invoice.value, invoice.invoice.total_payments()
+        )
         self.assertTrue(invoice.invoice.is_paid)
 
         # There should be a credit note generated out of the invoice.
@@ -46,7 +48,9 @@ class CreditNoteTestCase(TestHelperMixin, RegistrationCartTestCase):
         invoice.pay("Reference", invoice.invoice.value)
 
         # The total paid should be equal to the value of the invoice only
-        self.assertEqual(invoice.invoice.value, invoice.total_payments())
+        self.assertEqual(
+            invoice.invoice.value, invoice.invoice.total_payments()
+        )
         self.assertTrue(invoice.invoice.is_paid)
 
         # There should be no credit notes
@@ -64,7 +68,7 @@ class CreditNoteTestCase(TestHelperMixin, RegistrationCartTestCase):
         invoice.refund()
 
         # The total paid should be zero
-        self.assertEqual(0, invoice.total_payments())
+        self.assertEqual(0, invoice.invoice.total_payments())
         self.assertTrue(invoice.invoice.is_void)
 
         # There should be a credit note generated out of the invoice.
@@ -84,7 +88,7 @@ class CreditNoteTestCase(TestHelperMixin, RegistrationCartTestCase):
         invoice.refund()
 
         # The total paid should be zero
-        self.assertEqual(0, invoice.total_payments())
+        self.assertEqual(0, invoice.invoice.total_payments())
         self.assertTrue(invoice.invoice.is_refunded)
 
         # There should be a credit note generated out of the invoice.
@@ -367,7 +371,7 @@ class CreditNoteTestCase(TestHelperMixin, RegistrationCartTestCase):
         notes_value = self._generate_multiple_credit_notes()
         invoice = self._manual_invoice(notes_value + 1)
 
-        self.assertEqual(notes_value, invoice.total_payments())
+        self.assertEqual(notes_value, invoice.invoice.total_payments())
         self.assertTrue(invoice.invoice.is_unpaid)
 
         user_unclaimed = commerce.CreditNote.unclaimed()
@@ -384,7 +388,7 @@ class CreditNoteTestCase(TestHelperMixin, RegistrationCartTestCase):
         invoice = self._manual_invoice(notes_value - 1)
 
 
-        self.assertEqual(notes_value - 1, invoice.total_payments())
+        self.assertEqual(notes_value - 1, invoice.invoice.total_payments())
         self.assertTrue(invoice.invoice.is_paid)
 
         user_unclaimed = commerce.CreditNote.unclaimed().filter(
@@ -426,7 +430,7 @@ class CreditNoteTestCase(TestHelperMixin, RegistrationCartTestCase):
 
         # Because there's already an invoice open for this user
         # The credit notes are not automatically applied.
-        self.assertEqual(0, invoice.total_payments())
+        self.assertEqual(0, invoice.invoice.total_payments())
         self.assertTrue(invoice.invoice.is_unpaid)
 
     def test_credit_notes_are_applied_even_if_some_notes_are_claimed(self):

registrasion/tests/test_invoice.py

@@ -97,6 +97,17 @@ class InvoiceTestCase(TestHelperMixin, RegistrationCartTestCase):
         new_cart = TestingCartController.for_user(self.USER_1)
         self.assertNotEqual(invoice.invoice.cart, new_cart.cart)
 
+    def test_total_payments_balance_due(self):
+        invoice = self._invoice_containing_prod_1(2)
+        for i in xrange(0, invoice.invoice.value):
+            self.assertTrue(
+                i + 1, invoice.invoice.total_payments()
+            )
+            self.assertTrue(
+                invoice.invoice.value - i, invoice.invoice.balance_due()
+            )
+            invoice.pay("Pay 1", 1)
+
     def test_invoice_includes_discounts(self):
         voucher = inventory.Voucher.objects.create(
             recipient="Voucher recipient",