UTC = pytz.timezone('UTC')

class InvoiceTestCase(RegistrationCartTestCase):

    def test_create_invoice(self):

        current_cart = TestingCartController.for_user(self.USER_1)

        # Should be able to create an invoice after the product is added

        current_cart.add_to_cart(self.PROD_1, 1)

        invoice_1 = TestingInvoiceController.for_cart(current_cart.cart)

        # Invoice should have a value equal to cost of PROD_1 and PROD_2

        self.assertEqual(

            self.PROD_1.price + self.PROD_2.price,

            invoice_2.invoice.value)

    def test_invoice_controller_for_id_works(self):

        id_ = invoice.invoice.id

        invoice1 = TestingInvoiceController.for_id(id_)

        invoice2 = TestingInvoiceController.for_id(str(id_))

        # Now try to invoice the first user

        with self.assertRaises(ValidationError):

            TestingInvoiceController.for_cart(current_cart.cart)

    def test_paying_invoice_makes_new_cart(self):

        invoice.pay("A payment!", invoice.invoice.value)

        # This payment is for the correct amount invoice should be paid.

        self.assertTrue(invoice.invoice.is_paid)

        # Cart should not be active

        self.assertFalse(invoice.invoice.cart.active)

        # Asking for a cart should generate a new one

        new_cart = TestingCartController.for_user(self.USER_1)

    def test_invoice_includes_discounts(self):

        voucher = inventory.Voucher.objects.create(

            recipient="Voucher recipient",

            code="VOUCHER",

            limit=1

        # Viewing invoice_2's invoice should *not* show it as void

        invoice_2_new = TestingInvoiceController(invoice_2.invoice)

        self.assertFalse(invoice_2_new.invoice.is_void)

    def test_voiding_invoice_creates_new_invoice(self):

        self.assertFalse(invoice_1.invoice.is_void)

        invoice_1.void()

        self.assertNotEqual(invoice_1.invoice, invoice_2.invoice)

    def test_cannot_pay_void_invoice(self):

        invoice_1.void()

        with self.assertRaises(ValidationError):

            invoice_1.validate_allowed_to_pay()

    def test_cannot_void_paid_invoice(self):

        invoice.pay("Reference", invoice.invoice.value)

        with self.assertRaises(ValidationError):

            invoice.void()

    def test_cannot_void_partially_paid_invoice(self):

        invoice.pay("Reference", invoice.invoice.value - 1)

        self.assertTrue(invoice.invoice.is_unpaid)

        with self.assertRaises(ValidationError):

            invoice.void()

        cart.add_to_cart(self.PROD_1, 1)

        with self.assertRaises(ValidationError):

            invoice.validate_allowed_to_pay()

    def test_overpaid_invoice_results_in_credit_note(self):

        # Invoice is overpaid by 1 unit

        to_pay = invoice.invoice.value + 1

        invoice.pay("Reference", to_pay)

        # The total paid should be equal to the value of the invoice only

            invoice=invoice.invoice,

        )

        self.assertEqual(1, credit_notes.count())

        self.assertEqual(to_pay - invoice.invoice.value, credit_notes[0].value)

    def test_full_paid_invoice_does_not_generate_credit_note(self):

        # Invoice is paid evenly

        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())

        credit_notes = commerce.CreditNote.objects.filter(

            invoice=invoice.invoice,

        )

        self.assertEqual(0, credit_notes.count())

    def test_refund_partially_paid_invoice_generates_correct_credit_note(self):

        # Invoice is underpaid by 1 unit

        to_pay = invoice.invoice.value - 1

        invoice.pay("Reference", to_pay)

        invoice.refund()

            invoice=invoice.invoice,

        )

        self.assertEqual(1, credit_notes.count())

        self.assertEqual(to_pay, credit_notes[0].value)

    def test_refund_fully_paid_invoice_generates_correct_credit_note(self):

        to_pay = invoice.invoice.value

        invoice.pay("Reference", to_pay)

        self.assertTrue(invoice.invoice.is_paid)

        invoice.refund()

            invoice=invoice.invoice,

        )

        self.assertEqual(1, credit_notes.count())

        self.assertEqual(to_pay, credit_notes[0].value)

    def test_apply_credit_note_pays_invoice(self):

        to_pay = invoice.invoice.value

        invoice.pay("Reference", to_pay)

        self.assertTrue(invoice.invoice.is_paid)

        invoice.refund()

        self.assertTrue(invoice2.invoice.is_paid)

        # That invoice should not show up as unclaimed any more

        self.assertEquals(0, commerce.CreditNote.unclaimed().count())

    def test_apply_credit_note_generates_new_credit_note_if_overpaying(self):

        to_pay = invoice.invoice.value

        invoice.pay("Reference", to_pay)

        self.assertTrue(invoice.invoice.is_paid)

        invoice.refund()

        self.assertEquals(

            invoice.invoice.value - invoice2.invoice.value,

            credit_note2.value,

        )

    def test_cannot_apply_credit_note_on_invalid_invoices(self):

        to_pay = invoice.invoice.value

        invoice.pay("Reference", to_pay)

        self.assertTrue(invoice.invoice.is_paid)

        invoice.refund()

        # There should be one credit note generated out of the invoice.

        credit_note = commerce.CreditNote.objects.get(invoice=invoice.invoice)

        cn = TestingCreditNoteController(credit_note)

        # Create a new cart with invoice, pay it

        invoice_2.pay("LOL", invoice_2.invoice.value)

        # Cannot pay paid invoice

        with self.assertRaises(ValidationError):

            cn.apply_to_invoice(invoice_2.invoice)

        invoice_2.refund()

        # Cannot pay refunded invoice

        with self.assertRaises(ValidationError):

            cn.apply_to_invoice(invoice_2.invoice)

        # Create a new cart with invoice

        invoice_2.void()

        # Cannot pay void invoice

        with self.assertRaises(ValidationError):

            cn.apply_to_invoice(invoice_2.invoice)

    def test_cannot_apply_a_refunded_credit_note(self):

        to_pay = invoice.invoice.value

        invoice.pay("Reference", to_pay)

        self.assertTrue(invoice.invoice.is_paid)

        invoice.refund()

        # Cannot pay with this credit note.

        with self.assertRaises(ValidationError):

            cn.apply_to_invoice(invoice_2.invoice)

    def test_cannot_refund_an_applied_credit_note(self):

        to_pay = invoice.invoice.value

        invoice.pay("Reference", to_pay)

        self.assertTrue(invoice.invoice.is_paid)

        invoice.refund()