Add a maximum budget to vouchers (#1526)

* Data model changes

* Fix test failures

* Adjustments

* Some tests and API support

* Check when extending orders

* Make things more deterministic, fix style

* Do not apply negative discounts

* Update price_before_voucher on item/subevent changes

* Add tests for price_before_voucher in combination with free price

* Fix InvoiceAddress.DoesNotExist

src/tests/presale/test_cart.py

@@ -1388,6 +1388,32 @@ class CartTest(CartTestMixin, TestCase):
         self.assertEqual(objs[0].item, self.ticket)
         self.assertIsNone(objs[0].variation)
         self.assertEqual(objs[0].price, Decimal('21.00'))
+        self.assertEqual(objs[0].price_before_voucher, Decimal('23.00'))
+
+    def test_voucher_free_price_before_voucher_cap(self):
+        with scopes_disabled():
+            v = Voucher.objects.create(item=self.ticket, value=Decimal('10.00'), price_mode='percent', event=self.event)
+        self.ticket.free_price = True
+        self.ticket.save()
+        response = self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'item_%d' % self.ticket.id: '1',
+            'price_%d' % self.ticket.id: '41.00',
+            '_voucher_code': v.code,
+        }, follow=True)
+        self.assertRedirects(response, '/%s/%s/?require_cookie=true' % (self.orga.slug, self.event.slug),
+                             target_status_code=200)
+        doc = BeautifulSoup(response.rendered_content, "lxml")
+        self.assertIn('Early-bird', doc.select('.cart .cart-row')[0].select('strong')[0].text)
+        self.assertIn('1', doc.select('.cart .cart-row')[0].select('.count')[0].text)
+        self.assertIn('41', doc.select('.cart .cart-row')[0].select('.price')[0].text)
+        self.assertIn('41', doc.select('.cart .cart-row')[0].select('.price')[1].text)
+        with scopes_disabled():
+            objs = list(CartPosition.objects.filter(cart_id=self.session_key, event=self.event))
+        self.assertEqual(len(objs), 1)
+        self.assertEqual(objs[0].item, self.ticket)
+        self.assertIsNone(objs[0].variation)
+        self.assertEqual(objs[0].price, Decimal('41.00'))
+        self.assertEqual(objs[0].price_before_voucher, Decimal('41.00'))
 
     def test_voucher_free_price_lower_bound(self):
         with scopes_disabled():
@@ -1412,6 +1438,7 @@ class CartTest(CartTestMixin, TestCase):
         self.assertEqual(objs[0].item, self.ticket)
         self.assertIsNone(objs[0].variation)
         self.assertEqual(objs[0].price, Decimal('20.70'))
+        self.assertEqual(objs[0].price_before_voucher, Decimal('23.00'))
 
     def test_voucher_redemed(self):
         with scopes_disabled():
@@ -2438,6 +2465,20 @@ class CartAddonTest(CartTestMixin, TestCase):
         assert cp2.expires > now()
         assert cp2.addon_to_id == cp1.pk
 
+    @classscope(attr='orga')
+    def test_expand_expired_refresh_voucher(self):
+        v = Voucher.objects.create(item=self.ticket, value=Decimal('20.00'), event=self.event, price_mode='set',
+                                   valid_until=now() + timedelta(days=2), max_usages=999, redeemed=0)
+        cp1 = CartPosition.objects.create(
+            expires=now() - timedelta(minutes=10), item=self.ticket, price=Decimal('21.50'),
+            event=self.event, cart_id=self.session_key, voucher=v
+        )
+        self.cm.extend_expired_positions()
+        self.cm.commit()
+        cp1.refresh_from_db()
+        assert cp1.expires > now()
+        assert cp1.price_before_voucher == Decimal('23.00')
+
 
 class CartBundleTest(CartTestMixin, TestCase):
     @scopes_disabled()
@@ -2490,6 +2531,30 @@ class CartBundleTest(CartTestMixin, TestCase):
         assert cp.price == 23 - 1.5
         assert cp.addons.count() == 1
         assert cp.voucher == v
+        assert cp.price_before_voucher == 23 - 1.5
+        a = cp.addons.get()
+        assert a.item == self.trans
+        assert a.price == 1.5
+        assert not a.voucher
+
+    @classscope(attr='orga')
+    def test_discounted_voucher_on_base_product(self):
+        v = self.event.vouchers.create(code="foo", item=self.ticket, price_mode='subtract', value=Decimal('1.50'))
+        self.cm.add_new_items([
+            {
+                'item': self.ticket.pk,
+                'variation': None,
+                'voucher': v.code,
+                'count': 1
+            }
+        ])
+        self.cm.commit()
+        cp = CartPosition.objects.get(addon_to__isnull=True)
+        assert cp.item == self.ticket
+        assert cp.price == 23 - 1.5 - 1.5
+        assert cp.addons.count() == 1
+        assert cp.voucher == v
+        assert cp.price_before_voucher == 23 - 1.5
         a = cp.addons.get()
         assert a.item == self.trans
         assert a.price == 1.5