Merge pull request #720 from edx/ECOM-4312

ECOM-4312 Check added to prevent multiple order issue.

ecommerce/core/url_utils.py

@@ -33,6 +33,11 @@ def get_lms_enrollment_api_url():
     return get_lms_url('/api/enrollment/v1/enrollment')
 
 
+def get_lms_enrollment_base_api_url():
+    """ Returns the Base lms enrollment api url."""
+    return get_lms_url('/api/enrollment/v1')
+
+
 def get_lms_heartbeat_url():
     return get_lms_url('/heartbeat')
 

ecommerce/extensions/basket/tests/test_views.py

 import datetime
 import hashlib
+import json
 
 import ddt
 from django.conf import settings
@@ -16,6 +17,7 @@ from slumber.exceptions import SlumberBaseException
 from testfixtures import LogCapture
 
 from ecommerce.core.constants import ENROLLMENT_CODE_PRODUCT_CLASS_NAME, ENROLLMENT_CODE_SWITCH
+from ecommerce.core.url_utils import get_lms_enrollment_api_url
 from ecommerce.core.models import SiteConfiguration
 from ecommerce.core.tests import toggle_switch
 from ecommerce.core.url_utils import get_lms_url
@@ -39,6 +41,7 @@ StockRecord = get_model('partner', 'StockRecord')
 COUPON_CODE = 'COUPONTEST'
 
 
+@ddt.ddt
 class BasketSingleItemViewTests(CouponMixin, CourseCatalogTestMixin, LmsApiMockMixin, TestCase):
     """ BasketSingleItemView view tests. """
     path = reverse('basket:single-item')
@@ -55,6 +58,29 @@ class BasketSingleItemViewTests(CouponMixin, CourseCatalogTestMixin, LmsApiMockM
         self.catalog = Catalog.objects.create(partner=self.partner)
         self.catalog.stock_records.add(self.stock_record)
 
+    def mock_enrollment_api_success(self, course_id, mode='audit'):
+        """ Returns a successful response indicating self.user is enrolled in the specified course mode. """
+        self.assertTrue(httpretty.is_enabled())
+        url = '{host}/{username},{course_id}'.format(
+            host=get_lms_enrollment_api_url(),
+            username=self.user.username,
+            course_id=course_id
+        )
+        httpretty.register_uri(httpretty.GET, url, body=json.dumps({'mode': mode}), content_type='application/json')
+
+    def mock_enrollment_api_error(self, error):
+        """ Mock Enrollment api call which raises error when called """
+        self.assertTrue(httpretty.is_enabled())
+
+        def callback(request, uri, headers):  # pylint: disable=unused-argument
+            raise error
+        url = '{host}/{username},{course_id}'.format(
+            host=get_lms_enrollment_api_url(),
+            username=self.user.username,
+            course_id=self.course.id
+        )
+        httpretty.register_uri(httpretty.GET, url, body=callback, content_type='application/json')
+
     def test_login_required(self):
         """ The view should redirect to login page if the user is not logged in. """
         self.client.logout()
@@ -78,8 +104,10 @@ class BasketSingleItemViewTests(CouponMixin, CourseCatalogTestMixin, LmsApiMockM
         self.assertEqual(response.status_code, 400)
         self.assertEqual(response.content, expected_content)
 
+    @httpretty.activate
     def test_unavailable_product(self):
         """ The view should return HTTP 400 if the product is not available for purchase. """
+        self.mock_enrollment_api_success(self.course.id)
         product = self.stock_record.product
         product.expires = pytz.utc.localize(datetime.datetime.min)
         product.save()
@@ -96,6 +124,7 @@ class BasketSingleItemViewTests(CouponMixin, CourseCatalogTestMixin, LmsApiMockM
         """
         Verify the view redirects to the basket summary page, and that the user's basket is prepared for checkout.
         """
+        self.mock_enrollment_api_success(self.course.id)
         self.create_coupon(catalog=self.catalog, code=COUPON_CODE, benefit_value=5)
 
         self.mock_course_api_response(course=self.course)
@@ -111,6 +140,37 @@ class BasketSingleItemViewTests(CouponMixin, CourseCatalogTestMixin, LmsApiMockM
         self.assertTrue(basket.contains_a_voucher)
         self.assertEqual(basket.lines.first().product, self.stock_record.product)
 
+    @httpretty.activate
+    @ddt.data(('verified', False), ('professional', True), ('no-id-professional', False))
+    @ddt.unpack
+    def test_already_verified_student(self, mode, id_verification):
+        """
+        Verify the view return HTTP 400 if the student is already enrolled as verified student in the course
+        """
+        course = CourseFactory()
+        self.mock_enrollment_api_success(course.id, mode=mode)
+        product = course.create_or_update_seat(mode, id_verification, 0, self.partner)
+        stock_record = StockRecordFactory(product=product, partner=self.partner)
+        catalog = Catalog.objects.create(partner=self.partner)
+        catalog.stock_records.add(stock_record)
+
+        url = '{path}?sku={sku}'.format(path=self.path, sku=stock_record.partner_sku)
+        expected_content = 'You are already enrolled in {product}.'.format(product=product.course.name)
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 400)
+        self.assertEqual(response.content, expected_content)
+
+    @httpretty.activate
+    @ddt.data(ConnectionError, SlumberBaseException, Timeout)
+    def test_enrollment_api_failure(self, error):
+        """
+        Verify the view returns HTTP status 400 if the Enrollment API is not available.
+        """
+        self.mock_enrollment_api_error(error)
+        url = '{path}?sku={sku}'.format(path=self.path, sku=self.stock_record.partner_sku)
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 400)
+
 
 @httpretty.activate
 @ddt.ddt

ecommerce/extensions/basket/views.py

@@ -15,8 +15,9 @@ from edx_rest_api_client.client import EdxRestApiClient
 from slumber.exceptions import SlumberBaseException
 
 from ecommerce.core.constants import ENROLLMENT_CODE_PRODUCT_CLASS_NAME, SEAT_PRODUCT_CLASS_NAME
-from ecommerce.core.url_utils import get_lms_url
+from ecommerce.core.url_utils import get_lms_url, get_lms_enrollment_base_api_url
 from ecommerce.coupons.views import get_voucher_from_code
+from ecommerce.courses.utils import mode_for_seat
 from ecommerce.extensions.analytics.utils import prepare_analytics_data
 from ecommerce.extensions.basket.utils import get_certificate_type_display_value, prepare_basket
 from ecommerce.extensions.offer.utils import format_benefit_value
@@ -48,12 +49,43 @@ class BasketSingleItemView(View):
 
         try:
             product = StockRecord.objects.get(partner=partner, partner_sku=sku).product
+            course_key = product.attr.course_key
+
+            api = EdxRestApiClient(
+                get_lms_enrollment_base_api_url(),
+                oauth_access_token=request.user.access_token,
+                append_slash=False
+            )
+            logger.debug(
+                'Getting enrollment information for [%s] in [%s].',
+                request.user.username,
+                course_key
+            )
+            status = api.enrollment(','.join([request.user.username, course_key])).get()
+            username = request.user.username
+            seat_type = mode_for_seat(product)
+            if status and status.get('mode') == seat_type:
+                logger.warning(
+                    'User [%s] attempted to repurchase the [%s] seat of course [%s]',
+                    username,
+                    seat_type,
+                    course_key
+                )
+                return HttpResponseBadRequest(_('You are already enrolled in {course}.').format(
+                    course=product.course.name))
         except StockRecord.DoesNotExist:
-            return HttpResponseBadRequest(_('SKU [{sku}] does not exist.'.format(sku=sku)))
-
+            return HttpResponseBadRequest(_('SKU [{sku}] does not exist.').format(sku=sku))
+        except (ConnectionError, SlumberBaseException, Timeout) as ex:
+            logger.exception(
+                'Failed to retrieve enrollment details for [%s] in course [%s], Because of [%s]',
+                request.user.username,
+                course_key,
+                ex,
+            )
+            return HttpResponseBadRequest(_('An error occurred while retrieving enrollment details. Please try again.'))
         purchase_info = request.strategy.fetch_for_product(product)
         if not purchase_info.availability.is_available_to_buy:
-            return HttpResponseBadRequest(_('Product [{product}] not available to buy.'.format(product=product.title)))
+            return HttpResponseBadRequest(_('Product [{product}] not available to buy.').format(product=product.title))
 
         prepare_basket(request, product, voucher)
         return HttpResponseRedirect(reverse('basket:summary'), status=303)