Atomic Course publication

Facilitates atomic saving and publication of Courses and Products associated with them. XCOM-506.

ecommerce/core/constants.py

-"""Health check constants."""
+"""Constants core to the ecommerce app."""
 
 ISO_8601_FORMAT = u'%Y-%m-%dT%H:%M:%SZ'
 
 
+# Regex used to match course IDs.
+COURSE_ID_REGEX = r'[^/+]+(/|\+)[^/+]+(/|\+)[^/]+'
+COURSE_ID_PATTERN = r'(?P<course_id>{})'.format(COURSE_ID_REGEX)
+
+
 class Status(object):
     """Health statuses."""
     OK = u"OK"

ecommerce/courses/urls.py

-from django.conf import settings
 from django.conf.urls import patterns, url
 
+from ecommerce.core.constants import COURSE_ID_PATTERN
 from ecommerce.courses import views
 
+
 urlpatterns = patterns(
     '',
     url(r'^$', views.CourseListView.as_view(), name='list'),
     url(r'^migrate/$', views.CourseMigrationView.as_view(), name='migrate'),
-    url(r'^{}/$'.format(settings.COURSE_ID_PATTERN), views.CourseDetailView.as_view(), name='detail'),
+    url(r'^{}/$'.format(COURSE_ID_PATTERN), views.CourseDetailView.as_view(), name='detail'),
 )

ecommerce/credit/urls.py

-from django.conf import settings
 from django.conf.urls import patterns, url
 
+from ecommerce.core.constants import COURSE_ID_PATTERN
 from ecommerce.credit.views import Checkout
 
 
 urlpatterns = patterns(
     '',
-    url(r'^checkout/{course}/$'.format(course=settings.COURSE_ID_PATTERN),
+    url(r'^checkout/{course}/$'.format(course=COURSE_ID_PATTERN),
         Checkout.as_view(), name='checkout'),
 )

ecommerce/extensions/api/serializers.py

-"""Serializers for order and line item data."""
+"""Serializers for data manipulated by ecommerce API endpoints."""
+from decimal import Decimal
+import logging
 
+from dateutil.parser import parse
+from django.db import transaction
+from django.utils.translation import ugettext_lazy as _
 from oscar.core.loading import get_model, get_class
 from rest_framework import serializers
 from rest_framework.reverse import reverse
+import waffle
 
-from ecommerce.core.constants import ISO_8601_FORMAT
+from ecommerce.core.constants import ISO_8601_FORMAT, COURSE_ID_REGEX
 from ecommerce.courses.models import Course
 
+
+logger = logging.getLogger(__name__)
+
 BillingAddress = get_model('order', 'BillingAddress')
 Line = get_model('order', 'Line')
 Order = get_model('order', 'Order')
@@ -113,6 +122,7 @@ class RefundSerializer(serializers.ModelSerializer):
 
 
 class CourseSerializer(serializers.HyperlinkedModelSerializer):
+    id = serializers.RegexField(COURSE_ID_REGEX, max_length=255)
     products_url = serializers.SerializerMethodField()
     last_edited = serializers.SerializerMethodField()
 
@@ -130,3 +140,104 @@ class CourseSerializer(serializers.HyperlinkedModelSerializer):
         extra_kwargs = {
             'url': {'view_name': COURSE_DETAIL_VIEW}
         }
+
+
+class AtomicPublicationSerializer(serializers.Serializer):  # pylint: disable=abstract-method
+    """Serializer for saving and publishing a Course and associated products.
+
+    Using a ModelSerializer for the Course data makes it difficult to use this serializer to handle updates.
+    The automatically applied validation logic rejects course IDs which already exist in the database.
+    """
+    id = serializers.RegexField(COURSE_ID_REGEX, max_length=255)
+    name = serializers.CharField(max_length=255)
+    products = serializers.ListField()
+
+    def validate_products(self, products):
+        """Validate product data."""
+        for product in products:
+            # Verify that each product is intended to be a Seat.
+            product_class = product.get('product_class')
+            if product_class != 'Seat':
+                raise serializers.ValidationError(
+                    _(u"Invalid product class [{product_class}] requested.".format(product_class=product_class))
+                )
+
+            # Verify that attributes required to create a Seat are present.
+            attrs = self._flatten(product['attribute_values'])
+            if attrs.get('certificate_type') is None:
+                raise serializers.ValidationError(_(u"Products must have a certificate type."))
+            elif attrs.get('id_verification_required') is None:
+                raise serializers.ValidationError(_(u"Products must indicate whether ID verification is required."))
+
+            # Verify that a price is present.
+            if product.get('price') is None:
+                raise serializers.ValidationError(_(u"Products must have a price."))
+
+        return products
+
+    def save(self):
+        """Save and publish Course and associated products."
+
+        Returns:
+            tuple: A Boolean indicating whether the Course was created, an Exception,
+                if one was raised (else None), and a message for the user, if necessary (else None).
+        """
+        course_id = self.validated_data['id']
+        course_name = self.validated_data['name']
+        products = self.validated_data['products']
+
+        try:
+            # Explicitly delimit operations which will be rolled back if an exception is raised.
+            with transaction.atomic():
+                course, created = Course.objects.get_or_create(id=course_id, defaults={'name': course_name})
+
+                for product in products:
+                    attrs = self._flatten(product['attribute_values'])
+
+                    # Extract arguments required for Seat creation, deserializing as necessary.
+                    certificate_type = attrs['certificate_type']
+                    id_verification_required = (attrs['id_verification_required'] == 'True')
+                    price = Decimal(product['price'])
+
+                    # Extract arguments which are optional for Seat creation, deserializing as necessary.
+                    expires = product.get('expires')
+                    expires = parse(expires) if expires else None
+                    credit_provider = attrs.get('credit_provider')
+                    credit_hours = attrs.get('credit_hours')
+                    credit_hours = int(credit_hours) if credit_hours else None
+
+                    course.create_or_update_seat(
+                        certificate_type,
+                        id_verification_required,
+                        price,
+                        expires=expires,
+                        credit_provider=credit_provider,
+                        credit_hours=credit_hours,
+                    )
+
+                if waffle.switch_is_active('publish_course_modes_to_lms'):
+                    published = course.publish_to_lms()
+                    if published:
+                        return created, None, None
+                    else:
+                        message = (
+                            u'An error occurred while publishing [{course_id}] to LMS. '
+                            u'No data has been saved or published.'
+                        ).format(course_id=course_id)
+                        raise Exception(message)
+                else:
+                    message = (
+                        u'Course [{course_id}] was not published to LMS '
+                        u'because the switch [publish_course_modes_to_lms] is disabled. '
+                        u'Data has been saved, but not published.'
+                    ).format(course_id=course_id)
+                    logger.info(message)
+
+                    return created, None, message
+        except Exception as e:  # pylint: disable=broad-except
+            logger.exception(u'Failed to save and publish [%s]: [%s]', course_id, e.message)
+            return False, e, e.message
+
+    def _flatten(self, attrs):
+        """Transform a list of attribute names and values into a dictionary keyed on the names."""
+        return {attr['name']: attr['value'] for attr in attrs}

ecommerce/extensions/api/v2/urls.py

@@ -2,11 +2,14 @@ from django.conf.urls import patterns, url, include
 from django.views.decorators.cache import cache_page
 from rest_framework_extensions.routers import ExtendedSimpleRouter
 
+from ecommerce.core.constants import COURSE_ID_PATTERN
 from ecommerce.extensions.api.v2 import views
 
+
 ORDER_NUMBER_PATTERN = r'(?P<number>[-\w]+)'
 BASKET_ID_PATTERN = r'(?P<basket_id>[\w]+)'
 
+
 BASKET_URLS = patterns(
     '',
     url(r'^$', views.BasketCreateView.as_view(), name='create'),
@@ -43,12 +46,23 @@ REFUND_URLS = patterns(
     url(r'^(?P<pk>[\d]+)/process/$', views.RefundProcessView.as_view(), name='process'),
 )
 
+ATOMIC_PUBLICATION_URLS = patterns(
+    '',
+    url(r'^$', views.AtomicPublicationView.as_view(), name='create'),
+    url(
+        r'^{course_id}$'.format(course_id=COURSE_ID_PATTERN),
+        views.AtomicPublicationView.as_view(),
+        name='update'
+    ),
+)
+
 urlpatterns = patterns(
     '',
     url(r'^baskets/', include(BASKET_URLS, namespace='baskets')),
     url(r'^orders/', include(ORDER_URLS, namespace='orders')),
     url(r'^payment/', include(PAYMENT_URLS, namespace='payment')),
     url(r'^refunds/', include(REFUND_URLS, namespace='refunds')),
+    url(r'^publication/', include(ATOMIC_PUBLICATION_URLS, namespace='publication')),
 )
 
 router = ExtendedSimpleRouter()

ecommerce/extensions/api/v2/views.py

@@ -12,9 +12,10 @@ from rest_framework.response import Response
 from rest_framework_extensions.mixins import NestedViewSetMixin
 import waffle
 
+from ecommerce.core.constants import COURSE_ID_REGEX
 from ecommerce.courses.models import Course
 from ecommerce.extensions.analytics.utils import audit_log
-from ecommerce.extensions.api import data, exceptions as api_exceptions, serializers
+from ecommerce.extensions.api import data as data_api, exceptions as api_exceptions, serializers
 from ecommerce.extensions.api.constants import APIConstants as AC
 from ecommerce.extensions.api.exceptions import BadRequestException
 from ecommerce.extensions.api.permissions import CanActForUser
@@ -25,6 +26,7 @@ from ecommerce.extensions.payment.helpers import (get_processor_class, get_defau
                                                   get_processor_class_by_name)
 from ecommerce.extensions.refund.api import find_orders_associated_with_course, create_refunds
 
+
 logger = logging.getLogger(__name__)
 
 Order = get_model('order', 'Order')
@@ -125,7 +127,7 @@ class BasketCreateView(EdxOrderPlacementMixin, generics.CreateAPIView):
                 }
             }
         """
-        basket = data.get_basket(request.user)
+        basket = data_api.get_basket(request.user)
 
         requested_products = request.data.get(AC.KEYS.PRODUCTS)
         if requested_products:
@@ -134,7 +136,7 @@ class BasketCreateView(EdxOrderPlacementMixin, generics.CreateAPIView):
                 sku = requested_product.get(AC.KEYS.SKU)
                 if sku:
                     try:
-                        product = data.get_product(sku)
+                        product = data_api.get_product(sku)
                     except api_exceptions.ProductNotFoundError as error:
                         return self._report_bad_request(error.message, api_exceptions.PRODUCT_NOT_FOUND_USER_MESSAGE)
                 else:
@@ -220,7 +222,7 @@ class BasketCreateView(EdxOrderPlacementMixin, generics.CreateAPIView):
         response_data = self._generate_basic_response(basket)
 
         if basket.total_excl_tax == AC.FREE:
-            order_metadata = data.get_order_metadata(basket)
+            order_metadata = data_api.get_order_metadata(basket)
 
             logger.info(
                 u"Preparing to place order [%s] for the contents of basket [%d]",
@@ -493,7 +495,7 @@ class NonDestroyableModelViewSet(mixins.CreateModelMixin, mixins.UpdateModelMixi
 
 
 class CourseViewSet(NonDestroyableModelViewSet):
-    lookup_value_regex = settings.COURSE_ID_REGEX
+    lookup_value_regex = COURSE_ID_REGEX
     queryset = Course.objects.all()
     serializer_class = serializers.CourseSerializer
     permission_classes = (IsAuthenticated, IsAdminUser,)
@@ -521,3 +523,34 @@ class ProductViewSet(NestedViewSetMixin, NonDestroyableModelViewSet):
     queryset = Product.objects.all()
     serializer_class = serializers.ProductSerializer
     permission_classes = (IsAuthenticated, IsAdminUser,)
+
+
+class AtomicPublicationView(generics.CreateAPIView, generics.UpdateAPIView):
+    """Attempt to save and publish a Course and associated products.
+
+    If either fails, the entire operation is rolled back. This keeps Otto and the LMS in sync.
+    """
+    permission_classes = (IsAuthenticated, IsAdminUser,)
+    serializer_class = serializers.AtomicPublicationSerializer
+
+    def post(self, request, *args, **kwargs):
+        return self._save_and_publish(request.data)
+
+    def put(self, request, *args, **kwargs):
+        return self._save_and_publish(request.data, course_id=kwargs['course_id'])
+
+    def _save_and_publish(self, data, course_id=None):
+        """Create or update a Course and associated products, then publish the result."""
+        if course_id is not None:
+            data['id'] = course_id
+
+        serializer = self.get_serializer(data=data)
+        is_valid = serializer.is_valid(raise_exception=True)
+        if is_valid:
+            created, failure, message = serializer.save()
+            if failure:
+                return Response({'error': message}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
+            else:
+                content = serializer.data
+                content['message'] = message if message else None
+                return Response(content, status=status.HTTP_201_CREATED if created else status.HTTP_200_OK)

ecommerce/settings/base.py

@@ -409,9 +409,11 @@ REST_FRAMEWORK = {
 }
 # END DJANGO REST FRAMEWORK
 
+
 # Resolving deprecation warning
 TEST_RUNNER = 'django.test.runner.DiscoverRunner'
 
+
 # COOKIE CONFIGURATION
 # The purpose of customizing the cookie names is to avoid conflicts when
 # multiple Django services are running behind the same hostname.
@@ -421,9 +423,6 @@ CSRF_COOKIE_NAME = 'ecommerce_csrftoken'
 LANGUAGE_COOKIE_NAME = 'ecommerce_language'
 # END COOKIE CONFIGURATION
 
-# Standard regex for course_id.
-COURSE_ID_REGEX = r'[^/+]+(/|\+)[^/+]+(/|\+)[^/]+'
-COURSE_ID_PATTERN = r'(?P<course_id>{})'.format(COURSE_ID_REGEX)
 
 PLATFORM_NAME = 'Your Platform Name Here'
 THEME_SCSS = 'sass/themes/default.scss'