checkpoint

enterprise_access/apps/api/v1/tests/test_subsidy_access_policy_views.py

@@ -7,6 +7,7 @@
 from uuid import UUID, uuid4
 
 import ddt
+import requests
 from django.conf import settings
 from rest_framework import status
 from rest_framework.reverse import reverse
@@ -682,6 +683,52 @@ def test_redeem_policy(self, mock_transactions_cache_for_learner):  # pylint: di
             ),
         )
 
+    @mock.patch('enterprise_access.apps.subsidy_access_policy.models.get_and_cache_transactions_for_learner')
+    @mock.patch('enterprise_access.apps.api.v1.views.subsidy_access_policy.LmsApiClient')
+    @ddt.data(
+        {
+            'subsidy_error_code': 'fulfillment_error',
+            'subsidy_error_detail': [{'message': 'woozit duplicate order woohoo!'}],
+            'expected_redeem_error_payload': {
+                'reason': 'the-reason',
+                'user-message': 'the-user-message',
+                'metadata': {
+                    'enterprise_administrators': '[email protected]',
+                },
+            },
+        },
+    )
+    def test_redeem_policy_subsidy_api_error(
+        self, mock_lms_api_client, mock_transactions_cache_for_learner,
+        subsidy_error_code, subsidy_error_detail, expected_redeem_error_payload
+    ):
+        """
+        Verify that SubsidyAccessPolicyRedeemViewset redeem endpoint returns a well-structured
+        error response payload when the subsidy API call to redeem/fulfill responds with an error.
+        """
+        mock_lms_api_client().get_enterprise_customer_data.return_value = {
+            'slug': 'the-slug',
+            'admin_users': [{'email': '[email protected]'}],
+        }
+        self.mock_get_content_metadata.return_value = {'content_price': 123}
+        mock_response = mock.MagicMock()
+        mock_response.json.return_value = {
+            'code': subsidy_error_code,
+            'detail': subsidy_error_detail,
+        }
+        self.redeemable_policy.subsidy_client.create_subsidy_transaction.side_effect = requests.exceptions.HTTPError(
+            response=mock_response
+        )
+
+        payload = {
+            'lms_user_id': 1234,
+            'content_key': 'course-v1:edX+edXPrivacy101+3T2020',
+        }
+
+        response = self.client.post(self.subsidy_access_policy_redeem_endpoint, payload)
+
+        response_json = self.load_json(response.content)
+
     @mock.patch('enterprise_access.apps.subsidy_access_policy.models.get_and_cache_transactions_for_learner')
     def test_redeem_policy_with_metadata(self, mock_transactions_cache_for_learner):  # pylint: disable=unused-argument
         """

enterprise_access/apps/api/v1/views/subsidy_access_policy.py

@@ -47,6 +47,9 @@
     REASON_POLICY_NOT_ACTIVE,
     REASON_POLICY_SPEND_LIMIT_REACHED,
     MissingSubsidyAccessReasonUserMessages,
+    SubsidyRedemptionErrorCodes,
+    SubsidyRedemptionErrorReasons,
+    SubsidyFulfillmentErrorReasons,
     TransactionStateChoices
 )
 from enterprise_access.apps.subsidy_access_policy.content_metadata_api import get_and_cache_content_metadata
@@ -485,11 +488,71 @@ def redeem(self, request, *args, **kwargs):
             raise SubsidyAccessPolicyLockedException() from exc
         except SubsidyAPIHTTPError as exc:
             logger.exception(f'{exc} when creating transaction in subsidy API')
-            error_payload = exc.error_payload()
-            error_payload['detail'] = f"Subsidy Transaction API error: {error_payload['detail']}"
-            raise RedemptionRequestException(
-                detail=error_payload,
-            ) from exc
+            try:
+                error_payload = self._get_subsidy_api_error_reason(policy, exc)
+            except Exception:  # pylint: disable=broad-except
+                error_payload = exc.error_payload()
+                error_payload['detail'] = f"Subsidy Transaction API error: {error_payload['detail']}"
+
+            raise RedemptionRequestException(detail=error_payload) from exc
+
+    def _get_subsidy_api_error_reason(self, policy, exc_object):
+        """
+        Helper to build error response payload on Subsidy API errors.
+        """
+        subsidy_error_detail = exc_object.error_payload().get('detail')
+        subsidy_error_code = exc_object.error_payload().get('code')
+
+        metadata = {
+            'enterprise_administrators': self._get_enterprise_admin_users(policy.enterprise_customer_uuid),
+        }
+
+        # We currently only have enough data to say more specific things
+        # about fulfillment errors during subsidy API redemption.
+        if subsidy_error_code == SubsidyRedemptionErrorCodes.FULFILLMENT_ERROR:
+            return self._get_subsidy_fulfillment_error_reason(subsidy_error_detail, metadata)
+
+        default_reason = SubsidyRedemptionErrorReasons.DEFAULT_REASON
+        return {
+            'reason': default_reason,
+            'user_message': SubsidyRedemptionErrorReasons.USER_MESSAGES_BY_REASON[default_reason],
+            'metadata': metadata,
+        }
+
+    def _get_subsidy_fulfillment_error_reason(self, subsidy_error_detail, metadata):
+        """
+        Helper to return a reason, user_message, and metadata
+        for the given subsidy_error_detail.
+        """
+        reason = SubsidyFulfillmentErrorReasons.DEFAULT_REASON
+        metadata['subsidy_error_detail'] = subsidy_error_detail
+
+        if subsidy_error_detail:
+            message_string = self._get_subsidy_fulfillment_error_message(subsidy_error_detail)
+            if cause_of_message := SubsidyFulfillmentErrorReasons.get_cause_from_error_message(message_string):
+                reason = cause_of_message
+
+        return {
+            "reason": reason,
+            "user_message": SubsidyFulfillmentErrorReasons.USER_MESSAGES_BY_REASON.get(reason),
+            "metadata": metadata,
+        }
+
+    def _get_subsidy_fulfillment_error_message(self, subsidy_error_detail):
+        """
+        ``subsidy_error_detail`` is either a string describing an error message,
+        a dict with a "message" key describing an error message, or a list of such
+        dicts.  This helper method widdles any of those things down into a single
+        error message string.
+        """
+        if isinstance(subsidy_error_detail, str):
+            return subsidy_error_detail
+
+        subsidy_message_dict = subsidy_error_detail
+        if isinstance(subsidy_error_detail, list):
+            subsidy_message_dict = subsidy_error_detail[0]
+
+        return subsidy_message_dict.get('message')
 
     def get_existing_redemptions(self, policies, lms_user_id):
         """
@@ -673,9 +736,7 @@ def _get_reasons_for_no_redeemable_policies(self, enterprise_customer_uuid, non_
         for each non-redeemable policy.
         """
         reasons = []
-        lms_client = LmsApiClient()
-        enterprise_customer_data = lms_client.get_enterprise_customer_data(enterprise_customer_uuid)
-        enterprise_admin_users = enterprise_customer_data.get('admin_users')
+        enterprise_admin_users = self._get_enterprise_admin_users(enterprise_customer_uuid)
 
         for reason, policies in non_redeemable_policies.items():
             reasons.append({
@@ -689,6 +750,14 @@ def _get_reasons_for_no_redeemable_policies(self, enterprise_customer_uuid, non_
 
         return reasons
 
+    def _get_enterprise_admin_users(self, enterprise_customer_uuid):
+        """
+        Helper to fetch admin users for the given customer uuid.
+        """
+        lms_client = LmsApiClient()
+        enterprise_customer_data = lms_client.get_enterprise_customer_data(enterprise_customer_uuid)
+        return enterprise_customer_data.get('admin_users')
+
     def _get_list_price(self, enterprise_customer_uuid, content_key):
         """
         Determine the price for content for display purposes only.

enterprise_access/apps/subsidy_access_policy/constants.py

@@ -1,4 +1,5 @@
 """ Constants for the subsidy_access_policy app. """
+import re
 
 
 class AccessMethods:
@@ -99,3 +100,56 @@ class MissingSubsidyAccessReasonUserMessages:
 REASON_LEARNER_MAX_SPEND_REACHED = "learner_max_spend_reached"
 REASON_POLICY_SPEND_LIMIT_REACHED = "policy_spend_limit_reached"
 REASON_LEARNER_MAX_ENROLLMENTS_REACHED = "learner_max_enrollments_reached"
+
+
+class SubsidyRedemptionErrorCodes:
+    """
+    Collection of error ``code`` values that the subsidy API's
+    redeem endpoint might return in an error response payload.
+    """
+    FULFILLMENT_ERROR = 'fulfillment_error'
+
+
+class SubsidyRedemptionErrorReasons:
+    """
+    Somewhat more generic collection of reasons that redemption may have
+    failed in ways that are *not* related to fulfillment.
+    """
+    DEFAULT_REASON = 'default_subsidy_redemption_error'
+
+    USER_MESSAGES_BY_REASON = {
+        DEFAULT_REASON: "Something went wrong during subsidy redemption",
+    }
+
+
+class SubsidyFulfillmentErrorReasons:
+    """
+    Codifies standard reasons that fulfillment may have failed,
+    along with a mapping of those reasons to user-friendly display messages.
+    """
+    DEFAULT_REASON = 'default_fulfillment_error'
+    DUPLICATE_FULFILLMENT = 'duplicate_fulfillment'
+
+    USER_MESSAGES_BY_REASON = {
+        DEFAULT_REASON: "Something went wrong during fulfillment",
+        DUPLICATE_FULFILLMENT: "A legacy fulfillment already exists for this content.",
+    }
+
+    CAUSES_REGEXP_BY_REASON = {
+        DUPLICATE_FULFILLMENT: re.compile(".*duplicate order.*"),
+    }
+
+    @staticmethod
+    def get_cause_from_error_message(message_string):
+        """
+        Helper to find the cause of a given error message string
+        by matching against the regexs mapped above.
+        """
+        if not message_string:
+            return None
+
+        for cause_of_message, regex in SubsidyRedemptionErrorReasons.CAUSES_REGEXP_BY_REASON.items():
+            if regex.match(message_string):
+                return cause_of_message
+
+        return None