Added task to send course refund email via Sailthru

ECOM-6975

Makefile

@@ -16,13 +16,14 @@ help:
 	@echo '                                                                                             '
 
 requirements:
-	pip install -qr requirements/local.txt --exists-action w
+	pip install -r requirements/local.txt
 
 worker:
 	celery -A ecommerce_worker worker --app=$(PACKAGE).celery_app:app --loglevel=info --queue=fulfillment,email_marketing
 
 test:
 	WORKER_CONFIGURATION_MODULE=ecommerce_worker.configuration.test nosetests \
+	--with-ignore-docstrings --logging-level=DEBUG --logging-clear-handlers \
 	--with-coverage --cover-branches --cover-html --cover-package=$(PACKAGE) $(PACKAGE)
 
 html_coverage:

ecommerce_worker/configuration/base.py

@@ -87,5 +87,9 @@ SAILTHRU = {
     # dummy price for audit/honor (i.e., if cost = 0)
     #  Note: setting this value to 0 skips Sailthru calls for free transactions
     'SAILTHRU_MINIMUM_COST': 100,
-}
 
+    # Transactional email template name map
+    'templates': {
+        'course_refund': 'Course Refund',
+    }
+}

ecommerce_worker/sailthru/v1/tasks.py

@@ -304,3 +304,67 @@ def update_course_enrollment(self, email, course_url, purchase_incomplete, mode,
 
     if not _record_purchase(sailthru_client, email, item, purchase_incomplete, message_id, options):
         schedule_retry(self, config)
+
+
+@shared_task(bind=True, ignore_result=True)
+def send_course_refund_email(self, email, refund_id, amount, course_name, order_number, order_url, site_code=None):
+    """ Sends the course refund email.
+
+    Args:
+        self: Ignore.
+        email (str): Recipient's email address.
+        refund_id (int): ID of the refund that initiated this task.
+        amount (str): Formatted amount of the refund.
+        course_name (str): Name of the course for which payment was refunded.
+        order_number (str): Order number of the order that was refunded.
+        order_url (str): Receipt URL of the refunded order.
+        site_code (str): Identifier of the site sending the email.
+    """
+    config = get_sailthru_configuration(site_code)
+
+    try:
+        sailthru_client = get_sailthru_client(site_code)
+    except SailthruError:
+        # NOTE: We rely on the function to log the error for us
+        return
+
+    email_vars = {
+        'amount': amount,
+        'course_name': course_name,
+        'order_number': order_number,
+        'order_url': order_url,
+    }
+
+    try:
+        response = sailthru_client.send(
+            template=config['templates']['course_refund'],
+            email=email,
+            _vars=email_vars
+        )
+    except SailthruClientError:
+        logger.exception(
+            'A client error occurred while attempting to send a course refund notification for refund [%d].',
+            refund_id
+        )
+        return
+
+    if response.is_ok():
+        logger.info('Course refund notification sent for refund %d.', refund_id)
+    else:
+        error = response.get_error()
+        logger.error(
+            'An error occurred while attempting to send a course refund notification for refund [%d]: %d - %s',
+            refund_id, error.get_error_code(), error.get_message()
+        )
+
+        if can_retry_sailthru_request(error):
+            logger.info(
+                'An attempt will be made again to send a course refund notification for refund [%d].',
+                refund_id
+            )
+            schedule_retry(self, config)
+        else:
+            logger.warning(
+                'No further attempts will be made to send a course refund notification for refund [%d].',
+                refund_id
+            )

ecommerce_worker/sailthru/v1/tests/test_tasks.py

 """Tests of Sailthru worker code."""
 import json
-import logging
 from decimal import Decimal
 from unittest import TestCase
 
 import httpretty
+from celery.exceptions import Retry
 from mock import patch
+from sailthru import SailthruClient
 from sailthru.sailthru_error import SailthruClientError
+from testfixtures import LogCapture
 
+from ecommerce_worker.sailthru.v1.exceptions import SailthruError
 from ecommerce_worker.sailthru.v1.tasks import (
-    update_course_enrollment, _update_unenrolled_list, _get_course_content, _get_course_content_from_ecommerce
+    update_course_enrollment, _update_unenrolled_list, _get_course_content, _get_course_content_from_ecommerce,
+    send_course_refund_email
 )
 from ecommerce_worker.sailthru.v1.utils import get_sailthru_configuration
 from ecommerce_worker.utils import get_configuration
@@ -573,3 +577,98 @@ class SailthruTests(TestCase):
         mock_sailthru_client.api_get.side_effect = SailthruClientError
         self.assertFalse(_update_unenrolled_list(mock_sailthru_client, TEST_EMAIL,
                                                  self.course_url, False))
+
+
+class SendCourseRefundEmailTests(TestCase):
+    """ Validates the send_course_refund_email task. """
+    LOG_NAME = 'ecommerce_worker.sailthru.v1.tasks'
+    REFUND_ID = 1
+    SITE_CODE = 'test'
+
+    def execute_task(self):
+        """ Execute the send_course_refund_email task. """
+        send_course_refund_email(
+            'test@example.com', self.REFUND_ID, '$150.00', 'Test Course', 'EDX-123', 'http://example.com', None
+        )
+
+    def mock_api_response(self, status, body):
+        """ Mock the Sailthru send API. """
+        httpretty.register_uri(
+            httpretty.POST,
+            'https://api.sailthru.com/send',
+            status=status,
+            body=json.dumps(body),
+            content_type='application/json'
+        )
+
+    def test_client_instantiation_error(self):
+        """ Verify no message is sent if an error occurs while instantiating the Sailthru API client. """
+        with patch('ecommerce_worker.sailthru.v1.utils.get_sailthru_client', raises=SailthruError):
+            self.execute_task()
+
+    @patch('ecommerce_worker.sailthru.v1.tasks.logger.exception')
+    def test_api_client_error(self, mock_log):
+        """ Verify API client errors are logged. """
+        with patch.object(SailthruClient, 'send', side_effect=SailthruClientError):
+            self.execute_task()
+
+        mock_log.assert_called_once_with(
+            'A client error occurred while attempting to send a course refund notification for refund [%d].',
+            self.REFUND_ID
+        )
+
+    @httpretty.activate
+    def test_api_error_with_retry(self):
+        """ Verify the task is rescheduled if an API error occurs, and the request can be retried. """
+        error_code = 43
+        error_msg = 'This is a fake error.'
+        body = {
+            'error': error_code,
+            'errormsg': error_msg
+        }
+        self.mock_api_response(429, body)
+
+        with LogCapture() as log:
+            with self.assertRaises(Retry):
+                self.execute_task()
+
+        log.check(
+            (self.LOG_NAME, 'ERROR',
+             'An error occurred while attempting to send a course refund notification for refund [%d]: %d - %s' % (
+                 self.REFUND_ID, error_code, error_msg)),
+            (self.LOG_NAME, 'INFO',
+             'An attempt will be made again to send a course refund notification for refund [%d].' % self.REFUND_ID),
+        )
+
+    @httpretty.activate
+    def test_api_error_without_retry(self):
+        """ Verify error details are logged if an API error occurs, and the request can NOT be retried. """
+        error_code = 1
+        error_msg = 'This is a fake error.'
+        body = {
+            'error': error_code,
+            'errormsg': error_msg
+        }
+        self.mock_api_response(500, body)
+
+        with LogCapture() as log:
+            self.execute_task()
+
+        log.check(
+            (self.LOG_NAME, 'ERROR',
+             'An error occurred while attempting to send a course refund notification for refund [%d]: %d - %s' % (
+                 self.REFUND_ID, error_code, error_msg)),
+            (self.LOG_NAME, 'WARNING',
+             'No further attempts will be made to send a course refund notification for refund [%d].' % self.REFUND_ID),
+        )
+
+    @httpretty.activate
+    def test_message_sent(self):
+        """ Verify a message is logged after a successful API call to send the message. """
+        self.mock_api_response(200, {'send_id': '1234ABC'})
+
+        with LogCapture() as log:
+            self.execute_task()
+        log.check(
+            (self.LOG_NAME, 'INFO', 'Course refund notification sent for refund %d.' % self.REFUND_ID),
+        )

requirements/test.txt

@@ -3,8 +3,10 @@
 
 coverage==4.0.3
 ddt==1.0.1
-edx-lint==0.5.1
+edx-lint==0.5.2
 httpretty==0.8.10
 mock==1.3.0
 nose==1.3.7
+nose-ignore-docstring==0.2
 pep8==1.7.0
+testfixtures==4.13.3