Adding TTL check and coursepage (#2245)

* Adding ttl check rather than checking for exist and specifically checking coursepage rather than course

* if none, page break

* change amount

* empty list angers the homepage

cms/api.py

@@ -328,9 +328,15 @@ def create_featured_items():
     now = now_in_utc()
     end_of_day = now + timedelta(days=1)
 
+    valid_coursepages = cms_models.CoursePage.objects.filter(live=True).values_list(
+        "course_id", flat=True
+    )
+
     enrollable_courseruns = get_enrollable_courseruns_qs(
         end_of_day,
-        Course.objects.select_related("page").filter(page__live=True, live=True),
+        Course.objects.select_related("page").filter(
+            id__in=valid_coursepages, live=True
+        ),
     )
 
     # Figure out which courses are self-paced and select 2 at random

cms/constants.py

@@ -7,3 +7,5 @@
 CERTIFICATE_INDEX_SLUG = "certificate"
 SIGNATORY_INDEX_SLUG = "signatories"
 INSTRUCTOR_INDEX_SLUG = "instructors"
+
+ONE_MINUTE = 60

cms/models.py

@@ -731,7 +731,7 @@ def get_cached_featured_products(self):
         now = now_in_utc()
         redis_cache = caches["redis"]
         cached_featured_products = redis_cache.get("CMS_homepage_featured_courses")
-        if len(cached_featured_products) > 0:
+        if cached_featured_products and len(cached_featured_products) > 0:
             featured_product_ids = [course.id for course in cached_featured_products]
             relevant_run_course_ids = (
                 CourseRun.objects.filter(live=True)

cms/tasks.py

@@ -6,6 +6,7 @@
 from mitol.common.decorators import single_task
 
 from cms.api import create_featured_items
+from cms.constants import ONE_MINUTE
 from cms.models import Page
 from main.celery import app
 from main.settings import (
@@ -108,8 +109,9 @@ def refresh_featured_homepage_items():
     """
     logger = logging.getLogger("refresh_featured_homepage_items__task")
     logger.info("Refreshing featured homepage items...")
-    featured_courses = cache.get("CMS_homepage_featured_courses")
-    if featured_courses is not None:
+    # if the key is not found, the ttl will be 0 per their docs
+    # https://github.com/jazzband/django-redis?tab=readme-ov-file#get-ttl-time-to-live-from-key
+    if cache.ttl("CMS_homepage_featured_courses") > (10 * ONE_MINUTE):
         logger.info("Featured courses found in cache, moving on")
         return
     logger.info("No featured courses found in cache, refreshing")