Implement Request.last_submission_date

atst/models/request.py

@@ -5,6 +5,10 @@ from sqlalchemy.orm import relationship
 
 from atst.models import Base
 from atst.models.types import Id
+from atst.models.request_status_event import RequestStatus
+
+def first_or_none(predicate, lst):
+    return next((x for x in lst if predicate(x)), None,)
 
 
 class Request(Base):
@@ -47,3 +51,12 @@ class Request(Base):
         if self.task_order:
             return self.task_order.verified
         return False
+
+    @property
+    def last_submission_date(self):
+        def _is_submission(status_event):
+            return status_event.new_status == RequestStatus.SUBMITTED
+
+        last_submission = first_or_none(_is_submission, reversed(self.status_events))
+        if last_submission:
+            return last_submission.time_created