TMSS-207: handling of start/stop times

SAS/TMSS/src/tmss/tmssapp/models/scheduling.py

@@ -6,6 +6,8 @@ import os
 import logging
 logger = logging.getLogger(__name__)
 
+from datetime import datetime, timedelta
+
 from django.db.models import ForeignKey, CharField, DateTimeField, BooleanField, IntegerField, BigIntegerField, \
     ManyToManyField, CASCADE, SET_NULL, PROTECT, UniqueConstraint, QuerySet
 from django.contrib.postgres.fields import ArrayField, JSONField
@@ -204,9 +206,14 @@ class Subtask(BasicCommon):
             validate_json_against_schema(self.specifications_doc, self.specifications_template.schema)
 
         if self.state.value == SubtaskState.Choices.SCHEDULED.value and self.__original_state.value == SubtaskState.Choices.SCHEDULING.value:
-            if self.start_time is None or self.stop_time is None:
-                raise SubtaskSchedulingException("Cannot schedule subtask id=%s when start/stop times are NULL. start_time='%s' stoptime='%s'" %
-                                                 (self.pk, formatDatetime(self.start_time), formatDatetime(self.stop_time)))
+            if self.start_time is None:
+                if self.predecessors.all().count() is 0:
+                    raise SubtaskSchedulingException("Cannot schedule subtask id=%s when start time is 'None'." % (self.pk, ))
+                else:
+                    self.start_time = datetime.utcnow()
+
+        if self.state.value == SubtaskState.Choices.FINISHING.value:
+            self.stop_time = datetime.utcnow()
 
         super().save(force_insert, force_update, using, update_fields)