Merge branch 'ft-1380-adding-timestamp-artificial-start-end' into 'in…

…tegration'

FT 1380 Adding timestamp for artificial start/end when possible

See merge request pm4py/pm4py-core!527

pm4py/objects/log/util/artificial.py

@@ -6,10 +6,12 @@
 from pm4py.util import constants
 from pm4py.util import exec_utils
 from pm4py.util import xes_constants
+import datetime
 
 
 class Parameters(Enum):
     ACTIVITY_KEY = constants.PARAMETER_CONSTANT_ACTIVITY_KEY
+    TIMESTAMP_KEY = constants.PARAMETER_CONSTANT_TIMESTAMP_KEY
     PARAM_ARTIFICIAL_START_ACTIVITY = constants.PARAM_ARTIFICIAL_START_ACTIVITY
     PARAM_ARTIFICIAL_END_ACTIVITY = constants.PARAM_ARTIFICIAL_END_ACTIVITY
 
@@ -25,6 +27,7 @@ def insert_artificial_start_end(log: EventLog, parameters: Optional[Dict[Any, An
      parameters
         Parameters of the algorithm, including:
         - Parameters.ACTIVITY_KEY: the activity
+        - Parameters.TIMESTAMP_KEY: the timestamp
 
     Returns
     ------------------
@@ -35,13 +38,22 @@ def insert_artificial_start_end(log: EventLog, parameters: Optional[Dict[Any, An
         parameters = {}
 
     activity_key = exec_utils.get_param_value(Parameters.ACTIVITY_KEY, parameters, xes_constants.DEFAULT_NAME_KEY)
+    timestamp_key = exec_utils.get_param_value(Parameters.TIMESTAMP_KEY, parameters, xes_constants.DEFAULT_TIMESTAMP_KEY)
+
     artificial_start_activity = exec_utils.get_param_value(Parameters.PARAM_ARTIFICIAL_START_ACTIVITY, parameters,
                                                            constants.DEFAULT_ARTIFICIAL_START_ACTIVITY)
     artificial_end_activity = exec_utils.get_param_value(Parameters.PARAM_ARTIFICIAL_END_ACTIVITY, parameters,
                                                          constants.DEFAULT_ARTIFICIAL_END_ACTIVITY)
 
     for trace in log:
-        trace.insert(0, Event({activity_key: artificial_start_activity}))
-        trace.append(Event({activity_key: artificial_end_activity}))
+        start_event = Event({activity_key: artificial_start_activity})
+        end_event = Event({activity_key: artificial_end_activity})
+        if trace:
+            if timestamp_key in trace[0]:
+                start_event[timestamp_key] = trace[0][timestamp_key] - datetime.timedelta(seconds=1)
+            if timestamp_key in trace[-1]:
+                end_event[timestamp_key] = trace[-1][timestamp_key] + datetime.timedelta(seconds=1)
+        trace.insert(0, start_event)
+        trace.append(end_event)
 
     return log