Rework fsm_update API

lib/tfw/fsm/fsm_base.py

@@ -2,6 +2,7 @@
 # All Rights Reserved. See LICENSE file for details.
 
 from collections import defaultdict
+from datetime import datetime
 
 from transitions import Machine, MachineError
 
@@ -24,7 +25,7 @@ class FSMBase(Machine, CallbackMixin):
     def __init__(self, initial=None, accepted_states=None):
         self.accepted_states = accepted_states or [self.states[-1].name]
         self.trigger_predicates = defaultdict(list)
-        self.trigger_history = []
+        self.event_log = []
 
         Machine.__init__(
             self,
@@ -60,9 +61,22 @@ class FSMBase(Machine, CallbackMixin):
 
         if all(predicate_results):
             try:
+                from_state = self.state
                 self.trigger(trigger)
-                self.trigger_history.append(trigger)
+                self.update_event_log(from_state, trigger)
                 return True
             except (AttributeError, MachineError):
                 LOG.debug('FSM failed to execute nonexistent trigger: "%s"', trigger)
         return False
+
+    def update_event_log(self, from_state, trigger):
+        self.event_log.append({
+            'from_state': from_state,
+            'to_state': self.state,
+            'trigger': trigger,
+            'timestamp': datetime.utcnow()
+        })
+
+    @property
+    def in_accepted_state(self):
+        return self.state in self.accepted_states