Merge pull request #14 from avatao-content/fsm_api

FSM API implementation

lib/tfw/networking/server/tfw_server.py

@@ -1,8 +1,10 @@
 from tornado.web import Application
+from collections import defaultdict
 
 from tfw.networking.server.controller_responder import ControllerResponder
 from tfw.networking.server.zmq_websocket_handler import ZMQWebSocketProxy
 from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
+from tfw.message_sender import MessageSender
 from tfw.config.logs import logging
 log = logging.getLogger(__name__)
 
@@ -10,8 +12,9 @@ log = logging.getLogger(__name__)
 class TFWServer:
     def __init__(self, fsm_type):
         self._fsm = fsm_type()
-        self.fsm_updater = FSMUpdater(self._fsm)
-        self._fsm.subscribe(self.fsm_updater.update)
+        self._fsm_updater = FSMUpdater(self._fsm)
+        self._fsm_manager = FSMManager(self._fsm)
+        self._fsm.subscribe(self._fsm_updater.update)
 
         self.application = Application(
             [(r'/ws', ZMQWebSocketProxy, {'make_response': self.make_response,
@@ -23,9 +26,13 @@ class TFWServer:
     def fsm(self):
         return self._fsm
 
+    @property
+    def fsm_manager(self):
+        return self._fsm_manager
+
     def make_response(self, message):
         trigger = message.get('trigger', '')
-        try: self.fsm.trigger(trigger, message=message)
+        try: self._fsm_manager.trigger(trigger, message)
         except AttributeError: log.debug('FSM failed to execute nonexistent trigger: "{}"'.format(trigger))
         return message
 
@@ -36,6 +43,35 @@ class TFWServer:
         self.application.listen(port)
 
 
+class FSMManager:
+    def __init__(self, fsm):
+        self._fsm = fsm
+        self.trigger_predicates = defaultdict(list)
+        self.messenge_sender = MessageSender()
+
+    @property
+    def fsm(self):
+        return self._fsm
+
+    def trigger(self, trigger, message):
+        predicate_results = []
+        for predicate in self.trigger_predicates[trigger]:
+            success, message = predicate()
+            predicate_results.append(success)
+            self.messenge_sender.send('FSM', message)
+
+        if all(predicate_results):
+            try: self.fsm.trigger(trigger, message=message)
+            except AttributeError: log.debug('FSM failed to execute nonexistent trigger: "{}"'.format(trigger))
+
+    def subscribe_predicate(self, trigger, *predicates):
+        self.trigger_predicates[trigger].extend(predicates)
+
+    def unsubscribe_predicate(self, trigger, *predicates):
+        self.trigger_predicates[trigger] = [predicate for predicate in self.trigger_predicates[trigger]
+                                            not in predicates]
+
+
 class FSMUpdater:
     def __init__(self, fsm):
         self.fsm = fsm