Improve TFW lib layout

lib/tfw/server/__init__.py

@@ -0,0 +1 @@
+from .tfw_server import TFWServer

lib/tfw/server/tfw_server.py

@@ -0,0 +1,29 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+from tornado.web import Application
+
+from tfw.networking import EventHandlerConnector
+from tfw.config.logs import logging
+
+from .zmq_websocket_proxy import ZMQWebSocketProxy
+
+LOG = logging.getLogger(__name__)
+
+
+class TFWServer:
+    """
+    This class handles the proxying of messages between the frontend and event handers.
+    It proxies messages from the "/ws" route to all event handlers subscribed to a ZMQ
+    SUB socket.
+    """
+    def __init__(self):
+        self._event_handler_connector = EventHandlerConnector()
+        self.application = Application([(
+            r'/ws', ZMQWebSocketProxy, {
+                'event_handler_connector': self._event_handler_connector,
+            }
+        )])
+
+    def listen(self, port):
+        self.application.listen(port)

lib/tfw/server/zmq_websocket_proxy.py

@@ -0,0 +1,72 @@
+# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
+# All Rights Reserved. See LICENSE file for details.
+
+import json
+
+from tornado.websocket import WebSocketHandler
+
+from tfw.networking import Scope
+from tfw.config.logs import logging
+
+LOG = logging.getLogger(__name__)
+
+
+class ZMQWebSocketProxy(WebSocketHandler):
+    # pylint: disable=abstract-method
+    instances = set()
+
+    def initialize(self, **kwargs): # pylint: disable=arguments-differ
+        self.event_handler_connector = kwargs['event_handler_connector']
+        self.tfw_router = TFWRouter(self.send_to_zmq, self.send_to_websockets)
+
+    def send_to_zmq(self, message):
+        self.event_handler_connector.send_message(message)
+
+    @staticmethod
+    def send_to_websockets(message):
+        for instance in ZMQWebSocketProxy.instances:
+            instance.write_message(message)
+
+    def prepare(self):
+        ZMQWebSocketProxy.instances.add(self)
+
+    def on_close(self):
+        ZMQWebSocketProxy.instances.remove(self)
+
+    def open(self, *args, **kwargs):
+        LOG.debug('WebSocket connection initiated!')
+        self.event_handler_connector.register_callback(self.zmq_callback)
+
+    def zmq_callback(self, message):
+        LOG.debug('Received on ZMQ pull socket: %s', message)
+        self.tfw_router.route(message)
+
+    def on_message(self, message):
+        message = json.loads(message)
+        LOG.debug('Received on WebSocket: %s', message)
+        self.tfw_router.route(message)
+
+    # much secure, very cors, wow
+    def check_origin(self, origin):
+        return True
+
+
+class TFWRouter:
+    def __init__(self, send_to_zmq, send_to_websockets):
+        self.send_to_zmq = send_to_zmq
+        self.send_to_websockets = send_to_websockets
+
+    def route(self, message):
+        scope = Scope(message.get('scope', 'zmq'))
+
+        routing_table = {
+            Scope.ZMQ: self.send_to_zmq,
+            Scope.WEBSOCKET: self.send_to_websockets,
+            Scope.BROADCAST: self.broadcast
+        }
+        action = routing_table[scope]
+        action(message)
+
+    def broadcast(self, message):
+        self.send_to_zmq(message)
+        self.send_to_websockets(message)