New design

negstation/event_bus.py

@@ -0,0 +1,44 @@
+import threading
+import queue
+import logging
+
+
+class EventBus:
+    def __init__(self, logger: logging.Logger):
+        self.logger = logger
+        self.subscribers = {}
+        self.event_queue = queue.Queue()
+        self.main_queue = queue.Queue()
+        threading.Thread(target=self._dispatch_loop, daemon=True).start()
+
+    def subscribe(self, event_type: str, callback: callable, main_thread: bool = False):
+        self.logger.debug(f"Subscribed to {event_type}")
+        self.subscribers.setdefault(event_type, []).append((callback, main_thread))
+
+    def publish_deferred(self, event_type: str, data=None):
+        self.logger.debug(f"publish {event_type}")
+        self.event_queue.put((event_type, data))
+
+    def _dispatch_loop(self):
+        while True:
+            event_type, data = self.event_queue.get()
+            self.logger.debug(f"Dispatching {event_type}")
+            for callback, main_thread in self.subscribers.get(event_type, []):
+                if main_thread:
+                    self.main_queue.put((callback, data))
+                else:
+                    try:
+                        callback(data)
+                    except Exception as e:
+                        self.logger.error(
+                            f"Error in background handler '{
+                                     event_type}': {e}"
+                        )
+
+    def process_main_queue(self):
+        while True:
+            try:
+                callback, data = self.main_queue.get_nowait()
+                callback(data)
+            except queue.Empty:
+                break