config reload: rename-safe (watch dir not file, react to moved/created not just modified) — cfg-05

fjerkroa_bot/discord_bot.py

@@ -68,11 +68,29 @@ def split_answer(text: str, threshold: int, max_parts: int) -> list:
 
 
 class ConfigFileHandler(FileSystemEventHandler):
-    def __init__(self, on_modified):
-        self._on_modified = on_modified
+    """Rename-safe config watch (CFG-05).
 
-    def on_modified(self, event):
-        self._on_modified(event)
+    Editors and tools save atomically — write a temp file, then rename it
+    over the target — which fires a *moved*/*created* event (not
+    *modified*) and swaps the inode, so watching the file directly goes
+    deaf after the first save. We watch the config's *directory* and react
+    to any event whose src or dest path is the config file.
+    """
+
+    def __init__(self, config_path: str, on_change):
+        self._config_path = str(Path(config_path).resolve())
+        self._on_change = on_change
+
+    def _hits_config(self, event) -> bool:
+        for attr in ("src_path", "dest_path"):
+            path = getattr(event, attr, "")
+            if path and str(Path(path).resolve()) == self._config_path:
+                return True
+        return False
+
+    def on_any_event(self, event):
+        if not event.is_directory and self._hits_config(event):
+            self._on_change()
 
 
 class FjerkroaBot(commands.Bot):
@@ -102,8 +120,10 @@ class FjerkroaBot(commands.Bot):
 
     def init_observer(self):
         self.observer = Observer()
-        self.file_handler = ConfigFileHandler(self.on_config_file_modified)
-        self.observer.schedule(self.file_handler, path=self.config_file, recursive=False)
+        config_path = Path(self.config_file).resolve()
+        self.file_handler = ConfigFileHandler(str(config_path), self.on_config_file_changed)
+        # Watch the directory, not the file — atomic saves replace the inode (CFG-05)
+        self.observer.schedule(self.file_handler, path=str(config_path.parent), recursive=False)
         self.observer.start()
 
     def init_aichannels(self):
@@ -415,12 +435,10 @@ class FjerkroaBot(commands.Bot):
             airesponder.image_cache.purge_message(str(message.id))  # IMG-14
         await airesponder.observe_event(message.author.name, "delete", f"deleted: {message.content}")
 
-    def on_config_file_modified(self, event):
+    def on_config_file_changed(self):
         # Runs on the watchdog observer thread — the swap itself is
         # scheduled onto the event loop so no request reads a
         # half-swapped config (CFG-04 / D9)
-        if event.src_path != self.config_file:
-            return
         new_config = self.load_config(self.config_file)
         if repr(new_config) == repr(self.config):
             return