fix: improve watcher with per-file debounce, logging, and validation

src/companion/indexer_daemon/watcher.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import logging
 import time
 from pathlib import Path
 
@@ -10,39 +11,49 @@ from companion.config import load_config
 from companion.rag.indexer import Indexer
 from companion.rag.vector_store import VectorStore
 
+logger = logging.getLogger(__name__)
+
 
 class VaultEventHandler(FileSystemEventHandler):
+    """Handles file system events in the vault directory and triggers indexing."""
+
     def __init__(self, indexer: Indexer, debounce_seconds: float = 5.0):
         self.indexer = indexer
         self.debounce_seconds = debounce_seconds
-        self._last_sync = 0.0
+        self._last_sync: dict[str, float] = {}
 
     def on_any_event(self, event):
+        """Process a file system event and debounce per file path."""
         if event.is_directory:
             return
         if not event.src_path.endswith(".md"):
             return
+        path = event.src_path
         now = time.time()
-        if now - self._last_sync < self.debounce_seconds:
+        if now - self._last_sync.get(path, 0) < self.debounce_seconds:
             return
-        self._last_sync = now
+        self._last_sync[path] = now
         try:
             self.indexer.sync()
-        except Exception as exc:
-            print(f"Sync failed: {exc}")
+        except (OSError, RuntimeError) as exc:
+            logger.error("Sync failed: %s", exc)
 
 
 def start_watcher(config_path: str = "config.json") -> None:
+    """Load configuration and start watching the vault directory for changes."""
     config = load_config(config_path)
+    vault_path = Path(config.vault.path)
+    if not vault_path.exists():
+        raise FileNotFoundError(f"Vault path does not exist: {vault_path}")
     store = VectorStore(
         uri=config.rag.vector_store.path, dimensions=config.rag.embedding.dimensions
     )
     indexer = Indexer(config, store)
     handler = VaultEventHandler(indexer)
     observer = Observer()
-    observer.schedule(handler, str(config.vault.path), recursive=True)
+    observer.schedule(handler, str(vault_path), recursive=True)
     observer.start()
-    print(f"Watching {config.vault.path} for changes...")
+    logger.info("Watching %s for changes...", vault_path)
     try:
         while True:
             time.sleep(1)