diff --git a/.config.py.swp b/.config.py.swp
deleted file mode 100644
index 11cb0a2..0000000
Binary files a/.config.py.swp and /dev/null differ
diff --git a/pyinotifyd.py b/pyinotifyd.py
index cd3b32a..84f35ea 100755
--- a/pyinotifyd.py
+++ b/pyinotifyd.py
@@ -244,45 +244,56 @@ class Watch:
         return pyinotify.AsyncioNotifier(wm, loop, default_proc_fun=handler)
 
 
+class Rule:
+    valid_actions = ["copy", "move", "delete"]
+
+    def __init__(self, action, src_re, dst_re="", auto_create=False,
+            rec=False):
+
+        assert action in self.valid_actions, \
+            f"action: expected [{Rule.valid_actions.join(', ')}], got{action}"
+        self.action = action
+        self.src_re = re.compile(src_re)
+        assert isinstance(dst_re, str), \
+            f"dst_re: expected {type('')}, got {type(dst_re)}"
+        self.dst_re = dst_re
+        assert isinstance(auto_create, bool), \
+            f"auto_create: expected {type(bool)}, got {type(auto_create)}"
+        self.auto_create = auto_create
+        assert isinstance(rec, bool), \
+            f"rec: expected {type(bool)}, got {type(rec)}"
+        self.rec = rec
+
+
 class FileManager:
-    def __init__(self, rules, auto_create=True, rec=False,
-                 logname="FileManager"):
-        self._rules = []
+    def __init__(self, rules, logname="FileManager"):
         if not isinstance(rules, list):
             rules = [rules]
 
         for rule in rules:
-            if rule["action"] in ["copy", "move"]:
-                self._rules.append((rule["action"],
-                                    re.compile(rule["src_re"]),
-                                    rule["dst_re"]))
-            elif rule["action"] == "delete":
-                self._rules.append(
-                    (rule["action"], re.compile(rule["src_re"])))
-            else:
-                raise ValueError(f"invalid action type: {rule['action']}")
+            assert isinstance(rule, Rule), \
+                f"rules: expected {type(Rule)}, got {type(rule)}"
 
-        self._auto_create = auto_create
-        self._rec = rec
+        self._rules = rules
         self._log = logging.getLogger(logname)
 
+    def add_rule(self, *args, **kwargs):
+        self._rules.append(Rule(*args, **kwargs))
+
     async def task(self, event, task_id):
         path = event.pathname
         match = None
         for rule in self._rules:
-            src_re = rule[1]
-            match = src_re.match(path)
+            match = rule.src_re.match(path)
             if match:
                 break
 
         if match is not None:
-            action = rule[0]
             try:
-                if action in ["copy", "move"]:
-                    dst_re = rule[2]
-                    dest = src_re.sub(dst_re, path)
+                if rule.action in ["copy", "move"]:
+                    dest = src_re.sub(rule.dst_re, path)
                     dest_dir = os.path.dirname(dest)
-                    if not os.path.isdir(dest_dir) and self._auto_create:
+                    if not os.path.isdir(dest_dir) and rule.auto_create:
                         self._log.info(
                             f"{task_id}: create directory '{dest_dir}'")
                         os.makedirs(dest_dir)
@@ -301,11 +312,11 @@ class FileManager:
                     else:
                         os.rename(path, dest)
 
-                elif action == "delete":
+                elif rule.action == "delete":
                     self._log.info(
-                        f"{task_id}: {action} '{path}'")
+                        f"{task_id}: delete '{path}'")
                     if os.path.isdir(path):
-                        if self._rec:
+                        if rule.rec:
                             shutil.rmtree(path)
                         else:
                             shutil.rmdir(path)