feat: Add reminder cooldown for room notices

Introduces a customizable cooldown period for sending room notices
after message redaction to prevent flooding users with notifications.
Configurable via `reminder_cooldown` setting in the configuration file.

config.dist.yaml

@@ -1,4 +1,5 @@
 homeserver: https://matrix.example.com
 user_id: "@example:example.com"
 access_token: syt_1234567890
-check_room: # If you want to check for permissions in a specific room instead of the current room
+check_room: # If you want to check for permissions in a specific room instead of the current room
+reminder_cooldown: 30

src/matrix_redactorbot/main.py

@@ -1,4 +1,5 @@
 import re
+import datetime
 import asyncio
 import yaml
 import nio
@@ -10,14 +11,23 @@ url_regex = re.compile(r"(https?://\S+)|(www\.\S+)")
 
 class RedactorBot:
     def __init__(
-        self, homeserver, user_id, access_token, sync_timeout, check_room=None
+        self,
+        homeserver,
+        user_id,
+        access_token,
+        sync_timeout=30000,
+        reminder_cooldown=30,
+        check_room=None,
     ):
         self.client = AsyncClient(homeserver, user_id)
         self.client.access_token = access_token
         self.sync_timeout = sync_timeout
         self.client.add_event_callback(self.message_callback, RoomMessage)
+        self.reminder_cooldown = reminder_cooldown
         self.check_room = check_room
 
+        self.cooldown_log = {}
+
     async def message_callback(self, room: MatrixRoom, event: RoomMessage):
         if isinstance(event, (RoomMessageText, RoomMessageMedia)):
             check_room = (
@@ -42,6 +52,26 @@ class RedactorBot:
                         print(
                             f"Redacted message from {event.sender} in {room.display_name}"
                         )
+
+                        # Send a notice to the room to inform the user
+                        if (
+                            not self.cooldown_log.get(room.room_id)
+                            or (
+                                datetime.datetime.now()
+                                - self.cooldown_log[room.room_id]
+                            ).seconds
+                            > self.reminder_cooldown
+                        ):
+                            self.cooldown_log[room.room_id] = datetime.datetime.now()
+                            await self.client.room_send(
+                                room_id=room.room_id,
+                                message_type="m.room.message",
+                                content={
+                                    "msgtype": "m.notice",
+                                    "body": "New users cannot send links or uploads until powerlevel raised above zero.",
+                                },
+                            )
+
                     else:
                         print(f"Failed to redact message: {response}")
 
@@ -62,6 +92,7 @@ bot = RedactorBot(
     user_id=config["user_id"],
     access_token=config["access_token"],
     sync_timeout=config.get("sync_timeout", 30000),
+    reminder_cooldown=config.get("reminder_cooldown", 30),
     check_room=config.get("check_room", None),
 )