Added relay module for relaybot functionality

README.md

@@ -411,6 +411,26 @@ Example commands:
 * !md login https://my.instance/ me@email.invalid r00tm3
 * !md roomlogin #myroom:matrix.org https://my.instance/ me@email.invalid r00tm3
 
+### Relay bridge
+
+Bridges two or more Matrix rooms together via relaybot. 
+
+Note: Room ID is not same as room alias! Rooms can exist without aliases so ID's are more flexible. Room id is usually in format !123LotOfRandomChars:server.org
+
+To get room ID, it's in Element Web room settings | Advanced | Internal room ID
+
+Before bridging the bot must be present on both rooms.
+
+Commands:
+
+* !relay bridge [roomid] - Bridge room with given ID to this room (must be done as bot owner)
+* !relay list - List bridged rooms (and their index numbers) (must be done as bot owner)
+* !relay unbridge [number] - Remove the given bridge number (must be done as bot owner)
+
+File uploads, joins, leaves or other special events are not (yet) handled. Contributions welcome.
+
+Relaybots are stupid. Please prefer real Matrix bridges to this. Sometimes there's no alternative.
+
 ## Bot setup
 
 * Create a Matrix user

bot.py

@@ -142,7 +142,10 @@ class Bot:
                 self.client.event_callbacks.remove(cb_object)
 
     def get_room_by_id(self, room_id):
+        try:
             return self.client.rooms[room_id]
+        except KeyError:
+            return None
 
     async def get_room_by_alias(self, alias):
         rar = await self.client.room_resolve_alias(alias)
@@ -205,7 +208,7 @@ class Bot:
         # Ignore if asked to ignore
         if self.should_ignore_event(event):
             if self.debug:
-                print('Ignoring event!')
+                self.logger.debug('Ignoring event!')
             return
 
         body = event.body
@@ -450,4 +453,4 @@ async def main():
 try:
     asyncio.run(main())
 except Exception as e:
-    print(e)
+    traceback.print_exc(file=sys.stderr)

modules/relay.py

@@ -0,0 +1,108 @@
+from modules.common.module import BotModule
+from nio import RoomMessageText
+
+class MatrixModule(BotModule):
+    def __init__(self, name):
+        super().__init__(name)
+        self.bridges = dict()
+        self.bot = None
+
+    async def message_cb(self, room, event):
+        if self.bot.should_ignore_event(event):
+            return
+
+        if event.body.startswith('!'):
+            return
+
+        source_id = None
+        target_id = None
+
+        for src_id, tgt_id in self.bridges.items():
+            if room.room_id == src_id:
+                source_id = src_id
+                target_id = tgt_id
+            elif room.room_id == tgt_id:
+                source_id = tgt_id
+                target_id = src_id
+
+        if not source_id or not target_id:
+            return
+
+        target_room = self.bot.get_room_by_id(target_id)
+        if(target_room):
+            sendernick = target_room.user_name(event.sender)
+            if not sendernick:
+                sendernick = event.sender
+            await self.bot.send_text(target_room, f'<{sendernick}> {event.body}', msgtype="m.text", bot_ignore=True)
+        else:
+            self.logger.warning(f"Bot doesn't seem to be in bridged room {target_id}")
+
+    def matrix_start(self, bot):
+        super().matrix_start(bot)
+        bot.client.add_event_callback(self.message_cb, RoomMessageText)
+        self.bot = bot
+
+    def matrix_stop(self, bot):
+        super().matrix_stop(bot)
+        bot.remove_callback(self.message_cb)
+        self.bot = None
+
+    async def matrix_message(self, bot, room, event):
+        bot.must_be_admin(room, event)
+        args = event.body.split()
+        args.pop(0)
+        if len(args) == 1:
+            if args[0] == 'list':
+                i = 1
+                msg = f"Active relay bridges ({len(self.bridges)}):\n"
+                for src_id, tgt_id in self.bridges.items():
+                    srcroom = self.bot.get_room_by_id(src_id)
+                    tgtroom = self.bot.get_room_by_id(tgt_id)
+
+                    if srcroom:
+                        srcroom = srcroom.display_name
+                    else:
+                        srcroom = f'??? {src_id}'
+
+                    if tgtroom:
+                        tgtroom = tgtroom.display_name
+                    else:
+                        tgtroom = f'??? {tgt_id}'
+
+                    msg += f'{i}: {srcroom} <-> {tgtroom}'
+                    i = i + 1
+                await bot.send_text(room, msg)
+
+        if len(args) == 2:
+            if args[0] == 'bridge':
+                roomid = args[1]
+                room_to_bridge = bot.get_room_by_id(roomid)
+                if room_to_bridge:
+                    await bot.send_text(room, f'Bridging {room_to_bridge.display_name} here.')
+                    self.bridges[room.room_id] = roomid
+                    bot.save_settings()
+                else:
+                    await bot.send_text(room, f'I am not on room with id {roomid} (note: use id, not alias)!')
+            elif args[0] == 'unbridge':
+                idx = int(args[1]) - 1
+                i = 0
+                for src_id, tgt_id in self.bridges.items():
+                    if i == idx:
+                        del self.bridges[src_id]
+                        await bot.send_text(room, f'Unbridged {src_id} and {tgt_id}.')
+                        bot.save_settings()
+                        return
+                    i = i + 1
+
+    def help(self):
+        return 'Simple relaybot between two Matrix rooms'
+
+    def get_settings(self):
+        data = super().get_settings()
+        data["bridges"] = self.bridges
+        return data
+
+    def set_settings(self, data):
+        super().set_settings(data)
+        if data.get("bridges"):
+            self.bridges = data["bridges"]

modules/url.py

@@ -3,6 +3,8 @@ import shlex
 from functools import lru_cache
 
 import httpx
+import sys
+import traceback
 from bs4 import BeautifulSoup
 from nio import RoomMessageText
 
@@ -90,6 +92,7 @@ class MatrixModule(BotModule):
                 title, description = self.get_content_from_url(url)
             except Exception as e:
                 self.logger.warning(f"could not fetch url: {e}")
+                traceback.print_exc(file=sys.stderr)
                 # failed fetching, give up
                 continue