Handle re-joining on restart

Closes https://git.vvvvvvaria.org/decentral1se/xbotlib/issues/11.

README.md

@@ -28,6 +28,7 @@ XMPP bot experiments going on in
   - [Storage back-end](#storage-back-end)
   - [Loading Plugins](#loading-plugins)
   - [Serving HTTP](#serving-http)
+  - [Invitations](#invitations)
   - [API Reference](#api-reference)
     - [Bot.direct(message)](#bot-direct-message)
     - [Bot.group(message)](#bot-group-message)
@@ -200,8 +201,7 @@ deployments.
 In order to store data you can make use of the `self.db` attribute of the `Bot`
 class. It is a Python dictionary which will be saved to disk automatically for
 you as a `<nick>.json` in your current working directory. The name and path to
-this file can be configured using the output option (e.g. `python bot.py
+this file can be configured using the output option (e.g. `python bot.py --output /var/www/html`)
---output /var/www/html`)
 
 ```python
 def group(self, message):
@@ -302,6 +302,15 @@ storage](#storage-back-end). Your `serve` function can read from the storage
 back-end and then respond. This is usually as simple as accessing the `self.db`
 attribute.
 
+### Invitations
+
+As long as the `--no-auto-join` option is not set (via the configuration file
+or environment also), then your bot will automatically join any room it is
+invited to. Rooms that your bot has been invited to will be stored in the
+`.xbotlib/data.json` file. If your bot is turned off or fails for some reason
+then it will read this file when turned back on to see what rooms it should
+re-join automatically. The `data.json` file can be edited freely by hand.
+
 ### API Reference
 
 When writing your own bot, you always sub-class the `Bot` class provided from

xbotlib.py

@@ -594,6 +594,10 @@ class Bot(ClientXMPP):
             self.plugin["xep_0045"].join_muc(room, self.config.nick)
             self.log.info(f"Joining {room} automatically")
 
+        for room in self._data["invited"]:
+            self.plugin["xep_0045"].join_muc(room, self.config.nick)
+            self.log.info(f"Re-joining {room} (invited previously)")
+
     def group_invite(self, message):
         """Accept invites to group chats."""
         room = message["from"]
@@ -604,6 +608,10 @@ class Bot(ClientXMPP):
         self.plugin["xep_0045"].join_muc(room, self.config.nick)
         self.log.info(f"Joining {room} as invited")
 
+        if room not in self._data["invited"]:
+            self._data["invited"].append(str(room))
+            self._data._dumps()
+
     def group_message(self, message):
         """Handle group chat message events."""
         message = SimpleMessage(message, self)
@@ -706,6 +714,9 @@ class Bot(ClientXMPP):
             self.log.error(message)
             exit(1)
 
+        if "invited" not in self._data:
+            self._data["invited"] = []
+
     def run(self):
         """Run the bot."""
         self.connect()