Fire-and-Forget Bot
===================

A Matrix bot aimed at one-shot usage from the command line.


Features/usage
--------------
The command itself is most helpful:
```
Usage: fafbot [OPTIONS] <COMMAND>

Commands:
  login                  Login to server with user and password
  login-sso              Login to server through SSO
  login-restore-session  Login to server by reusing an existing token
  join                   Join room
  leave                  Leave room
  list-joined            List joined rooms
  list-invited           List rooms invited to
  send                   Send message
  help                   Print this message or the help of the given subcommand(s)

Options:
      --debug            Enable debug logging
      --dry-run          Do everything but send the message and join/leave channels (still log in, etc)
  -d, --db-dir <db-dir>  Directory where the bot state is stored [env: FAFBOT_DB_DIR] [default: /home/user/.local/state/fafbot]
  -h, --help             Print help
```

In essence:
1. You need to login to the server by running one of the three first
   subcommands.
2. For the next invocation, you should join a room using the `join` subcommand.
   If you want to join a private room, make sure to be invited first. The
   `list-invited` subcommand is available for your convenience.
3. Do whatever; join/leave rooms, send messages. I'm not your mother.

If you are not familiar with Matrix, please note that a user may have one or
more devices. Matrix' E2E encryption works by sending encryption keys to each
user's device which means that it's customary to keep your device count down as
a user. This is why login is separated from join/leave/send, and why there
is a state directory: Each sign-in will create a session, i.e. a device.


Known issues 1
--------------
Sometimes when running, fafbot may stumble upon issues in decryption. This
seems to be an issue with the Matrix SDK, and looks to be benign:
```
Failed to decrypt a non-pre-key message with all available sessions sender=@user:example.org sender_key=f0O69NqwrEVNjdnqlwhQPdn4xVqF05YGr8wR1Jhi+mTNr0UFAaOiQtu1Q
An Olm message got replayed, decryption failed sender="@user:example.org" sender_key=vf0O69NqwrEVNjdnqlwhQPdn4xVqF05YGr8wR1Jhi+mTNr0UFAaOiQtu1Q
```
And:
```
Failed to deserialize a global account data event error=Error("unknown variant `org.matrix.msc3931.room_version_supports`, expected one of `event_match`, `contains_display_name`, `room_member_count`, `sender_notification_permission`", line: 1, column: 1018)
Failed to deserialize a global account data event error=Error("unknown variant `org.matrix.msc3931.room_version_supports`, expected one of `event_match`, `contains_display_name`, `room_member_count`, `sender_notification_permission`", line: 1, column: 1018)
```

Known issues 2
--------------
If using the `login-restore-session` subcommand, there must be no keys
registered for the device. If there are, you will see errors like this and will
need to set up a new session:
```
Error when sending out an outgoing E2EE request error=Http(Api(Server(Known(ClientApi(Error { kind: Unknown, message: "One time key signed_curve25519:AAAAAAAAAA0 already exists. Old key: {\"key\":\"mme2Wf6Bj4wfx50ZHIr6LbR7eVGByKQFwHtmgOYjpoOqAQa1gM1SLKD2hg\",\"signatures\":{\"@user:example.org\":{\"ed25519:\":\"a072/U1At3i1JXi7XzOaCsRTR8hhjcgLwMS4Q5pOFCkRBA9KX2J8RWcX+/m5adqcybUzHrgtQ3TCaz9N1rmAEP2eNfsVA1Ug/IcImub7MT1xQ4kzr2Y\"}}}; new key: {'key': 'd44FTHHoKWazpSZhHKUpPFoakL0p3RhUrxoyFmEphmoBxfO+cA2KOkh4AQ', 'signatures': {'@user:example.org': {'ed25519:BIEPEEXIEN': '9cynKfWRywWX3y1+dp3XzrS7HMa2v9DKButSZYv/F4gLCI3pnSLH+NRuMpEMiIsMcrW6xsg6cImK9nbZ/f/lYlbWfTUUIMRsx5inyTWl9qvnpepegNM'}}}", status_code: 400 })))))
```