added notify-away support

[casperstorm]

This adds support for notify-away extension.
We call WHO when joining a channel to get initial state, and then keeps it synced with AWAY responses.
Away users is appear slightly transparent. This idea is stolen from Textual.

[tarkah]

Looks great @casperstorm! A couple minor things. Also, we may want to handle RPL_NOWAWAY and RPL_UNAWAY so when we issue an /away command, it'll update our nick in the nicklists. I noticed these are what's sent when we're the ones sending the /away.

[tarkah]

I noticed a message from libera about "rate-limiting" so I'm not sure WHO was sent on each of my joined channels. Thoughts around how we should handle this? Do we know what other clients do to circumvent this issue?

Maybe we keep track of a map of channels and the last time they're polled for WHO. If they haven't been polled, we can execute WHO. We check this every X seconds / minutes. We only ensure it's sent once if away-notify is set, otherwise we can use this as a mechanism to poll every X if that feature isn't enabled?

[casperstorm]

I noticed a message from libera about "rate-limiting" so I'm not sure WHO was sent on each of my joined channels. Thoughts around how we should handle this? Do we know what other clients do to circumvent this issue?

Maybe we keep track of a map of channels and the last time they're polled for WHO. If they haven't been polled, we can execute WHO. We check this every X seconds / minutes. We only ensure it's sent once if away-notify is set, otherwise we can use this as a mechanism to poll every X if that feature isn't enabled?

This might be because of the WHO being called for all users joining previously. Can you test again? I don't think we have to make a special case for it - doesn't seem others do that 🤔

[tarkah]

I noticed a message from libera about "rate-limiting" so I'm not sure WHO was sent on each of my joined channels. Thoughts around how we should handle this? Do we know what other clients do to circumvent this issue?
Maybe we keep track of a map of channels and the last time they're polled for WHO. If they haven't been polled, we can execute WHO. We check this every X seconds / minutes. We only ensure it's sent once if away-notify is set, otherwise we can use this as a mechanism to poll every X if that feature isn't enabled?

This might be because of the WHO being called for all users joining previously. Can you test again? I don't think we have to make a special case for it - doesn't seem others do that thinking

I'm still getting it:

13:43:29.812:TRACE -- Message received => Message { tags: [Tag { key: "time", value: Some("2023-07-24T20:43:29.722Z") }], source: Some(Server("erbium.libera.chat")), command: Numeric(RPL_TRYAGAIN, ["tarkah", "WHO", "This command could not be completed because it has been used recently, and is rate-limited."]) }

[casperstorm]

Gotcha, yeah let's then add a system which keeps track which we can also use for polling.

[tarkah]

Awesome feature!