From 1a8fbe56090990fd0ae1a204dc2ada2744a1c32e Mon Sep 17 00:00:00 2001
From: Val Lorentz <progval+git@progval.net>
Date: Sat, 2 Sep 2023 19:36:19 +0200
Subject: [PATCH] Implement IRCv3 away-notify

---
 sable_ircd/src/capability/mod.rs          |  1 +
 sable_ircd/src/messages/message.rs        |  2 ++
 sable_ircd/src/messages/send_history.rs   | 18 +++++++++++++++++-
 sable_network/src/node/update_receiver.rs | 17 ++++++++++++++++-
 4 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/sable_ircd/src/capability/mod.rs b/sable_ircd/src/capability/mod.rs
index fd923091..88dae55b 100644
--- a/sable_ircd/src/capability/mod.rs
+++ b/sable_ircd/src/capability/mod.rs
@@ -70,6 +70,7 @@ define_capabilities! (
         Batch:                  0x10 => ("batch", true),
         LabeledResponse:        0x20 => ("labeled-response", true),
         UserhostInNames:        0x40 => ("userhost-in-names", true),
+        AwayNotify:             0x80 => ("away-notify", true),
 
         ChatHistory:            0x100 => ("draft/chathistory", true),
         PersistentSession:      0x200 => ("sable.libera.chat/persistent-session", true),
diff --git a/sable_ircd/src/messages/message.rs b/sable_ircd/src/messages/message.rs
index 2bb94d18..4bd8265a 100644
--- a/sable_ircd/src/messages/message.rs
+++ b/sable_ircd/src/messages/message.rs
@@ -4,6 +4,8 @@ use super::*;
 use sable_macros::define_messages;
 
 define_messages! {
+    Away    => { (source, reason: &str)                     => ":{source} AWAY :{reason}" },
+    Unaway  => { (source)                                   => ":{source} AWAY" },
     Cap     => { (source, target, subcmd: &str, text: &str) => ":{source} CAP {target} {subcmd} :{text}" },
     Nick    => { (source, newnick: &Nickname)               => ":{source} NICK {newnick}" },
     Join    => { (source, chan: &ChannelName)               => ":{source} JOIN {chan}" },
diff --git a/sable_ircd/src/messages/send_history.rs b/sable_ircd/src/messages/send_history.rs
index 7ec8b773..995bf331 100644
--- a/sable_ircd/src/messages/send_history.rs
+++ b/sable_ircd/src/messages/send_history.rs
@@ -50,13 +50,22 @@ impl SendHistoryItem for update::NewUser {
 }
 
 impl SendHistoryItem for update::UserAwayChange {
-    fn send_to(&self, conn: impl MessageSink, _from_entry: &HistoryLogEntry) -> HandleResult {
+    fn send_to(&self, conn: impl MessageSink, from_entry: &HistoryLogEntry) -> HandleResult {
         if Some(self.user.user.id) == conn.user_id() {
+            // Echo back to the user
             let message = match self.new_reason {
                 None => numeric::Unaway::new(),
                 Some(_) => numeric::NowAway::new(),
             };
             conn.send(message.format_for(&self.user, &self.user));
+        } else {
+            // Tell other users sharing a channel if they enabled away-notify
+            let message = match self.new_reason {
+                None => message::Unaway::new(&self.user),
+                Some(reason) => message::Away::new(&self.user, reason.value()),
+            };
+            let message = message.with_tags_from(from_entry);
+            conn.send(message.with_required_capabilities(ClientCapability::AwayNotify));
         }
 
         Ok(())
@@ -193,6 +202,13 @@ impl SendHistoryItem for update::ChannelJoin {
             conn.send(msg);
         }
 
+        if let Some(away_reason) = self.user.user.away_reason {
+            let message =
+                message::Away::new(&self.user, &away_reason.value()).with_tags_from(from_entry);
+
+            conn.send(message.with_required_capabilities(ClientCapability::AwayNotify));
+        }
+
         Ok(())
     }
 }
diff --git a/sable_network/src/node/update_receiver.rs b/sable_network/src/node/update_receiver.rs
index 85d0f3bf..cddd6bb9 100644
--- a/sable_network/src/node/update_receiver.rs
+++ b/sable_network/src/node/update_receiver.rs
@@ -26,7 +26,22 @@ impl<Policy: crate::policy::PolicyService> NetworkNode<Policy> {
         entry: &HistoryLogEntry,
         detail: &update::UserAwayChange,
     ) -> HandleResult {
-        self.notify_user(detail.user.user.id, entry.id);
+        let net = self.network();
+        let source = net.user(detail.user.user.id)?;
+
+        let mut notified = HashSet::new();
+
+        // Notify the source user themselves, even if they are not in any channel
+        notified.insert(detail.user.user.id);
+
+        for m1 in source.channels() {
+            let chan = m1.channel()?;
+            for m2 in chan.members() {
+                notified.insert(m2.user_id());
+            }
+        }
+
+        self.notify_users(notified, entry.id);
         Ok(())
     }