From 63f31aa42f8305488afc666eb0812904ae3e105d Mon Sep 17 00:00:00 2001
From: Nikita Vilunov <nikita@vilunov.me>
Date: Thu, 16 Feb 2023 19:47:51 +0100
Subject: [PATCH] support who for global channels

---
 src/projections/irc/mod.rs | 70 ++++++++++++++++++++++++++++++--------
 1 file changed, 56 insertions(+), 14 deletions(-)

diff --git a/src/projections/irc/mod.rs b/src/projections/irc/mod.rs
index 544694f..bf5bac3 100644
--- a/src/projections/irc/mod.rs
+++ b/src/projections/irc/mod.rs
@@ -29,7 +29,7 @@ struct RegisteredUser {
     nickname: Vec<u8>,
     /**
      * Username is mostly unused in modern IRC.
-     * 
+     *
      * [https://stackoverflow.com/questions/31666247/what-is-the-difference-between-the-nick-username-and-real-name-in-irc-and-wha]
      */
     username: Vec<u8>,
@@ -226,7 +226,7 @@ async fn handle_registered_socket<'a>(
                 } else {
                     len
                 };
-                handle_incoming_message(&buffer[0..len], &config, &user, &mut connection, writer).await?;
+                handle_incoming_message(&buffer[0..len], &config, &user, &rooms, &mut connection, writer).await?;
                 buffer.clear();
             },
             update = connection.receiver.recv() => {
@@ -328,6 +328,7 @@ async fn handle_incoming_message(
     buffer: &[u8],
     config: &ServerConfig,
     user: &RegisteredUser,
+    rooms: &RoomRegistry,
     user_handle: &mut PlayerConnection,
     writer: &mut (impl AsyncWrite + Unpin),
 ) -> Result<()> {
@@ -397,16 +398,7 @@ async fn handle_incoming_message(
                     ServerMessage {
                         tags: vec![],
                         sender: Some(config.server_name.as_bytes().to_vec()),
-                        body: ServerMessageBody::N352WhoReply {
-                            client: user.nickname.clone(),
-                            username,
-                            host,
-                            server: config.server_name.as_bytes().to_vec(),
-                            flags: AwayStatus::Here,
-                            nickname: nick.clone(),
-                            hops: 0,
-                            realname: user.realname.clone(),
-                        },
+                        body: user_to_who_msg(config, user, nick),
                     }
                     .write_async(writer)
                     .await?;
@@ -423,8 +415,35 @@ async fn handle_incoming_message(
                     .await?;
                     writer.flush().await?;
                 }
-                Recipient::Chan(_) => {
-                    log::warn!("WHO for chans not implemented")
+                Recipient::Chan(Chan::Global(chan)) => {
+                    let room = rooms.get_room(&RoomId::from_bytes(chan.clone())?);
+                    if let Some(room) = room {
+                        let room_info = room.get_room_info().await;
+                        for member in room_info.members {
+                            ServerMessage {
+                                tags: vec![],
+                                sender: Some(config.server_name.as_bytes().to_vec()),
+                                body: user_to_who_msg(config, user, member.as_bytes()),
+                            }
+                            .write_async(writer)
+                            .await?;
+                        }
+                    }
+                    ServerMessage {
+                        tags: vec![],
+                        sender: Some(config.server_name.as_bytes().to_vec()),
+                        body: ServerMessageBody::N315EndOfWho {
+                            client: user.nickname.clone(),
+                            mask: target.clone(),
+                            msg: b"End of WHO list".to_vec(),
+                        },
+                    }
+                    .write_async(writer)
+                    .await?;
+                    writer.flush().await?;
+                }
+                Recipient::Chan(Chan::Local(_)) => {
+                    log::warn!("Local chans not supported");
                 }
             },
             cmd => {
@@ -438,6 +457,29 @@ async fn handle_incoming_message(
     Ok(())
 }
 
+fn user_to_who_msg(config: &ServerConfig, requestor: &RegisteredUser, target_user_nickname: &ByteVec) -> ServerMessageBody {
+    // Username is equal to nickname
+    let mut username = Vec::with_capacity(target_user_nickname.len() + 1);
+    username.push(b'~');
+    username.extend_from_slice(target_user_nickname.as_slice());
+
+    // User's host is not public, replace it with `user/<nickname>` pattern
+    let mut host = b"user/".to_vec();
+    host.extend_from_slice(target_user_nickname.as_slice());
+
+    ServerMessageBody::N352WhoReply {
+        client: requestor.nickname.clone(),
+        username,
+        host,
+        server: config.server_name.as_bytes().to_vec(),
+        flags: AwayStatus::Here,
+        nickname: target_user_nickname.clone(),
+        hops: 0,
+        // TODO Realname is not available yet, should be matched to a future core's player field
+        realname: target_user_nickname.clone(),
+    }
+}
+
 async fn handle_join(
     config: &ServerConfig,
     user: &RegisteredUser,