move draft/multiline into its own module file

src/modules/multiline.rs

@@ -0,0 +1,138 @@
+//! multiline — the server side of IRCv3 draft/multiline. A client wraps one long
+//! message in a `BATCH +<ref> draft/multiline <target>`; the `@batch=<ref>`-tagged
+//! PRIVMSG/NOTICE lines are buffered here (see `Ircd::dispatch`) and, when
+//! `BATCH -<ref>` closes, reassembled (honouring `draft/multiline-concat`) and
+//! delivered as normal messages. Self-contained: the in-flight batches live in
+//! `Server.ext`, cleaned up by the on_user_quit hook; the BATCH command and the
+//! accumulate/close logic are all here.
+
+use std::collections::HashMap;
+
+use crate::command::{CmdResult, Command};
+use crate::coremods::core_message::deliver;
+use crate::module::Module;
+use crate::server::Server;
+use crate::Uid;
+
+/// Limits advertised in the `draft/multiline` cap and enforced while buffering.
+pub const MAX_BYTES: usize = 4096;
+pub const MAX_LINES: usize = 24;
+
+/// An in-progress inbound multiline batch — one long client message being
+/// assembled from several `@batch=`-tagged PRIVMSG/NOTICE lines.
+pub struct MlineBatch {
+    pub bref: String,
+    pub target: String,
+    pub notice: bool,
+    pub parts: Vec<(String, bool)>, // (text, concat-with-previous-part)
+    pub bytes: usize,
+}
+
+/// uid -> its open batch. Stored in `Server.ext`.
+#[derive(Default)]
+pub struct Mline(pub HashMap<Uid, MlineBatch>);
+
+/// Open an inbound batch for `uid` (a client assembling one long message from
+/// several tagged PRIVMSG/NOTICE lines).
+fn open(s: &mut Server, uid: Uid, bref: &str, target: &str) {
+    s.ext.get_or_insert_with::<Mline>(Mline::default).0.insert(
+        uid,
+        MlineBatch {
+            bref: bref.to_string(),
+            target: target.to_string(),
+            notice: false,
+            parts: Vec::new(),
+            bytes: 0,
+        },
+    );
+}
+
+/// Buffer one PRIVMSG/NOTICE line into `uid`'s open batch when `bref` matches
+/// (bounded by the advertised byte/line limits). Returns true if it was part of
+/// the batch — i.e. it should not be delivered on its own. Called from dispatch.
+pub fn accumulate(
+    s: &mut Server,
+    uid: Uid,
+    bref: &str,
+    notice: bool,
+    text: &str,
+    concat: bool,
+) -> bool {
+    match s.ext.get_mut::<Mline>().and_then(|m| m.0.get_mut(&uid)) {
+        Some(mb) if mb.bref == bref => {
+            if mb.parts.len() < MAX_LINES && mb.bytes + text.len() <= MAX_BYTES {
+                mb.notice = notice;
+                mb.bytes += text.len();
+                mb.parts.push((text.to_string(), concat));
+            }
+            true
+        }
+        _ => false,
+    }
+}
+
+/// Close `uid`'s batch `bref` and return `(target, is_notice, lines)` with `concat`
+/// parts joined into single logical lines. `None` if no match.
+fn close(s: &mut Server, uid: Uid, bref: &str) -> Option<(String, bool, Vec<String>)> {
+    let store = s.ext.get_mut::<Mline>()?;
+    match store.0.get(&uid) {
+        Some(mb) if mb.bref == bref => {}
+        _ => return None,
+    }
+    let mb = store.0.remove(&uid)?;
+    let mut lines: Vec<String> = Vec::new();
+    for (text, concat) in mb.parts {
+        if concat && !lines.is_empty() {
+            lines.last_mut().unwrap().push_str(&text);
+        } else {
+            lines.push(text);
+        }
+    }
+    Some((mb.target, mb.notice, lines))
+}
+
+/// Cleanup hook: drop any half-open batch on disconnect.
+pub struct Multiline;
+impl Module for Multiline {
+    fn name(&self) -> &'static str {
+        "multiline"
+    }
+    fn on_user_quit(&mut self, s: &mut Server, uid: Uid, _reason: &str) {
+        if let Some(m) = s.ext.get_mut::<Mline>() {
+            m.0.remove(&uid);
+        }
+    }
+}
+
+pub fn commands() -> Vec<Box<dyn Command>> {
+    vec![Box::new(Batch)]
+}
+
+/// BATCH — the client side of draft/multiline. `BATCH +<ref> draft/multiline
+/// <target>` opens a batch; the tagged lines are buffered; `BATCH -<ref>` assembles
+/// them and delivers each logical line as a normal PRIVMSG/NOTICE.
+struct Batch;
+impl Command for Batch {
+    fn name(&self) -> &'static str {
+        "BATCH"
+    }
+    fn min_params(&self) -> usize {
+        1
+    }
+    fn handle(&self, s: &mut Server, uid: Uid, params: &[String]) -> CmdResult {
+        let tag = &params[0];
+        if let Some(bref) = tag.strip_prefix('+') {
+            if params.get(1).map(|t| t.as_str()) == Some("draft/multiline") {
+                let target = params.get(2).cloned().unwrap_or_default();
+                open(s, uid, bref, &target);
+            }
+        } else if let Some(bref) = tag.strip_prefix('-') {
+            if let Some((target, notice, lines)) = close(s, uid, bref) {
+                for line in lines {
+                    deliver(s, uid, &[target.clone(), line], notice);
+                }
+            }
+        }
+        CmdResult::Ok
+    }
+}