huskies: merge 1144 story Gateway trampoline-restart: detached helper survives the gateway's own death

server/src/chat/transport/matrix/bot/messages/on_room_message.rs

@@ -19,6 +19,28 @@ use super::super::verification::check_sender_verified;
 
 use super::handle_message;
 
+/// Return `true` when the message is a "rebuild gateway" command addressed to the bot.
+///
+/// The command is recognised case-insensitively as `rebuild gateway` after stripping
+/// the bot mention prefix so both `@Timmy rebuild gateway` and `Timmy rebuild gateway`
+/// match.
+fn extract_rebuild_gateway_command(message: &str, bot_name: &str, bot_user_id: &str) -> bool {
+    let stripped = crate::chat::util::strip_bot_mention(message, bot_name, bot_user_id);
+    let trimmed = stripped
+        .trim()
+        .trim_start_matches(|c: char| !c.is_alphanumeric());
+    let (cmd, rest) = match trimmed.split_once(char::is_whitespace) {
+        Some((c, r)) => (c, r.trim()),
+        None => return false,
+    };
+    cmd.eq_ignore_ascii_case("rebuild")
+        && rest
+            .split_whitespace()
+            .next()
+            .map(|w| w.eq_ignore_ascii_case("gateway"))
+            .unwrap_or(false)
+}
+
 /// Evaluate a `switch <arg>` command against the live project store.
 ///
 /// Reads valid project names from the store at call time so newly added
@@ -657,6 +679,87 @@ pub(in crate::chat::transport::matrix::bot) async fn on_room_message(
         return;
     }
 
+    // In gateway mode, intercept "rebuild gateway" and route it through the
+    // detached trampoline so the process swap survives any bash-tool kill cascade.
+    if ctx.gateway_active_project.is_some()
+        && extract_rebuild_gateway_command(
+            &user_message,
+            &ctx.services.bot_name,
+            ctx.matrix_user_id.as_str(),
+        )
+    {
+        slog!("[matrix-bot] Handling 'rebuild gateway' command from {sender}");
+        let ack = "Rebuilding gateway\u{2026} this may take a moment.";
+        let ack_html = markdown_to_html(ack);
+        if let Ok(msg_id) = ctx
+            .transport
+            .send_message(&room_id_str, ack, &ack_html)
+            .await
+            && let Ok(event_id) = msg_id.parse()
+        {
+            ctx.bot_sent_event_ids.lock().await.insert(event_id);
+        }
+        let config_dir = ctx.services.project_root.clone();
+        let gateway_port: u16 = ctx.gateway_port.unwrap_or(3000);
+        match crate::gateway::rebuild::rebuild_gateway(&config_dir, gateway_port).await {
+            Ok(()) => {
+                // Trampoline is running detached — it kills this gateway and starts
+                // the new one, which will post "gateway X.Y.Z ready" on startup.
+            }
+            Err(e) => {
+                let msg = format!("Gateway rebuild failed: {e}");
+                let html = markdown_to_html(&msg);
+                if let Ok(msg_id) = ctx.transport.send_message(&room_id_str, &msg, &html).await
+                    && let Ok(event_id) = msg_id.parse()
+                {
+                    ctx.bot_sent_event_ids.lock().await.insert(event_id);
+                }
+            }
+        }
+        return;
+    }
+
+    // In gateway mode, intercept "rebuild gateway" before the plain "rebuild"
+    // handler so the trampoline path is used instead of a direct re-exec.
+    if ctx.gateway_port.is_some()
+        && super::super::super::rebuild::extract_rebuild_gateway_command(
+            &user_message,
+            &ctx.services.bot_name,
+            ctx.matrix_user_id.as_str(),
+        )
+        .is_some()
+    {
+        slog!("[matrix-bot] Handling rebuild-gateway command from {sender}");
+        let ack = "Rebuilding gateway… this may take a moment. \
+                   The gateway will announce itself when the new version is ready.";
+        let ack_html = markdown_to_html(ack);
+        if let Ok(msg_id) = ctx
+            .transport
+            .send_message(&room_id_str, ack, &ack_html)
+            .await
+            && let Ok(event_id) = msg_id.parse()
+        {
+            ctx.bot_sent_event_ids.lock().await.insert(event_id);
+        }
+        let port = ctx.gateway_port.unwrap_or(3000);
+        match crate::gateway::rebuild::rebuild_gateway(&ctx.services.project_root, port).await {
+            Ok(()) => {
+                // Trampoline is running — this gateway will be killed shortly.
+                // No further reply needed; the new gateway posts "gateway X.Y.Z ready".
+            }
+            Err(e) => {
+                let msg = format!("Gateway rebuild failed: {e}");
+                let html = markdown_to_html(&msg);
+                if let Ok(msg_id) = ctx.transport.send_message(&room_id_str, &msg, &html).await
+                    && let Ok(event_id) = msg_id.parse()
+                {
+                    ctx.bot_sent_event_ids.lock().await.insert(event_id);
+                }
+            }
+        }
+        return;
+    }
+
     // Check for the rebuild command, which requires async agent and process ops
     // and cannot be handled by the sync command registry.
     if super::super::super::rebuild::extract_rebuild_command(