Gateway: show subagent requests on the parent's card, and settle threads

gateway/src/views.ts

@@ -180,7 +180,56 @@ export function routeKind(url: string): RouteKind {
   return hostname.includes("vpn") ? "vpn" : "direct";
 }
 
-function feedItem(host: T3Host, thread: ThreadShell, phase: Phase, summary: ThreadSummary | undefined): FeedItem {
+/** A thread on the feed. With `via`, the card shows that subagent's request on this thread. */
+interface Candidate {
+  host: T3Host;
+  thread: ThreadShell;
+  phase: Phase;
+  via?: { host: T3Host; thread: ThreadShell; phase: Phase };
+}
+
+const isWaiting = (phase: Phase | null) => phase === "waiting_for_approval" || phase === "waiting_for_input";
+
+/** The thread that delegated `child`, if the gateway is connected to its host. */
+function delegator(hosts: T3Host[], child: ThreadShell): { host: T3Host; thread: ThreadShell } | null {
+  const from = child.delegatedFrom;
+  if (!from) return null;
+  const host = hosts.find((candidate) => candidate.config.environmentId === from.environmentId);
+  const thread = host?.threads.get(from.threadId);
+  return host && thread ? { host, thread } : null;
+}
+
+/**
+ * Moves each waiting subagent's request onto the card of the thread that delegated it, the oldest
+ * request first. A subagent keeps its own card when its parent is unknown, hidden, archived, or
+ * already showing a request.
+ */
+function attachDelegates(candidates: Candidate[], hosts: T3Host[]): Candidate[] {
+  const result = [...candidates];
+  const delegates = candidates
+    .filter(({ thread, phase }) => thread.delegatedFrom && isWaiting(phase))
+    .sort((a, b) => requestAge(a.thread).localeCompare(requestAge(b.thread)));
+  for (const child of delegates) {
+    const parent = delegator(hosts, child.thread);
+    const index = parent ? result.findIndex(({ host, thread }) => host === parent.host && thread.id === parent.thread.id) : -1;
+    const card = result[index];
+    const own = result.indexOf(child);
+    if (!card || own === -1 || card.via || isWaiting(card.phase)) continue;
+    result[index] = { ...card, phase: child.phase, via: { host: child.host, thread: child.thread, phase: child.phase } };
+    result.splice(own, 1);
+  }
+  return result;
+}
+
+const requestAge = (thread: ThreadShell) => thread.pendingRuntimeRequest?.createdAt ?? "";
+
+function feedItem(
+  host: T3Host,
+  thread: ThreadShell,
+  phase: Phase,
+  summary: ThreadSummary | undefined,
+  via?: { host: T3Host; thread: ThreadShell; summary: ThreadSummary | undefined },
+): FeedItem {
   return {
     hostId: host.id,
     hostLabel: host.label,
@@ -191,10 +240,26 @@ function feedItem(host: T3Host, thread: ThreadShell, phase: Phase, summary: Thre
     phase,
     updatedAt: thread.updatedAt,
     lastMessage: summary?.lastAssistantMessage ?? null,
-    request: summary?.request ?? null,
+    request: (via ? via.summary : summary)?.request ?? null,
+    via: via ? { hostId: via.host.id, threadId: via.thread.id, title: via.thread.title } : null,
   };
 }
 
+/** The longest waiting subagent that `parent` delegated to, if any. */
+function waitingDelegate(hosts: T3Host[], parentHost: T3Host, parent: ThreadShell): Candidate | undefined {
+  let oldest: Candidate | undefined;
+  for (const host of hosts) {
+    for (const thread of host.threads.values()) {
+      const from = thread.delegatedFrom;
+      if (from?.threadId !== parent.id || from.environmentId !== parentHost.config.environmentId) continue;
+      const phase = threadPhase(thread);
+      if (!isWaiting(phase) || thread.archivedAt || thread.deletedAt) continue;
+      if (!oldest || requestAge(thread) < requestAge(oldest.thread)) oldest = { host, thread, phase: phase! };
+    }
+  }
+  return oldest;
+}
+
 /** Counts for the complication, from thread shells alone. */
 export function buildSummary(hosts: T3Host[]): Summary {
   let needsYou = 0;
@@ -221,37 +286,37 @@ export function buildSummary(hosts: T3Host[]): Summary {
 
 /** Builds the feed across every host, waiting briefly for summaries it has not read yet. */
 export async function buildFeed(hosts: T3Host[], cache: SummaryCache, now = Date.now()): Promise<Feed> {
-  const candidates: Array<{ host: T3Host; thread: ThreadShell; phase: Phase }> = [];
+  const found: Candidate[] = [];
   for (const host of hosts) {
     for (const thread of host.threads.values()) {
       const phase = threadPhase(thread);
       if (phase === null || thread.archivedAt || thread.deletedAt) continue;
       if ((phase === "completed" || phase === "failed") && now - Date.parse(thread.updatedAt) > RECENT_WINDOW_MS) continue;
-      candidates.push({ host, thread, phase });
+      found.push({ host, thread, phase });
     }
   }
+  const candidates = attachDelegates(found, hosts);
 
   const byNewest = (a: { thread: ThreadShell }, b: { thread: ThreadShell }) =>
     b.thread.updatedAt.localeCompare(a.thread.updatedAt);
+  const asker = (candidate: Candidate) => candidate.via?.thread ?? candidate.thread;
   const needsYou = candidates
-    .filter(({ phase }) => phase === "waiting_for_approval" || phase === "waiting_for_input")
-    .sort((a, b) =>
-      (a.thread.pendingRuntimeRequest?.createdAt ?? "").localeCompare(b.thread.pendingRuntimeRequest?.createdAt ?? ""),
-    );
+    .filter(({ phase }) => isWaiting(phase))
+    .sort((a, b) => requestAge(asker(a)).localeCompare(requestAge(asker(b))));
   const working = candidates.filter(({ phase }) => phase === "starting" || phase === "running").sort(byNewest);
   const recent = candidates
     .filter(({ phase }) => phase === "completed" || phase === "failed")
     .sort(byNewest)
     .slice(0, RECENT_LIMIT);
 
-  const shown = [...needsYou, ...working, ...recent];
+  const shown = [...needsYou, ...working, ...recent].flatMap((candidate) => (candidate.via ? [candidate, candidate.via] : [candidate]));
   const missing = shown
     .filter(({ host, thread }) => !cache.peek(host, thread))
     .map(({ host, thread }) => cache.get(host, thread).catch(() => undefined));
   if (missing.length > 0) await Promise.race([Promise.all(missing), Bun.sleep(SUMMARY_WAIT_MS)]);
 
-  const toItem = ({ host, thread, phase }: (typeof candidates)[number]) =>
-    feedItem(host, thread, phase, cache.peek(host, thread));
+  const toItem = ({ host, thread, phase, via }: Candidate) =>
+    feedItem(host, thread, phase, cache.peek(host, thread), via && { ...via, summary: cache.peek(via.host, via.thread) });
   return {
     needsYou: needsYou.map(toItem),
     working: working.map(toItem),
@@ -260,12 +325,22 @@ export async function buildFeed(hosts: T3Host[], cache: SummaryCache, now = Date
   };
 }
 
-/** One thread with its recent messages. Fetches the summary if it is not cached. */
-export async function buildThreadDetail(host: T3Host, thread: ThreadShell, cache: SummaryCache): Promise<ThreadDetail> {
+/**
+ * One thread with its recent messages. Fetches the summary if it is not cached. When the thread
+ * has no request of its own but a subagent it delegated to is waiting, shows that request.
+ */
+export async function buildThreadDetail(
+  host: T3Host,
+  thread: ThreadShell,
+  cache: SummaryCache,
+  hosts: T3Host[],
+): Promise<ThreadDetail> {
   const summary = await cache.get(host, thread);
-  const phase = threadPhase(thread) ?? (thread.status === "failed" ? "failed" : "completed");
+  const own = threadPhase(thread) ?? (thread.status === "failed" ? "failed" : "completed");
+  const child = isWaiting(own) ? undefined : waitingDelegate(hosts, host, thread);
+  const via = child && { host: child.host, thread: child.thread, summary: await cache.get(child.host, child.thread).catch(() => undefined) };
   return {
-    item: feedItem(host, thread, phase, summary),
+    item: feedItem(host, thread, child?.phase ?? own, summary, via),
     messages: summary.messages,
     canStop: thread.activeRunId !== null,
   };