feat(maestro): spawn form rerolls from a fetched name batch (#53)

web/src/spawnForm.ts

@@ -1,8 +1,7 @@
 import { escapeHtml } from "./html.js";
-import { createSession, getDaemonInfo, projects as fetchProjects, gitRoot } from "./api.js";
+import { createSession, fetchNames, getDaemonInfo, projects as fetchProjects, gitRoot } from "./api.js";
 import { attachDirAutocomplete } from "./dirAutocomplete.js";
 import { filterProjects, groupProjects, isStale, sortProjects } from "./projectList.js";
-import { generateName } from "./names.js";
 import type { CreateSessionRequest, Project, Session, SpawnPreset } from "./types.js";
 import { abbreviateCwd, abbreviateFolderName } from "./types.js";
 
@@ -197,8 +196,46 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   const syncBranchToName = () => {
     if (!branchEdited) branchInput.value = nameInput.value;
   };
-  nameInput.value = prefill.name ?? generateName();
+  // Handles come from `GET /api/names` in batches (#53): the first one seeds
+  // the field, rerolls consume the rest locally so they stay instant, and a
+  // new batch is fetched when (and only when) the queue runs dry. One refill
+  // at a time keeps rapid rerolls from storming the daemon.
+  const NAME_BATCH_SIZE = 20;
+  let nameQueue: string[] = [];
+  let nameFetch: Promise<void> | null = null;
+  // Guards against a late batch clobbering something the operator already
+  // typed or rerolled.
+  let nameTouched = Boolean(prefill.name);
+  const refillNames = (): Promise<void> => {
+    if (!nameFetch) {
+      nameFetch = fetchNames(NAME_BATCH_SIZE)
+        .then((batch) => {
+          if (!destroyed) nameQueue.push(...batch.names);
+        })
+        .catch(() => {
+          /* reroll just stays on the current name */
+        })
+        .finally(() => {
+          nameFetch = null;
+        });
+    }
+    return nameFetch;
+  };
+
+  nameInput.value = prefill.name ?? "";
+  if (!nameTouched) {
+    void refillNames().then(() => {
+      if (destroyed || nameTouched || nameInput.value) return;
+      const next = nameQueue.shift();
+      if (next !== undefined) {
+        nameInput.value = next;
+        syncBranchToName();
+        emit();
+      }
+    });
+  }
   nameInput.addEventListener("input", () => {
+    nameTouched = true;
     syncBranchToName();
     emit();
   });
@@ -207,9 +244,21 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     emit();
   });
   (form.querySelector(".reroll") as HTMLButtonElement).addEventListener("click", () => {
-    nameInput.value = generateName();
-    syncBranchToName();
-    emit();
+    nameTouched = true;
+    const apply = () => {
+      if (destroyed) return;
+      const next = nameQueue.shift();
+      if (next === undefined) return;
+      nameInput.value = next;
+      syncBranchToName();
+      emit();
+    };
+    // Only hit the daemon when the local batch is exhausted.
+    if (nameQueue.length === 0) {
+      void refillNames().then(apply);
+    } else {
+      apply();
+    }
   });
   syncBranchToName(); // seed the branch from the initial name