import { EventEmitter } from "node:events";
import type { ServerMessage } from "../ws/protocol";

declare global {
  var __triggershellRunEvents: EventEmitter | undefined;
}

/** Decouples the run engine from the WS transport: the engine emits, ws/server.ts broadcasts.
 * Anchored on `globalThis` because Next compiles Route Handlers through its own module graph,
 * separate from the modules `server.ts` requires directly via tsx - a plain module-level
 * singleton would silently end up duplicated (one copy per graph) instead of shared. */
export const runEvents: EventEmitter =
  globalThis.__triggershellRunEvents ?? new EventEmitter();
globalThis.__triggershellRunEvents = runEvents;
runEvents.setMaxListeners(0);

export function emitRunMessage(message: ServerMessage) {
  runEvents.emit("message", message);
}