// server/ws/outputHub.ts
type Listener = (chunk: string) => void;
const MAX_BUFFER = 5000; // lignes/chunks gardés pour le rejeu

export class OutputHub {
  private buffers = new Map<string, string[]>();
  private listeners = new Map<string, Set<Listener>>();

  publish(machineId: string, chunk: string): void {
    const buf = this.buffers.get(machineId) ?? [];
    buf.push(chunk);
    if (buf.length > MAX_BUFFER) buf.shift();
    this.buffers.set(machineId, buf);
    this.listeners.get(machineId)?.forEach((l) => l(chunk));
  }

  /** S'abonne et reçoit immédiatement le buffer existant (rejeu). */
  subscribe(machineId: string, listener: Listener): () => void {
    (this.buffers.get(machineId) ?? []).forEach((c) => listener(c));
    const set = this.listeners.get(machineId) ?? new Set();
    set.add(listener);
    this.listeners.set(machineId, set);
    return () => set.delete(listener);
  }

  clear(machineId: string): void {
    this.buffers.delete(machineId);
  }
}

export const outputHub = new OutputHub();