"use client";

/**
 * Tiny toast bus: destructive-but-reversible actions (delete deck, remove a
 * file) show an Undo toast instead of a blocking confirm.
 */

export type ToastInput = {
  message: string;
  actionLabel?: string;
  onAction?: () => void;
  durationMs?: number;
};

export type Toast = ToastInput & { id: number };

const listeners = new Set<(toast: Toast) => void>();
let nextId = 1;

export function showToast(input: ToastInput): number {
  const toast: Toast = { durationMs: 5000, ...input, id: nextId++ };
  listeners.forEach((listener) => listener(toast));
  return toast.id;
}

export const toastBus = {
  subscribe(listener: (toast: Toast) => void): () => void {
    listeners.add(listener);
    return () => listeners.delete(listener);
  },
};