export type ToastVariant = "success" | "error" | "info";
export type ToastItem = { id: string; variant: ToastVariant; message: string; createdAt: number };

const listeners = new Set<() => void>();
let items: ToastItem[] = [];

function emit() {
  for (const fn of listeners) fn();
}

export function subscribe(fn: () => void) {
  listeners.add(fn);
  return () => listeners.delete(fn);
}

export function snapshot() {
  return items;
}

function push(variant: ToastVariant, message: string) {
  const id = `${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 7)}`;
  items = [...items, { id, variant, message, createdAt: Date.now() }];
  emit();
  return id;
}

export function dismissToast(id: string) {
  items = items.filter((t) => t.id !== id);
  emit();
}

export const toast = {
  success: (message: string) => push("success", message),
  error: (message: string) => push("error", message),
  info: (message: string) => push("info", message),
  dismiss: dismissToast,
};