const KEY = 'zapbot_last_incoming';

type IncomingMap = Record<string, number>;

function loadAll(): IncomingMap {
  try {
    const raw = localStorage.getItem(KEY);
    if (!raw) return {};
    return JSON.parse(raw);
  } catch (error) {
    return {};
  }
}

function saveAll(data: IncomingMap) {
  localStorage.setItem(KEY, JSON.stringify(data));
}

export function getLastIncomingMessage(chatId: string) {
  const all = loadAll();
  return all[chatId] || null;
}

export function setLastIncomingMessage(chatId: string, timestamp: number) {
  const all = loadAll();
  all[chatId] = timestamp;
  saveAll(all);
}