// Copied from claudegram — proven deduplication pattern
const processedMessages = new Map();
const MESSAGE_TTL = 60000;
let cleanupInterval = null;

export function isDuplicate(messageId) {
  return processedMessages.has(messageId);
}

export function markProcessed(messageId) {
  processedMessages.set(messageId, Date.now());
  ensureCleanupRunning();
}

function ensureCleanupRunning() {
  if (cleanupInterval) return;
  cleanupInterval = setInterval(() => {
    const now = Date.now();
    for (const [id, timestamp] of processedMessages) {
      if (now - timestamp > MESSAGE_TTL) processedMessages.delete(id);
    }
    if (processedMessages.size === 0 && cleanupInterval) {
      clearInterval(cleanupInterval);
      cleanupInterval = null;
    }
  }, 30000);
}