// Adapted from claudegram's request-queue.ts — per-chat sequential processing
const pendingQueues = new Map();
const processingFlags = new Map();

export function isProcessing(sessionKey) {
  return processingFlags.get(sessionKey) === true;
}

export function getQueuePosition(sessionKey) {
  const queue = pendingQueues.get(sessionKey);
  return queue ? queue.length : 0;
}

export function clearQueue(sessionKey) {
  pendingQueues.delete(sessionKey);
  processingFlags.delete(sessionKey);
}

export async function queueRequest(sessionKey, message, handler) {
  return new Promise((resolve, reject) => {
    const request = { message, handler, resolve, reject };
    let queue = pendingQueues.get(sessionKey);
    if (!queue) {
      queue = [];
      pendingQueues.set(sessionKey, queue);
    }
    queue.push(request);
    processQueue(sessionKey);
  });
}

async function processQueue(sessionKey) {
  if (processingFlags.get(sessionKey)) return;
  processingFlags.set(sessionKey, true);

  const queue = pendingQueues.get(sessionKey);
  while (queue && queue.length > 0) {
    const request = queue[0];
    try {
      const result = await request.handler();
      request.resolve(result);
    } catch (error) {
      request.reject(error);
    }
    queue.shift();
  }

  processingFlags.delete(sessionKey);
  pendingQueues.delete(sessionKey);
}