const queue = require('../../queue/queue');
const logger = require('../../util/logger');
const config = require('../../config/config');
const { deliverOutboxEntry } = require('../../host/resultService');

let running = false;
let workerPromise;

const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function loop() {
  while (running) {
    try {
      const batch = await queue.claimPending(config.worker.batchSize, config.worker.workerId);
      if (!batch.length) {
        await sleep(config.worker.pollInterval);
        continue;
      }

      for (const entry of batch) {
        await deliverOutboxEntry(entry);
      }
    } catch (err) {
      logger.error({ err: err.message }, 'delivery worker error');
      await sleep(config.worker.pollInterval);
    }
  }
}

async function startWorker() {
  if (running) return;
  running = true;
  workerPromise = loop();
}

async function stopWorker() {
  running = false;
  if (workerPromise) {
    await workerPromise;
  }
}

module.exports = { startWorker, stopWorker };