import {Worker} from 'worker_threads';
import {fileURLToPath} from 'url';
import path from 'path';

const WorkerTypes = Object.freeze({
  Collector: 'collector',
  Process: 'process',
  Notifier: 'notifier',
});

const kickOffWorker = (workerType, workerData) => {
  return new Promise((resolve, reject) => {
    const __filename = fileURLToPath(import.meta.url);
    const __dirname = path.dirname(__filename);
    const workerPath = path.join(
        __dirname,
        '..',
        '..',
        'workers',
        `${workerType}.js`);
    const worker = new Worker(workerPath, {workerData});
    worker.on('message', resolve);
    worker.on('error', reject);
    worker.on('exit', (code) => {
      if (code !== 0) {
        reject(
            new Error(`Worker '${workerType}' stopped with exit code ${code}`));
      }
    });
  });
};

export default class WorkerStarter {
  constructor(workerData) {
    this.workerData = workerData;
  }

  collect = () => kickOffWorker(WorkerTypes.Collector, this.workerData);
  process = () => kickOffWorker(WorkerTypes.Process, this.workerData);
  notify = () => kickOffWorker(WorkerTypes.Notifier, this.workerData);
};