const PubSub = require('@google-cloud/pubsub');
const pubsub = PubSub();

const publishers = {
  hourly: pubsub.topic('cron-hourly').publisher(),
  daily: pubsub.topic('cron-daily').publisher(),
  weekly: pubsub.topic('cron-weekly').publisher(),
  monthly: pubsub.topic('cron-monthly').publisher(),
  test: {publish: (f,c) => {console.log('test publish',f);c();}}
};

/**
 * Queues a message on the appropiate frequency queue.
 *
 * @param {Object} req - Cloud Function request context.
 * @param {Object} res - Cloud Function response context.
 */
exports.cron = function(req, res) {
  const frequency = req.query.frequency;
  const payload = {frequency, timestamp: +new Date()};
  publishers[frequency].publish({}, err => {
    if(err) console.error(err);
    else {
      res.set('Access-Control-Allow-Origin', "*");
      res.set('Access-Control-Allow-Methods', 'GET');
      res.status(200).end();
    }
  });
};