var MQTT = require("async-mqtt");

const deviceId = "TheDeviceId";
const iotHubName = "poorlyfundedskynet";
const userName = `${iotHubName}.azure-devices.net/${deviceId}/api-version=2016-11-14`;
const iotHubTopic = `devices/${deviceId}/messages/events/`;
const sas = `SharedAccessSignature sr=${iotHubName}.azure-devices.net%2Fdevices%2F${deviceId}&sig=THeSignaTurE&se=1565174493`;

var client = MQTT.connect(`mqtts://${iotHubName}.azure-devices.net:8883`, {
  keepalive: 10,
  clientId: deviceId,
  protocolId: 'MQTT',
  clean: false,
  protocolVersion: 4,
  reconnectPeriod: 1000,
  connectTimeout: 30 * 1000,
  username: userName,
  password: sas,
  rejectUnauthorized: false,
});

async function doStuff() {

    console.log("Starting");
    try {
        await client.publish(iotHubTopic, "It works!");
        // This line doesn't run until the server responds to the publish
        await client.end();
        // This line doesn't run until the client has disconnected without error
        console.log("Done");
    } catch (e){
        // Do something about it!
        console.log("Error while sending a message...");
        console.log(e.stack);
        process.exit();
    }
}

const ceremony = () => {
  return new Promise((resolve, reject) => {
      client.on("connect", doStuff);
      return resolve();
    })
    .then((stuff) => {
      console.log("Done?", stuff);
    })
    .catch((err) => {
      console.log("Err...", err);
      process.exit();
    });
}

ceremony();