// A lock whose bolt takes longer than the 7 seconds Alex2MQTT waits for an answer: Alexa.LockController. The
// handler sends a DeferredResponse at once and the Response when the bolt has moved. Alex2MQTT waits 10 seconds for
// the Response after a DeferredResponse.
//
//   ALEX2MQTT_USERNAME=... ALEX2MQTT_PASSWORD=... ALEX2MQTT_ROOT_TOPIC=... node examples/lock.js
//
// "alex2node" is the installed package; inside this checkout it resolves to the built dist/.
const { Alex2MQTT, LockController } = require("alex2node");

const missing = ["ALEX2MQTT_USERNAME", "ALEX2MQTT_PASSWORD", "ALEX2MQTT_ROOT_TOPIC"].filter((name) => !process.env[name]);
if (missing.length > 0) {
  console.error(`${missing.join(", ")} not set. Set the MQTT user name, the password and the root topic of your Alex2MQTT account.`);
  process.exit(1);
}
const { ALEX2MQTT_USERNAME, ALEX2MQTT_PASSWORD, ALEX2MQTT_ROOT_TOPIC } = process.env;

const bridge = new Alex2MQTT(ALEX2MQTT_USERNAME, ALEX2MQTT_PASSWORD, ALEX2MQTT_ROOT_TOPIC);
bridge.on("connect", () => console.log("connected, discover the devices in the Alexa app"));
bridge.on("error", (err) => console.error("bridge:", err.message));

// How long the bolt takes, in seconds
const BOLT_SECONDS = Number(process.env.BOLT_SECONDS ?? 8);
const lock = { state: "LOCKED" };

const moveBolt = (state) => new Promise((resolve) => {
  setTimeout(() => {
    lock.state = state;
    resolve();
  }, BOLT_SECONDS * 1000);
});

const device = bridge.addDevice({ endpointId: "front-door-lock", name: "Front Door", categories: ["SMARTLOCK"] });
const bolt = device.add(LockController);

device.state((s) => s.set(bolt, "lockState", lock.state).health("OK"));

function move(state) {
  return async (ctx) => {
    // The argument is optional: how many seconds the answer will take
    await ctx.defer(Math.ceil(BOLT_SECONDS));
    await moveBolt(state);
    // After defer() the answer goes to <root>/<endpointId>/deferredResponse
    return ctx.respond();
  };
}
bolt.on("Lock", move("LOCKED"));
bolt.on("Unlock", move("UNLOCKED"));

bridge.connect();