// A roller blind: Alexa.RangeController with the position in percent, 0 closed and 100 open. The semantics say
// what "open", "close", "raise" and "lower" do, and which positions count as open and as closed.
//
//   ALEX2MQTT_USERNAME=... ALEX2MQTT_PASSWORD=... ALEX2MQTT_ROOT_TOPIC=... node examples/blind.js
//
// "alex2node" is the installed package; inside this checkout it resolves to the built dist/.
const { Alex2MQTT, RangeController, asset, text, semantics } = 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));

const blind = { position: 0 };

const device = bridge.addDevice({ endpointId: "bedroom-blind", name: "Bedroom Blind", categories: ["INTERIOR_BLIND"] });
const lift = device.add(RangeController, {
  instance: "Blind.Lift",
  friendlyNames: [asset("Alexa.Setting.Opening"), text("Position", "en-US")],
  range: { min: 0, max: 100, precision: 1 },
  unit: "Alexa.Unit.Percent",
  semantics: semantics()
    .action("Close", "SetRangeValue", { rangeValue: 0 })
    .action("Open", "SetRangeValue", { rangeValue: 100 })
    .action("Lower", "AdjustRangeValue", { rangeValueDelta: -10, rangeValueDeltaDefault: false })
    .action("Raise", "AdjustRangeValue", { rangeValueDelta: 10, rangeValueDeltaDefault: false })
    .state("Closed", 0)
    .stateRange("Open", 1, 100),
});

// lift carries the instance: the property is reported under "Blind.Lift"
device.state((s) => s.set(lift, "rangeValue", blind.position).health("OK"));

const within = (position) => Math.min(100, Math.max(0, Math.round(position)));

lift.on("SetRangeValue", (ctx) => {
  blind.position = within(ctx.payload.rangeValue);
  return ctx.respond();
});
// rangeValueDeltaDefault: the user named no amount, and the blind picks its own step
lift.on("AdjustRangeValue", (ctx) => {
  const { rangeValueDelta, rangeValueDeltaDefault } = ctx.payload;
  const delta = rangeValueDeltaDefault ? Math.sign(rangeValueDelta) * 10 : rangeValueDelta;
  blind.position = within(blind.position + delta);
  return ctx.respond();
});

bridge.connect();