// A lamp that shows a colour or a white: Alexa.ColorController and Alexa.ColorTemperatureController, with power
// and brightness. It reports the colour or the colour temperature, whichever it shows.
//
//   ALEX2MQTT_USERNAME=... ALEX2MQTT_PASSWORD=... ALEX2MQTT_ROOT_TOPIC=... node examples/color-lamp.js
//
// "alex2node" is the installed package; inside this checkout it resolves to the built dist/.
const { Alex2MQTT, AlexaErrors, PowerController, BrightnessController, ColorController, ColorTemperatureController } = 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));

// The whites Alexa asks for by name: warm, soft, white, daylight, cool
const WHITES = [2200, 2700, 4000, 5500, 7000];
// color is null while the lamp shows a white
const lamp = { on: false, brightness: 100, color: null, kelvin: 2700 };

const device = bridge.addDevice({ endpointId: "floor-lamp", name: "Floor Lamp", categories: ["LIGHT"] });
const power = device.add(PowerController);
const brightness = device.add(BrightnessController);
const color = device.add(ColorController);
const white = device.add(ColorTemperatureController);

device.state((s) => {
  s.set(power, "powerState", lamp.on ? "ON" : "OFF").set(brightness, "brightness", lamp.brightness);
  if (lamp.color) s.set(color, "color", { ...lamp.color, brightness: lamp.brightness / 100 });
  else s.set(white, "colorTemperatureInKelvin", lamp.kelvin);
  s.health("OK");
});

power.on("TurnOn", (ctx) => {
  lamp.on = true;
  return ctx.respond();
});
power.on("TurnOff", (ctx) => {
  lamp.on = false;
  return ctx.respond();
});
brightness.on("SetBrightness", (ctx) => {
  lamp.brightness = ctx.payload.brightness;
  lamp.on = true;
  return ctx.respond();
});
// SetColor comes with brightness 1 whatever the lamp shows: the lamp takes hue and saturation and keeps its brightness
color.on("SetColor", (ctx) => {
  const { hue, saturation } = ctx.payload.color;
  lamp.color = { hue, saturation };
  lamp.on = true;
  return ctx.respond();
});
white.on("SetColorTemperature", (ctx) => {
  lamp.kelvin = Math.min(7000, Math.max(2200, ctx.payload.colorTemperatureInKelvin));
  lamp.color = null;
  lamp.on = true;
  return ctx.respond();
});
// "Warmer" and "cooler" have no meaning while the lamp shows a colour. A handler that throws answers with the error.
function step(by) {
  return (ctx) => {
    if (lamp.color) throw AlexaErrors.notSupportedInCurrentMode("The lamp shows a colour", "COLOR");
    const next = WHITES.indexOf(WHITES.find((kelvin) => kelvin >= lamp.kelvin) ?? 7000) + by;
    lamp.kelvin = WHITES[Math.min(WHITES.length - 1, Math.max(0, next))];
    return ctx.respond();
  };
}
white.on("IncreaseColorTemperature", step(1));
white.on("DecreaseColorTemperature", step(-1));

bridge.connect();