huestream

WARNING: this example makes use of fast changing light effects conditions and it may trigger previously undetected epileptic symptoms or seizures in persons who have no history of prior seizures or epilepsy.

package main

import (
	"context"
	"image/color"
	"log"
	"math/rand/v2"
	"time"

	"github.com/amimof/huego"
	"github.com/rschio/huestream"
)

// WARNING: this example makes use of fast changing light effects conditions
// and it may trigger previously undetected epileptic symptoms or seizures
// in persons who have no history of prior seizures or epilepsy.
func main() {
	// Run this only the first time and store the creds in an ENV var.
	host, username, clientKey, err := genClientCreds()
	if err != nil {
		log.Fatal(err)
	}

	// If you don't have an entertainment area yet, create it using the
	// Philips Hue App:
	// Settings > Entertainment areas > +.
	//
	// Use this command to get the ID of your first entertainment area,
	// if you have more than one and want to choose, adapt the command:
	//
	// curl -s -k \
	//    -H 'hue-application-key: <username>' \
	//    https://<host>/clip/v2/resource/entertainment_configuration | jq '.data.[0].id'
	//
	// Yes, I'm too lazy to write this function.
	areaID := ""

	// Create a context with timeout so the stream will finish in 5s.
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	// Start a stream in the selected Entertainment area.
	stream, err := huestream.Start(ctx, host, username, clientKey, areaID)
	if err != nil {
		log.Fatal(err)
	}
	defer stream.Close()

	log.Println("Connected")

	// From Hue Docs:
	// "The streaming makes use of UDP, which can result in that certain messages
	// get lost, that is why it is important to continuously stream messages, even
	// when it would mean repeating the same messages or light values, typically a
	// streaming rate of 50-60Hz is used."
	//
	// 50 Hz = 1 message each 20 ms.
	sendRate := time.Tick(time.Second / 50)

	// From Hue Docs:
	// "The bridge sends maximum at 25 Hz messages over ZigBee.
	// Thus, the (fastest) effect rate should be 2 – 3 times slower
	// than this 25 Hz, i.e < 12.5 Hz."
	//
	// 10 Hz = 1 message each 100 ms.
	changeColorRate := time.Tick(time.Second / 10)

	c0, c1 := randColor(), randColor()
	for {
		select {
		case <-ctx.Done():
			return

		case <-changeColorRate:
			c0, c1 = randColor(), randColor()

		case <-sendRate:
			// Here we are sending two colors because my Entertainment Area has 2 lights.
			// The int represents the Channel ID (the light).
			// If you have 5 lights in your area, send a map of 5 colors.
			IDColors := map[int]color.Color{
				0: c0,
				1: c1,
			}
			if err := stream.Send(IDColors); err != nil {
				log.Println(err)
			}
		}
	}

}

func genClientCreds() (host, username, clientKey string, err error) {
	bridge, err := huego.Discover()
	if err != nil {
		return "", "", "", err
	}
	host = bridge.Host

	// Press the Bridge link button.
	user, err := bridge.CreateUserWithClientKey("my entertainment app")
	if err != nil {
		return "", "", "", err
	}

	return host, user.Username, user.ClientKey, nil
}

func randColor() color.Color {
	rnd := func() uint8 { return uint8(rand.IntN(256)) }
	return color.RGBA{R: rnd(), G: rnd(), B: rnd()}
}