Refactored code to make it more readable

main.go

@@ -20,23 +20,39 @@ var defaultHandler MQTT.MessageHandler = func(client MQTT.Client, msg MQTT.Messa
 	fmt.Printf("MSG: %s\n", msg.Payload())
 }
 
-type DeviceStatus struct {
-	Name string
-	Present bool
-}
-
 // Handler got automation/presence/+
-func presenceHandler(status chan DeviceStatus) func(MQTT.Client, MQTT.Message) {
+func presenceHandler(presence chan bool) func(MQTT.Client, MQTT.Message) {
+	devices := make(map[string]bool)
+	var current *bool
+
 	return func(client MQTT.Client, msg MQTT.Message) {
-		device := strings.Split(msg.Topic(), "/")[2]
+		name := strings.Split(msg.Topic(), "/")[2]
+		if len(msg.Payload()) == 0 {
+			// @TODO What happens if we delete a device that does not exist
+			delete(devices, name)
+		} else {
 			value, err := strconv.Atoi(string(msg.Payload()))
 			if err != nil {
 				panic(err)
 			}
 
-		fmt.Println("presenceHandler", device, value)
+			devices[name] = value == 1
+		}
+
+		present := false
+		fmt.Println(devices)
+		for _, value := range devices {
+			if value {
+				present = true
+				break;
+			}
+		}
+
+		if current == nil || *current != present {
+			current = &present
+			presence <- present
+		}
 
-		status <- DeviceStatus{Name: device, Present: value == 1}
 	}
 }
 
@@ -67,9 +83,18 @@ func (hue *Hue) updateFlag(id int, value bool) {
 	}
 }
 
-func main() {
-	_ = godotenv.Load()
+func connectToHue() Hue {
+	login, _ := os.LookupEnv("HUE_BRIDGE")
 
+	// @TODO Discover the bridge here
+	hue := Hue{ip: "10.0.0.146", login: login}
+
+	// @TODO Make sure we actually are connected here
+
+	return hue
+}
+
+func connectMQTT() MQTT.Client {
 	host, ok := os.LookupEnv("MQTT_HOST")
 	if !ok {
 		host = "localhost"
@@ -90,13 +115,6 @@ func main() {
 	if !ok {
 		clientID = "automation"
 	}
-	login, _ := os.LookupEnv("HUE_BRIDGE")
-
-	halt := make(chan os.Signal, 1)
-	signal.Notify(halt, os.Interrupt, syscall.SIGTERM)
-
-	// @TODO Discover the bridge here
-	hue := Hue{ip: "10.0.0.146", login: login}
 
 	opts := MQTT.NewClientOptions().AddBroker(fmt.Sprintf("%s:%s", host, port))
 	opts.SetClientID(clientID)
@@ -104,19 +122,31 @@ func main() {
 	opts.SetUsername(user)
 	opts.SetPassword(pass)
 
-	c := MQTT.NewClient(opts)
-	if token := c.Connect(); token.Wait() && token.Error() != nil {
+	client := MQTT.NewClient(opts)
+	if token := client.Connect(); token.Wait() && token.Error() != nil {
 		panic(token.Error())
 	}
 
-	status := make(chan DeviceStatus, 1)
-	if token := c.Subscribe("automation/presence/+", 0, presenceHandler(status)); token.Wait() && token.Error() != nil {
+	return client
+}
+
+func main() {
+	_ = godotenv.Load()
+
+	// Signals
+	halt := make(chan os.Signal, 1)
+	signal.Notify(halt, os.Interrupt, syscall.SIGTERM)
+
+	// MQTT
+	presence := make(chan bool, 1)
+	client := connectMQTT()
+	if token := client.Subscribe("automation/presence/+", 0, presenceHandler(presence)); token.Wait() && token.Error() != nil {
 		fmt.Println(token.Error())
 		os.Exit(1)
 	}
 
-	devices := make(map[string]bool)
-	isHome := false
+	// Hue
+	hue := connectToHue()
 
 	fmt.Println("Starting event loop")
 
@@ -124,32 +154,11 @@ func main() {
 events:
 	for {
 		select {
-		case state := <-status:
-			// Update the device state
-			devices[state.Name] = state.Present
-
-			// Check if there is any device home
-			temp := false
-			for key, value := range devices {
-				fmt.Println(key, value)
-				if value {
-					temp = true
-					break;
-				}
-			}
-
-			// Only do stuff if the state changes
-			if temp == isHome {
-				break
-			}
-			isHome = temp
-
-			if isHome {
+		case present := <-presence:
+			if present {
 				fmt.Println("Coming home")
 				hue.updateFlag(41, true)
 			} else {
-				fmt.Println("Leaving home")
-				hue.updateFlag(41, false)
 			}
 
 			fmt.Println("Done")
@@ -160,10 +169,10 @@ events:
 	}
 
 	// Cleanup
-	if token := c.Unsubscribe("automation/presence/+"); token.Wait() && token.Error() != nil {
+	if token := client.Unsubscribe("automation/presence/+"); token.Wait() && token.Error() != nil {
 		fmt.Println(token.Error())
 		os.Exit(1)
 	}
 
-	c.Disconnect(250)
+	client.Disconnect(250)
 }