initial commit

internal/MqttService/Helpers.go

@@ -0,0 +1,17 @@
+package MqttService
+
+import (
+	"errors"
+	"strings"
+)
+
+func PinNameFromTopic(topic string) (string,error) {
+	topicComponents := strings.Split(topic, "/")
+	if len(topicComponents) >= 2 {
+		gpioCh := topicComponents[len(topicComponents)-2]
+		return gpioCh, nil
+
+	} else {
+		return "", errors.New("invalid topic")
+	}
+}

internal/MqttService/MqttService.go

@@ -0,0 +1,102 @@
+package MqttService
+
+import (
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+	log "github.com/sirupsen/logrus"
+	"rpiMqttControl/internal/PinControlService"
+	"time"
+)
+
+type OnCompletionHandler func()
+
+type MqttService struct {
+	mqttClient mqtt.Client
+	quit       chan struct{}
+	config     MqttServiceConfig
+	pinService *PinControlService.PinControlService
+}
+
+func (m *MqttService) pinEventCallback(pinName string, pinState PinControlService.PinState) {
+	topic := m.config.TopicPrefix + "/gpio/" + pinName + "/event"
+	token := m.mqttClient.Publish(topic, 1, false, string(pinState))
+	go m._asyncWait(token, nil)
+}
+
+func (m *MqttService) pinCyclicCallback(pinName string, pinState PinControlService.PinState) {
+	topic := m.config.TopicPrefix + "/gpio/" + pinName + "/value"
+	token := m.mqttClient.Publish(topic, 1, false, string(pinState))
+	go m._asyncWait(token, nil)
+}
+func (m *MqttService) controlCallback(client mqtt.Client, message mqtt.Message) {
+	if pinNo, err := PinNameFromTopic(message.Topic()); err == nil {
+		if err := m.pinService.Command(pinNo, PinControlService.PinCommand(message.Payload())); err != nil {
+			log.Error(err.Error())
+		}
+	} else {
+		log.Error(err.Error())
+	}
+}
+func (m *MqttService) Stop() {
+	m.quit <- struct{}{}
+	m.mqttClient.Disconnect(100)
+}
+
+func (m *MqttService) _asyncWait(token mqtt.Token, onComplete OnCompletionHandler) {
+	for {
+		select {
+		case <-token.Done():
+			if err := token.Error(); err != nil {
+				log.Fatal(err)
+			} else {
+				if onComplete != nil {
+					onComplete()
+				}
+			}
+			return
+		case <-m.quit:
+			return
+		}
+	}
+}
+func (m *MqttService) _subscribe() {
+	topic := m.config.TopicPrefix + "/gpio/+/control"
+	token := m.mqttClient.Subscribe(topic, 1, m.controlCallback)
+
+	go m._asyncWait(token, nil)
+}
+
+func (m *MqttService) Start() {
+	token := m.mqttClient.Connect()
+	go m._asyncWait(token, func() {
+		m._subscribe()
+	})
+}
+
+func NewMqttService(config MqttServiceConfig, pinService *PinControlService.PinControlService) MqttService {
+	clientOptions := mqtt.NewClientOptions()
+	clientOptions.AddBroker(config.BrokerAddress)
+
+	if config.Username != "" {
+		clientOptions.Username = config.Username
+		clientOptions.Password = config.Password
+	}
+
+	clientOptions.SetConnectRetry(true)
+	clientOptions.SetConnectRetryInterval(10 * time.Second)
+	clientOptions.SetAutoReconnect(config.AutoReconnect)
+	clientOptions.SetConnectTimeout(time.Duration(config.ConnectTimeoutMs) * time.Millisecond)
+
+	mqttClient := mqtt.NewClient(clientOptions)
+
+	m := MqttService{
+		mqttClient: mqttClient,
+		quit:       make(chan struct{}, 1),
+		pinService: pinService,
+		config:     config,
+	}
+
+	pinService.OnCycleCallback = m.pinCyclicCallback
+	pinService.OnChangeCallback = m.pinEventCallback
+
+	return m
+}

internal/MqttService/MqttServiceConfig.go

@@ -0,0 +1,21 @@
+package MqttService
+
+type MqttServiceConfig struct {
+	BrokerAddress string `yaml:"broker-address"`
+	TopicPrefix string `yaml:"topic-prefix"`
+	AutoReconnect bool `yaml:"auto-reconnect"`
+	ConnectTimeoutMs int `yaml:"connect-timeout-ms"`
+	Username string `yaml:"username"`
+	Password string `yaml:"password"`
+
+}
+
+func NewMqttServiceConfig() MqttServiceConfig {
+	return MqttServiceConfig{
+		BrokerAddress: "tcp://localhost:1883",
+		TopicPrefix: "/rpicontrol",
+		AutoReconnect: true,
+		ConnectTimeoutMs: 10000,
+
+	}
+}