robocar-throttle/vendor/github.com/cyrilix/robocar-base/mqttdevice/mqttdevice.go

157 lines
3.6 KiB
Go

package mqttdevice
import (
"encoding/json"
"fmt"
"github.com/cyrilix/robocar-base/types"
MQTT "github.com/eclipse/paho.mqtt.golang"
"io"
"log"
"strconv"
)
type Publisher interface {
Publish(topic string, payload MqttValue)
}
type Subscriber interface {
Subscribe(topic string, mh MQTT.MessageHandler)
}
type MQTTPubSub interface {
Publisher
Subscriber
io.Closer
}
type pahoMqttPubSub struct {
Uri string
Username string
Password string
ClientId string
Qos int
Retain bool
client MQTT.Client
}
func NewPahoMqttPubSub(uri string, username string, password string, clientId string, qos int, retain bool) MQTTPubSub {
p := pahoMqttPubSub{Uri: uri, Username: username, Password: password, ClientId: clientId, Qos: qos, Retain: retain}
p.Connect()
return &p
}
// Publish message to broker
func (p *pahoMqttPubSub) Publish(topic string, payload MqttValue) {
tokenResp := p.client.Publish(topic, byte(p.Qos), p.Retain, string(payload))
if tokenResp.Error() != nil {
log.Fatalf("%+v\n", tokenResp.Error())
}
}
// Register func to execute on message
func (p *pahoMqttPubSub) Subscribe(topic string, callback MQTT.MessageHandler) {
tokenResp := p.client.Subscribe(topic, byte(p.Qos), callback)
if tokenResp.Error() != nil {
log.Fatalf("%+v\n", tokenResp.Error())
}
}
// Close connection to broker
func (p *pahoMqttPubSub) Close() error {
p.client.Disconnect(500)
return nil
}
func (p *pahoMqttPubSub) Connect() {
if p.client != nil && p.client.IsConnected() {
return
}
//create a ClientOptions struct setting the broker address, clientid, turn
//off trace output and set the default message handler
opts := MQTT.NewClientOptions().AddBroker(p.Uri)
opts.SetUsername(p.Username)
opts.SetPassword(p.Password)
opts.SetClientID(p.ClientId)
opts.SetAutoReconnect(true)
opts.SetDefaultPublishHandler(
//define a function for the default message handler
func(client MQTT.Client, msg MQTT.Message) {
fmt.Printf("TOPIC: %s\n", msg.Topic())
fmt.Printf("MSG: %s\n", msg.Payload())
})
//create and start a client using the above ClientOptions
p.client = MQTT.NewClient(opts)
if token := p.client.Connect(); token.Wait() && token.Error() != nil {
panic(token.Error())
}
}
type MqttValue []byte
func NewMqttValue(v interface{}) MqttValue {
switch val := v.(type) {
case string:
return MqttValue(val)
case float32, float64:
return MqttValue(fmt.Sprintf("%0.2f", val))
case int, int8, int16, int32, int64:
return MqttValue(fmt.Sprintf("%d", val))
case bool:
if val {
return []byte("ON")
} else {
return []byte("OFF")
}
case []byte:
return val
case MqttValue:
return val
default:
jsonValue, err := json.Marshal(v)
if err != nil {
log.Printf("unable to mashall to json value '%v': %v", v, err)
return nil
}
return jsonValue
}
}
func (m *MqttValue) IntValue() (int, error) {
return strconv.Atoi(string(*m))
}
func (m *MqttValue) Float32Value() (float32, error) {
val := string(*m)
r, err := strconv.ParseFloat(val, 32)
return float32(r), err
}
func (m *MqttValue) Float64Value() (float64, error) {
val := string(*m)
return strconv.ParseFloat(val, 64)
}
func (m *MqttValue) StringValue() (string, error) {
return string(*m), nil
}
func (m *MqttValue) DriveModeValue() (types.DriveMode, error) {
val, err := m.IntValue()
if err != nil {
return types.DriveModeInvalid, err
}
return types.DriveMode(val), nil
}
func (m *MqttValue) ByteSliceValue() ([]byte, error) {
return *m, nil
}
func (m *MqttValue) BoolValue() (bool, error) {
val := string(*m)
switch val {
case "ON":
return true, nil
case "OFF":
return false, nil
default:
return false, fmt.Errorf("value %v can't be converted to bool", val)
}
}