Mainflux.mainflux/lora/paho/sub.go

56 lines
1.2 KiB
Go

package paho
// LoraSubscribe subscribe to lora server messages
import (
"encoding/json"
"fmt"
"github.com/mainflux/mainflux/logger"
"github.com/mainflux/mainflux/lora"
mqtt "github.com/eclipse/paho.mqtt.golang"
)
// MqttBroker represents the MQTT broker.
type MqttBroker interface {
// Subscribes to geven subject and receives events.
Subscribe(string) error
}
type broker struct {
svc lora.Service
client mqtt.Client
logger logger.Logger
}
// NewBroker returns new MQTT broker instance.
func NewBroker(svc lora.Service, client mqtt.Client, log logger.Logger) MqttBroker {
return broker{
svc: svc,
client: client,
logger: log,
}
}
// Subscribe subscribes to the Lora MQTT message broker
func (b broker) Subscribe(subject string) error {
s := b.client.Subscribe(subject, 0, b.handleMsg)
if err := s.Error(); s.Wait() && err != nil {
return err
}
return nil
}
// handleMsg triggered when new message is received on Lora MQTT broker
func (b broker) handleMsg(c mqtt.Client, msg mqtt.Message) {
m := lora.Message{}
if err := json.Unmarshal(msg.Payload(), &m); err != nil {
b.logger.Warn(fmt.Sprintf("Failed to Unmarshal message: %s", err.Error()))
return
}
b.svc.Publish(m)
return
}