evcc-io/vehicle/bmw/cardata/mqtt.go
2026-02-12 15:56:06 +01:00

155 lines
3.4 KiB
Go

package cardata
import (
"context"
"encoding/json"
"errors"
"fmt"
"sync"
"testing"
"time"
"github.com/cenkalti/backoff/v4"
mqtt "github.com/eclipse/paho.mqtt.golang"
"github.com/eclipse/paho.mqtt.golang/packets"
"github.com/evcc-io/evcc/api"
"github.com/evcc-io/evcc/util"
"golang.org/x/oauth2"
)
type MqttConnector struct {
mu sync.RWMutex
log *util.Logger
subscriptions map[string]chan StreamingMessage
}
var (
mqttMu sync.Mutex
mqttConnections = make(map[string]*MqttConnector)
)
func NewMqttConnector(ctx context.Context, log *util.Logger, clientID string, ts oauth2.TokenSource) *MqttConnector {
mqttMu.Lock()
defer mqttMu.Unlock()
if conn, ok := mqttConnections[clientID]; ok {
return conn
}
v := &MqttConnector{
log: log,
subscriptions: make(map[string]chan StreamingMessage),
}
if !testing.Testing() {
go v.run(ctx, ts)
}
mqttConnections[clientID] = v
return v
}
func (v *MqttConnector) Subscribe(vin string) <-chan StreamingMessage {
v.mu.Lock()
defer v.mu.Unlock()
ch := make(chan StreamingMessage, 1)
v.subscriptions[vin] = ch
return ch
}
func (v *MqttConnector) Unsubscribe(vin string) {
v.mu.Lock()
defer v.mu.Unlock()
if ch, ok := v.subscriptions[vin]; ok {
delete(v.subscriptions, vin)
close(ch)
}
}
func (v *MqttConnector) run(ctx context.Context, ts oauth2.TokenSource) {
bo := backoff.NewExponentialBackOff(backoff.WithInitialInterval(time.Second), backoff.WithMaxInterval(time.Minute), backoff.WithMaxElapsedTime(0))
for ctx.Err() == nil {
time.Sleep(bo.NextBackOff())
token, err := ts.Token()
if err != nil {
if _, ok := errors.AsType[*api.ErrLoginRequired](err); !ok {
v.log.ERROR.Println(err)
}
continue
}
if err := v.runMqtt(ctx, token); err != nil {
v.log.ERROR.Println(err)
// don't reset backoff
if errors.Is(err, packets.ErrorRefusedBadUsernameOrPassword) || errors.Is(err, packets.ErrorRefusedNotAuthorised) {
continue
}
}
bo.Reset()
}
}
func (v *MqttConnector) runMqtt(ctx context.Context, token *oauth2.Token) error {
gcid := TokenExtra(token, "gcid")
idToken := TokenExtra(token, "id_token")
v.log.DEBUG.Printf("connect streaming (using gcid %s, id_token %s, valid: %v)", gcid, idToken, token.Expiry.Round(time.Second))
paho := mqtt.NewClient(
mqtt.NewClientOptions().
AddBroker(StreamingURL).
SetAutoReconnect(true).
SetUsername(gcid).
SetPassword(idToken))
timeout := 30 * time.Second
if t := paho.Connect(); !t.WaitTimeout(timeout) {
return errors.New("connect timeout")
} else if err := t.Error(); err != nil {
return fmt.Errorf("connect: %w", err)
}
defer paho.Disconnect(1000)
topic := fmt.Sprintf("%s/+", gcid)
if t := paho.Subscribe(topic, 0, v.handler); !t.WaitTimeout(timeout) {
return errors.New("subcribe timeout")
} else if err := t.Error(); err != nil {
return fmt.Errorf("subscribe: %w", err)
}
v.log.DEBUG.Println("connected streaming")
ctx, cancel := context.WithDeadline(ctx, token.Expiry)
defer cancel()
<-ctx.Done()
return nil
}
func (v *MqttConnector) handler(_ mqtt.Client, m mqtt.Message) {
var res StreamingMessage
if err := json.Unmarshal(m.Payload(), &res); err != nil {
v.log.ERROR.Println(m.Topic(), string(m.Payload()), err)
return
}
v.log.TRACE.Println("recv: " + string(m.Payload()))
v.mu.RLock()
defer v.mu.RUnlock()
if ch, ok := v.subscriptions[res.Vin]; ok {
ch <- res
}
}