Bluelink: fix handling of stamps (evcc-io#2936)

vehicle/bluelink/identity.go

@@ -55,19 +55,15 @@ func NewIdentity(log *util.Logger, config Config) *Identity {
 		config: config,
 	}
 
-	// fetch updated stamps
-	updateStamps(log, config.CCSPApplicationID)
-
 	return v
 }
 
-// Credits to https://openwb.de/forum/viewtopic.php?f=5&t=1215&start=10#p11877
-
-func (v *Identity) stamp() string {
-	return Stamps.New(v.config.CCSPApplicationID)
-}
-
 func (v *Identity) getDeviceID() (string, error) {
+	stamp, err := Stamps[v.config.CCSPApplicationID].Get()
+	if err != nil {
+		return "", err
+	}
+
 	uniID, _ := uuid.NewUUID()
 	data := map[string]interface{}{
 		"pushRegId": "1",
@@ -79,7 +75,7 @@ func (v *Identity) getDeviceID() (string, error) {
 		"ccsp-service-id": v.config.CCSPServiceID,
 		"Content-type":    "application/json;charset=UTF-8",
 		"User-Agent":      "okhttp/3.10.0",
-		"Stamp":           v.stamp(),
+		"Stamp":           stamp,
 	}
 
 	var resp struct {
@@ -362,6 +358,11 @@ func (v *Identity) Login(user, password, language string) (err error) {
 
 // Request decorates requests with authorization headers
 func (v *Identity) Request(req *http.Request) error {
+	stamp, err := Stamps[v.config.CCSPApplicationID].Get()
+	if err != nil {
+		return err
+	}
+
 	token, err := v.Token()
 	if err != nil {
 		return err
@@ -373,7 +374,7 @@ func (v *Identity) Request(req *http.Request) error {
 		"ccsp-application-id": v.config.CCSPApplicationID,
 		"offset":              "1",
 		"User-Agent":          "okhttp/3.10.0",
-		"Stamp":               v.stamp(),
+		"Stamp":               stamp,
 	} {
 		req.Header.Set(k, v)
 	}

vehicle/bluelink/stamps.go

@@ -15,72 +15,62 @@ const (
 	HyundaiAppID = "014d2225-8495-4735-812d-2616334fd15d"
 )
 
-// StampsRegistry collects stamps for a single brand
-type StampsRegistry map[string]*StampCollection
-
-type StampCollection struct {
-	Stamps    []string
-	Generated time.Time
-	Frequency float64
-}
-
-var Stamps = StampsRegistry{
-	KiaAppID:     nil,
-	HyundaiAppID: nil,
+type stampCollection struct {
+	mu           sync.Mutex
+	log          *util.Logger
+	AppID, Brand string
+	Stamps       []string
+	Generated    time.Time
+	Frequency    float64
+	updated      time.Time
 }
 
 var (
-	mu      sync.Mutex
-	updater map[string]struct{} = make(map[string]struct{})
-
 	client = request.NewHelper(util.NewLogger("http"))
-	brands = map[string]string{
-		KiaAppID:     "kia",
-		HyundaiAppID: "hyundai",
+
+	Stamps = map[string]*stampCollection{
+		KiaAppID:     {log: util.NewLogger("kia"), AppID: KiaAppID, Brand: "kia"},
+		HyundaiAppID: {log: util.NewLogger("hyundai"), AppID: HyundaiAppID, Brand: "hyundai"},
 	}
 )
 
-func download(log *util.Logger, id, brand string) {
-	var res StampCollection
-	uri := fmt.Sprintf("https://raw.githubusercontent.com/neoPix/bluelinky-stamps/master/%s-%s.v2.json", brand, id)
+// New creates a new stamp
+func (c *stampCollection) Get() (string, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	length := float64(len(c.Stamps))
+	position := float64(time.Since(c.Generated).Milliseconds()) / c.Frequency
+
+	// download
+	if position >= 0.9*length {
+		if time.Since(c.updated) > 15*time.Minute {
+			c.log.TRACE.Printf("retry stamps download, last attempt: %v", c.updated)
+			if err := c.download(); err != nil {
+				return "", err
+			}
+		}
 
-	if err := client.GetJSON(uri, &res); err != nil {
-		log.ERROR.Println(err)
-		return
+		length = float64(len(c.Stamps))
+		position = float64(time.Since(c.Generated).Milliseconds()) / c.Frequency
 	}
 
-	mu.Lock()
-	Stamps[id] = &res
-	mu.Unlock()
-}
-
-// updateStamps updates stamps according to https://github.com/Hacksore/bluelinky/pull/144
-func updateStamps(log *util.Logger, id string) {
-	if _, ok := updater[id]; ok {
-		return
+	if position >= length {
+		position = length - 1
 	}
 
-	updater[id] = struct{}{}
-	download(log, id, brands[id])
-
-	go func() {
-		for range time.NewTicker(24 * time.Hour).C {
-			download(log, id, brands[id])
-		}
-	}()
+	return c.Stamps[int64(position+5*rand.Float64())], nil
 }
 
-// New creates a new stamp
-func (s StampsRegistry) New(id string) string {
-	mu.Lock()
-	defer mu.Unlock()
+// updateStamps updates stamps according to https://github.com/Hacksore/bluelinky/pull/144
+func (c *stampCollection) download() error {
+	c.updated = time.Now()
 
-	source := s[id]
-	if source == nil {
-		panic(id)
-	}
+	uri := fmt.Sprintf("https://raw.githubusercontent.com/neoPix/bluelinky-stamps/master/%s-%s.v2.json", c.Brand, c.AppID)
 
-	position := float64(time.Since(source.Generated).Milliseconds()) / source.Frequency
+	if err := client.GetJSON(uri, &c); err != nil {
+		return fmt.Errorf("failed to download stamps: %w", err)
+	}
 
-	return source.Stamps[int64(position+5*rand.Float64())]
+	return nil
 }