Minor cleanup

internal/vehicle/niu.go

@@ -20,10 +20,11 @@ import (
 type Niu struct {
 	*embed
 	*request.Helper
-	user, password, sn string
-	tokens             niu.Token
-	accessTokenExpiry  time.Time
-	chargeStateG       func() (float64, error)
+	user, password    string
+	serial            string
+	tokens            niu.Token
+	accessTokenExpiry time.Time
+	chargeStateG      func() (float64, error)
 }
 
 func init() {
@@ -56,33 +57,17 @@ func NewNiuFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 		Helper:   request.NewHelper(log),
 		user:     cc.User,
 		password: cc.Password,
-		sn:       strings.ToUpper(cc.Serial),
+		serial:   strings.ToUpper(cc.Serial),
 	}
 
 	v.chargeStateG = provider.NewCached(v.chargeState, cc.Cache).FloatGetter()
 
 	return v, nil
 }
 
-// SoC implements the api.Vehicle interface
-func (v *Niu) SoC() (float64, error) {
-	return v.chargeStateG()
-}
-
-// chargeState implements the api.Vehicle interface
-func (v *Niu) chargeState() (float64, error) {
-	var resp niu.SoC
-
-	req, err := v.request(niu.API + "/v3/motor_data/index_info?sn=" + v.sn)
-	if err == nil {
-		err = v.DoJSON(req, &resp)
-	}
-	return float64(resp.Data.Batteries.CompartmentA.BatteryCharging), err
-}
-
 // login implements the Niu oauth2 api
 func (v *Niu) login() error {
-	md5hash, err := getMD5Hash(v.password)
+	md5hash, err := md5Hash(v.password)
 	if err != nil {
 		return err
 	}
@@ -95,23 +80,29 @@ func (v *Niu) login() error {
 		"app_id":     []string{"niu_8xt1afu6"},
 	}
 
-	uri := niu.Auth + "/v3/api/oauth2/token"
+	uri := niu.AuthURI + "/v3/api/oauth2/token"
 	req, err := request.New(http.MethodPost, uri, strings.NewReader(data.Encode()), map[string]string{
 		"Content-Type": "application/x-www-form-urlencoded",
 	})
-	if err != nil {
-		return err
-	}
 
-	var tokens niu.Token
-	if err = v.DoJSON(req, &tokens); err == nil {
-		v.tokens = tokens
-		v.accessTokenExpiry = time.Unix(v.tokens.Data.Token.TokenExpiresIn, 0)
+	if err == nil {
+		var tokens niu.Token
+		if err = v.DoJSON(req, &tokens); err == nil {
+			v.tokens = tokens
+			v.accessTokenExpiry = time.Unix(v.tokens.Data.Token.TokenExpiresIn, 0)
+		}
 	}
 
 	return err
 }
 
+// md5Hash creates a MD5 hash based on a string
+func md5Hash(text string) (string, error) {
+	hasher := md5.New()
+	_, err := hasher.Write([]byte(text))
+	return hex.EncodeToString(hasher.Sum(nil)), err
+}
+
 // request implements the Niu web request
 func (v *Niu) request(uri string) (*http.Request, error) {
 	if v.tokens.Data.Token.AccessToken == "" || v.accessTokenExpiry.Before(time.Now()) {
@@ -127,11 +118,19 @@ func (v *Niu) request(uri string) (*http.Request, error) {
 	return req, err
 }
 
-// getMD5Hash creates a MD5 hash based on a string
-func getMD5Hash(text string) (string, error) {
-	hasher := md5.New()
-	if _, err := hasher.Write([]byte(text)); err != nil {
-		return "", err
+// chargeState implements the api.Vehicle interface
+func (v *Niu) chargeState() (float64, error) {
+	var resp niu.SoC
+
+	req, err := v.request(niu.ApiURI + "/v3/motor_data/index_info?sn=" + v.serial)
+	if err == nil {
+		err = v.DoJSON(req, &resp)
 	}
-	return hex.EncodeToString(hasher.Sum(nil)), nil
+
+	return float64(resp.Data.Batteries.CompartmentA.BatteryCharging), err
+}
+
+// SoC implements the api.Vehicle interface
+func (v *Niu) SoC() (float64, error) {
+	return v.chargeStateG()
 }

internal/vehicle/niu/types.go

@@ -1,8 +1,8 @@
 package niu
 
 const (
-	Auth = "https://account-fk.niu.com"
-	API  = "https://app-api-fk.niu.com"
+	AuthURI = "https://account-fk.niu.com"
+	ApiURI  = "https://app-api-fk.niu.com"
 )
 
 // Token is the Niu oauth2 api response