Nissan: use OAuth2 for code exchange and token refresh (#3302)

vehicle/nissan/identity.go

@@ -1,6 +1,7 @@
 package nissan
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -8,7 +9,6 @@ import (
 
 	"github.com/evcc-io/evcc/api"
 	"github.com/evcc-io/evcc/util"
-	"github.com/evcc-io/evcc/util/oauth"
 	"github.com/evcc-io/evcc/util/request"
 	"golang.org/x/oauth2"
 )
@@ -115,45 +115,26 @@ func (v *Identity) Login(user, password string) error {
 		}
 	}
 
-	var token oauth.Token
-	if err == nil {
-		data := url.Values{
-			"code":          {code},
-			"client_id":     {ClientID},
-			"client_secret": {ClientSecret},
-			"redirect_uri":  {RedirectURI},
-			"grant_type":    {"authorization_code"},
-		}
-
-		uri = fmt.Sprintf("%s/oauth2/%s/access_token?%s", AuthURL, realm, data.Encode())
-		req, err = request.New(http.MethodPost, uri, nil, request.URLEncoding)
-		if err == nil {
-			err = v.DoJSON(req, &token)
-		}
+	uri = fmt.Sprintf("%s/oauth2/%s/access_token", AuthURL, realm)
+	config := oauth2.Config{
+		ClientID:     ClientID,
+		ClientSecret: ClientSecret,
+		RedirectURL:  RedirectURI,
+		Endpoint: oauth2.Endpoint{
+			AuthURL:   uri,
+			TokenURL:  uri,
+			AuthStyle: oauth2.AuthStyleInParams,
+		},
 	}
 
+	ctx := context.WithValue(context.Background(), oauth2.HTTPClient, v.Client)
+
+	var token *oauth2.Token
 	if err == nil {
-		v.TokenSource = oauth.RefreshTokenSource((*oauth2.Token)(&token), v)
+		token, err = config.Exchange(ctx, code)
 	}
 
+	v.TokenSource = config.TokenSource(ctx, token)
+
 	return err
 }
-
-func (v *Identity) RefreshToken(token *oauth2.Token) (*oauth2.Token, error) {
-	data := url.Values{
-		"client_id":     {ClientID},
-		"client_secret": {ClientSecret},
-		"grant_type":    {"refresh_token"},
-		"refresh_token": {token.RefreshToken},
-	}
-
-	uri := fmt.Sprintf("%s/oauth2/%s/access_token?%s", AuthURL, Realm, data.Encode())
-	req, err := request.New(http.MethodPost, uri, nil, request.URLEncoding)
-
-	var res oauth.Token
-	if err == nil {
-		err = v.DoJSON(req, &res)
-	}
-
-	return (*oauth2.Token)(&res), err
-}