evcc-io/util/oauth/tokensource.go
2021-05-26 11:45:49 +02:00

42 lines
983 B
Go

package oauth
import (
"errors"
"time"
"github.com/imdario/mergo"
"golang.org/x/oauth2"
)
type TokenRefresher interface {
RefreshToken(token *oauth2.Token) (*oauth2.Token, error)
}
type TokenSource struct {
token *oauth2.Token
refresher TokenRefresher
}
func RefreshTokenSource(token *oauth2.Token, refresher TokenRefresher) oauth2.TokenSource {
return &TokenSource{token, refresher}
}
func (ts *TokenSource) Token() (*oauth2.Token, error) {
var err error
if time.Until(ts.token.Expiry) < time.Minute {
var token *oauth2.Token
if token, err = ts.refresher.RefreshToken(ts.token); err == nil {
if token.AccessToken == "" {
err = errors.New("token refresh failed to obtain access token")
} else {
err = ts.mergeToken(token)
}
}
}
return ts.token, err
}
// mergeToken updates a token while preventing wiping the refresh token
func (ts *TokenSource) mergeToken(t *oauth2.Token) error {
return mergo.Merge(ts.token, t, mergo.WithOverride)
}