From 46569c73acdbf80df307bda89721351dfa38d11e Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Mon, 3 Jul 2023 17:05:27 +0200
Subject: [PATCH] Easee: refresh token within access token validity time
 (#8783)

---
 charger/easee.go          | 10 +++++-----
 charger/easee/identity.go |  2 +-
 util/oauth/tokensource.go | 25 ++++++++++++++++++++++---
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/charger/easee.go b/charger/easee.go
index e0a766b68..23e9dc3cb 100644
--- a/charger/easee.go
+++ b/charger/easee.go
@@ -178,17 +178,17 @@ func NewEasee(user, password, charger string, timeout time.Duration) (*Easee, er
 	}
 
 	if err == nil {
-		go c.heartbeat()
+		go c.keepalive()
 	}
 
 	return c, err
 }
 
-// heartbeat ensures tokens are refreshed even when not charging for longer time
-func (c *Easee) heartbeat() {
-	for range time.Tick(6 * time.Hour) {
+// keepalive ensures tokens are refreshed even when not charging for longer time
+func (c *Easee) keepalive() {
+	for range time.Tick(time.Hour) {
 		if _, err := c.chargerSite(c.charger); err != nil {
-			c.log.ERROR.Println("heartbeat:", err)
+			c.log.ERROR.Println("keep alive:", err)
 		}
 	}
 }
diff --git a/charger/easee/identity.go b/charger/easee/identity.go
index aebbb3173..e0860daa7 100644
--- a/charger/easee/identity.go
+++ b/charger/easee/identity.go
@@ -58,7 +58,7 @@ func TokenSource(log *util.Logger, user, password string) (oauth2.TokenSource, e
 	if err == nil {
 		var token Token
 		if err = c.DoJSON(req, &token); err == nil {
-			c.TokenSource = oauth.RefreshTokenSource(token.AsOAuth2Token(), c)
+			c.TokenSource = oauth.RefreshTokenSource(token.AsOAuth2Token(), c, oauth.WithExpiryMargin(6*time.Hour))
 		}
 	}
 
diff --git a/util/oauth/tokensource.go b/util/oauth/tokensource.go
index f996a0c76..664e84c33 100644
--- a/util/oauth/tokensource.go
+++ b/util/oauth/tokensource.go
@@ -17,17 +17,36 @@ type TokenSource struct {
 	mu        sync.Mutex
 	token     *oauth2.Token
 	refresher TokenRefresher
+	margin    time.Duration
 }
 
-func RefreshTokenSource(token *oauth2.Token, refresher TokenRefresher) oauth2.TokenSource {
-	return &TokenSource{token: token, refresher: refresher}
+type TokenSourceOption func(*TokenSource)
+
+func WithExpiryMargin(margin time.Duration) TokenSourceOption {
+	return func(ts *TokenSource) {
+		ts.margin = margin
+	}
+}
+
+func RefreshTokenSource(token *oauth2.Token, refresher TokenRefresher, opt ...TokenSourceOption) oauth2.TokenSource {
+	ts := &TokenSource{
+		token:     token,
+		refresher: refresher,
+		margin:    time.Minute,
+	}
+
+	for _, o := range opt {
+		o(ts)
+	}
+
+	return ts
 }
 
 func (ts *TokenSource) Token() (*oauth2.Token, error) {
 	ts.mu.Lock()
 	defer ts.mu.Unlock()
 	var err error
-	if ts.token == nil || time.Until(ts.token.Expiry) < time.Minute {
+	if ts.token == nil || time.Until(ts.token.Expiry) < ts.margin {
 		var token *oauth2.Token
 		if token, err = ts.refresher.RefreshToken(ts.token); err == nil {
 			if token.AccessToken == "" {