From fe07fa78381ae995b464dc47357a42dfd6301be0 Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmail.com>
Date: Fri, 5 Jun 2026 17:39:02 +0200
Subject: [PATCH] DriveSomethingGreater: guard against losing data on error

---
 vehicle/drivesomethinggreater.go       |  2 +-
 vehicle/vw/eudataact/eudataact_test.go | 16 ----------------
 vehicle/vw/eudataact/provider.go       | 17 +++++++----------
 3 files changed, 8 insertions(+), 27 deletions(-)

diff --git a/vehicle/drivesomethinggreater.go b/vehicle/drivesomethinggreater.go
index 6d17bafcb..29ba2499b 100644
--- a/vehicle/drivesomethinggreater.go
+++ b/vehicle/drivesomethinggreater.go
@@ -60,7 +60,7 @@ func NewDriveSomethingGreaterFromConfig(other map[string]any) (api.Vehicle, erro
 
 	if err == nil {
 		v.fromVehicle(vehicle.Name(), 0)
-		v.Provider = eudataact.NewProvider(api, vehicle.Vin(), cc.Cache)
+		v.Provider = eudataact.NewProvider(log, api, vehicle.Vin(), cc.Cache)
 	}
 
 	return v, err
diff --git a/vehicle/vw/eudataact/eudataact_test.go b/vehicle/vw/eudataact/eudataact_test.go
index e36c3d202..663c31b97 100644
--- a/vehicle/vw/eudataact/eudataact_test.go
+++ b/vehicle/vw/eudataact/eudataact_test.go
@@ -106,19 +106,3 @@ func TestMerge(t *testing.T) {
 	assert.Equal(t, "100", dst[FieldOdometer].Value, "older datapoint ignored")
 	assert.Equal(t, "200", dst[FieldRangeSecondary].Value, "new field added")
 }
-
-// TestResetDelay verifies the cache reset is scheduled for when the portal is
-// expected to deliver the dataset following the one just read.
-func TestResetDelay(t *testing.T) {
-	now := time.Date(2026, 5, 31, 12, 0, 0, 0, time.UTC)
-
-	// fresh dataset: reset one interval + latency later
-	assert.Equal(t, portalInterval+portalLatency, resetDelay(now, now))
-
-	// dataset already 5 min old: reset interval + latency after its timestamp
-	assert.Equal(t, portalInterval+portalLatency-5*time.Minute, resetDelay(now.Add(-5*time.Minute), now))
-
-	// next dataset already due: never reset sooner than the latency margin
-	assert.Equal(t, portalLatency, resetDelay(now.Add(-portalInterval), now))
-	assert.Equal(t, portalLatency, resetDelay(now.Add(-time.Hour), now))
-}
diff --git a/vehicle/vw/eudataact/provider.go b/vehicle/vw/eudataact/provider.go
index 588e08512..76fdf2e1e 100644
--- a/vehicle/vw/eudataact/provider.go
+++ b/vehicle/vw/eudataact/provider.go
@@ -10,11 +10,9 @@ import (
 )
 
 const (
-	// portalInterval is the cadence at which the portal delivers a new dataset
-	portalInterval = 15 * time.Minute
 	// portalLatency is the margin added to a dataset's timestamp before the
 	// following dataset is expected to be available for download
-	portalLatency = 30 * time.Second
+	portalLatency = time.Minute
 )
 
 // Provider implements the vehicle api on top of the EU Data Act dataset.
@@ -32,7 +30,7 @@ type Provider struct {
 }
 
 // NewProvider creates a vehicle api provider
-func NewProvider(api *API, vin string, cache time.Duration) *Provider {
+func NewProvider(log *util.Logger, api *API, vin string, cache time.Duration) *Provider {
 	v := &Provider{}
 	s := sharedStore(api)
 
@@ -40,10 +38,9 @@ func NewProvider(api *API, vin string, cache time.Duration) *Provider {
 	cached = util.ResettableCached(func() (map[string]point, error) {
 		ts, err := s.update(vin)
 		if err != nil {
-			return nil, err
-		}
-		if !ts.IsZero() {
-			time.AfterFunc(resetDelay(ts, time.Now()), cached.Reset)
+			log.ERROR.Println(err)
+		} else if !ts.IsZero() {
+			time.AfterFunc(resetDelay(ts, cache), cached.Reset)
 		}
 		return s.snapshot(vin), nil
 	}, cache)
@@ -56,8 +53,8 @@ func NewProvider(api *API, vin string, cache time.Duration) *Provider {
 // resetDelay returns the delay until the dataset following the one delivered at
 // ts is expected to be available. It never returns less than portalLatency so a
 // late or repeated dataset does not cause immediate re-polling.
-func resetDelay(ts, now time.Time) time.Duration {
-	if d := ts.Add(portalInterval + portalLatency).Sub(now); d > portalLatency {
+func resetDelay(ts time.Time, cache time.Duration) time.Duration {
+	if d := time.Until(ts.Add(cache + portalLatency)); d > portalLatency {
 		return d
 	}
 	return portalLatency