EEBus: await control-write results across all use cases (#31350)

server/eebus/helper.go

@@ -2,9 +2,12 @@ package eebus
 
 import (
 	"errors"
+	"fmt"
 	"log"
+	"time"
 
 	eebusapi "github.com/enbility/eebus-go/api"
+	"github.com/enbility/spine-go/model"
 	"github.com/evcc-io/evcc/api"
 )
 
@@ -15,6 +18,33 @@ func WrapError(err error) error {
 	return err
 }
 
+// WriteTimeout bounds how long an awaited eebus write waits for its result.
+const WriteTimeout = 10 * time.Second
+
+// Await runs a control write and waits for the remote device's result, returning
+// an error if the write is rejected or no result arrives within WriteTimeout.
+func Await(write func(func(model.ResultDataType)) (*model.MsgCounterType, error)) error {
+	res := make(chan model.ResultDataType, 1)
+
+	if _, err := write(func(r model.ResultDataType) { res <- r }); err != nil {
+		return err
+	}
+
+	select {
+	case r := <-res:
+		if r.ErrorNumber != nil && *r.ErrorNumber != 0 {
+			err := fmt.Errorf("write rejected: %d", *r.ErrorNumber)
+			if r.Description != nil {
+				err = fmt.Errorf("%w (%s)", err, *r.Description)
+			}
+			return err
+		}
+		return nil
+	case <-time.After(WriteTimeout):
+		return errors.New("write result timeout")
+	}
+}
+
 func LogEntities(log *log.Logger, actor string, uc eebusapi.UseCaseInterface) {
 	ss := uc.RemoteEntitiesScenarios()
 	if len(ss) > 0 {