Support openWB type composite status provider

provider/config.go

@@ -21,8 +21,8 @@ type Config struct {
 // mqttConfig is the specific mqtt getter/setter configuration
 type mqttConfig struct {
 	Topic, Payload string // Payload only applies to setters
-	Multiplier float64
-	Timeout    time.Duration
+	Multiplier     float64
+	Timeout        time.Duration
 }
 
 // scriptConfig is the specific script getter/setter configuration
@@ -114,6 +114,8 @@ func NewStringGetterFromConfig(log *api.Logger, config Config) (res StringGetter
 		if pc.Cache > 0 {
 			res = NewCached(res, pc.Cache).StringGetter()
 		}
+	case "openwb":
+		res = openWBStatusFromConfig(log, config.Other)
 	default:
 		log.FATAL.Fatalf("invalid provider type %s", config.Type)
 	}

provider/openwb.go

@@ -0,0 +1,43 @@
+package provider
+
+import (
+	"github.com/andig/evcc/api"
+)
+
+type openWBStatusProvider struct {
+	plugged, charging BoolGetter
+}
+
+func openWBStatusFromConfig(log *api.Logger, other map[string]interface{}) StringGetter {
+	cc := struct {
+		Plugged, Charging Config
+	}{}
+	api.DecodeOther(log, other, &cc)
+
+	o := &openWBStatusProvider{
+		plugged:  NewBoolGetterFromConfig(log, cc.Plugged),
+		charging: NewBoolGetterFromConfig(log, cc.Charging),
+	}
+
+	return o.stringGetter
+}
+
+func (o *openWBStatusProvider) stringGetter() (string, error) {
+	charging, err := o.charging()
+	if err != nil {
+		return "", err
+	}
+	if charging {
+		return string(api.StatusC), nil
+	}
+
+	plugged, err := o.plugged()
+	if err != nil {
+		return "", err
+	}
+	if plugged {
+		return string(api.StatusB), nil
+	}
+
+	return string(api.StatusA), nil
+}