Simplify dummy meter to use power instead of current

core/loadpoint.go

@@ -204,19 +204,20 @@ func (lp *LoadPoint) evChargeStopHandler() {
 
 // evChargeCurrentHandler updates proxy charge meter's charge current.
 // If physical charge meter is present this handler is not used.
-func (lp *LoadPoint) evChargeCurrentHandler(m *wrapper.ChargeMeter) func(para ...interface{}) {
-	return func(para ...interface{}) {
-		current := para[0].(int64)
+// It assumes that the charge meter cannot consume more than total household consumption
+func (lp *LoadPoint) evChargeCurrentHandler(m *wrapper.ChargeMeter) func(current int64) {
+	return func(current int64) {
+		power := float64(current*lp.Phases) * lp.Voltage
+
 		if !lp.enabled || lp.status != api.StatusC {
-			current = 0
-		}
-		if current > 0 {
+			power = 0
+		} else if power > 0 {
 			// limit available power to generation plus consumption/ minus delivery
-			availablePower := math.Abs(lp.pvPower) + lp.availableBatteryPower() + lp.gridPower
-			availableCurrent := int64(powerToCurrent(availablePower, lp.Voltage, lp.Phases))
-			current = min(current, availableCurrent)
+			consumedPower := math.Abs(lp.pvPower) + lp.availableBatteryPower() + lp.gridPower
+			power = math.Min(power, consumedPower)
 		}
-		m.SetChargeCurrent(current)
+
+		m.SetPower(power)
 	}
 }
 
@@ -243,13 +244,10 @@ func (lp *LoadPoint) Prepare(uiChan chan<- Param, notificationChan chan<- push.E
 		if mt, ok := lp.charger.(api.Meter); ok {
 			lp.chargeMeter = mt
 		} else {
-			mt := &wrapper.ChargeMeter{
-				Phases:  lp.Phases,
-				Voltage: lp.Voltage,
-			}
+			mt := &wrapper.ChargeMeter{}
 			_ = lp.bus.Subscribe(evChargeCurrent, lp.evChargeCurrentHandler(mt))
 			_ = lp.bus.Subscribe(evStopCharge, func() {
-				mt.SetChargeCurrent(0)
+				mt.SetPower(0)
 			})
 			lp.chargeMeter = mt
 		}

core/wrapper/chargemeter.go

@@ -8,20 +8,14 @@ import (
 // It uses the charger's actual or max current to calculate power consumption.
 type ChargeMeter struct {
 	sync.Mutex
-	Phases  int64
-	Voltage float64
-	power   float64
+	power float64
 }
 
-func currentToPower(current, voltage float64, phases int64) float64 {
-	return float64(phases) * current * voltage
-}
-
-// SetChargeCurrent updates meter's current power based on actual current
-func (m *ChargeMeter) SetChargeCurrent(current int64) {
+// SetPower updates meter's current power
+func (m *ChargeMeter) SetPower(power float64) {
 	m.Lock()
 	defer m.Unlock()
-	m.power = currentToPower(float64(current), m.Voltage, m.Phases)
+	m.power = power
 }
 
 // CurrentPower implements the Meter.CurrentPower interface

core/wrapper/chargemeter_test.go

@@ -6,31 +6,18 @@ import (
 	"github.com/golang/mock/gomock"
 )
 
-func TestProxyMeterSinglePhase(t *testing.T) {
+func TestProxyChargeMeter(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
 
-	tc := []struct {
-		phases  int64
-		voltage float64
-		current int64
-		power   float64
-	}{
-		{1, 100, 10, 1000},
-		{3, 200, 1, 600},
-	}
+	tc := []float64{600, 1000, 2000}
+	m := ChargeMeter{}
 
-	for _, tc := range tc {
-		m := ChargeMeter{
-			Phases:  tc.phases,
-			Voltage: tc.voltage,
-		}
+	for _, f := range tc {
+		m.SetPower(f)
 
-		m.SetChargeCurrent(tc.current)
-
-		if p, err := m.CurrentPower(); p != tc.power || err != nil {
+		if p, err := m.CurrentPower(); p != f || err != nil {
 			t.Errorf("power: %.1f %v", p, err)
 		}
 	}
-
 }