From 4dd1c4649734148d3f635ed6f814e760edcdf6fb Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Wed, 6 May 2020 19:17:29 +0200
Subject: [PATCH] =?UTF-8?q?Ensure=20charger=20target=20status=20is=20alway?=
 =?UTF-8?q?s=20updated=20even=20while=20car=20disconn=E2=80=A6=20(#106)?=
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---
 core/chargerhandler.go |  6 ++---
 core/loadpoint.go      | 51 ++++++++++++++++++++++++++----------------
 core/loadpoint_test.go |  5 +++--
 3 files changed, 38 insertions(+), 24 deletions(-)

diff --git a/core/chargerhandler.go b/core/chargerhandler.go
index ea6b3c930e..7cce716660 100644
--- a/core/chargerhandler.go
+++ b/core/chargerhandler.go
@@ -118,11 +118,11 @@ func (lp *ChargerHandler) rampUpDown(target int64) error {
 // Setting current and disabling are two steps. If already disabled, this is a nop.
 func (lp *ChargerHandler) rampOff() error {
 	if lp.enabled {
-		if lp.targetCurrent == lp.MinCurrent {
-			return lp.chargerEnable(false)
+		if lp.targetCurrent != lp.MinCurrent {
+			return lp.setTargetCurrent(lp.MinCurrent)
 		}
 
-		return lp.setTargetCurrent(lp.MinCurrent)
+		return lp.chargerEnable(false)
 	}
 
 	return nil
diff --git a/core/loadpoint.go b/core/loadpoint.go
index cca544ac5f..f51538a3bb 100644
--- a/core/loadpoint.go
+++ b/core/loadpoint.go
@@ -345,8 +345,7 @@ func (lp *LoadPoint) updateChargeStatus() api.ChargeStatus {
 	return status
 }
 
-// updateModePV sets "minpv" or "pv" load modes
-func (lp *LoadPoint) updateModePV(mode api.ChargeMode) error {
+func (lp *LoadPoint) maxCurrent(mode api.ChargeMode) int64 {
 	// grid meter will always be available, if as wrapped pv meter
 	targetPower := lp.chargePower - lp.gridPower - lp.batteryPower - lp.ResidualPower
 	if lp.batteryMeter == nil {
@@ -366,6 +365,19 @@ func (lp *LoadPoint) updateModePV(mode api.ChargeMode) error {
 		}
 	}
 
+	return targetCurrent
+}
+
+// updateModePV handles "minpv" or "pv" modes by setting charger enabled/disabled state
+// and maximum current according to available PV power
+func (lp *LoadPoint) updateModePV(mode api.ChargeMode) error {
+	targetCurrent := lp.maxCurrent(mode)
+	if !lp.connected() {
+		// ensure minimum current when not connected
+		// https://github.com/andig/evcc/issues/105
+		targetCurrent = min(lp.MinCurrent, targetCurrent)
+	}
+
 	log.DEBUG.Printf("%s target charge current: %dA", lp.Name, targetCurrent)
 
 	if targetCurrent == 0 {
@@ -435,24 +447,25 @@ func (lp *LoadPoint) update() {
 
 	// check if car connected and ready for charging
 	var err error
-	if !lp.connected() {
-		// ensure restart at min current
-		err = lp.setTargetCurrent(lp.MinCurrent)
-	} else {
-		// execute loading strategy
-		switch mode := lp.GetMode(); mode {
-		case api.ModeOff:
-			err = lp.rampOff()
-		case api.ModeNow:
-			err = lp.rampOn(lp.MaxCurrent)
-		case api.ModeMinPV, api.ModePV:
-			if meterErr == nil {
-				// pv modes require meter measurements
-				err = lp.updateModePV(mode)
-			} else {
-				log.WARN.Printf("%s aborting due to meter error", lp.Name)
-			}
+
+	// execute loading strategy
+	switch mode := lp.GetMode(); mode {
+	case api.ModeOff:
+		err = lp.rampOff()
+	case api.ModeNow:
+		// ensure that new connections happen at min current
+		current := lp.MinCurrent
+		if lp.connected() {
+			current = lp.MaxCurrent
+		}
+		err = lp.rampOn(current)
+	case api.ModeMinPV, api.ModePV:
+		// pv modes require meter measurements
+		if meterErr != nil {
+			log.WARN.Printf("%s aborting due to meter error", lp.Name)
+			break
 		}
+		err = lp.updateModePV(mode)
 	}
 
 	if err != nil {
diff --git a/core/loadpoint_test.go b/core/loadpoint_test.go
index a0ad214ec2..69684de80c 100644
--- a/core/loadpoint_test.go
+++ b/core/loadpoint_test.go
@@ -133,7 +133,8 @@ func TestMeterConfigurations(t *testing.T) {
 
 		ctrl := gomock.NewController(t)
 		lp, wb := newEnvironment(t, ctrl, pm, gm, cm)
-		wb.EXPECT().Status().Return(api.StatusA, nil)
+		wb.EXPECT().Status().Return(api.StatusA, nil) // disconnected
+		wb.EXPECT().Enable(false)                     // "off" mode
 
 		lp.update()
 	}
@@ -184,7 +185,7 @@ func TestInitialUpdate(t *testing.T) {
 		}
 
 		// disable if not connected
-		if tc.status != api.StatusA && tc.mode == api.ModeOff {
+		if tc.mode == api.ModeOff {
 			wb.EXPECT().Enable(false)
 		}