Meter (Home Assistant): grid charging via switch entities (#30191)

meter/homeassistant.go

@@ -3,6 +3,7 @@ package meter
 import (
 	"errors"
 	"fmt"
+	"strings"
 
 	"github.com/evcc-io/evcc/api"
 	"github.com/evcc-io/evcc/api/implement"
@@ -34,6 +35,11 @@ func NewHomeAssistantFromConfig(other map[string]any) (api.Meter, error) {
 		batteryCapacity    `mapstructure:",squash"`
 		batterySocLimits   `mapstructure:",squash"`
 		batteryPowerLimits `mapstructure:",squash"`
+
+		// battery mode control - optional switch-like entities per mode
+		ModeNormal string
+		ModeHold   string
+		ModeCharge string
 	}{
 		batterySocLimits: batterySocLimits{
 			MinSoc: 20,
@@ -98,6 +104,26 @@ func NewHomeAssistantFromConfig(other map[string]any) (api.Meter, error) {
 		implement.May(m, implement.BatteryCapacity(cc.batteryCapacity.Decorator()))
 		implement.May(m, implement.BatterySocLimiter(cc.batterySocLimits.Decorator()))
 		implement.May(m, implement.BatteryPowerLimiter(cc.batteryPowerLimits.Decorator()))
+
+		if cc.ModeHold != "" || cc.ModeCharge != "" {
+			if cc.ModeNormal == "" {
+				return nil, errors.New("modeNormal is required when modeHold or modeCharge is configured")
+			}
+			modes := map[api.BatteryMode]string{
+				api.BatteryNormal: cc.ModeNormal,
+				api.BatteryHold:   cc.ModeHold,
+				api.BatteryCharge: cc.ModeCharge,
+			}
+			for _, entity := range modes {
+				if entity != "" && !strings.HasPrefix(entity, "script.") {
+					return nil, fmt.Errorf("battery mode entity must be a script: %s", entity)
+				}
+			}
+			implement.Has(m, implement.BatteryController(batteryModeController(conn, modes)))
+		} else if cc.ModeNormal != "" {
+			return nil, errors.New("modeNormal alone has no effect; configure modeHold and/or modeCharge")
+		}
+
 		return m, nil
 	}
 
@@ -108,3 +134,19 @@ func NewHomeAssistantFromConfig(other map[string]any) (api.Meter, error) {
 
 	return m, nil
 }
+
+// batteryModeController returns a BatteryController function that activates
+// the switch-like Home Assistant entity configured for the requested evcc
+// battery mode. Each mode is self-contained: evcc only triggers the matching
+// entity and never deactivates others - any mutual exclusion is the HA side's
+// responsibility. modeHold and modeCharge are optional and return
+// api.ErrNotAvailable when requested without a backing entity.
+func batteryModeController(conn *homeassistant.Connection, modes map[api.BatteryMode]string) func(api.BatteryMode) error {
+	return func(mode api.BatteryMode) error {
+		target, ok := modes[mode]
+		if !ok || target == "" {
+			return api.ErrNotAvailable
+		}
+		return conn.CallSwitchService(target, true)
+	}
+}