From 0de4c93a3a6f75565374a0294ca6cda2cb33bead Mon Sep 17 00:00:00 2001
From: andig <cpuidle@gmx.de>
Date: Sun, 19 Dec 2021 11:01:07 +0100
Subject: [PATCH] Enable modbus meter to read phase currents (#2072)

---
 meter/modbus.go            | 31 ++++++++++++++-
 meter/modbus_decorators.go | 78 +++++++++++++++++++++++++++++++++++---
 2 files changed, 102 insertions(+), 7 deletions(-)

diff --git a/meter/modbus.go b/meter/modbus.go
index 3206a81cc..5f81b5547 100644
--- a/meter/modbus.go
+++ b/meter/modbus.go
@@ -26,7 +26,7 @@ func init() {
 	registry.Add("modbus", NewModbusFromConfig)
 }
 
-//go:generate go run ../cmd/tools/decorate.go -f decorateModbus -b api.Meter -t "api.MeterEnergy,TotalEnergy,func() (float64, error)" -t "api.Battery,SoC,func() (float64, error)"
+//go:generate go run ../cmd/tools/decorate.go -f decorateModbus -b api.Meter -t "api.MeterEnergy,TotalEnergy,func() (float64, error)" -t "api.MeterCurrent,Currents,func() (float64, float64, float64, error)" -t "api.Battery,SoC,func() (float64, error)"
 
 // NewModbusFromConfig creates api.Meter from config
 func NewModbusFromConfig(other map[string]interface{}) (api.Meter, error) {
@@ -34,6 +34,7 @@ func NewModbusFromConfig(other map[string]interface{}) (api.Meter, error) {
 		Model              string
 		modbus.Settings    `mapstructure:",squash"`
 		Power, Energy, SoC string
+		Currents           []string
 		Timeout            time.Duration
 	}{
 		Power: "Power",
@@ -107,6 +108,32 @@ func NewModbusFromConfig(other map[string]interface{}) (api.Meter, error) {
 		totalEnergy = m.totalEnergy
 	}
 
+	// decorate Meter with MeterCurrent
+	var currentsG func() (float64, float64, float64, error)
+	if len(cc.Currents) > 0 {
+		if len(cc.Currents) != 3 {
+			return nil, errors.New("need 3 currents")
+		}
+
+		var curr []func() (float64, error)
+		for _, cc := range cc.Currents {
+			var opCurrent modbus.Operation
+
+			cc = modbus.ReadingName(cc)
+			if err := modbus.ParseOperation(device, cc, &opCurrent); err != nil {
+				return nil, fmt.Errorf("invalid measurement for current: %s", cc)
+			}
+
+			c := func() (float64, error) {
+				return m.floatGetter(opCurrent)
+			}
+
+			curr = append(curr, c)
+		}
+
+		currentsG = collectCurrentProviders(curr)
+	}
+
 	// decorate soc reading
 	var soc func() (float64, error)
 	if cc.SoC != "" {
@@ -118,7 +145,7 @@ func NewModbusFromConfig(other map[string]interface{}) (api.Meter, error) {
 		soc = m.soc
 	}
 
-	return decorateModbus(m, totalEnergy, soc), nil
+	return decorateModbus(m, totalEnergy, currentsG, soc), nil
 }
 
 // floatGetter executes configured modbus read operation and implements func() (float64, error)
diff --git a/meter/modbus_decorators.go b/meter/modbus_decorators.go
index f3625a301..0a6e23e92 100644
--- a/meter/modbus_decorators.go
+++ b/meter/modbus_decorators.go
@@ -6,12 +6,12 @@ import (
 	"github.com/evcc-io/evcc/api"
 )
 
-func decorateModbus(base api.Meter, meterEnergy func() (float64, error), battery func() (float64, error)) api.Meter {
+func decorateModbus(base api.Meter, meterEnergy func() (float64, error), meterCurrent func() (float64, float64, float64, error), battery func() (float64, error)) api.Meter {
 	switch {
-	case battery == nil && meterEnergy == nil:
+	case battery == nil && meterCurrent == nil && meterEnergy == nil:
 		return base
 
-	case battery == nil && meterEnergy != nil:
+	case battery == nil && meterCurrent == nil && meterEnergy != nil:
 		return &struct {
 			api.Meter
 			api.MeterEnergy
@@ -22,7 +22,33 @@ func decorateModbus(base api.Meter, meterEnergy func() (float64, error), battery
 			},
 		}
 
-	case battery != nil && meterEnergy == nil:
+	case battery == nil && meterCurrent != nil && meterEnergy == nil:
+		return &struct {
+			api.Meter
+			api.MeterCurrent
+		}{
+			Meter: base,
+			MeterCurrent: &decorateModbusMeterCurrentImpl{
+				meterCurrent: meterCurrent,
+			},
+		}
+
+	case battery == nil && meterCurrent != nil && meterEnergy != nil:
+		return &struct {
+			api.Meter
+			api.MeterCurrent
+			api.MeterEnergy
+		}{
+			Meter: base,
+			MeterCurrent: &decorateModbusMeterCurrentImpl{
+				meterCurrent: meterCurrent,
+			},
+			MeterEnergy: &decorateModbusMeterEnergyImpl{
+				meterEnergy: meterEnergy,
+			},
+		}
+
+	case battery != nil && meterCurrent == nil && meterEnergy == nil:
 		return &struct {
 			api.Meter
 			api.Battery
@@ -33,7 +59,7 @@ func decorateModbus(base api.Meter, meterEnergy func() (float64, error), battery
 			},
 		}
 
-	case battery != nil && meterEnergy != nil:
+	case battery != nil && meterCurrent == nil && meterEnergy != nil:
 		return &struct {
 			api.Meter
 			api.Battery
@@ -47,6 +73,40 @@ func decorateModbus(base api.Meter, meterEnergy func() (float64, error), battery
 				meterEnergy: meterEnergy,
 			},
 		}
+
+	case battery != nil && meterCurrent != nil && meterEnergy == nil:
+		return &struct {
+			api.Meter
+			api.Battery
+			api.MeterCurrent
+		}{
+			Meter: base,
+			Battery: &decorateModbusBatteryImpl{
+				battery: battery,
+			},
+			MeterCurrent: &decorateModbusMeterCurrentImpl{
+				meterCurrent: meterCurrent,
+			},
+		}
+
+	case battery != nil && meterCurrent != nil && meterEnergy != nil:
+		return &struct {
+			api.Meter
+			api.Battery
+			api.MeterCurrent
+			api.MeterEnergy
+		}{
+			Meter: base,
+			Battery: &decorateModbusBatteryImpl{
+				battery: battery,
+			},
+			MeterCurrent: &decorateModbusMeterCurrentImpl{
+				meterCurrent: meterCurrent,
+			},
+			MeterEnergy: &decorateModbusMeterEnergyImpl{
+				meterEnergy: meterEnergy,
+			},
+		}
 	}
 
 	return nil
@@ -60,6 +120,14 @@ func (impl *decorateModbusBatteryImpl) SoC() (float64, error) {
 	return impl.battery()
 }
 
+type decorateModbusMeterCurrentImpl struct {
+	meterCurrent func() (float64, float64, float64, error)
+}
+
+func (impl *decorateModbusMeterCurrentImpl) Currents() (float64, float64, float64, error) {
+	return impl.meterCurrent()
+}
+
 type decorateModbusMeterEnergyImpl struct {
 	meterEnergy func() (float64, error)
 }