Add meter plugin (#21477)

meter/config.go

@@ -2,14 +2,12 @@ package meter
 
 import (
 	"context"
-	"fmt"
-	"strings"
 
 	"github.com/evcc-io/evcc/api"
-	reg "github.com/evcc-io/evcc/util/registry"
+	"github.com/evcc-io/evcc/meter/config"
 )
 
-var registry = reg.New[api.Meter]("meter")
+var registry = config.Registry
 
 // Types returns the list of types
 func Types() []string {
@@ -18,15 +16,5 @@ func Types() []string {
 
 // NewFromConfig creates meter from configuration
 func NewFromConfig(ctx context.Context, typ string, other map[string]interface{}) (api.Meter, error) {
-	factory, err := registry.Get(strings.ToLower(typ))
-	if err != nil {
-		return nil, err
-	}
-
-	v, err := factory(ctx, other)
-	if err != nil {
-		err = fmt.Errorf("cannot create meter type '%s': %w", typ, err)
-	}
-
-	return v, err
+	return config.NewFromConfig(ctx, typ, other)
 }

meter/config/config.go

@@ -0,0 +1,27 @@
+package config
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/evcc-io/evcc/api"
+	reg "github.com/evcc-io/evcc/util/registry"
+)
+
+var Registry = reg.New[api.Meter]("meter")
+
+// NewFromConfig creates meter from configuration
+func NewFromConfig(ctx context.Context, typ string, other map[string]interface{}) (api.Meter, error) {
+	factory, err := Registry.Get(strings.ToLower(typ))
+	if err != nil {
+		return nil, err
+	}
+
+	v, err := factory(ctx, other)
+	if err != nil {
+		err = fmt.Errorf("cannot create meter type '%s': %w", typ, err)
+	}
+
+	return v, err
+}

plugin/meter.go

@@ -0,0 +1,72 @@
+package plugin
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/evcc-io/evcc/api"
+	meter "github.com/evcc-io/evcc/meter/config"
+	"github.com/evcc-io/evcc/util"
+	"github.com/evcc-io/evcc/util/config"
+)
+
+type meterPlugin struct {
+	meter  api.Meter
+	method Method
+}
+
+func init() {
+	registry.AddCtx("meter", NewMeterFromConfig)
+}
+
+// NewMeterFromConfig creates type conversion provider
+func NewMeterFromConfig(ctx context.Context, other map[string]interface{}) (Plugin, error) {
+	var cc struct {
+		Config config.Typed
+		Method
+	}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	meter, err := meter.NewFromConfig(ctx, cc.Config.Type, cc.Config.Other)
+	if err != nil {
+		return nil, err
+	}
+
+	o := &meterPlugin{
+		meter:  meter,
+		method: cc.Method,
+	}
+
+	return o, nil
+}
+
+var _ FloatGetter = (*meterPlugin)(nil)
+
+func (o *meterPlugin) FloatGetter() (func() (float64, error), error) {
+	err := fmt.Errorf("unsupported method: %s", o.method.String())
+
+	switch o.method {
+	case Energy:
+		if _, ok := o.meter.(api.MeterEnergy); !ok {
+			return nil, err
+		}
+	case Soc:
+		if _, ok := o.meter.(api.Battery); !ok {
+			return nil, err
+		}
+	}
+
+	return func() (float64, error) {
+		switch o.method {
+		case Energy:
+			return o.meter.(api.MeterEnergy).TotalEnergy()
+		case Soc:
+			return o.meter.(api.Battery).Soc()
+		default:
+			return o.meter.CurrentPower()
+		}
+	}, nil
+}

plugin/method.go

@@ -0,0 +1,11 @@
+package plugin
+
+//go:generate go tool enumer -type Method
+type Method int
+
+const (
+	_ Method = iota
+	Energy
+	Power
+	Soc
+)

plugin/method_enumer.go

@@ -0,0 +1,83 @@
+// Code generated by "enumer -type Method"; DO NOT EDIT.
+
+package plugin
+
+import (
+	"fmt"
+	"strings"
+)
+
+const _MethodName = "EnergyPowerSoc"
+
+var _MethodIndex = [...]uint8{0, 6, 11, 14}
+
+const _MethodLowerName = "energypowersoc"
+
+func (i Method) String() string {
+	i -= 1
+	if i < 0 || i >= Method(len(_MethodIndex)-1) {
+		return fmt.Sprintf("Method(%d)", i+1)
+	}
+	return _MethodName[_MethodIndex[i]:_MethodIndex[i+1]]
+}
+
+// An "invalid array index" compiler error signifies that the constant values have changed.
+// Re-run the stringer command to generate them again.
+func _MethodNoOp() {
+	var x [1]struct{}
+	_ = x[Energy-(1)]
+	_ = x[Power-(2)]
+	_ = x[Soc-(3)]
+}
+
+var _MethodValues = []Method{Energy, Power, Soc}
+
+var _MethodNameToValueMap = map[string]Method{
+	_MethodName[0:6]:        Energy,
+	_MethodLowerName[0:6]:   Energy,
+	_MethodName[6:11]:       Power,
+	_MethodLowerName[6:11]:  Power,
+	_MethodName[11:14]:      Soc,
+	_MethodLowerName[11:14]: Soc,
+}
+
+var _MethodNames = []string{
+	_MethodName[0:6],
+	_MethodName[6:11],
+	_MethodName[11:14],
+}
+
+// MethodString retrieves an enum value from the enum constants string name.
+// Throws an error if the param is not part of the enum.
+func MethodString(s string) (Method, error) {
+	if val, ok := _MethodNameToValueMap[s]; ok {
+		return val, nil
+	}
+
+	if val, ok := _MethodNameToValueMap[strings.ToLower(s)]; ok {
+		return val, nil
+	}
+	return 0, fmt.Errorf("%s does not belong to Method values", s)
+}
+
+// MethodValues returns all values of the enum
+func MethodValues() []Method {
+	return _MethodValues
+}
+
+// MethodStrings returns a slice of all String values of the enum
+func MethodStrings() []string {
+	strs := make([]string, len(_MethodNames))
+	copy(strs, _MethodNames)
+	return strs
+}
+
+// IsAMethod returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Method) IsAMethod() bool {
+	for _, v := range _MethodValues {
+		if i == v {
+			return true
+		}
+	}
+	return false
+}