chore: refactor plugin structure (#18335)

plugin/error.go

@@ -0,0 +1,45 @@
+package plugin
+
+import (
+	"fmt"
+
+	"github.com/evcc-io/evcc/util"
+)
+
+type errorPlugin struct {
+	err error
+}
+
+func init() {
+	registry.Add("error", NewErrorFromConfig)
+}
+
+// NewErrorFromConfig creates error provider
+func NewErrorFromConfig(other map[string]interface{}) (Plugin, error) {
+	var cc struct {
+		Error string
+	}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	err := knownErrors([]byte(cc.Error))
+	if err == nil {
+		return nil, fmt.Errorf("unknown error: %s", cc.Error)
+	}
+
+	o := &errorPlugin{
+		err: err,
+	}
+
+	return o, nil
+}
+
+var _ IntSetter = (*errorPlugin)(nil)
+
+func (o *errorPlugin) IntSetter(param string) (func(int64) error, error) {
+	return func(int64) error {
+		return o.err
+	}, nil
+}