Use the opencloud reva from now on

vendor/github.com/opencloud-eu/reva/v2/pkg/utils/cfg/cfg.go

@@ -0,0 +1,89 @@
+// Copyright 2018-2023 CERN
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+package cfg
+
+import (
+	"errors"
+	"reflect"
+
+	"github.com/go-playground/locales/en"
+	ut "github.com/go-playground/universal-translator"
+	"github.com/go-playground/validator/v10"
+	en_translations "github.com/go-playground/validator/v10/translations/en"
+	"github.com/mitchellh/mapstructure"
+)
+
+// Setter is the interface a configuration struct may implement
+// to set the default options.
+type Setter interface {
+	// ApplyDefaults applies the default options.
+	ApplyDefaults()
+}
+
+var validate = validator.New()
+var english = en.New()
+var uni = ut.New(english, english)
+var trans, _ = uni.GetTranslator("en")
+var _ = en_translations.RegisterDefaultTranslations(validate, trans)
+
+func init() {
+	validate.RegisterTagNameFunc(func(field reflect.StructField) string {
+		if k := field.Tag.Get("mapstructure"); k != "" {
+			return k
+		}
+		// if not specified, fall back to field name
+		return field.Name
+	})
+}
+
+// Decode decodes the given raw input interface to the target pointer c.
+// It applies the default configuration if the target struct
+// implements the Setter interface.
+// It also perform a validation to all the fields of the configuration.
+func Decode(input map[string]any, c any) error {
+	config := &mapstructure.DecoderConfig{
+		Metadata: nil,
+		Result:   c,
+	}
+
+	decoder, err := mapstructure.NewDecoder(config)
+	if err != nil {
+		return err
+	}
+	if err := decoder.Decode(input); err != nil {
+		return err
+	}
+	if s, ok := c.(Setter); ok {
+		s.ApplyDefaults()
+	}
+
+	return translateError(validate.Struct(c), trans)
+}
+
+func translateError(err error, trans ut.Translator) error {
+	if err == nil {
+		return nil
+	}
+	errs := err.(validator.ValidationErrors)
+	translated := make([]error, 0, len(errs))
+	for _, err := range errs {
+		translated = append(translated, errors.New(err.Translate(trans)))
+	}
+	return errors.Join(translated...)
+}