// Copyright 2016 IBM Corporation
//
//   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.

package auth

import "context"

type defaultAuthenticator struct{}

var defaultAuth = &defaultAuthenticator{}
var defaultNamespace = Namespace("default")

// DefaultAuthenticator returns the default authenticator provided by this package,
// which resolves "" (empty string) as well as "default" token to the default namespace.
func DefaultAuthenticator() Authenticator {
	return defaultAuth
}

func (aut *defaultAuthenticator) Authenticate(ctx context.Context, token string) (*Namespace, error) {
	if token == "" || token == defaultNamespace.String() {
		return &defaultNamespace, nil
	}
	return nil, ErrUnrecognizedToken
}
