/*
Copyright 2017 The Kubernetes Authors.

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 group

import (
	"net/http"

	"k8s.io/apiserver/pkg/authentication/authenticator"
	"k8s.io/apiserver/pkg/authentication/user"
)

// AuthenticatedGroupAdder adds system:authenticated group when appropriate
type AuthenticatedGroupAdder struct {
	// Authenticator is delegated to make the authentication decision
	Authenticator authenticator.Request
}

// NewAuthenticatedGroupAdder wraps a request authenticator, and adds the system:authenticated group when appropriate.
// Authentication must succeed, the user must not be system:anonymous, the groups system:authenticated or system:unauthenticated must
// not be present
func NewAuthenticatedGroupAdder(auth authenticator.Request) authenticator.Request {
	return &AuthenticatedGroupAdder{auth}
}

func (g *AuthenticatedGroupAdder) AuthenticateRequest(req *http.Request) (*authenticator.Response, bool, error) {
	r, ok, err := g.Authenticator.AuthenticateRequest(req)
	if err != nil || !ok {
		return nil, ok, err
	}

	if r.User.GetName() == user.Anonymous {
		return r, true, nil
	}
	for _, group := range r.User.GetGroups() {
		if group == user.AllAuthenticated || group == user.AllUnauthenticated {
			return r, true, nil
		}
	}

	newGroups := make([]string, 0, len(r.User.GetGroups())+1)
	newGroups = append(newGroups, r.User.GetGroups()...)
	newGroups = append(newGroups, user.AllAuthenticated)

	ret := *r // shallow copy
	ret.User = &user.DefaultInfo{
		Name:   r.User.GetName(),
		UID:    r.User.GetUID(),
		Groups: newGroups,
		Extra:  r.User.GetExtra(),
	}
	return &ret, true, nil
}