/*
Copyright 2015 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 validation

import (
	apiequality "k8s.io/apimachinery/pkg/api/equality"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/validation/field"
	authorizationapi "k8s.io/kubernetes/pkg/apis/authorization"
)

func ValidateSubjectAccessReviewSpec(spec authorizationapi.SubjectAccessReviewSpec, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if spec.ResourceAttributes != nil && spec.NonResourceAttributes != nil {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("nonResourceAttributes"), spec.NonResourceAttributes, `cannot be specified in combination with resourceAttributes`))
	}
	if spec.ResourceAttributes == nil && spec.NonResourceAttributes == nil {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("resourceAttributes"), spec.NonResourceAttributes, `exactly one of nonResourceAttributes or resourceAttributes must be specified`))
	}
	if len(spec.User) == 0 && len(spec.Groups) == 0 {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("user"), spec.User, `at least one of user or group must be specified`))
	}

	return allErrs
}

func ValidateSelfSubjectAccessReviewSpec(spec authorizationapi.SelfSubjectAccessReviewSpec, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if spec.ResourceAttributes != nil && spec.NonResourceAttributes != nil {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("nonResourceAttributes"), spec.NonResourceAttributes, `cannot be specified in combination with resourceAttributes`))
	}
	if spec.ResourceAttributes == nil && spec.NonResourceAttributes == nil {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("resourceAttributes"), spec.NonResourceAttributes, `exactly one of nonResourceAttributes or resourceAttributes must be specified`))
	}

	return allErrs
}

func ValidateSubjectAccessReview(sar *authorizationapi.SubjectAccessReview) field.ErrorList {
	allErrs := ValidateSubjectAccessReviewSpec(sar.Spec, field.NewPath("spec"))
	if !apiequality.Semantic.DeepEqual(metav1.ObjectMeta{}, sar.ObjectMeta) {
		allErrs = append(allErrs, field.Invalid(field.NewPath("metadata"), sar.ObjectMeta, `must be empty`))
	}
	return allErrs
}

func ValidateSelfSubjectAccessReview(sar *authorizationapi.SelfSubjectAccessReview) field.ErrorList {
	allErrs := ValidateSelfSubjectAccessReviewSpec(sar.Spec, field.NewPath("spec"))
	if !apiequality.Semantic.DeepEqual(metav1.ObjectMeta{}, sar.ObjectMeta) {
		allErrs = append(allErrs, field.Invalid(field.NewPath("metadata"), sar.ObjectMeta, `must be empty`))
	}
	return allErrs
}

func ValidateLocalSubjectAccessReview(sar *authorizationapi.LocalSubjectAccessReview) field.ErrorList {
	allErrs := ValidateSubjectAccessReviewSpec(sar.Spec, field.NewPath("spec"))

	objectMetaShallowCopy := sar.ObjectMeta
	objectMetaShallowCopy.Namespace = ""
	if !apiequality.Semantic.DeepEqual(metav1.ObjectMeta{}, objectMetaShallowCopy) {
		allErrs = append(allErrs, field.Invalid(field.NewPath("metadata"), sar.ObjectMeta, `must be empty except for namespace`))
	}

	if sar.Spec.ResourceAttributes != nil && sar.Spec.ResourceAttributes.Namespace != sar.Namespace {
		allErrs = append(allErrs, field.Invalid(field.NewPath("spec.resourceAttributes.namespace"), sar.Spec.ResourceAttributes.Namespace, `must match metadata.namespace`))
	}
	if sar.Spec.NonResourceAttributes != nil {
		allErrs = append(allErrs, field.Invalid(field.NewPath("spec.nonResourceAttributes"), sar.Spec.NonResourceAttributes, `disallowed on this kind of request`))
	}

	return allErrs
}