/*
Copyright 2016 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 apiservice

import (
	"context"
	"fmt"

	"k8s.io/apimachinery/pkg/fields"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/util/validation/field"
	"k8s.io/apiserver/pkg/registry/generic"
	"k8s.io/apiserver/pkg/storage"
	"k8s.io/apiserver/pkg/storage/names"

	"k8s.io/kube-aggregator/pkg/apis/apiregistration"
	"k8s.io/kube-aggregator/pkg/apis/apiregistration/validation"
)

type apiServerStrategy struct {
	runtime.ObjectTyper
	names.NameGenerator
}

func NewStrategy(typer runtime.ObjectTyper) apiServerStrategy {
	return apiServerStrategy{typer, names.SimpleNameGenerator}
}

func (apiServerStrategy) NamespaceScoped() bool {
	return false
}

func (apiServerStrategy) PrepareForCreate(ctx context.Context, obj runtime.Object) {
	apiservice := obj.(*apiregistration.APIService)
	apiservice.Status = apiregistration.APIServiceStatus{}

	// mark local API services as immediately available on create
	if apiservice.Spec.Service == nil {
		apiregistration.SetAPIServiceCondition(apiservice, apiregistration.NewLocalAvailableAPIServiceCondition())
	}
}

func (apiServerStrategy) PrepareForUpdate(ctx context.Context, obj, old runtime.Object) {
	newAPIService := obj.(*apiregistration.APIService)
	oldAPIService := old.(*apiregistration.APIService)
	newAPIService.Status = oldAPIService.Status
}

func (apiServerStrategy) Validate(ctx context.Context, obj runtime.Object) field.ErrorList {
	return validation.ValidateAPIService(obj.(*apiregistration.APIService))
}

func (apiServerStrategy) AllowCreateOnUpdate() bool {
	return false
}

func (apiServerStrategy) AllowUnconditionalUpdate() bool {
	return false
}

func (apiServerStrategy) Canonicalize(obj runtime.Object) {
}

func (apiServerStrategy) ValidateUpdate(ctx context.Context, obj, old runtime.Object) field.ErrorList {
	return validation.ValidateAPIServiceUpdate(obj.(*apiregistration.APIService), old.(*apiregistration.APIService))
}

type apiServerStatusStrategy struct {
	runtime.ObjectTyper
	names.NameGenerator
}

func NewStatusStrategy(typer runtime.ObjectTyper) apiServerStatusStrategy {
	return apiServerStatusStrategy{typer, names.SimpleNameGenerator}
}

func (apiServerStatusStrategy) NamespaceScoped() bool {
	return false
}

func (apiServerStatusStrategy) PrepareForUpdate(ctx context.Context, obj, old runtime.Object) {
	newAPIService := obj.(*apiregistration.APIService)
	oldAPIService := old.(*apiregistration.APIService)
	newAPIService.Spec = oldAPIService.Spec
	newAPIService.Labels = oldAPIService.Labels
	newAPIService.Annotations = oldAPIService.Annotations
	newAPIService.Finalizers = oldAPIService.Finalizers
	newAPIService.OwnerReferences = oldAPIService.OwnerReferences
}

func (apiServerStatusStrategy) AllowCreateOnUpdate() bool {
	return false
}

func (apiServerStatusStrategy) AllowUnconditionalUpdate() bool {
	return false
}

func (apiServerStatusStrategy) Canonicalize(obj runtime.Object) {
}

func (apiServerStatusStrategy) ValidateUpdate(ctx context.Context, obj, old runtime.Object) field.ErrorList {
	return validation.ValidateAPIServiceStatusUpdate(obj.(*apiregistration.APIService), old.(*apiregistration.APIService))
}

func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, bool, error) {
	apiserver, ok := obj.(*apiregistration.APIService)
	if !ok {
		return nil, nil, false, fmt.Errorf("given object is not a APIService.")
	}
	return labels.Set(apiserver.ObjectMeta.Labels), APIServiceToSelectableFields(apiserver), apiserver.Initializers != nil, nil
}

// MatchAPIService is the filter used by the generic etcd backend to watch events
// from etcd to clients of the apiserver only interested in specific labels/fields.
func MatchAPIService(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
	return storage.SelectionPredicate{
		Label:    label,
		Field:    field,
		GetAttrs: GetAttrs,
	}
}

// APIServiceToSelectableFields returns a field set that represents the object.
func APIServiceToSelectableFields(obj *apiregistration.APIService) fields.Set {
	return generic.ObjectMetaFieldsSet(&obj.ObjectMeta, true)
}