/*
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 admission

import (
	"k8s.io/apimachinery/pkg/api/meta"
	"k8s.io/apiserver/pkg/admission"
	"k8s.io/apiserver/pkg/authorization/authorizer"
	"k8s.io/apiserver/pkg/util/webhook"
	quota "k8s.io/kubernetes/pkg/quota/v1"
)

// TODO add a `WantsToRun` which takes a stopCh.  Might make it generic.

// WantsCloudConfig defines a function which sets CloudConfig for admission plugins that need it.
type WantsCloudConfig interface {
	SetCloudConfig([]byte)
}

// WantsRESTMapper defines a function which sets RESTMapper for admission plugins that need it.
type WantsRESTMapper interface {
	SetRESTMapper(meta.RESTMapper)
}

// WantsQuotaConfiguration defines a function which sets quota configuration for admission plugins that need it.
type WantsQuotaConfiguration interface {
	SetQuotaConfiguration(quota.Configuration)
	admission.InitializationValidator
}

// PluginInitializer is used for initialization of the Kubernetes specific admission plugins.
type PluginInitializer struct {
	authorizer                        authorizer.Authorizer
	cloudConfig                       []byte
	restMapper                        meta.RESTMapper
	quotaConfiguration                quota.Configuration
	serviceResolver                   webhook.ServiceResolver
	authenticationInfoResolverWrapper webhook.AuthenticationInfoResolverWrapper
}

var _ admission.PluginInitializer = &PluginInitializer{}

// NewPluginInitializer constructs new instance of PluginInitializer
// TODO: switch these parameters to use the builder pattern or just make them
// all public, this construction method is pointless boilerplate.
func NewPluginInitializer(
	cloudConfig []byte,
	restMapper meta.RESTMapper,
	quotaConfiguration quota.Configuration,
) *PluginInitializer {
	return &PluginInitializer{
		cloudConfig:        cloudConfig,
		restMapper:         restMapper,
		quotaConfiguration: quotaConfiguration,
	}
}

// Initialize checks the initialization interfaces implemented by each plugin
// and provide the appropriate initialization data
func (i *PluginInitializer) Initialize(plugin admission.Interface) {
	if wants, ok := plugin.(WantsCloudConfig); ok {
		wants.SetCloudConfig(i.cloudConfig)
	}

	if wants, ok := plugin.(WantsRESTMapper); ok {
		wants.SetRESTMapper(i.restMapper)
	}

	if wants, ok := plugin.(WantsQuotaConfiguration); ok {
		wants.SetQuotaConfiguration(i.quotaConfiguration)
	}
}