/*
Copyright 2016 The Kubernetes Authors.
Copyright 2020 Authors of Arktos - file modified.

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 app implements a server that runs a set of active
// components.  This includes replication controllers, service endpoints and
// nodes.
//
package app

import (
	"fmt"
	"net/http"
	"time"

	"k8s.io/apimachinery/pkg/runtime/schema"
	utilfeature "k8s.io/apiserver/pkg/util/feature"
	clientset "k8s.io/client-go/kubernetes"
	"k8s.io/client-go/util/flowcontrol"
	"k8s.io/klog"
	"k8s.io/kubernetes/pkg/controller/daemon"
	"k8s.io/kubernetes/pkg/controller/deployment"
	"k8s.io/kubernetes/pkg/controller/replicaset"
	"k8s.io/kubernetes/pkg/controller/statefulset"
	"k8s.io/kubernetes/pkg/features"
)

func startDaemonSetController(ctx ControllerContext) (http.Handler, bool, error) {
	if !ctx.AvailableResources[schema.GroupVersionResource{Group: "apps", Version: "v1", Resource: "daemonsets"}] {
		return nil, false, nil
	}

	dsc, err := daemon.NewDaemonSetsController(
		ctx.InformerFactory.Apps().V1().DaemonSets(),
		ctx.InformerFactory.Apps().V1().ControllerRevisions(),
		ctx.InformerFactory.Core().V1().Pods(),
		ctx.ResourceProviderNodeInformers,
		ctx.ClientBuilder.ClientOrDie("daemon-set-controller"),
		flowcontrol.NewBackOff(1*time.Second, 15*time.Minute),
	)
	if err != nil {
		return nil, true, fmt.Errorf("error creating DaemonSets controller: %v", err)
	}
	go dsc.Run(int(ctx.ComponentConfig.DaemonSetController.ConcurrentDaemonSetSyncs), ctx.Stop)
	return nil, true, nil
}

func startStatefulSetController(ctx ControllerContext) (http.Handler, bool, error) {
	if !ctx.AvailableResources[schema.GroupVersionResource{Group: "apps", Version: "v1", Resource: "statefulsets"}] {
		return nil, false, nil
	}
	go statefulset.NewStatefulSetController(
		ctx.InformerFactory.Core().V1().Pods(),
		ctx.InformerFactory.Apps().V1().StatefulSets(),
		ctx.InformerFactory.Core().V1().PersistentVolumeClaims(),
		ctx.InformerFactory.Apps().V1().ControllerRevisions(),
		ctx.ClientBuilder.ClientOrDie("statefulset-controller"),
	).Run(1, ctx.Stop)
	return nil, true, nil
}

func startReplicaSetController(ctx ControllerContext) (http.Handler, bool, error) {
	if !ctx.AvailableResources[schema.GroupVersionResource{Group: "apps", Version: "v1", Resource: "replicasets"}] {
		return nil, false, nil
	}

	config := ctx.ClientBuilder.ConfigOrDie("replicaset-controller")
	if utilfeature.DefaultFeatureGate.Enabled(features.QPSDoubleRSController) {
		// Increase replicaset controller QPS as during density test create pods step, also trying to acchieve QPS
		// in larger scale cluster
		// TODO - re-evaluate RS QPS with perf test data
		for _, rsKubeconfig := range config.GetAllConfigs() {
			rsKubeconfig.QPS *= 2
			rsKubeconfig.Burst *= 2
		}
	}
	klog.Infof("QPS for replicaset controller: %v", config.GetConfig().QPS)
	rsclient := clientset.NewForConfigOrDie(config)

	go replicaset.NewReplicaSetController(
		ctx.InformerFactory.Apps().V1().ReplicaSets(),
		ctx.InformerFactory.Core().V1().Pods(),
		rsclient,
		replicaset.BurstReplicas,
	).Run(int(ctx.ComponentConfig.ReplicaSetController.ConcurrentRSSyncs), ctx.Stop)
	return nil, true, nil
}

func startDeploymentController(ctx ControllerContext) (http.Handler, bool, error) {
	if !ctx.AvailableResources[schema.GroupVersionResource{Group: "apps", Version: "v1", Resource: "deployments"}] {
		return nil, false, nil
	}
	dc, err := deployment.NewDeploymentController(
		ctx.InformerFactory.Apps().V1().Deployments(),
		ctx.InformerFactory.Apps().V1().ReplicaSets(),
		ctx.InformerFactory.Core().V1().Pods(),
		ctx.ClientBuilder.ClientOrDie("deployment-controller"),
	)
	if err != nil {
		return nil, true, fmt.Errorf("error creating Deployment controller: %v", err)
	}
	go dc.Run(int(ctx.ComponentConfig.DeploymentController.ConcurrentDeploymentSyncs), ctx.Stop)
	return nil, true, nil
}
