/*
Copyright 2015 The Kubernetes Authors All rights reserved.

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 benchmark

import (
	"net/http"
	"net/http/httptest"

	"github.com/golang/glog"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/resource"
	"k8s.io/kubernetes/pkg/api/testapi"
	"k8s.io/kubernetes/pkg/client/record"
	client "k8s.io/kubernetes/pkg/client/unversioned"
	"k8s.io/kubernetes/pkg/master"
	"k8s.io/kubernetes/plugin/pkg/scheduler"
	_ "k8s.io/kubernetes/plugin/pkg/scheduler/algorithmprovider"
	"k8s.io/kubernetes/plugin/pkg/scheduler/factory"
	"k8s.io/kubernetes/test/integration/framework"
)

// mustSetupScheduler starts the following components:
// - k8s api server (a.k.a. master)
// - scheduler
// It returns scheduler config factory and destroyFunc which should be used to
// remove resources after finished.
// Notes on rate limiter:
//   - client rate limit is set to 5000.
func mustSetupScheduler() (schedulerConfigFactory *factory.ConfigFactory, destroyFunc func()) {
	framework.DeleteAllEtcdKeys()

	var m *master.Master
	masterConfig := framework.NewIntegrationTestMasterConfig()
	m = master.New(masterConfig)
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		m.Handler.ServeHTTP(w, req)
	}))

	c := client.NewOrDie(&client.Config{
		Host:          s.URL,
		ContentConfig: client.ContentConfig{GroupVersion: testapi.Default.GroupVersion()},
		QPS:           5000.0,
		Burst:         5000,
	})

	schedulerConfigFactory = factory.NewConfigFactory(c, api.DefaultSchedulerName)
	schedulerConfig, err := schedulerConfigFactory.Create()
	if err != nil {
		panic("Couldn't create scheduler config")
	}
	eventBroadcaster := record.NewBroadcaster()
	schedulerConfig.Recorder = eventBroadcaster.NewRecorder(api.EventSource{Component: "scheduler"})
	eventBroadcaster.StartRecordingToSink(c.Events(""))
	scheduler.New(schedulerConfig).Run()

	destroyFunc = func() {
		glog.Infof("destroying")
		close(schedulerConfig.StopEverything)
		// TODO: Uncomment when fix #19254
		// s.Close()
		glog.Infof("destroyed")
	}
	return
}

func makeNodes(c client.Interface, nodeCount int) {
	glog.Infof("making %d nodes", nodeCount)
	baseNode := &api.Node{
		ObjectMeta: api.ObjectMeta{
			GenerateName: "scheduler-test-node-",
		},
		Spec: api.NodeSpec{
			ExternalID: "foobar",
		},
		Status: api.NodeStatus{
			Capacity: api.ResourceList{
				api.ResourcePods:   *resource.NewQuantity(32, resource.DecimalSI),
				api.ResourceCPU:    resource.MustParse("4"),
				api.ResourceMemory: resource.MustParse("32Gi"),
			},
			Phase: api.NodeRunning,
			Conditions: []api.NodeCondition{
				{Type: api.NodeReady, Status: api.ConditionTrue},
			},
		},
	}
	for i := 0; i < nodeCount; i++ {
		if _, err := c.Nodes().Create(baseNode); err != nil {
			panic("error creating node: " + err.Error())
		}
	}
}

// makePods will setup specified number of scheduled pods.
// Currently it goes through scheduling path and it's very slow to setup large number of pods.
// TODO: Setup pods evenly on all nodes and quickly/non-linearly.
func makePods(c client.Interface, podCount int) {
	glog.Infof("making %d pods", podCount)
	basePod := &api.Pod{
		ObjectMeta: api.ObjectMeta{
			GenerateName: "scheduler-test-pod-",
		},
		Spec: api.PodSpec{
			Containers: []api.Container{{
				Name:  "pause",
				Image: "gcr.io/google_containers/pause:1.0",
				Resources: api.ResourceRequirements{
					Limits: api.ResourceList{
						api.ResourceCPU:    resource.MustParse("100m"),
						api.ResourceMemory: resource.MustParse("500Mi"),
					},
					Requests: api.ResourceList{
						api.ResourceCPU:    resource.MustParse("100m"),
						api.ResourceMemory: resource.MustParse("500Mi"),
					},
				},
			}},
		},
	}
	threads := 30
	remaining := make(chan int, 1000)
	go func() {
		for i := 0; i < podCount; i++ {
			remaining <- i
		}
		close(remaining)
	}()
	for i := 0; i < threads; i++ {
		go func() {
			for {
				_, ok := <-remaining
				if !ok {
					return
				}
				for {
					_, err := c.Pods("default").Create(basePod)
					if err == nil {
						break
					}
				}
			}
		}()
	}
}