/*
Copyright 2014 Google Inc. 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 standalone

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

	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/apiserver"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
	minionControllerPkg "github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider/controller"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/controller"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/config"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/dockertools"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/master"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/resources"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/service"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/tools"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler"
	"github.com/GoogleCloudPlatform/kubernetes/plugin/pkg/scheduler/factory"

	"github.com/golang/glog"
)

type delegateHandler struct {
	delegate http.Handler
}

func (h *delegateHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	if h.delegate != nil {
		h.delegate.ServeHTTP(w, req)
		return
	}
	w.WriteHeader(http.StatusNotFound)
}

// Get a docker endpoint, either from the string passed in, or $DOCKER_HOST environment variables
func GetDockerEndpoint(dockerEndpoint string) string {
	var endpoint string
	if len(dockerEndpoint) > 0 {
		endpoint = dockerEndpoint
	} else if len(os.Getenv("DOCKER_HOST")) > 0 {
		endpoint = os.Getenv("DOCKER_HOST")
	} else {
		endpoint = "unix:///var/run/docker.sock"
	}
	glog.Infof("Connecting to docker on %s", endpoint)

	return endpoint
}

// RunApiServer starts an API server in a go routine.
func RunApiServer(cl *client.Client, etcdClient tools.EtcdClient, addr string, port int) {
	handler := delegateHandler{}

	helper, err := master.NewEtcdHelper(etcdClient, "")
	if err != nil {
		glog.Fatalf("Unable to get etcd helper: %v", err)
	}

	// Create a master and install handlers into mux.
	m := master.New(&master.Config{
		Client:     cl,
		EtcdHelper: helper,
		KubeletClient: &client.HTTPKubeletClient{
			Client: http.DefaultClient,
			Port:   10250,
		},
		EnableLogsSupport: false,
		APIPrefix:         "/api",
		Authorizer:        apiserver.NewAlwaysAllowAuthorizer(),

		ReadWritePort: port,
		ReadOnlyPort:  port,
		PublicAddress: addr,
	})

	handler.delegate = m.InsecureHandler

	go http.ListenAndServe(fmt.Sprintf("%s:%d", addr, port), &handler)
}

// RunScheduler starts up a scheduler in it's own goroutine
func RunScheduler(cl *client.Client) {
	// Scheduler
	schedulerConfigFactory := &factory.ConfigFactory{cl}
	schedulerConfig := schedulerConfigFactory.Create()
	scheduler.New(schedulerConfig).Run()
}

// RunControllerManager starts a controller
func RunControllerManager(machineList []string, cl *client.Client, nodeMilliCPU, nodeMemory int64) {
	if int64(int(nodeMilliCPU)) != nodeMilliCPU {
		glog.Warningf("node_milli_cpu is too big for platform. Clamping: %d -> %d",
			nodeMilliCPU, math.MaxInt32)
		nodeMilliCPU = math.MaxInt32
	}

	if int64(int(nodeMemory)) != nodeMemory {
		glog.Warningf("node_memory is too big for platform. Clamping: %d -> %d",
			nodeMemory, math.MaxInt32)
		nodeMemory = math.MaxInt32
	}

	nodeResources := &api.NodeResources{
		Capacity: api.ResourceList{
			resources.CPU:    util.NewIntOrStringFromInt(int(nodeMilliCPU)),
			resources.Memory: util.NewIntOrStringFromInt(int(nodeMemory)),
		},
	}
	minionController := minionControllerPkg.NewMinionController(nil, "", machineList, nodeResources, cl)
	minionController.Run(10 * time.Second)

	endpoints := service.NewEndpointController(cl)
	go util.Forever(func() { endpoints.SyncServiceEndpoints() }, time.Second*10)

	controllerManager := controller.NewReplicationManager(cl)
	controllerManager.Run(10 * time.Second)
}

// SimpleRunKubelet is a simple way to start a Kubelet talking to dockerEndpoint, using an etcdClient.
// Under the hood it calls RunKubelet (below)
func SimpleRunKubelet(etcdClient tools.EtcdClient, dockerClient dockertools.DockerInterface, hostname, rootDir, manifestURL, address string, port uint) {
	kcfg := KubeletConfig{
		EtcdClient:            etcdClient,
		DockerClient:          dockerClient,
		HostnameOverride:      hostname,
		RootDirectory:         rootDir,
		ManifestURL:           manifestURL,
		NetworkContainerImage: kubelet.NetworkContainerImage,
		Port:                    port,
		Address:                 util.IP(net.ParseIP(address)),
		EnableServer:            true,
		EnableDebuggingHandlers: true,
	}
	RunKubelet(&kcfg)
}

// RunKubelet is responsible for setting up and running a kubelet.  It is used in three different applications:
//   1 Integration tests
//   2 Kubelet binary
//   3 Standalone 'kubernetes' binary
// Eventually, #2 will be replaced with instances of #3
func RunKubelet(kcfg *KubeletConfig) {
	kubelet.SetupEventSending(kcfg.AuthPath, kcfg.ApiServerList)
	kubelet.SetupLogging()
	kubelet.SetupCapabilities(kcfg.AllowPrivileged)

	kcfg.Hostname = kubelet.GetHostname(kcfg.HostnameOverride)
	if len(kcfg.RootDirectory) > 0 {
		kubelet.SetupRootDirectoryOrDie(kcfg.RootDirectory)
	}

	cfg := makePodSourceConfig(kcfg)
	k := createAndInitKubelet(kcfg)
	// process pods and exit.
	if kcfg.Runonce {
		if _, err := k.RunOnce(cfg.Updates()); err != nil {
			glog.Errorf("--runonce failed: %v", err)
		}
	} else {
		startKubelet(k, cfg, kcfg)
	}
}

func startKubelet(k *kubelet.Kubelet, cfg *config.PodConfig, kc *KubeletConfig) {
	// start the kubelet
	go util.Forever(func() { k.Run(cfg.Updates()) }, 0)

	// start the kubelet server
	if kc.EnableServer {
		go util.Forever(func() {
			kubelet.ListenAndServeKubeletServer(k, cfg.Channel("http"), net.IP(kc.Address), kc.Port, kc.EnableDebuggingHandlers)
		}, 0)
	}
}

func makePodSourceConfig(kc *KubeletConfig) *config.PodConfig {
	// source of all configuration
	cfg := config.NewPodConfig(config.PodConfigNotificationSnapshotAndUpdates)

	// define file config source
	if kc.ConfigFile != "" {
		config.NewSourceFile(kc.ConfigFile, kc.FileCheckFrequency, cfg.Channel("file"))
	}

	// define url config source
	if kc.ManifestURL != "" {
		config.NewSourceURL(kc.ManifestURL, kc.HttpCheckFrequency, cfg.Channel("http"))
	}

	if kc.EtcdClient != nil {
		glog.Infof("Watching for etcd configs at %v", kc.EtcdClient.GetCluster())
		config.NewSourceEtcd(config.EtcdKeyForHost(kc.Hostname), kc.EtcdClient, cfg.Channel("etcd"))
	}
	return cfg
}

type KubeletConfig struct {
	EtcdClient              tools.EtcdClient
	DockerClient            dockertools.DockerInterface
	Address                 util.IP
	AuthPath                string
	ApiServerList           util.StringList
	AllowPrivileged         bool
	HostnameOverride        string
	RootDirectory           string
	ConfigFile              string
	ManifestURL             string
	FileCheckFrequency      time.Duration
	HttpCheckFrequency      time.Duration
	Hostname                string
	NetworkContainerImage   string
	SyncFrequency           time.Duration
	RegistryPullQPS         float64
	RegistryBurst           int
	MinimumGCAge            time.Duration
	MaxContainerCount       int
	EnableServer            bool
	EnableDebuggingHandlers bool
	Port                    uint
	Runonce                 bool
}

func createAndInitKubelet(kc *KubeletConfig) *kubelet.Kubelet {
	// TODO: block until all sources have delivered at least one update to the channel, or break the sync loop
	// up into "per source" synchronizations

	k := kubelet.NewMainKubelet(
		kc.Hostname,
		kc.DockerClient,
		kc.EtcdClient,
		kc.RootDirectory,
		kc.NetworkContainerImage,
		kc.SyncFrequency,
		float32(kc.RegistryPullQPS),
		kc.RegistryBurst,
		kc.MinimumGCAge,
		kc.MaxContainerCount)

	k.BirthCry()

	go kubelet.GarbageCollectLoop(k)
	go kubelet.MonitorCAdvisor(k)
	kubelet.InitHealthChecking(k)

	return k
}