package main

import (
	"encoding/json"
	"errors"
	"flag"
	"io/ioutil"
	"math/rand"
	"os"
	"time"

	"k8s.io/apimachinery/pkg/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	typedcertificatesv1beta1 "k8s.io/client-go/kubernetes/typed/certificates/v1beta1"
	"k8s.io/klog/klogr"
	"k8s.io/klog/v2"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/healthz"

	"git.giftfish.de/ston1th/cloud-controller-manager-pve/pkg/approver"
	pve "git.giftfish.de/ston1th/pve-go"
)

var (
	scheme   = runtime.NewScheme()
	setupLog = ctrl.Log.WithName("setup")
)

func init() {
	_ = clientgoscheme.AddToScheme(scheme)
}

type config struct {
	PVE pve.Config `json:"pve"`
}

func main() {
	rand.Seed(time.Now().UnixNano())
	klog.InitFlags(nil)

	var (
		leaderElect    bool
		healthAddr     string
		cloudConfig    string
		csrConcurrency int
		syncPeriod     time.Duration
	)

	flag.BoolVar(&leaderElect, "leader-elect", true,
		"Enable leader election for controller manager. "+
			"Enabling this will ensure there is only one active controller manager.")
	flag.StringVar(&cloudConfig,
		"cloud-config",
		"",
		"The path to the cloud provider configuration file. Empty string for no configuration file.",
	)
	flag.StringVar(&healthAddr,
		"health-addr",
		":9449",
		"The address the health endpoint binds to.",
	)
	flag.IntVar(&csrConcurrency,
		"csr-concurrency",
		1,
		"Number of CSRs to process simultaneously",
	)
	flag.DurationVar(&syncPeriod,
		"sync-period",
		10*time.Minute,
		"The minimum interval at which watched resources are reconciled (e.g. 15m)",
	)
	flag.Parse()
	ctrl.SetLogger(klogr.New())

	rcfg := ctrl.GetConfigOrDie()

	mgr, err := ctrl.NewManager(rcfg, ctrl.Options{
		Scheme:                 scheme,
		LeaderElection:         leaderElect,
		LeaderElectionID:       "pve-csr-approver-manager",
		HealthProbeBindAddress: healthAddr,
		MetricsBindAddress:     "0",
		SyncPeriod:             &syncPeriod,
	})
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	var opts []pve.ClientOption
	cr, err := os.Open(cloudConfig)
	if err == nil {
		buf, _ := ioutil.ReadAll(cr)
		if len(buf) != 0 {
			var cfg config
			err = json.Unmarshal(buf, &cfg)
			if err != nil {
				setupLog.Error(err, "failed to read config file")
				os.Exit(1)
			}
			opts, err = pve.ClientOptionsFromConfig(cfg.PVE)
			if err != nil {
				setupLog.Error(err, "failed to create client options from file")
				os.Exit(1)
			}
		}
	} else {
		opts, err = pve.ClientOptionsFromEnv()
		if err != nil {
			setupLog.Error(err, "failed to create client options from env")
			os.Exit(1)
		}
	}
	if len(opts) == 0 {
		setupLog.Error(errors.New("missing pve config"), "")
		os.Exit(1)
	}
	pveClient := pve.NewClient(opts...)

	if err = (&approver.CSRReconciler{
		Client:    mgr.GetClient(),
		Log:       ctrl.Log.WithName("approver"),
		Scheme:    mgr.GetScheme(),
		PVEClient: pveClient,
		CSRClient: typedcertificatesv1beta1.NewForConfigOrDie(rcfg),
	}).SetupWithManager(mgr, controller.Options{MaxConcurrentReconciles: csrConcurrency}); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "approver")
		os.Exit(1)
	}
	if err := mgr.AddReadyzCheck("ping", healthz.Ping); err != nil {
		setupLog.Error(err, "unable to create ready check")
		os.Exit(1)
	}

	if err := mgr.AddHealthzCheck("ping", healthz.Ping); err != nil {
		setupLog.Error(err, "unable to create health check")
		os.Exit(1)
	}

	setupLog.Info("starting manager")
	if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
		setupLog.Error(err, "problem running manager")
		os.Exit(1)
	}
	/*
		cfg, err := rest.InClusterConfig()
		if err != nil {
			log.Error(err, "could not configure kubernetes client")
			os.Exit(1)
		}

		cl, err := kubernetes.NewForConfig(cfg)
		if err != nil {
			log.Error(err, "could not create kubernetes client")
			os.Exit(1)
		}

		id, err := os.Hostname()
		if err != nil {
			log.Error(err, "could not get hostname")
			os.Exit(1)
		}
		lock := &resourcelock.LeaseLock{
			LeaseMeta: metav1.ObjectMeta{
				Name:      csrLock,
				Namespace: namespace,
			},
			Client: cl.CoordinationV1(),
			LockConfig: resourcelock.ResourceLockConfig{
				Identity: id,
			},
		}

		ctx, cancel := context.WithCancel(context.Background())
		defer cancel()

		leaderelection.RunOrDie(ctx, leaderelection.LeaderElectionConfig{
			Lock:            lock,
			ReleaseOnCancel: true,
			LeaseDuration:   time.Duration(leaseDuration) * time.Second,
			RenewDeadline:   time.Duration(renewDeadline) * time.Second,
			RetryPeriod:     time.Duration(retryPeriod) * time.Second,
			Callbacks: leaderelection.LeaderCallbacks{
				OnStartedLeading: func(ctx context.Context) {
					log.Info("Leader election successful")
					factory := informers.NewSharedInformerFactory(cl, time.Second*30)
					certInformerV1beta1 := factory.Certificates().V1beta1().CertificateSigningRequests().Informer()
					fV1beta1 := func(obj interface{}) {
						if req, ok := obj.(*certificatesv1beta1.CertificateSigningRequest); ok {
							if err := approver.ApproveV1beta1(log, pveClient, cl.CertificatesV1beta1().CertificateSigningRequests(), req); err != nil {
								log.Error(err, "csr approval failed", "name", req.ObjectMeta.Name)
								return
							}
						}
					}
					certInformerV1beta1.AddEventHandler(cache.ResourceEventHandlerFuncs{
						AddFunc: func(obj interface{}) {
							fV1beta1(obj)
						},
						UpdateFunc: func(_, obj interface{}) {
							fV1beta1(obj)
						},
					})
					stop := make(chan struct{})
					factory.Start(stop)
					<-ctx.Done()
					close(stop)
				},
				OnStoppedLeading: func() {
					cancel()
					log.Info("Leader election lost")
				},
			}})

		log.Info("csr approver started")

		sigs := make(chan os.Signal)
		signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
		<-sigs
		cancel()
		log.Info("csr approver stopped")
	*/
}