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"
	typedcertificatesv1 "k8s.io/client-go/kubernetes/typed/certificates/v1"
	"k8s.io/klog/v2"
	"k8s.io/klog/v2/klogr"
	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"
)

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

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

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

const name = "pve-csr-approver-manager"

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

func main() {
	rand.Seed(time.Now().UnixNano())
	klog.InitFlags(nil)
	ctrl.SetLogger(klogr.New())
	initFlags()
	flag.Parse()

	rcfg := ctrl.GetConfigOrDie()
	rcfg.UserAgent = name

	mgr, err := ctrl.NewManager(rcfg, ctrl.Options{
		Scheme:                     scheme,
		LeaderElection:             leaderElect,
		LeaderElectionID:           name,
		LeaderElectionResourceLock: "leases",
		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("controllers").WithName("approver"),
		Scheme:    mgr.GetScheme(),
		PVEClient: pveClient,
		CSRClient: typedcertificatesv1.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)
	}
}

func initFlags() {
	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)",
	)
}