package main

import (
	"flag"
	"os"
	"os/signal"
	"syscall"

	"github.com/linkerd/linkerd2/controller/api/proxy"
	spclient "github.com/linkerd/linkerd2/controller/gen/client/clientset/versioned"
	"github.com/linkerd/linkerd2/controller/k8s"
	"github.com/linkerd/linkerd2/pkg/admin"
	"github.com/linkerd/linkerd2/pkg/flags"
	log "github.com/sirupsen/logrus"
)

func main() {
	addr := flag.String("addr", ":8086", "address to serve on")
	metricsAddr := flag.String("metrics-addr", ":9996", "address to serve scrapable metrics on")
	kubeConfigPath := flag.String("kubeconfig", "", "path to kube config")
	k8sDNSZone := flag.String("kubernetes-dns-zone", "", "The DNS suffix for the local Kubernetes zone.")
	enableH2Upgrade := flag.Bool("enable-h2-upgrade", true, "Enable transparently upgraded HTTP2 connections among pods in the service mesh")
	enableTLS := flag.Bool("enable-tls", false, "Enable TLS connections among pods in the service mesh")
	controllerNamespace := flag.String("controller-namespace", "linkerd", "namespace in which Linkerd is installed")
	singleNamespace := flag.Bool("single-namespace", false, "only operate in the controller namespace")
	flags.ConfigureAndParse()

	stop := make(chan os.Signal, 1)
	signal.Notify(stop, os.Interrupt, syscall.SIGTERM)

	k8sClient, err := k8s.NewClientSet(*kubeConfigPath)
	if err != nil {
		log.Fatal(err.Error())
	}

	var spClient *spclient.Clientset
	restrictToNamespace := ""
	resources := []k8s.APIResource{k8s.Endpoint, k8s.Pod, k8s.RS, k8s.Svc}

	if *singleNamespace {
		restrictToNamespace = *controllerNamespace
	} else {
		spClient, err = k8s.NewSpClientSet(*kubeConfigPath)
		if err != nil {
			log.Fatal(err.Error())
		}

		resources = append(resources, k8s.SP)
	}

	k8sAPI := k8s.NewAPI(
		k8sClient,
		spClient,
		restrictToNamespace,
		resources...,
	)

	done := make(chan struct{})

	server, lis, err := proxy.NewServer(*addr, *k8sDNSZone, *controllerNamespace, *enableTLS, *enableH2Upgrade, *singleNamespace, k8sAPI, done)
	if err != nil {
		log.Fatal(err)
	}

	k8sAPI.Sync() // blocks until caches are synced

	go func() {
		log.Infof("starting gRPC server on %s", *addr)
		server.Serve(lis)
	}()

	go admin.StartServer(*metricsAddr)

	<-stop

	log.Infof("shutting down gRPC server on %s", *addr)
	close(done)
	server.GracefulStop()
}