package main

import (
	"context"
	"crypto/x509"
	"flag"
	"fmt"
	"os"
	"os/user"
	"syscall"

	"github.com/golang/glog"
	"golang.org/x/crypto/ssh/terminal"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials"

	"code.hackerspace.pl/hscloud/cluster/certs"
	pb "code.hackerspace.pl/hscloud/cluster/prodvider/proto"
)

var (
	flagProdvider string
	flagUsername  string
	flagForce     bool
)

func init() {
	flag.Set("logtostderr", "true")
}

func main() {
	user, err := user.Current()
	if err == nil {
		flagUsername = user.Username
	}

	flag.StringVar(&flagProdvider, "prodvider", "prodvider.hswaw.net:443", "Prodvider endpoint")
	flag.StringVar(&flagUsername, "username", flagUsername, "Username to authenticate with")
	flag.BoolVar(&flagForce, "force", false, "Force retrieving certificates even if they already exist")
	flag.Parse()

	if flagUsername == "" {
		glog.Exitf("Username could not be detected, please provide with -username flag")
	}

	cp := x509.NewCertPool()
	if ok := cp.AppendCertsFromPEM(certs.Data["ca-kube.crt"]); !ok {
		glog.Exitf("Could not load k8s CA")
	}

	creds := credentials.NewClientTLSFromCert(cp, "")
	conn, err := grpc.Dial(flagProdvider, grpc.WithTransportCredentials(creds))
	if err != nil {
		glog.Exitf("Could not dial prodvider: %v", err)
	}

	prodvider := pb.NewProdviderClient(conn)
	ctx := context.Background()

	if !needKubernetesCreds() && !flagForce {
		fmt.Printf("Kubernetes credentials exist. Use `prodaccess -force` to force update.\n")
		os.Exit(0)
	}

	attempts := 0
	for {
		ok := authenticate(ctx, prodvider)
		attempts += 1
		if !ok {
			if attempts >= 3 {
				os.Exit(1)
			}
		} else {
			fmt.Printf("Good evening professor. I see you have driven here in your Ferrari.\n")
			os.Exit(0)
		}
	}
}

func authenticate(ctx context.Context, prodvider pb.ProdviderClient) bool {
	req := &pb.AuthenticateRequest{
		Username: flagUsername,
		Password: password(),
	}

	res, err := prodvider.Authenticate(ctx, req)
	if err != nil {
		glog.Exitf("Prodvider error: %v", err)
	}

	switch res.Result {
	case pb.AuthenticateResponse_RESULT_AUTHENTICATED:
		break
	case pb.AuthenticateResponse_RESULT_INVALID_CREDENTIALS:
		fmt.Printf("Invalid username or password.\n")
		return false
	default:
		glog.Exitf("Unknown authentication result: %v", res.Result)
	}

	useKubernetesKeys(res.KubernetesKeys)
	fmt.Printf("-> Kubernetes credentials installed\n")
	useHSPKIKeys(res.HspkiKeys)
	fmt.Printf("-> HSPKI credentials installed\n")

	return true
}

func password() string {
	fmt.Printf("Enter SSO/LDAP password for %s@hackerspace.pl: ", flagUsername)
	bytePassword, err := terminal.ReadPassword(int(syscall.Stdin))
	if err != nil {
		return ""
	}
	fmt.Printf("\n")
	return string(bytePassword)
}