/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package main

import (
	"flag"
	"log"

	"github.com/talos-systems/talos/internal/app/ntpd/pkg/ntp"
	"github.com/talos-systems/talos/internal/app/ntpd/pkg/reg"
	"github.com/talos-systems/talos/pkg/constants"
	"github.com/talos-systems/talos/pkg/grpc/factory"
	"github.com/talos-systems/talos/pkg/startup"
	"github.com/talos-systems/talos/pkg/userdata"
)

// https://access.redhat.com/solutions/39194
// Using the above as reference for setting min/max
const (
	// TODO: Once we get naming sorted we need to apply
	// for a project specific address
	// https://manage.ntppool.org/manage/vendor
	DefaultServer = "pool.ntp.org"
)

var (
	dataPath *string
)

func init() {
	log.SetFlags(log.Lshortfile | log.Ldate | log.Lmicroseconds | log.Ltime)
	dataPath = flag.String("userdata", "", "the path to the user data")
	flag.Parse()
}

// New instantiates a new ntp instance against a given server
// If no servers are specified, the default will be used
func main() {
	if err := startup.RandSeed(); err != nil {
		log.Fatalf("startup: %s", err)
	}

	server := DefaultServer

	data, err := userdata.Open(*dataPath)
	if err != nil {
		log.Fatalf("open user data: %v", err)
	}

	// Check if ntp servers are defined
	if data.Services.NTPd != nil && data.Services.NTPd.Server != "" {
		server = data.Services.NTPd.Server
	}

	n := &ntp.NTP{Server: server}

	log.Println("Starting ntpd")
	errch := make(chan error)
	go func() {
		errch <- n.Daemon()
	}()

	go func() {
		errch <- factory.ListenAndServe(
			reg.NewRegistrator(n),
			factory.Network("unix"),
			factory.SocketPath(constants.NtpdSocketPath),
		)
	}()

	log.Fatal(<-errch)
}