package server


import (
	"errors"
	"log"
	"net"

	"github.com/davecgh/go-spew/spew"
)

// github.com/insomniacslk/dhcp

type addr struct {
	IP  net.IP
	ipn *net.IPNet
}

type Config struct {
	Device string `yaml:"device"`
}

type Server struct {
	addrs []net.IP
	l     net.Listener
}

func addrsForDevice(dev string) ([]addr, error) {
	netInterface, err := net.InterfaceByName(dev)
	if err != nil {
		return nil, err
	}

	spew.Dump(netInterface)

	var addrs []addr
	devAddrs, err := netInterface.Addrs()
	if err != nil {
		return nil, err
	}

	for _, devAddr := range devAddrs {
		log.Printf("consider %s", devAddr.String())
		ip, ipn, err := net.ParseCIDR(devAddr.String())
		if err != nil {
			continue
		}

		if ip == nil {
			continue // address isn't an IP address
		}

		log.Printf("found IP: %s", ip)
		ip = ip.To4()

		// DHCP should only listen on private addresses.
		if !ip.IsPrivate() {
			log.Println("skipping non-private")
			continue
		}

		// only support IPv4 for now
		if len(ip) != 4 {
			log.Printf("%d IP, only supporting v4 right now", len(ip))
			continue
		}

		addrs = append(addrs, addr{ip, ipn})
	}

	return addrs, nil
}

func NewServer(cfg *Config) (*Server, error) {
	addrs, err := addrsForDevice(cfg.Device)
	if err != nil {
		return nil, err
	}

	log.Println("server IP list: ", addrs)
	return nil, errors.New("not implemented")
}