package main

/*
This is a small utility that is designed to accompany the vyatta-yggdrasil
package. It takes a HJSON configuration file, makes changes to it based on
the command line arguments, and then spits out an updated file.
*/

import (
	"bytes"
	"encoding/json"
  "flag"
	"fmt"
	"io/ioutil"
  "strconv"

	"golang.org/x/text/encoding/unicode"
	"github.com/neilalexander/hjson-go"

	"yggdrasil/config"
)

type nodeConfig = config.NodeConfig

func main() {
  useconffile := flag.String("useconffile", "/etc/yggdrasil.conf", "update config at specified file path")
  flag.Parse()
	cfg := nodeConfig{}
	var config []byte
	var err error
	config, err = ioutil.ReadFile(*useconffile)
	if err != nil {
		panic(err)
	}
	if bytes.Compare(config[0:2], []byte{0xFF, 0xFE}) == 0 ||
		bytes.Compare(config[0:2], []byte{0xFE, 0xFF}) == 0 {
		utf := unicode.UTF16(unicode.BigEndian, unicode.UseBOM)
		decoder := utf.NewDecoder()
		config, err = decoder.Bytes(config)
		if err != nil {
			panic(err)
		}
	}
	var dat map[string]interface{}
	if err := hjson.Unmarshal(config, &dat); err != nil {
		panic(err)
	}
	confJson, err := json.Marshal(dat)
	if err != nil {
		panic(err)
	}
	json.Unmarshal(confJson, &cfg)
  switch flag.Arg(0) {
  case "setMTU":
    cfg.IfMTU, err = strconv.Atoi(flag.Arg(1))
    if err != nil {
      cfg.IfMTU = 1280
    }
    if mtu, _ := strconv.Atoi(flag.Arg(1)); mtu < 1280 {
      cfg.IfMTU = 1280
    }
  case "setIfName":
    cfg.IfName = flag.Arg(1)
  case "setListen":
    cfg.Listen = flag.Arg(1)
  case "setAdminListen":
    cfg.AdminListen = flag.Arg(1)
  case "setIfTapMode":
    if flag.Arg(1) == "true" {
      cfg.IfTAPMode = true
    } else {
      cfg.IfTAPMode = false
    }
  case "addPeer":
    found := false
    for _, v := range cfg.Peers {
      if v == flag.Arg(1) {
        found = true
      }
    }
    if !found {
      cfg.Peers = append(cfg.Peers, flag.Arg(1))
    }
  case "removePeer":
    for k, v := range cfg.Peers {
      if v == flag.Arg(1) {
        cfg.Peers = append(cfg.Peers[:k], cfg.Peers[k+1:]...)
      }
    }
  }
	bs, err := hjson.Marshal(cfg)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(bs))
	return
}