package main

import (
	"fmt"
	"os"
	"strconv"
	"bufio"
	docopt "github.com/docopt/docopt.go"
	"github.com/luc10/zykgen"
)

func replaceAtIndex(in string, r rune, i int) string {
	out := []rune(in)
	out[i] = r
	return string(out)
}

const usage = `Zyxel VMG8823-B50B WPA Keygen

Usage:
  zykgen (-m|-n|-c) [-l <length> -L <letter>] <startserial> <endserial>
  zykgen -h | --help

Options:
  -l <length>     Output key length [default: 10].
  -L <letter>     Fifth letter of the serial [default: V].
  -h --help       Show this screen.`

func main() {
	var cocktail zykgen.Cocktail
	var seriale string

	var args struct {
		Sserial string `docopt:"<startserial>"`
		Eserial string `docopt:"<endserial>"`

		Letter       string `docopt:"-L"`
		Length       int    `docopt:"-l"`
		Mojito       bool   `docopt:"-m"`
		Negroni      bool   `docopt:"-n"`
		Cosmopolitan bool   `docopt:"-c"`
	}

	opts, err := docopt.DefaultParser.ParseArgs(usage, os.Args[1:], "")
	if err != nil {
		return
	}

	opts.Bind(&args)
	if args.Mojito {
		cocktail = zykgen.Mojito
	}
	if args.Negroni {
		cocktail = zykgen.Negroni
	}
	if args.Cosmopolitan {
		cocktail = zykgen.Cosmopolitan
	}

	start, err := strconv.Atoi(args.Sserial)
	if err != nil {
		fmt.Println(err)
		fmt.Println("Serial number should be 12 chars long, (exluding the first char which is 'S'),should contain only numbers, letter 'V' is automatically added")
		return
	}

	end, err := strconv.Atoi(args.Eserial)
	if err != nil {
		fmt.Println(err)
		fmt.Println("Serial number should be 12 chars long, (exluding the first char which is 'S'),should contain only numbers, letter 'V' is automatically added")
		return
	}

	if start > end {
		fmt.Println("End of the serial should be at least > start of the serial")
		return
	}

	if len(args.Sserial) != 12 {
		fmt.Println("Serial number should be 12 chars long, (exluding the first char which is 'S'),should contain only numbers, letter 'V' is automatically added ")
		return
	}

	if len(args.Eserial) != 12 {
		fmt.Println("Serial number should be 12 chars long, (exluding the first char which is 'S'),should contain only numbers, letter 'V' is automatically added  ")
		return
	}

	f, err := os.Create("wpa_keys_" + args.Sserial + "_" + args.Eserial + "_" + strconv.Itoa(args.Length) + "_" + args.Letter + "_c.txt")
	if err != nil {
		fmt.Println(err)
		return
	}

	writer := bufio.NewWriter(f)
	defer writer.Flush()

	for i := start; i < end; i++ {

		seriale = fmt.Sprintf("%12d", i)
		seriale = "S" + replaceAtIndex(seriale, []rune(args.Letter)[0], 3)
		_, err := writer.WriteString(zykgen.Wpa(seriale, args.Length, cocktail) + "\n")
		if err != nil {
			fmt.Println(err)
			f.Close()
			return
		}

	}

	fmt.Println("Dictionary of keys was created on the root directory!, now use Hashcat.")

	err = f.Close()
	if err != nil {
		fmt.Println(err)
		return
	}

}