package main

import (
	"io"
	"os"
	"strings"
	"fmt"
)

// TODO: Finish this

type rot13Reader struct {
	r io.Reader
}

func (r rot13Reader) Read(b []byte) (int, error) {
	tmp := make([]byte, 8)
	n, err := r.Read(tmp)
	fmt.Println(tmp)
	if err != nil {
		return n, err
	}
	for i, e := range tmp {
		b[i] = rot13shift(e)
	}
	fmt.Println(b)
	return n, nil
}

func rot13shift(b byte) byte {
	if b >= 'N' && b <= 'Z' {
		return 'A' + ('N' - b)
	} else if b >= 'n' && b <= 'z' {
		return 'a' + ('n' - b)
	} else if b >= 'A' && b <= 'M' {
		return 'N' + ('A' - b)
	} else if b >= 'a' && b <= 'm' {
		return 'n' + ('a' - b)
	}
	return 0
}

func main() {
	s := strings.NewReader("Lbh penpxrq gur pbqr!")
	r := rot13Reader{s}
	io.Copy(os.Stdout, &r)
}