de_encrupt.go

package main

import (
	"slices"
	"strings"
)

var alphabets = []string{
	"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w",
	"x", "y", "z",
}

var specials = []string{
	"`", "~", "!", "@", "#", "$", "%", "^", "&", "*", "(", ")", "-", "_", "=", "+",
	"[", "]", "{", "}", "\\", "|", ";", ":", "'", "\"", ",", "<", ".", ">", "/", "?",
	"0", "1", "2", "3", "4", "5", "6", "7", "8", "9",
}

func shiftAlphabets(char string, shiftAmount int) string {
	lowerChar := strings.ToLower(char)
	isLowerCase := lowerChar == char
	index := slices.Index(alphabets, lowerChar)
	alphabetLength := len(alphabets)
	shiftedIndex := index + shiftAmount
	newIndex := (shiftedIndex) % alphabetLength
	if newIndex < 0 {
		newIndex += alphabetLength
	}
	newAlphaChar := alphabets[newIndex]

	if isLowerCase {
		return newAlphaChar
	}
	return strings.ToUpper(newAlphaChar)
}

func reverseString(s string) string {
	// Convert string to rune slice to handle Unicode correctly
	runes := []rune(s)

	// Reverse the rune slice
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	// Convert back to string
	return string(runes)
}

func shiftSpecials(char string, shiftAmount int) string {
	index := slices.Index(specials, char)
	specialLength := len(specials)
	shiftedIndex := index + shiftAmount
	newIndex := (shiftedIndex) % specialLength
	if newIndex < 0 {
		newIndex += specialLength
	}
	newSpChar := specials[newIndex]
	return newSpChar
}

func encrypt(text string, sA int) string {
	e := ""
	for _, j := range text {
		char := string(j)
		if slices.Contains(alphabets, char) {
			e += shiftAlphabets(char, sA)
		} else {
			e += shiftSpecials(char, sA)
		}
	}
	return reverseString(e)
}

func decrypt(text string, sA int) string {
	d := ""
	for _, j := range text {
		char := string(j)
		if slices.Contains(alphabets, char) {
			d += shiftAlphabets(char, -sA)
		} else {
			d += shiftSpecials(char, -sA)
		}
	}
	return reverseString(d)
}

func main() {
	password := "applie##"
	sA := 2
	enc := encrypt(password, sA)
	println(enc)

	println(decrypt(enc, sA))
}