package com.reactnativeaesgcmcrypto

private val HEX_CHARS_STR = "0123456789abcdef"
private val HEX_CHARS = HEX_CHARS_STR.toCharArray()

fun ByteArray.toHex() : String{
  val result = StringBuffer()

  forEach {
    val st = String.format("%02x", it)
    result.append(st)
  }

  return result.toString()
}

fun String.hexStringToByteArray() : ByteArray {

  val result = ByteArray(length / 2)

  for (i in 0 until length step 2) {
    val firstIndex = HEX_CHARS_STR.indexOf(this[i]);
    val secondIndex = HEX_CHARS_STR.indexOf(this[i + 1]);

    val octet = firstIndex.shl(4).or(secondIndex)
    result.set(i.shr(1), octet.toByte())
  }

  return result
}