'use strict';

/**
 * Extract n bits from a position
 * @param numVal the number
 * @param bits number of bits to extract
 * @param from the bit postion right to left to extract. Zero index.
 */
function extractBits(numVal, bits, from) {
  let _from = Math.max(0, from);
  let _bits = Math.abs(bits);
  return (((1 << _bits) - 1) & (numVal >> _from));
};

/**
 * Check if k-th bit of a given number is set or not using right shift operator.
 * @param {*} n the number value to check
 * @param {*} at the bit position. Zero index.
 */
function isBitOn(n, bit) {
  let _at = Math.max(0, bit);
  return ((n >> _at) & 1);
};

function bytesToHex(bytes, delimeter = "") {
  return bytes && Array.isArray(bytes) ? Array.from(
    bytes,
    byte => byte.toString(16).padStart(2, "0").toUpperCase()
  ).join(delimeter) : '';
}

module.exports = { extractBits, isBitOn, bytesToHex }