foronce/dist/base32.mjs

The OTP Library

/*!
 * base-32.js
 * Copyright(c) 2024 Reaper
 * MIT Licensed
 */
const pad = "=";
const base32alphaMap = [
  "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",
  "2",
  "3",
  "4",
  "5",
  "6",
  "7"
];
const encode = (str) => {
  const splits = str.split("");
  if (!splits.length) {
    return "";
  }
  let binaryGroup = [];
  let bitText = "";
  splits.forEach((c) => {
    bitText += toBinary(c);
    if (bitText.length == 40) {
      binaryGroup.push(bitText);
      bitText = "";
    }
  });
  if (bitText.length > 0) {
    binaryGroup.push(bitText);
    bitText = "";
  }
  return binaryGroup.map((x) => {
    let fiveBitGrouping = [];
    let lex = "";
    let bitOn = x;
    bitOn.split("").forEach((d) => {
      lex += d;
      if (lex.length == 5) {
        fiveBitGrouping.push(lex);
        lex = "";
      }
    });
    if (lex.length > 0) {
      fiveBitGrouping.push(lex.padEnd(5, "0"));
      lex = "";
    }
    let paddedArray = Array.from(fiveBitGrouping);
    paddedArray.length = 8;
    paddedArray = paddedArray.fill("-1", fiveBitGrouping.length, 8);
    return paddedArray.map((f) => {
      if (f == "-1") {
        return pad;
      }
      return base32alphaMap[parseInt(f, 2).toString(10)];
    }).join("");
  }).join("");
};
const decode = (str) => {
  const overallBinary = str.split("").map((x) => {
    if (x === pad) {
      return "00000";
    }
    const decodeIndex = base32alphaMap.indexOf(x);
    const binary = decodeIndex.toString(2);
    return binary.padStart(5, "0");
  }).join("");
  const characterBitGrouping = chunk(overallBinary.split(""), 8);
  return characterBitGrouping.map((x) => {
    const binaryL = x.join("");
    const str2 = String.fromCharCode(+parseInt(binaryL, 2).toString(10));
    return str2.replace("\0", "");
  }).join("");
};
const toBinary = (char, padLimit = 8) => {
  const binary = String(char).charCodeAt(0).toString(2);
  return binary.padStart(padLimit, "0");
};
const chunk = (arr, chunkSize = 1, cache = []) => {
  const tmp = [...arr];
  if (chunkSize <= 0)
    return cache;
  while (tmp.length)
    cache.push(tmp.splice(0, chunkSize));
  return cache;
};

export { decode, encode };