cursors converter

String.prototype.lstrip = function (char) {
  return this.replace(new RegExp('^'+char+'+'), '')
}

function reverseBin (n) {
  return BigInt('0b' + n.toString(2).padStart(64, '0').split('').map(e => e === '0' ? '1' : '0').join(''))
}

class B32 {

  static encode (num, numerals="0123456789ABCDEFGHIJKLMNOPQRSTUV") {
    num = BigInt(num)
    return ((num == 0n) && numerals[0]) || (B32.encode(num / 32n, numerals).lstrip(numerals[0]) + numerals[num % 32n])
  }

  static decode (b32Str, numerals="0123456789ABCDEFGHIJKLMNOPQRSTUV") {
    return b32Str.split('').reduce((ac, cv, i, a) => ac + BigInt(numerals.indexOf(cv)) * (32n ** BigInt(a.length - (i + 1))), 0n).toString()
  }

}

function v1ToV2 (v1, reverse) {

  let res = 0n
  let intV1 = BigInt(v1)

  if (reverse)
    intV1 = reverseBin(intV1) + 1n

  for (let i = 0; i < 8; i++) {
    res <<= 8n
    res |= intV1 & 0xffn
    intV1 >>= 8n
  }

  res <<= 1n

  return B32.encode(res).padStart(13, '0').padEnd(16, 'Z')

}

function v2ToV1 (v2) {

  v2 = v2.replace(/Z+$/, '')
  let decodedV2 = BigInt(B32.decode(v2))
  let intV2 = decodedV2 >> 1n
  let res = 0n

  for (let i = 0; i < 8; i++) {
    res <<= 8n
    res |= intV2 & 0xffn
    intV2 >>= 8n
  }

  if (res & (2n ** 63n))
    res = reverseBin(res) + 1n

  return res.toString()

}

/**
 * 11110011 01010000 11000110 001
 * 00001100 10101111 00111001 110
 * 11100101 01111001 011001110
 * 11111111 11111111 11111111 11111111 11111111111001010111100111001111
 * 11110011 10011110 10100111 11111111 11111111111111111111111111111111
 * 11001111 01111001 01100101 11111000 111111111111111111111111111111110
 * 11001111 01111001 11100101 11111111 111111111111111111111111111111110
 */

//SOADUTK00PFHEZZZ 1111111111111111111111111111111111111000011001010111100111001111
//console.log(v1ToV2(127567409))
//console.log(v1ToV2('1684071934479766758'))

//console.log(v2ToV1('PTSMBU7VVVVVUZZZ'))
//console.log(v2ToV1('6639K1O000000ZZZ'))
//console.log(v1ToV2('127567409', true))

let exV1 = '1686614667972415444'
let exV2 = 'QI7NBF8Q1TK1EZZZ'
let exV2rev = '5HO8KGN5U2BUGZZZ'

console.assert(v1ToV2(exV1) === exV2, `v1ToV2('${exV1}') should return '${exV2}'`)
console.assert(v1ToV2(exV1, true) === exV2rev, `v1ToV2('${exV1}', true) should return '${exV2rev}'`)
console.assert(v2ToV1(exV2) === exV1, `v2ToV1('${exV2}') should return '${exV1}'`)
console.assert(v2ToV1(exV2rev) === exV1, `v2ToV1('${exV2rev}') should return '${exV1}'`)