// @ts-nocheck
/* eslint-disable */
var BN = require('bn.js')

// from: https://github.com/indutny/minimalistic-crypto-utils
// and
// https://github.com/indutny/elliptic/blob/master/lib/elliptic/utils.js
// copyright: Fedor Indutny
// https://github.com/indutny
// and
// https://github.com/indutny/elliptic/blob/master/lib/elliptic/ec/signature.js

function Position() {
  this.place = 0
}

function getLength(buf, p) {
  var initial = buf[p.place++]
  if (!(initial & 0x80)) {
    return initial
  }
  var octetLen = initial & 0xf

  // Indefinite length or overflow
  if (octetLen === 0 || octetLen > 4) {
    return false
  }

  var val = 0
  for (var i = 0, off = p.place; i < octetLen; i++, off++) {
    val <<= 8
    val |= buf[off]
    val >>>= 0
  }

  // Leading zeroes
  if (val <= 0x7f) {
    return false
  }

  p.place = off
  return val
}

function rmPadding(buf) {
  var i = 0
  var len = buf.length - 1
  while (!buf[i] && !(buf[i + 1] & 0x80) && i < len) {
    i++
  }
  if (i === 0) {
    return buf
  }
  return buf.slice(i)
}

function toArray(msg, enc) {
  if (Array.isArray(msg)) return msg.slice()
  if (!msg) return []
  var res = []
  if (typeof msg !== 'string') {
    for (var i = 0; i < msg.length; i++) res[i] = msg[i] | 0
    return res
  }
  if (enc === 'hex') {
    msg = msg.replace(/[^a-z0-9]+/gi, '')
    if (msg.length % 2 !== 0) msg = '0' + msg
    for (var i = 0; i < msg.length; i += 2)
      res.push(parseInt(msg[i] + msg[i + 1], 16))
  } else {
    for (var i = 0; i < msg.length; i++) {
      var c = msg.charCodeAt(i)
      var hi = c >> 8
      var lo = c & 0xff
      if (hi) res.push(hi, lo)
      else res.push(lo)
    }
  }
  return res
}

function zero2(word) {
  if (word.length === 1) return '0' + word
  else return word
}

function toHex(msg) {
  var res = ''
  for (var i = 0; i < msg.length; i++) res += zero2(msg[i].toString(16))
  return res
}

function encode(arr, enc) {
  if (enc === 'hex') return toHex(arr)
  else return arr
}

function __js_importDER(data, enc) {
  data = toArray(data, enc)
  var p = new Position()
  if (data[p.place++] !== 0x30) {
    return null
  }
  var len = getLength(data, p)
  if (len === false) {
    return null
  }
  if (len + p.place !== data.length) {
    return null
  }
  if (data[p.place++] !== 0x02) {
    return null
  }
  var rlen = getLength(data, p)
  if (rlen === false) {
    return null
  }
  var r = data.slice(p.place, rlen + p.place)
  p.place += rlen
  if (data[p.place++] !== 0x02) {
    return null
  }
  var slen = getLength(data, p)
  if (slen === false) {
    return null
  }
  if (data.length !== slen + p.place) {
    return null
  }
  var s = data.slice(p.place, slen + p.place)
  if (r[0] === 0) {
    if (r[1] & 0x80) {
      r = r.slice(1)
    } else {
      // Leading zeroes
      return null
    }
  }
  if (s[0] === 0) {
    if (s[1] & 0x80) {
      s = s.slice(1)
    } else {
      // Leading zeroes
      return null
    }
  }

  return {
    r: new BN(r),
    s: new BN(s),
  }
}

function constructLength(arr, len) {
  if (len < 0x80) {
    arr.push(len)
    return
  }
  var octets = 1 + ((Math.log(len) / Math.LN2) >>> 3)
  arr.push(octets | 0x80)
  while (--octets) {
    arr.push((len >>> (octets << 3)) & 0xff)
  }
  arr.push(len)
}

function __js_toDER(r, s, enc) {
  var r = r.toArray()
  var s = s.toArray()

  // Pad values
  if (r[0] & 0x80) r = [0].concat(r)
  // Pad values
  if (s[0] & 0x80) s = [0].concat(s)

  r = rmPadding(r)
  s = rmPadding(s)

  while (!s[0] && !(s[1] & 0x80)) {
    s = s.slice(1)
  }
  var arr = [0x02]
  constructLength(arr, r.length)
  arr = arr.concat(r)
  arr.push(0x02)
  constructLength(arr, s.length)
  var backHalf = arr.concat(s)
  var res = [0x30]
  constructLength(res, backHalf.length)
  res = res.concat(backHalf)
  return encode(res, enc)
}

export default {
  __js_importDER,
  __js_toDER,
}
/* eslint-enable */