nova-ui/services/core/utils.ts

import crypto from 'crypto'

import { BigNumber, utils } from 'ethers'
// @ts-expect-error
import { poseidon } from 'circomlib'

import { numbers, FIELD_SIZE } from '@/constants'

import { BaseUtxo } from './@types'

const BYTES_31 = 31
const BYTES_32 = 32
const ADDRESS_BYTES_LENGTH = 20

// eslint-disable-next-line
function poseidonHash(items: any[]) {
  return BigNumber.from(poseidon(items).toString())
}

function poseidonHash2(a: string, b: string) {
  return poseidonHash([a, b])
}

function randomBN(nbytes = BYTES_31) {
  return BigNumber.from(crypto.randomBytes(nbytes))
}

interface Params {
  recipient: string // address || 0
  relayer: string // address || 0
  encryptedOutput1: string
  extAmount: string
  fee: string
  l1Fee: string
  isL1Withdrawal: boolean
  encryptedOutput2: string
}

function getExtDataHash({
  recipient,
  extAmount,
  isL1Withdrawal,
  relayer,
  fee,
  l1Fee,
  encryptedOutput1,
  encryptedOutput2,
}: Params) {
  const abi = new utils.AbiCoder()

  const encodedData = abi.encode(
    [
      'tuple(address recipient,int256 extAmount,address relayer,uint256 fee,bytes encryptedOutput1,bytes encryptedOutput2,bool isL1Withdrawal,uint256 l1Fee)',
    ],
    [
      {
        recipient: toFixedHex(recipient, ADDRESS_BYTES_LENGTH),
        extAmount: toFixedHex(extAmount),
        relayer: toFixedHex(relayer, ADDRESS_BYTES_LENGTH),
        fee: toFixedHex(fee),
        encryptedOutput1: encryptedOutput1,
        encryptedOutput2: encryptedOutput2,
        isL1Withdrawal: isL1Withdrawal,
        l1Fee: toFixedHex(l1Fee),
      },
    ],
  )
  const hash = utils.keccak256(encodedData)
  return BigNumber.from(hash).mod(FIELD_SIZE)
}

function toFixedHex(number?: number | Buffer | BigNumber | string, length = BYTES_32) {
  let result =
    '0x' +
    (number instanceof Buffer ? number.toString('hex') : BigNumber.from(number).toHexString().replace('0x', '')).padStart(
      length * numbers.TWO,
      '0',
    )
  if (result.includes('-')) {
    result = '-' + result.replace('-', '')
  }
  return result
}

function toBuffer(value: string | number | BigNumber, length: number) {
  const number = BigNumber.from(value)
    .toHexString()
    .slice(numbers.TWO)
    .padStart(length * numbers.TWO, '0')

  return Buffer.from(number, 'hex')
}

function shuffle(array: BaseUtxo[]) {
  let currentIndex = array.length
  let randomIndex

  // While there remain elements to shuffle...
  while (currentIndex !== numbers.ZERO) {
    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex)
    currentIndex--

    // And swap it with the current element.
    ;[array[currentIndex], array[randomIndex]] = [array[randomIndex], array[currentIndex]]
  }

  return array
}

export { randomBN, toFixedHex, toBuffer, poseidonHash, poseidonHash2, getExtDataHash, shuffle }