import BN from 'bn.js'

import { Logger } from '../common'

import { TEN } from './constant'

const logger = Logger.from('entity/bignumber')

export type BigNumberish = BN | string | number | bigint

const MAX_SAFE = 0x1fffffffffffff

export function parseBigNumberish(value: BigNumberish) {
  // BN
  if (value instanceof BN) {
    return value
  }

  // string
  if (typeof value === 'string') {
    if (value.match(/^-?[0-9]+$/)) {
      return new BN(value)
    }

    return logger.throwArgumentError('invalid BigNumberish string', 'value', value)
  }

  // number
  if (typeof value === 'number') {
    if (value % 1) {
      return logger.throwArgumentError('BigNumberish number underflow', 'value', value)
    }

    if (value >= MAX_SAFE || value <= -MAX_SAFE) {
      return logger.throwArgumentError('BigNumberish number overflow', 'value', value)
    }

    return new BN(String(value))
  }

  // bigint
  if (typeof value === 'bigint') {
    return new BN(value.toString())
  }

  return logger.throwArgumentError('invalid BigNumberish value', 'value', value)
}

export function tenExponentiate(shift: BigNumberish) {
  return TEN.pow(parseBigNumberish(shift))
}

// round up
export function divCeil(a: BN, b: BN): BN {
  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
  // @ts-ignore
  const dm = a.divmod(b)

  // Fast case - exact division
  if (dm.mod.isZero()) return dm.div

  // Round up
  return dm.div.isNeg() ? dm.div.isubn(1) : dm.div.iaddn(1)
}