fs.jsy

import {bkc_hexkey_api, as_hex_key, as_u8_key} from '../_utils.jsy'

export {as_hex_key, as_u8_key}

export default bkc_with_fs
export async function bkc_with_fs(opt={}) ::
  let immutable = !! opt.immutable
  let _enc_r = @{} encoding: null, flag: 'r'
  let _enc_w = @{} encoding: null, flag: immutable ? 'wx' : 'w'
  let {stat, readFile, writeFile} = await opt.fs
  let base = opt.base || './var/'
  let ext = opt.ext || '.bin'

  return bkc_hexkey_api @:
    bkc_opt: @{} immutable

    hk_has: hex_key =>
      new Promise @\ resolve, reject ::
        stat @ `${base}${hex_key}${ext}`,
          (err) => ::
            if ! err ::
              resolve(1)
            else if 'ENOENT' === err.code ::
              resolve(0)
            else reject(err)

    hk_get: hex_key =>
      new Promise @\ resolve, reject ::
        readFile @ `${base}${hex_key}${ext}`, _enc_r,
          (err, buf) => ::
            if ! err ::
              resolve @ Uint8Array.from(buf)
            else if 'ENOENT' === err.code ::
              resolve()
            else reject(err)

    hk_set: @\ hex_key, u8_content =>
      new Promise @\ resolve, reject ::
        writeFile @ `${base}${hex_key}${ext}`,
          u8_content, _enc_w,
          err => !err ? resolve()
            : immutable && 'EEXIST' === err.code ? resolve(false)
            : resolve(err)