'use strict'

const { MathFloor, NumberIsInteger } = require('../../ours/primordials')

const { ERR_INVALID_ARG_VALUE } = require('../../ours/errors').codes

function highWaterMarkFrom(options, isDuplex, duplexKey) {
  return options.highWaterMark != null ? options.highWaterMark : isDuplex ? options[duplexKey] : null
}

function getDefaultHighWaterMark(objectMode) {
  return objectMode ? 16 : 16 * 1024
}

function getHighWaterMark(state, options, duplexKey, isDuplex) {
  const hwm = highWaterMarkFrom(options, isDuplex, duplexKey)

  if (hwm != null) {
    if (!NumberIsInteger(hwm) || hwm < 0) {
      const name = isDuplex ? `options.${duplexKey}` : 'options.highWaterMark'
      throw new ERR_INVALID_ARG_VALUE(name, hwm)
    }

    return MathFloor(hwm)
  } // Default value

  return getDefaultHighWaterMark(state.objectMode)
}

module.exports = {
  getHighWaterMark,
  getDefaultHighWaterMark
}
