/**
 * @function scaledSize
 */

'use strict'

const numcal = require('numcal')

/** @lends scaledSize */
function scaledSize (contentSize, frameSize, policy) {
  let cw = contentSize.width
  let ch = contentSize.height
  let fw = frameSize.width
  let fh = frameSize.height

  let wRate = numcal.min(1, fw / cw)
  let hRate = numcal.min(1, fh / ch)

  let sizeWithRate = (rate) => ({
    width: contentSize.width * rate,
    height: contentSize.height * rate
  })

  switch (policy) {
    case 'none':
      return sizeWithRate(1)
    case 'fit':
      return sizeWithRate(
        numcal.min(wRate, hRate)
      )
    case 'fill':
      return sizeWithRate(
        numcal.max(wRate, hRate)
      )
    default:
      throw new Error(`Unknown policy: ${policy}`)
  }
}

export default scaledSize