export function generateSource(item, cover) {
  if (!item) return

  if (item.media_alt_prefix) {
    item.pictureFallback = item.media_alt_prefix + '_small.jpg'
    item.pictureJpeg = item.media_alt_prefix + '_small.jpg' + ' 720w, '
                    + item.media_alt_prefix + '_medium.jpg' + ' 1300w, '
                    + item.media_alt_prefix + '_large.jpg  1920w'
    item.pictureAvif = item.media_alt_prefix + '_small.avif' + ' 720w, '
                    + item.media_alt_prefix + '_medium.avif' + ' 1300w, '
                    + item.media_alt_prefix + '_large.avif 1920w'

    item.pictureCover = cover
  } else {
    item.pictureFallback = null
    item.pictureJpeg = null
    item.pictureAvif = null
    item.pictureCover = null
  }
}

export function getBannerImage(item, prefix) {
  if (!item || !item.banner_alt_prefix) return null

  let out = {
    path: prefix + item.path,
    name: item.name,
    original: item.banner_path,
    banner: item.banner_alt_prefix
  }

  var deviceWidth = window.innerWidth
  var pixelRatio = window.devicePixelRatio || 1
  if ((deviceWidth < 720 && pixelRatio <= 1)
      || (deviceWidth < 360 && pixelRatio <= 2)) {
    out.banner += '_small'
  } else if ((deviceWidth < 1300 && pixelRatio <= 1)
            || (deviceWidth < 650 && pixelRatio <= 2)) {
    out.banner += '_medium'
  } else {
    out.banner += '_large'
  }
  if (window.supportsavif) {
    out.banner += '.avif'
  } else {
    out.banner += '.jpg'
  }

  return out
}