audiobookshelf/client/players/castUtils.js

function getMediaInfoFromTrack(libraryItem, castImage, track) {
  let metadata = null
  if (libraryItem.mediaType === 'podcast') {
    metadata = new chrome.cast.media.MusicTrackMediaMetadata()
    metadata.albumArtist = libraryItem.media.metadata.author
    metadata.artist = libraryItem.media.metadata.author
    metadata.title = track.title
    metadata.albumName = libraryItem.media.metadata.title
    metadata.images = [castImage]
  } else {
    // https://developers.google.com/cast/docs/reference/web_sender/chrome.cast.media.AudiobookChapterMediaMetadata
    metadata = new chrome.cast.media.AudiobookChapterMediaMetadata()
    metadata.bookTitle = libraryItem.media.metadata.title
    metadata.chapterNumber = track.index
    metadata.chapterTitle = track.title
    metadata.images = [castImage]
    metadata.title = track.title
    metadata.subtitle = libraryItem.media.metadata.title
  }

  var trackurl = track.fullContentUrl
  var mimeType = track.mimeType
  var mediainfo = new chrome.cast.media.MediaInfo(trackurl, mimeType)
  mediainfo.metadata = metadata
  mediainfo.itemId = track.index
  mediainfo.duration = track.duration
  return mediainfo
}

function buildCastMediaInfo(libraryItem, coverUrl, tracks) {
  const castImage = new chrome.cast.Image(coverUrl)
  return tracks.map((t) => getMediaInfoFromTrack(libraryItem, castImage, t))
}

function buildCastQueueRequest(libraryItem, coverUrl, tracks, startTime) {
  var mediaInfoItems = buildCastMediaInfo(libraryItem, coverUrl, tracks)

  let containerMetadata = null
  let queueType = chrome.cast.media.QueueType.AUDIOBOOK
  if (libraryItem.mediaType === 'podcast') {
    queueType = chrome.cast.media.QueueType.PODCAST_SERIES
    containerMetadata = new chrome.cast.media.ContainerMetadata(chrome.cast.media.ContainerType.GENERIC_CONTAINER)
    containerMetadata.title = libraryItem.media.metadata.title
  } else {
    containerMetadata = new chrome.cast.media.AudiobookContainerMetadata()
    containerMetadata.authors = libraryItem.media.metadata.authors?.map((a) => a.name)
    containerMetadata.narrators = libraryItem.media.metadata.narrators || []
    containerMetadata.publisher = libraryItem.media.metadata.publisher || undefined
    containerMetadata.title = libraryItem.media.metadata.title
  }

  var mediaQueueItems = mediaInfoItems.map((mi) => {
    var queueItem = new chrome.cast.media.QueueItem(mi)
    return queueItem
  })

  // Find track to start playback and calculate track start offset
  var track = tracks.find((at) => at.startOffset <= startTime && at.startOffset + at.duration > startTime)
  var trackStartIndex = track ? track.index - 1 : 0
  var trackStartTime = Math.floor(track ? startTime - track.startOffset : 0)

  var queueData = new chrome.cast.media.QueueData(libraryItem.id, libraryItem.media.metadata.title, '', false, mediaQueueItems, trackStartIndex, trackStartTime)
  queueData.containerMetadata = containerMetadata
  queueData.queueType = queueType
  return queueData
}

function castLoadMedia(castSession, request) {
  return new Promise((resolve) => {
    castSession.loadMedia(request).then(
      () => resolve(true),
      (reason) => {
        console.error('Load media failed', reason)
        resolve(false)
      }
    )
  })
}

function buildCastLoadRequest(libraryItem, coverUrl, tracks, startTime, autoplay, playbackRate) {
  var request = new chrome.cast.media.LoadRequest()

  request.queueData = buildCastQueueRequest(libraryItem, coverUrl, tracks, startTime)
  request.currentTime = request.queueData.startTime

  request.autoplay = autoplay
  request.playbackRate = playbackRate
  return request
}

export { buildCastLoadRequest, castLoadMedia }