webpub static method

Future<MediaType?> webpub(SnifferContext context)

Sniffs a Readium Web Publication, protected or not by LCP.

Implementation

static Future<MediaType?> webpub(SnifferContext context) async {
  if (context.hasFileExtension(["audiobook"]) ||
      context.hasMediaType("application/audiobook+zip")) {
    return MediaType.readiumAudiobook;
  }
  if (context.hasMediaType("application/audiobook+json")) {
    return MediaType.readiumAudiobookManifest;
  }
  if (context.hasFileExtension(["divina"]) ||
      context.hasMediaType("application/divina+zip")) {
    return MediaType.divina;
  }
  if (context.hasMediaType("application/divina+json")) {
    return MediaType.divinaManifest;
  }
  if (context.hasFileExtension(["webpub"]) ||
      context.hasMediaType("application/webpub+zip")) {
    return MediaType.readiumWebpub;
  }
  if (context.hasMediaType("application/webpub+json")) {
    return MediaType.readiumWebpubManifest;
  }
  if (context.hasFileExtension(["lcpa"]) ||
      context.hasMediaType("application/audiobook+lcp")) {
    return MediaType.lcpProtectedAudiobook;
  }
  if (context.hasFileExtension(["lcpdf"]) ||
      context.hasMediaType("application/pdf+lcp")) {
    return MediaType.lcpProtectedPdf;
  }
  // Reads a RWPM, either from a manifest.json file, or from a manifest.json archive entry, if
  // the file is an archive.
  bool isManifest = true;
  Manifest? manifest;
  try {
    // manifest.json
    manifest = await context.contentAsRwpm() ??
        // Archive package
        (await context.readArchiveEntryAt("manifest.json"))
            ?.let((it) => Manifest.fromJson(
                utf8.decode(it.buffer.asUint8List()).toJsonOrNull()))
            ?.also((it) => isManifest = false);
  } on Exception {
    manifest = null;
  }

  if (manifest != null) {
    bool isLcpProtected =
        await context.containsArchiveEntryAt("license.lcpl");

    if (manifest.metadata.type == "http://schema.org/Audiobook" ||
        manifest.readingOrder.allAreAudio) {
      if (isManifest) {
        return MediaType.readiumAudiobookManifest;
      } else {
        return (isLcpProtected)
            ? MediaType.lcpProtectedAudiobook
            : MediaType.readiumAudiobook;
      }
    }
    if (manifest.readingOrder.allAreBitmap) {
      return (isManifest) ? MediaType.divinaManifest : MediaType.divina;
    }
    if (isLcpProtected &&
        manifest.readingOrder.allMatchMediaType(MediaType.pdf)) {
      return MediaType.lcpProtectedPdf;
    }
    if (manifest
            .linkWithRel("self")
            ?.mediaType
            .matchesFromName("application/webpub+json") ==
        true) {
      return (isManifest)
          ? MediaType.readiumWebpubManifest
          : MediaType.readiumWebpub;
    }
  }
  return null;
}