Generator.kt

fun extractMetadataOrNull(audioFile: AudioFile): JsonObject? {
    val js = JsonObject()

    with(audioFile.tag ?: return null) {
        js["title"] = getFirst(FieldKey.TITLE) ?: return null
        js["artist"] = getFirst(FieldKey.ARTIST) ?: getFirst(FieldKey.ALBUM_ARTIST) ?: return null
        js["album"] = getFirst(FieldKey.ALBUM) ?: return null
        js["genre"] = if (getFirst(FieldKey.GENRE).isNullOrBlank()) "unknown" else getFirst(FieldKey.GENRE)
        js["source"] = audioFile.file.absolutePath
        js["image"] = ""
        js["trackNumber"] = getFirst(FieldKey.TRACK).toIntOrNull() ?: 0
        js["totalTrackCount"] = getFirst(FieldKey.TRACK_TOTAL).toIntOrNull() ?: 0
        js["duration"] = audioFile.audioHeader.trackLength
        js["site"] = getFirst(FieldKey.URL_WIKIPEDIA_RELEASE_SITE)
            ?: getFirst(FieldKey.URL_WIKIPEDIA_ARTIST_SITE)
            ?: getFirst(FieldKey.URL_DISCOGS_ARTIST_SITE)
            ?: getFirst(FieldKey.URL_OFFICIAL_ARTIST_SITE)
            ?: ""

        return js
    }
}