YoutubeDlHelper.kt

object YoutubeDlHelper {

    enum class Selection(val value: Int) {
        PREVIEW(0),
        UNLOCKED(1)
    }

    private const val TAG = "youtube-dl"

    fun download(url: String, selection: Selection, file: File, showDebugLogs: Boolean = true): Boolean {
        Log.d(TAG, "Start downloading $url to ${file.path}")
        val hasAudioTrack = checkAudioTrack(url, showDebugLogs)
        val auth = Config.auth
        val selectionValue = if (hasAudioTrack) "${selection.value}+bestaudio" else selection.value.toString()
        val path = file.absolutePath.replace("%", "%%")
        val command = "youtube-dl -f $selectionValue --add-header Authorization:\"$auth\" -o \"$path\" \"${url}\""
        try {
            val process = Runtime.getRuntime().exec(command)
            if (showDebugLogs) {
                BufferedReader(InputStreamReader(process.inputStream)).useLines { lines ->
                    lines.forEach { Log.d(TAG, it) }
                }
            }
            BufferedReader(InputStreamReader(process.errorStream)).useLines { lines ->
                lines.forEach { Log.e(TAG, it) }
            }
        } catch (e: IOException) {
            Log.d(TAG, "Download ${file.name} failed: ${e.javaClass.simpleName}, ${e.message}")
        }
        val isSuccessful = file.exists()
        if (isSuccessful) {
            Log.d(TAG, "Downloaded as ${file.name}.")
        }
        return isSuccessful
    }

    private fun checkAudioTrack(url: String, showDebugLogs: Boolean = false): Boolean {
        var hasAudioTrack = false
        val command = "youtube-dl -F \"$url\""
        try {
            val process = Runtime.getRuntime().exec(command)
            BufferedReader(InputStreamReader(process.inputStream)).useLines { lines ->
                lines.forEach {
                    if (showDebugLogs) Log.d(TAG, it)
                    if (it.contains("DASH audio")) hasAudioTrack = true
                }
            }
            BufferedReader(InputStreamReader(process.errorStream)).useLines { lines ->
                lines.forEach { Log.e(TAG, it) }
            }
        } catch (e: IOException) {
            e.printStackTrace()
        }
        return hasAudioTrack
    }
}