Download anything with work manager

DownloadWorker.kt

class DownloadWorker(
    private val context: Context,
    params: WorkerParameters
) : CoroutineWorker(context, params) {

    private val urlString: String? = inputData.getString("urlFile")
    private val fileName: String? = inputData.getString("fileName")

    override suspend fun doWork(): Result {
        urlString ?: return Result.failure()


        val notificationBuilder = NotificationCompat.Builder(context, CHANNEL_ID)
            .setContentTitle("Downloading")
            .setContentText("0%")
            .setSmallIcon(R.mipmap.ic_launcher)

        val notificationManager = NotificationManagerCompat.from(context)

        setForeground(
            ForegroundInfo(
                12, notificationBuilder
                    .setProgress(100, 0, false)
                    .build()
            )
        )

        val result = download(urlString) {
            val progress = workDataOf(Progress to it)
            setProgress(progress)
            notificationManager.notify(12,
                notificationBuilder
                    .setProgress(100, it.toInt(), false)
                    .setContentText("${it.toInt()}%")
                    .build())
        }

        return if (result.isSuccess) {
            val file = File(context.filesDir, fileName ?: "file-${Date().time}.jpg")
            withContext(Dispatchers.IO) {
                file.writeBytes(result.getOrThrow())
            }
            val output = workDataOf(Output to file.absolutePath)
            Result.success(output)
        } else Result.retry()
    }


    companion object {
        const val Progress = "progress"
        const val Output = "output"
    }

    private suspend fun download(
        url: String,
        progress: suspend (Double) -> Unit = {}
    ): kotlin.Result<ByteArray> {
        return kotlin.runCatching {
            val ktor = HttpClient(Android)
            val response = ktor.get<HttpStatement> {
                url(url)
                onDownload { bytesSentTotal, contentLength ->
                    val l = bytesSentTotal.toDouble() / contentLength.toDouble()
                    progress(l * 100)
                }
            }.execute()
            response.readBytes()
        }
    }

}