A callback to receive information with Android Nearby

receiver.kt

private inner class DataReceivedCallback : PayloadCallback() {
    private val incomingFilePayloads = SimpleArrayMap<Long, Payload>()
    private val completedFilePayloads = SimpleArrayMap<Long, Payload>()
    private var filePayloadFilename: String = ""

    override fun onPayloadReceived(endPointId: String, payload: Payload) {
        when (payload.type) {
            Payload.Type.BYTES -> {
                val gson = Gson()
                val recipe =
                    gson.fromJson(String(payload.asBytes()!!), RecipeWithIng::class.java)
                filePayloadFilename = recipe.domainRecipe.image
                viewModel.setRecipeReceivedWithNearby(recipe)
                Log.d(GENERAL, recipe.toString())
            }
            Payload.Type.FILE -> {
                incomingFilePayloads.put(payload.id, payload)
            }
        }
    }

    override fun onPayloadTransferUpdate(endPointId: String, update: PayloadTransferUpdate) {
        if (update.status == PayloadTransferUpdate.Status.SUCCESS) {
            val payload = incomingFilePayloads.remove(update.payloadId)
            completedFilePayloads.put(update.payloadId, payload)
            if (payload?.type == Payload.Type.FILE) {
                val filePayload = completedFilePayloads[update.payloadId]
                if (filePayload != null && filePayloadFilename != "") {
                    completedFilePayloads.remove(update.payloadId)
                    // Get the received file (which will be in the Downloads folder)
                    // Because of https://developer.android.com/preview/privacy/scoped-storage, we are not
                    // allowed to access filepaths from another process directly. Instead, we must open the
                    // uri using our ContentResolver.
                    val uri = filePayload.asFile()!!.asUri()
                    try {
                        // Copy the file to a new location.
                        val input: InputStream? = context.contentResolver.openInputStream(uri!!)
                        if (input != null) {
                            val storageDir: File? =
                                context.getExternalFilesDir(Environment.DIRECTORY_PICTURES)
                            val file = File(storageDir, filePayloadFilename.split("/").last())
                            copyStream(input, FileOutputStream(file))
                            viewModel.updateWithRecipeReceivedWithNearby()
                        }
                    } catch (e: IOException) {
                        Log.d(GENERAL, "error al guardar el fichero", e)
                    } finally {
                        // Delete the original file.
                        context.contentResolver.delete(uri!!, null, null)
                    }
                }
            }
        }
    }
}