NextIntentAndPreviousIntentHandler.kt

class NextIntentHandler : RequestHandler {

    override fun canHandle(input: HandlerInput) = input.matches(intentName("AMAZON.NextIntent"))

    override fun handle(input: HandlerInput) =
        input.attributesManager.persistentAttributes["lastPlayedAudio"]?.let {
            PlayAudioResponseBuilder.buildNewsResponse(
                input,
                Audio(it.toAudio().getNextDate())
            )
        } ?: input.responseBuilder.build()
}

class PreviousIntentHandler : RequestHandler {

    override fun canHandle(input: HandlerInput) = input.matches(intentName("AMAZON.PreviousIntent"))

    override fun handle(input: HandlerInput) =
        input.attributesManager.persistentAttributes["lastPlayedAudio"]?.let {
            PlayAudioResponseBuilder.buildNewsResponse(
                input,
                Audio(it.toAudio().getPreviousDate())
            )
        } ?: input.responseBuilder.build()
}