abstract class CoroutineDialog<T>(context : Context, private val channel: Channel<DialogMessage<T>>) : AlertDialog(context) {

    init {
        setOnCancelListener {
            channel.offer(DialogMessage.Cancelled)
        }
    }

    fun positiveChannel(text : String,  block : (() -> T)? = null) {
        setButton(AlertDialog.BUTTON_POSITIVE, text){d, _ ->
            channel.offer(DialogMessage.Positive(block?.invoke() ?: Unit as T))
            d.dismiss()
        }
    }

    fun negativeChannel(text : String) {
        setButton(AlertDialog.BUTTON_NEGATIVE, text){d, _ ->
            channel.offer(DialogMessage.Negative)
            d.dismiss()
        }
    }

    suspend fun showAndReceive() : DialogMessage<T>{
        show()
        return channel.receive()
    }

    sealed class DialogMessage<out T> {
        class Positive<T>(val value : T) : DialogMessage<T>()
        object Negative : DialogMessage<Nothing>()
        object Cancelled : DialogMessage<Nothing>()
    }
}