PinpointInit.kt

fun init() {
    val awsConfig: AWSConfiguration = AWSConfiguration(this)

    AWSMobileClient.getInstance().initializes(this, awsConfig) {
      onResult {
        Log.d("MainActivity", "${it.userState}")
      }
      onError { e ->
        e.printStackTrace()
      }
    }
    val pinpoint = PinpointManager(PinpointConfiguration(
            this,
            AWSMobileClient.getInstance(),
            awsConfig))


    FirebaseInstanceId.getInstance().instanceId.addOnCompleteListener { task ->
      if (task.isSuccessful()) {
        val token = task?.result?.token
        Log.d("MainActivity", "Registering push notifications token: ${token}")
        token?.let { pinpoint.getNotificationClient().registerDeviceToken(token) }
      } else {
        Log.w("MainActivity", "getInstanceId failed", task.getException())
      }
}

fun AWSMobileClient.initializes(context: Context, config: AWSConfiguration, init: Callbacks<UserStateDetails>.() -> Unit) : AWSCredentialsProvider {
  val callbacks = Callbacks<UserStateDetails>()
  callbacks.init()
  this.initialize(context, config, callbacks)
  return this
}

class Callbacks<T> : com.amazonaws.mobile.client.Callback<T> {
  var onResultFunc: (T) -> Unit = {}
  var onErrorFunc: (Throwable) -> Unit = {}

  override fun onResult(result: T) {
      onResultFunc(result)
  }

  fun onResult(onResult: (T) -> Unit) {
      this.onResultFunc = onResult
  }

  override fun onError(e: Exception?) {
      onErrorFunc(e ?: Exception())
  }

  fun onError(onError: (Throwable) -> Unit) {
      this.onErrorFunc = onError
  }
}