/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * license agreements; and to You under the Apache License, version 2.0:
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * This file is part of the Apache Pekko project, which was derived from Akka.
 */

/*
 * Copyright (C) 2009-2022 Lightbend Inc. <https://www.lightbend.com>
 */

package org.apache.pekko.stream.impl

import org.apache.pekko
import pekko.annotation.InternalApi
import pekko.stream.{ Attributes, Outlet, SourceShape }
import pekko.stream.impl.Stages.DefaultAttributes
import pekko.stream.impl.fusing.GraphStages.ValuePresentedSource
import pekko.stream.stage.{ GraphStage, GraphStageLogic, OutHandler }

/**
 * INTERNAL API
 */
@InternalApi private[pekko] final class FailedSource[T](val failure: Throwable)
    extends GraphStage[SourceShape[T]]
    with ValuePresentedSource {
  val out = Outlet[T]("FailedSource.out")
  override val shape = SourceShape(out)

  override protected def initialAttributes: Attributes = DefaultAttributes.failedSource

  override def createLogic(inheritedAttributes: Attributes): GraphStageLogic =
    new GraphStageLogic(shape) with OutHandler {

      override def onPull(): Unit = ()

      override def preStart(): Unit = {
        failStage(failure)
      }
      setHandler(out, this)
    }

  override def toString = s"FailedSource(${failure.getClass.getName})"
}
