/*
 * Copyright (c) 2018, SnakeYAML
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package org.snakeyaml.engine.v2.events;

import java.util.Optional;
import org.snakeyaml.engine.v2.common.Anchor;
import org.snakeyaml.engine.v2.exceptions.Mark;

/**
 * Marks the inclusion of a previously anchored node.
 */
public final class AliasEvent extends NodeEvent {

  private final Anchor alias;

  public AliasEvent(Optional<Anchor> anchor, Optional<Mark> startMark, Optional<Mark> endMark) {
    super(anchor, startMark, endMark);
    alias = anchor.orElseThrow(() -> new NullPointerException("Anchor is required in AliasEvent"));
  }

  public AliasEvent(Optional<Anchor> anchor) {
    this(anchor, Optional.empty(), Optional.empty());
  }

  @Override
  public ID getEventId() {
    return ID.Alias;
  }

  @Override
  public String toString() {
    return "=ALI *" + alias;
  }

  public Anchor getAlias() {
    return alias;
  }
}
