/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you 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.apache.hadoop.yarn.util;

import java.util.Iterator;

import org.apache.hadoop.yarn.YarnException;
import org.apache.hadoop.yarn.api.records.ApplicationId;
import org.apache.hadoop.yarn.factory.providers.RecordFactoryProvider;

import static org.apache.hadoop.yarn.util.StringHelper.*;

/**
 * Yarn application related utilities
 */
public class Apps {
  public static final String APP = "app";
  public static final String ID = "ID";

  public static String toString(ApplicationId id) {
    return _join("app", id.getClusterTimestamp(), id.getId());
  }

  public static ApplicationId toAppID(String aid) {
    Iterator<String> it = _split(aid).iterator();
    return toAppID(APP, aid, it);
  }

  public static ApplicationId toAppID(String prefix, String s, Iterator<String> it) {
    if (!it.hasNext() || !it.next().equals(prefix)) {
      throwParseException(sjoin(prefix, ID), s);
    }
    shouldHaveNext(prefix, s, it);
    ApplicationId appId = RecordFactoryProvider.getRecordFactory(null).newRecordInstance(ApplicationId.class);
    appId.setClusterTimestamp(Long.parseLong(it.next()));
    shouldHaveNext(prefix, s, it);
    appId.setId(Integer.parseInt(it.next()));
    return appId;
  }

  public static void shouldHaveNext(String prefix, String s, Iterator<String> it) {
    if (!it.hasNext()) {
      throwParseException(sjoin(prefix, ID), s);
    }
  }

  public static void throwParseException(String name, String s) {
    throw new YarnException(join("Error parsing ", name, ": ", s));
  }
}