/*
    * Copyright 2013 The Netty Project
    *
    * The Netty Project 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:
    *
    *   https://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 io.netty5.channel.group;
  
  import io.netty5.channel.Channel;
  import io.netty5.channel.ChannelException;
  import io.netty5.util.concurrent.Future;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.Map;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * {@link ChannelException} which holds {@link Future}s that failed because of an error.
   */
  public class ChannelGroupException extends ChannelException implements Iterable<Map.Entry<Channel, Throwable>> {
      private static final long serialVersionUID = -4093064295562629453L;
      private final Collection<Map.Entry<Channel, Throwable>> failed;
  
      public ChannelGroupException(Collection<Map.Entry<Channel, Throwable>> causes) {
          requireNonNull(causes, "causes");
          if (causes.isEmpty()) {
              throw new IllegalArgumentException("causes must be non empty");
          }
          failed = Collections.unmodifiableCollection(causes);
      }
  
      /**
       * Returns a {@link Iterator} which contains all the {@link Throwable} that was a cause of the failure and the
       * related id of the {@link Channel}.
       */
      @Override
      public Iterator<Map.Entry<Channel, Throwable>> iterator() {
          return failed.iterator();
      }
  }