/*
    * Copyright 2012 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.netty.channel.group;
  
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelFuture;
  import io.netty.channel.ChannelFutureListener;
  import io.netty.util.concurrent.BlockingOperationException;
  import io.netty.util.concurrent.DefaultPromise;
  import io.netty.util.concurrent.EventExecutor;
  import io.netty.util.concurrent.Future;
  import io.netty.util.concurrent.GenericFutureListener;
  import io.netty.util.concurrent.ImmediateEventExecutor;
  import io.netty.util.internal.ObjectUtil;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  
  
  /**
   * The default {@link ChannelGroupFuture} implementation.
   */
  final class DefaultChannelGroupFuture extends DefaultPromise<Void> implements ChannelGroupFuture {
  
      private final ChannelGroup group;
      private final Map<Channel, ChannelFuture> futures;
      private int successCount;
      private int failureCount;
  
      private final ChannelFutureListener childListener = new ChannelFutureListener() {
          @Override
          public void operationComplete(ChannelFuture future) throws Exception {
              boolean success = future.isSuccess();
              boolean callSetDone;
              synchronized (DefaultChannelGroupFuture.this) {
                  if (success) {
                      successCount ++;
                  } else {
                      failureCount ++;
                  }
  
                  callSetDone = successCount + failureCount == futures.size();
                  assert successCount + failureCount <= futures.size();
              }
  
              if (callSetDone) {
                  if (failureCount > 0) {
                      List<Map.Entry<Channel, Throwable>> failed =
                              new ArrayList<Map.Entry<Channel, Throwable>>(failureCount);
                      for (ChannelFuture f: futures.values()) {
                          if (!f.isSuccess()) {
                              failed.add(new DefaultEntry<Channel, Throwable>(f.channel(), f.cause()));
                          }
                      }
                      setFailure0(new ChannelGroupException(failed));
                  } else {
                      setSuccess0();
                  }
              }
          }
      };
  
      /**
       * Creates a new instance.
       */
      DefaultChannelGroupFuture(ChannelGroup group, Collection<ChannelFuture> futures,  EventExecutor executor) {
          super(executor);
          this.group = ObjectUtil.checkNotNull(group, "group");
          ObjectUtil.checkNotNull(futures, "futures");
  
          Map<Channel, ChannelFuture> futureMap = new LinkedHashMap<Channel, ChannelFuture>();
          for (ChannelFuture f: futures) {
              futureMap.put(f.channel(), f);
          }
  
          this.futures = Collections.unmodifiableMap(futureMap);
  
          for (ChannelFuture f: this.futures.values()) {
              f.addListener(childListener);
          }
  
         // Done on arrival?
         if (this.futures.isEmpty()) {
             setSuccess0();
         }
     }
 
     DefaultChannelGroupFuture(ChannelGroup group, Map<Channel, ChannelFuture> futures, EventExecutor executor) {
         super(executor);
         this.group = group;
         this.futures = Collections.unmodifiableMap(futures);
         for (ChannelFuture f: this.futures.values()) {
             f.addListener(childListener);
         }
 
         // Done on arrival?
         if (this.futures.isEmpty()) {
             setSuccess0();
         }
     }
 
     @Override
     public ChannelGroup group() {
         return group;
     }
 
     @Override
     public ChannelFuture find(Channel channel) {
         return futures.get(channel);
     }
 
     @Override
     public Iterator<ChannelFuture> iterator() {
         return futures.values().iterator();
     }
 
     @Override
     public synchronized boolean isPartialSuccess() {
         return successCount != 0 && successCount != futures.size();
     }
 
     @Override
     public synchronized boolean isPartialFailure() {
         return failureCount != 0 && failureCount != futures.size();
     }
 
     @Override
     public DefaultChannelGroupFuture addListener(GenericFutureListener<? extends Future<? super Void>> listener) {
         super.addListener(listener);
         return this;
     }
 
     @Override
     public DefaultChannelGroupFuture addListeners(GenericFutureListener<? extends Future<? super Void>>... listeners) {
         super.addListeners(listeners);
         return this;
     }
 
     @Override
     public DefaultChannelGroupFuture removeListener(GenericFutureListener<? extends Future<? super Void>> listener) {
         super.removeListener(listener);
         return this;
     }
 
     @Override
     public DefaultChannelGroupFuture removeListeners(
             GenericFutureListener<? extends Future<? super Void>>... listeners) {
         super.removeListeners(listeners);
         return this;
     }
 
     @Override
     public DefaultChannelGroupFuture await() throws InterruptedException {
         super.await();
         return this;
     }
 
     @Override
     public DefaultChannelGroupFuture awaitUninterruptibly() {
         super.awaitUninterruptibly();
         return this;
     }
 
     @Override
     public DefaultChannelGroupFuture syncUninterruptibly() {
         super.syncUninterruptibly();
         return this;
     }
 
     @Override
     public DefaultChannelGroupFuture sync() throws InterruptedException {
         super.sync();
         return this;
     }
 
     @Override
     public ChannelGroupException cause() {
         return (ChannelGroupException) super.cause();
     }
 
     private void setSuccess0() {
         super.setSuccess(null);
     }
 
     private void setFailure0(ChannelGroupException cause) {
         super.setFailure(cause);
     }
 
     @Override
     public DefaultChannelGroupFuture setSuccess(Void result) {
         throw new IllegalStateException();
     }
 
     @Override
     public boolean trySuccess(Void result) {
         throw new IllegalStateException();
     }
 
     @Override
     public DefaultChannelGroupFuture setFailure(Throwable cause) {
         throw new IllegalStateException();
     }
 
     @Override
     public boolean tryFailure(Throwable cause) {
         throw new IllegalStateException();
     }
 
     @Override
     protected void checkDeadLock() {
         EventExecutor e = executor();
         if (e != null && e != ImmediateEventExecutor.INSTANCE && e.inEventLoop()) {
             throw new BlockingOperationException();
         }
     }
 
     private static final class DefaultEntry<K, V> implements Map.Entry<K, V> {
         private final K key;
         private final V value;
 
         DefaultEntry(K key, V value) {
             this.key = key;
             this.value = value;
         }
 
         @Override
         public K getKey() {
             return key;
         }
 
         @Override
         public V getValue() {
             return value;
         }
 
         @Override
         public V setValue(V value) {
             throw new UnsupportedOperationException("read-only");
         }
     }
 }