/*
    * Copyright 2019 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.testsuite.transport;
  
  import io.netty.channel.Channel;
  import io.netty.channel.DefaultEventLoopGroup;
  import io.netty.channel.EventLoop;
  import io.netty.channel.EventLoopGroup;
  import io.netty.channel.MultithreadEventLoopGroup;
  import io.netty.channel.ServerChannel;
  import io.netty.channel.SingleThreadEventLoop;
  import io.netty.channel.local.LocalChannel;
  import io.netty.channel.local.LocalServerChannel;
  import io.netty.util.concurrent.EventExecutorChooserFactory;
  import io.netty.util.concurrent.RejectedExecutionHandlers;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.Timeout;
  import org.junit.jupiter.api.function.Executable;
  
  import java.util.concurrent.Executor;
  import java.util.concurrent.TimeUnit;
  
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  public class DefaultEventLoopTest extends AbstractSingleThreadEventLoopTest {
  
      @Test
      @Timeout(value = 3000, unit = TimeUnit.MILLISECONDS)
      public void testChannelsIteratorNotSupported() throws Exception {
          EventLoopGroup group = newEventLoopGroup();
          final SingleThreadEventLoop loop = (SingleThreadEventLoop) group.next();
          try {
              final Channel ch = newChannel();
              loop.register(ch).syncUninterruptibly();
  
              assertThrows(UnsupportedOperationException.class, new Executable() {
                  @Override
                  public void execute() throws Throwable {
                      loop.registeredChannelsIterator();
                  }
              });
          } finally {
              group.shutdownGracefully();
          }
      }
  
      @Override
      protected EventLoopGroup newEventLoopGroup() {
          return new DefaultEventLoopGroup();
      }
  
      @Override
      protected EventLoopGroup newAutoScalingEventLoopGroup() {
          return new AutoScalingDefaultEventLoopGroup(SCALING_MAX_THREADS, AUTO_SCALING_CHOOSER_FACTORY);
      }
  
      @Override
      protected Channel newChannel() {
          return new LocalChannel();
      }
  
      @Override
      protected Class<? extends ServerChannel> serverChannelClass() {
          return LocalServerChannel.class;
      }
  
      private static final class SuspendableDefaultEventLoop extends SingleThreadEventLoop {
          SuspendableDefaultEventLoop(EventLoopGroup parent, Executor executor) {
              super(parent, executor, true, true, DEFAULT_MAX_PENDING_TASKS,
                    RejectedExecutionHandlers.reject());
          }
  
          @Override
          protected void run() {
              for (;;) {
                  Runnable task = takeTask();
                  if (task != null) {
                      runTask(task);
                      updateLastExecutionTime();
                  }
  
                  // Check if a suspend is requested and we have no more tasks. If so,
                  // exit the run() method to allow the suspension to complete.
                  if (canSuspend()) {
                      break;
                  }
 
                 if (confirmShutdown()) {
                     break;
                 }
             }
         }
     }
 
     private static final class AutoScalingDefaultEventLoopGroup extends MultithreadEventLoopGroup {
         AutoScalingDefaultEventLoopGroup(int nThreads, EventExecutorChooserFactory chooserFactory) {
             super(nThreads, (Executor) null, chooserFactory);
         }
 
         @Override
         protected EventLoop newChild(Executor executor, Object... args) throws Exception {
             return new SuspendableDefaultEventLoop(this, executor);
         }
     }
 }