/*
    * 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.testsuite.transport.socket;
  
  import io.netty.bootstrap.Bootstrap;
  import io.netty.bootstrap.ServerBootstrap;
  import io.netty.buffer.ByteBuf;
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.SimpleChannelInboundHandler;
  import io.netty.util.concurrent.DefaultEventExecutorGroup;
  import io.netty.util.concurrent.DefaultPromise;
  import io.netty.util.concurrent.DefaultThreadFactory;
  import io.netty.util.concurrent.EventExecutor;
  import io.netty.util.concurrent.Promise;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.TestInfo;
  
  import java.util.Random;
  import java.util.concurrent.CountDownLatch;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  public class SocketBufReleaseTest extends AbstractSocketTest {
  
      private static final EventExecutor executor =
              new DefaultEventExecutorGroup(1, new DefaultThreadFactory(SocketBufReleaseTest.class, true)).next();
  
      @Test
      public void testBufRelease(TestInfo testInfo) throws Throwable {
          run(testInfo, new Runner<ServerBootstrap, Bootstrap>() {
              @Override
              public void run(ServerBootstrap serverBootstrap, Bootstrap bootstrap) throws Throwable {
                  testBufRelease(serverBootstrap, bootstrap);
              }
          });
      }
  
      public void testBufRelease(ServerBootstrap sb, Bootstrap cb) throws Throwable {
          BufWriterHandler serverHandler = new BufWriterHandler();
          BufWriterHandler clientHandler = new BufWriterHandler();
  
          sb.childHandler(serverHandler);
          cb.handler(clientHandler);
  
          Channel sc = sb.bind().sync().channel();
          Channel cc = cb.connect(sc.localAddress()).sync().channel();
  
          // Ensure the server socket accepted the client connection *and* initialized pipeline successfully.
          serverHandler.channelFuture.sync();
  
          // and then close all sockets.
          sc.close().sync();
          cc.close().sync();
  
          serverHandler.check();
          clientHandler.check();
  
          serverHandler.release();
          clientHandler.release();
      }
  
      private static class BufWriterHandler extends SimpleChannelInboundHandler<Object> {
  
          private final Random random = new Random();
          private final CountDownLatch latch = new CountDownLatch(1);
          private ByteBuf buf;
          private final Promise<Channel> channelFuture = new DefaultPromise<Channel>(executor);
  
          @Override
          public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
              channelFuture.setSuccess(ctx.channel());
          }
  
          @Override
          public void channelActive(final ChannelHandlerContext ctx) throws Exception {
              byte[] data = new byte[1024];
              random.nextBytes(data);
  
              buf = ctx.alloc().buffer();
              // call retain on it so it can't be put back on the pool
              buf.writeBytes(data).retain();
  
              ctx.channel().writeAndFlush(buf).addListener(future -> latch.countDown());
          }
  
         @Override
         public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception {
             // discard
         }
 
         public void check() throws InterruptedException {
             latch.await();
             assertEquals(1, buf.refCnt());
         }
 
         void release() {
             buf.release();
         }
     }
 }