/*
    * Copyright 2026 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.buffer.ByteBuf;
  import io.netty.buffer.Unpooled;
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.ChannelOption;
  import io.netty.channel.SimpleChannelInboundHandler;
  import io.netty.channel.socket.DatagramPacket;
  import io.netty.testsuite.transport.TestsuitePermutation;
  import io.netty.util.CharsetUtil;
  import io.netty.util.NetUtil;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.TestInfo;
  import org.junit.jupiter.api.Timeout;
  import org.junit.jupiter.api.condition.DisabledOnOs;
  import org.junit.jupiter.api.condition.OS;
  
  import java.net.InetSocketAddress;
  import java.net.PortUnreachableException;
  import java.util.List;
  import java.util.concurrent.CountDownLatch;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicReference;
  
  import static org.junit.jupiter.api.Assertions.assertInstanceOf;
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  public class DatagramConnectedWriteExceptionTest extends AbstractClientSocketTest {
  
      @Override
      protected List<TestsuitePermutation.BootstrapFactory<Bootstrap>> newFactories() {
          return SocketTestPermutation.INSTANCE.datagramSocket();
      }
  
      @Test
      @Timeout(value = 10000, unit = TimeUnit.MILLISECONDS)
      @DisabledOnOs(OS.WINDOWS)
      public void testWriteThrowsPortUnreachableException(TestInfo testInfo) throws Throwable {
          run(testInfo, (Runner<Bootstrap>) this::testWriteExceptionAfterServerStop);
      }
  
      protected void testWriteExceptionAfterServerStop(Bootstrap clientBootstrap) throws Throwable {
          CountDownLatch serverReceivedLatch = new CountDownLatch(1);
          Bootstrap serverBootstrap = clientBootstrap.clone()
                  .option(ChannelOption.SO_BROADCAST, false)
                  .handler(new SimpleChannelInboundHandler<DatagramPacket>() {
  
                      @Override
                      protected void channelRead0(ChannelHandlerContext ctx, DatagramPacket msg) {
                          serverReceivedLatch.countDown();
                      }
                  });
  
          Channel serverChannel = serverBootstrap.bind(new InetSocketAddress(NetUtil.LOCALHOST, 0)).sync().channel();
          InetSocketAddress serverAddress = (InetSocketAddress) serverChannel.localAddress();
  
          clientBootstrap.option(ChannelOption.AUTO_READ, false)
                  .handler(new SimpleChannelInboundHandler<DatagramPacket>() {
  
                      @Override
                      protected void channelRead0(ChannelHandlerContext ctx, DatagramPacket msg) {
                          // no-op
                      }
                  });
  
          Channel clientChannel = clientBootstrap.connect(serverAddress).sync().channel();
  
          CountDownLatch clientFirstSendLatch = new CountDownLatch(1);
          try {
              ByteBuf firstMessage = Unpooled.wrappedBuffer("First message".getBytes(CharsetUtil.UTF_8));
              clientChannel.writeAndFlush(firstMessage)
                      .addListener(future -> {
                          if (future.isSuccess()) {
                              clientFirstSendLatch.countDown();
                          }
                      });
  
              assertTrue(serverReceivedLatch.await(5, TimeUnit.SECONDS), "Server should receive first message");
              assertTrue(clientFirstSendLatch.await(5, TimeUnit.SECONDS), "Client should send first message");
  
              serverChannel.close().sync();
 
             AtomicReference<Throwable> writeException = new AtomicReference<>();
             CountDownLatch writesCompleteLatch = new CountDownLatch(10);
 
             for (int i = 0; i < 10; i++) {
                 ByteBuf message = Unpooled.wrappedBuffer(("Message " + i).getBytes(CharsetUtil.UTF_8));
                 clientChannel.writeAndFlush(message)
                         .addListener(future -> {
                             if (!future.isSuccess()) {
                                 writeException.compareAndSet(null, future.cause());
                             }
                             writesCompleteLatch.countDown();
                         });
                 Thread.sleep(50);
             }
 
             assertTrue(writesCompleteLatch.await(5, TimeUnit.SECONDS), "All writes should complete");
 
             assertNotNull(writeException.get(), "Should have captured a write exception");
 
             assertInstanceOf(PortUnreachableException.class, writeException.get(), "Expected " +
                     "PortUnreachableException but got: " + writeException.get().getClass().getName());
         } finally {
             if (clientChannel != null) {
                 clientChannel.close().sync();
             }
         }
     }
 }