/*
    * 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.ChannelInboundHandlerAdapter;
  import io.netty.channel.ChannelInitializer;
  import io.netty.channel.ChannelOption;
  import io.netty.channel.SimpleChannelInboundHandler;
  import io.netty.util.concurrent.DefaultEventExecutorGroup;
  import io.netty.util.concurrent.EventExecutorGroup;
  import io.netty.util.internal.PlatformDependent;
  import org.junit.jupiter.api.AfterAll;
  import org.junit.jupiter.api.BeforeAll;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.TestInfo;
  import org.junit.jupiter.api.Timeout;
  
  import java.io.IOException;
  import java.util.Random;
  import java.util.SplittableRandom;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicReference;
  
  import static io.netty.testsuite.transport.TestsuitePermutation.randomBufferType;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNotEquals;
  
  public class SocketEchoTest extends AbstractSocketTest {
  
      private static final Random random = new Random();
      static final byte[] data = new byte[1048576];
  
      private static EventExecutorGroup group;
  
      static {
          PlatformDependent.splittableRandomNextBytes(new SplittableRandom(random.nextLong()), data);
      }
  
      @BeforeAll
      public static void createGroup() {
          group = new DefaultEventExecutorGroup(2);
      }
  
      @AfterAll
      public static void destroyGroup() throws Exception {
          group.shutdownGracefully().sync();
      }
  
      @Test
      @Timeout(value = 30000, unit = TimeUnit.MILLISECONDS)
      public void testSimpleEcho(TestInfo testInfo) throws Throwable {
          run(testInfo, new Runner<ServerBootstrap, Bootstrap>() {
              @Override
              public void run(ServerBootstrap serverBootstrap, Bootstrap bootstrap) throws Throwable {
                  testSimpleEcho(serverBootstrap, bootstrap);
              }
          });
      }
  
      public void testSimpleEcho(ServerBootstrap sb, Bootstrap cb) throws Throwable {
          testSimpleEcho0(sb, cb, false, false, true);
      }
  
      @Test
      @Timeout(value = 30000, unit = TimeUnit.MILLISECONDS)
      public void testSimpleEchoNotAutoRead(TestInfo testInfo) throws Throwable {
          run(testInfo, new Runner<ServerBootstrap, Bootstrap>() {
              @Override
              public void run(ServerBootstrap sb1, Bootstrap cb1) throws Throwable {
                  testSimpleEchoNotAutoRead(sb1, cb1);
              }
          });
      }
  
      public void testSimpleEchoNotAutoRead(ServerBootstrap sb, Bootstrap cb) throws Throwable {
          testSimpleEcho0(sb, cb, false, false, false);
      }
  
      @Test
      public void testSimpleEchoWithAdditionalExecutor(TestInfo testInfo) throws Throwable {
          run(testInfo, new Runner<ServerBootstrap, Bootstrap>() {
             @Override
             public void run(ServerBootstrap sb1, Bootstrap cb1) throws Throwable {
                 testSimpleEchoWithAdditionalExecutor(sb1, cb1);
             }
         });
     }
 
     public void testSimpleEchoWithAdditionalExecutor(ServerBootstrap sb, Bootstrap cb) throws Throwable {
         testSimpleEcho0(sb, cb, true, false, true);
     }
 
     @Test
     public void testSimpleEchoWithAdditionalExecutorNotAutoRead(TestInfo testInfo) throws Throwable {
         run(testInfo, new Runner<ServerBootstrap, Bootstrap>() {
             @Override
             public void run(ServerBootstrap sb1, Bootstrap cb1) throws Throwable {
                 testSimpleEchoWithAdditionalExecutorNotAutoRead(sb1, cb1);
             }
         });
     }
 
     public void testSimpleEchoWithAdditionalExecutorNotAutoRead(ServerBootstrap sb, Bootstrap cb) throws Throwable {
         testSimpleEcho0(sb, cb, true, false, false);
     }
 
     @Test
     public void testSimpleEchoWithVoidPromise(TestInfo testInfo) throws Throwable {
         run(testInfo, new Runner<ServerBootstrap, Bootstrap>() {
             @Override
             public void run(ServerBootstrap sb1, Bootstrap cb1) throws Throwable {
                 testSimpleEchoWithVoidPromise(sb1, cb1);
             }
         });
     }
 
     public void testSimpleEchoWithVoidPromise(ServerBootstrap sb, Bootstrap cb) throws Throwable {
         testSimpleEcho0(sb, cb, false, true, true);
     }
 
     @Test
     public void testSimpleEchoWithVoidPromiseNotAutoRead(TestInfo testInfo) throws Throwable {
         run(testInfo, new Runner<ServerBootstrap, Bootstrap>() {
             @Override
             public void run(ServerBootstrap sb1, Bootstrap cb1) throws Throwable {
                 testSimpleEchoWithVoidPromiseNotAutoRead(sb1, cb1);
             }
         });
     }
 
     public void testSimpleEchoWithVoidPromiseNotAutoRead(ServerBootstrap sb, Bootstrap cb) throws Throwable {
         testSimpleEcho0(sb, cb, false, true, false);
     }
 
     @Test
     @Timeout(value = 30000, unit = TimeUnit.MILLISECONDS)
     public void testSimpleEchoWithAdditionalExecutorAndVoidPromise(TestInfo testInfo) throws Throwable {
         run(testInfo, new Runner<ServerBootstrap, Bootstrap>() {
             @Override
             public void run(ServerBootstrap sb1, Bootstrap cb1) throws Throwable {
                 testSimpleEchoWithAdditionalExecutorAndVoidPromise(sb1, cb1);
             }
         });
     }
 
     public void testSimpleEchoWithAdditionalExecutorAndVoidPromise(ServerBootstrap sb, Bootstrap cb) throws Throwable {
         testSimpleEcho0(sb, cb, true, true, true);
     }
 
     private static void testSimpleEcho0(
             ServerBootstrap sb, Bootstrap cb, boolean additionalExecutor, boolean voidPromise, boolean autoRead)
             throws Throwable {
 
         final EchoHandler sh = new EchoHandler(autoRead);
         final EchoHandler ch = new EchoHandler(autoRead);
 
         if (additionalExecutor) {
             sb.childHandler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel c) throws Exception {
                     c.pipeline().addLast(group, sh);
                 }
             });
             cb.handler(new ChannelInitializer<Channel>() {
                 @Override
                 protected void initChannel(Channel c) throws Exception {
                     c.pipeline().addLast(group, ch);
                 }
             });
         } else {
             sb.childHandler(sh);
             sb.handler(new ChannelInboundHandlerAdapter() {
                 @Override
                 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                     cause.printStackTrace();
                 }
             });
             cb.handler(ch);
         }
         sb.childOption(ChannelOption.AUTO_READ, autoRead);
         cb.option(ChannelOption.AUTO_READ, autoRead);
 
         Channel sc = sb.bind().sync().channel();
         Channel cc = cb.connect(sc.localAddress()).sync().channel();
 
         SplittableRandom rng = new SplittableRandom(random.nextLong());
         for (int i = 0; i < data.length;) {
             int length = Math.min(rng.nextInt(1024 * 64), data.length - i);
             ByteBuf buf = randomBufferType(cc.alloc(), data, i, length);
             if (voidPromise) {
                 assertEquals(cc.voidPromise(), cc.writeAndFlush(buf, cc.voidPromise()));
             } else {
                 assertNotEquals(cc.voidPromise(), cc.writeAndFlush(buf));
             }
             i += length;
         }
 
         while (ch.counter < data.length) {
             if (sh.exception.get() != null) {
                 break;
             }
             if (ch.exception.get() != null) {
                 break;
             }
 
             Thread.sleep(50);
         }
 
         while (sh.counter < data.length) {
             if (sh.exception.get() != null) {
                 break;
             }
             if (ch.exception.get() != null) {
                 break;
             }
 
             Thread.sleep(50);
         }
 
         sh.channel.close().sync();
         ch.channel.close().sync();
         sc.close().sync();
 
         if (sh.exception.get() != null && !(sh.exception.get() instanceof IOException)) {
             throw sh.exception.get();
         }
         if (ch.exception.get() != null && !(ch.exception.get() instanceof IOException)) {
             throw ch.exception.get();
         }
         if (sh.exception.get() != null) {
             throw sh.exception.get();
         }
         if (ch.exception.get() != null) {
             throw ch.exception.get();
         }
     }
 
     private static class EchoHandler extends SimpleChannelInboundHandler<ByteBuf> {
         private final boolean autoRead;
         volatile Channel channel;
         final AtomicReference<Throwable> exception = new AtomicReference<Throwable>();
         volatile int counter;
 
         EchoHandler(boolean autoRead) {
             this.autoRead = autoRead;
         }
 
         @Override
         public void channelActive(ChannelHandlerContext ctx)
                 throws Exception {
             channel = ctx.channel();
             if (!autoRead) {
                 ctx.read();
             }
         }
 
         @Override
         public void channelRead0(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
             byte[] actual = new byte[in.readableBytes()];
             in.readBytes(actual);
 
             int lastIdx = counter;
             for (int i = 0; i < actual.length; i ++) {
                 assertEquals(data[i + lastIdx], actual[i]);
             }
 
             // Update the counter before calling write(...) as write could in theory trigger another channelRead(...)
             // which then would use the wrong lastIdx.
             counter += actual.length;
 
             if (channel.parent() != null) {
                 channel.write(randomBufferType(channel.alloc(), actual, 0, actual.length));
             }
         }
 
         @Override
         public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
             try {
                 ctx.flush();
             } finally {
                 if (!autoRead) {
                     ctx.read();
                 }
             }
         }
 
         @Override
         public void exceptionCaught(ChannelHandlerContext ctx,
                 Throwable cause) throws Exception {
             if (exception.compareAndSet(null, cause)) {
                 cause.printStackTrace();
                 ctx.close();
             }
         }
     }
 }