package org.jboss.resteasy.plugins.server.netty;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpRequestDecoder;
import io.netty.handler.codec.http.HttpResponseEncoder;
import io.netty.handler.ssl.SniHandler;
import io.netty.handler.ssl.SslHandler;
import io.netty.handler.timeout.IdleStateHandler;
import io.netty.util.concurrent.EventExecutor;
import jakarta.ws.rs.SeBootstrap.Configuration;
import org.jboss.resteasy.core.ResteasyDeploymentImpl;
import org.jboss.resteasy.core.SynchronousDispatcher;
import org.jboss.resteasy.plugins.server.embedded.EmbeddedJaxrsServer;
import org.jboss.resteasy.plugins.server.embedded.SecurityDomain;
import org.jboss.resteasy.spi.ResteasyDeployment;
import org.jboss.resteasy.util.EmbeddedServerHelper;
import org.jboss.resteasy.util.PortProvider;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLEngine;
import java.net.InetSocketAddress;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import java.util.Map;

/**
 * An HTTP server that sends back the content of the received HTTP request
 * in a pretty plaintext form.
 *
 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
 * @author Andy Taylor (andy.taylor@jboss.org)
 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
 * @author Norman Maurer
 * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
 */
public class NettyJaxrsServer implements EmbeddedJaxrsServer<NettyJaxrsServer>
{
   protected ServerBootstrap bootstrap = new ServerBootstrap();
   protected String hostname = null;
   protected int configuredPort = PortProvider.getPort();
   protected int runtimePort = -1;
   protected ResteasyDeployment deployment;
   protected String root = "";
   protected SecurityDomain domain;
   private EventLoopGroup eventLoopGroup;
   private EventLoopGroup eventExecutor;
   private int ioWorkerCount = Runtime.getRuntime().availableProcessors() * 2;
   private int executorThreadCount = 16;
   private SSLContext sslContext;
   private SniConfiguration sniConfiguration;
   private int maxRequestSize = 1024 * 1024 * 10;
   private int maxInitialLineLength = 4096;
   private int maxHeaderSize = 8192;
   private int maxChunkSize = 8192;
   private int backlog = 128;
   // default no idle timeout.
   private int idleTimeout = -1;
   private List<ChannelHandler> channelHandlers = Collections.emptyList();
   private Map<ChannelOption, Object> channelOptions = Collections.emptyMap();
   private Map<ChannelOption, Object> childChannelOptions = Collections.emptyMap();
   private List<ChannelHandler> httpChannelHandlers = Collections.emptyList();
   private EmbeddedServerHelper serverHelper = new EmbeddedServerHelper();

   @Override
   public NettyJaxrsServer deploy() {
      // no-op
      return this;
   }

   @Override
   public NettyJaxrsServer start() {
      final Configuration.Builder builder = Configuration.builder()
              .host(hostname)
              .port(configuredPort)
              .rootPath(root)
              .sslContext(sslContext);
      start(builder.build());
      return this;
   }

   @SuppressWarnings("unchecked")
   @Override
   public void start(final Configuration configuration) {

      final String hostname = configuration.host();
      final int configuredPort = configuration.port();
      String contextPath = configuration.rootPath();
      serverHelper.checkDeployment(deployment);

      eventLoopGroup = new NioEventLoopGroup(ioWorkerCount);
      eventExecutor = new NioEventLoopGroup(executorThreadCount);

      // dynamically set the root path (the user can rewrite it by calling setRootResourcePath)
      String appPath = serverHelper.checkAppDeployment(deployment);
      if (appPath != null && (contextPath == null || "".equals(contextPath) || "/".equals(contextPath))) {
         contextPath = appPath;
      }
      if (!contextPath.startsWith("/")) {
         contextPath = "/" + contextPath;
      }

      // Configure the server.
      bootstrap.group(eventLoopGroup)
         .channel(NioServerSocketChannel.class)
         .childHandler(createChannelInitializer(configuration, contextPath))
         .option(ChannelOption.SO_BACKLOG, backlog)
         .childOption(ChannelOption.SO_KEEPALIVE, true);

      for (Map.Entry<ChannelOption, Object> entry : channelOptions.entrySet()) {
         bootstrap.option(entry.getKey(), entry.getValue());
      }

      for (Map.Entry<ChannelOption, Object> entry : childChannelOptions.entrySet()) {
         bootstrap.childOption(entry.getKey(), entry.getValue());
      }

      final InetSocketAddress socketAddress;
      if (null == hostname || hostname.isEmpty()) {
         socketAddress = new InetSocketAddress(configuredPort);
      } else {
         socketAddress = new InetSocketAddress(hostname, configuredPort);
      }

      Channel channel = bootstrap.bind(socketAddress).syncUninterruptibly().channel();
      runtimePort = ((InetSocketAddress) channel.localAddress()).getPort();
   }

   @Override
   public void stop()
   {
      runtimePort = -1;
      eventLoopGroup.shutdownGracefully();
      eventExecutor.shutdownGracefully();

      if (deployment != null) {
         deployment.stop();
      }
   }

   @Override
   public ResteasyDeployment getDeployment() {
      if (deployment == null)
      {
         deployment = new ResteasyDeploymentImpl();
      }
      return deployment;
   }

   @Override
   public NettyJaxrsServer setDeployment(ResteasyDeployment deployment)
   {
      this.deployment = deployment;
      return this;
   }

   @Override
   public NettyJaxrsServer setPort(int port) {
      this.configuredPort = port;
      return this;
   }

   public int getPort() {
      return runtimePort > 0 ? runtimePort : configuredPort;
   }

   @Override
   public NettyJaxrsServer setHostname(String hostname) {
      this.hostname = hostname;
      return this;
   }

   public String getHostname() {
      return hostname;
   }

   @Override
   public NettyJaxrsServer setRootResourcePath(String rootResourcePath)
   {
      if (rootResourcePath == null || rootResourcePath.equals("/")) {
         root = "";
      } else if (!rootResourcePath.startsWith("/")) {
         root = "/" + rootResourcePath;
      } else {
         root = rootResourcePath;
      }
      return this;
   }

   @Override
   public NettyJaxrsServer setSecurityDomain(SecurityDomain sc)
   {
      this.domain = sc;
      return this;
   }



   public NettyJaxrsServer setSSLContext(SSLContext sslContext)
   {
      this.sslContext = sslContext;
      return this;
   }

   public NettyJaxrsServer setSniConfiguration(SniConfiguration sniConfiguration)
   {
      this.sniConfiguration = sniConfiguration;
      return this;
   }

   public SniConfiguration getSniConfiguration()
   {
      return sniConfiguration;
   }

   /**
    * Specify the worker count to use. For more information about this please see the javadocs of {@link EventLoopGroup}
    *
    * @param ioWorkerCount worker count
    */
   public NettyJaxrsServer setIoWorkerCount(int ioWorkerCount)
   {
      this.ioWorkerCount = ioWorkerCount;
      return this;
   }

   /**
    * Set the number of threads to use for the EventExecutor. For more information please see the javadocs of {@link EventExecutor}.
    * If you want to disable the use of the {@link EventExecutor} specify a value {@literal <=} 0.  This should only be done if you are 100% sure that you don't have any blocking
    * code in there.
    *
    * @param executorThreadCount thread count
    */
   public NettyJaxrsServer setExecutorThreadCount(int executorThreadCount)
   {
      this.executorThreadCount = executorThreadCount;
      return this;
   }

   /**
    * Set the max. request size in bytes. If this size is exceed we will send a "413 Request Entity Too Large" to the client.
    *
    * @param maxRequestSize the max request size. This is 10mb by default.
    */
   public NettyJaxrsServer setMaxRequestSize(int maxRequestSize) {
      this.maxRequestSize = maxRequestSize;
      return this;
   }

   public NettyJaxrsServer setMaxInitialLineLength(int maxInitialLineLength) {
      this.maxInitialLineLength = maxInitialLineLength;
      return this;
   }

   public NettyJaxrsServer setMaxHeaderSize(int maxHeaderSize) {
      this.maxHeaderSize = maxHeaderSize;
      return this;
   }

   public NettyJaxrsServer setMaxChunkSize(int maxChunkSize) {
      this.maxChunkSize = maxChunkSize;
      return this;
   }

   public NettyJaxrsServer setBacklog(int backlog)
   {
      this.backlog = backlog;
      return this;
   }

   public int getIdleTimeout() {
      return idleTimeout;
   }

   /**
    * Set the idle timeout.
    * Set this value to turn on idle connection cleanup.
    * If there is no traffic within idleTimeoutSeconds, it'll close connection.
    * @param idleTimeoutSeconds - How many seconds to cleanup client connection. default value -1 meaning no idle timeout.
    */
   public NettyJaxrsServer setIdleTimeout(int idleTimeoutSeconds) {
      this.idleTimeout = idleTimeoutSeconds;
      return this;
   }

   /**
    * Add additional {@link io.netty.channel.ChannelHandler}s to the {@link io.netty.bootstrap.ServerBootstrap}.
    * <p>The additional channel handlers are being added <em>before</em> the HTTP handling.</p>
    *
    * @param channelHandlers the additional {@link io.netty.channel.ChannelHandler}s.
    */
   public NettyJaxrsServer setChannelHandlers(final List<ChannelHandler> channelHandlers) {
      this.channelHandlers = channelHandlers == null ? Collections.<ChannelHandler>emptyList() : channelHandlers;
      return this;
   }

   /**
    * Add additional {@link io.netty.channel.ChannelHandler}s to the {@link io.netty.bootstrap.ServerBootstrap}.
    * <p>The additional channel handlers are being added <em>after</em> the HTTP handling.</p>
    *
    * @param httpChannelHandlers the additional {@link io.netty.channel.ChannelHandler}s.
    */
   public NettyJaxrsServer setHttpChannelHandlers(final List<ChannelHandler> httpChannelHandlers) {
      this.httpChannelHandlers = httpChannelHandlers == null ? Collections.<ChannelHandler>emptyList() : httpChannelHandlers;
      return this;
   }

   /**
    * Add Netty {@link io.netty.channel.ChannelOption}s to the {@link io.netty.bootstrap.ServerBootstrap}.
    *
    * @param channelOptions the additional {@link io.netty.channel.ChannelOption}s.
    * @see io.netty.bootstrap.ServerBootstrap#option(io.netty.channel.ChannelOption, Object)
    */
   public NettyJaxrsServer setChannelOptions(final Map<ChannelOption, Object> channelOptions) {
      this.channelOptions = channelOptions == null ? Collections.<ChannelOption, Object>emptyMap() : channelOptions;
      return this;
   }

   /**
    * Add child options to the {@link io.netty.bootstrap.ServerBootstrap}.
    *
    * @param channelOptions the additional child {@link io.netty.channel.ChannelOption}s.
    * @see io.netty.bootstrap.ServerBootstrap#childOption(io.netty.channel.ChannelOption, Object)
    */
   public NettyJaxrsServer setChildChannelOptions(final Map<ChannelOption, Object> channelOptions) {
      this.childChannelOptions = channelOptions == null ? Collections.<ChannelOption, Object>emptyMap() : channelOptions;
      return this;
   }


   protected RequestDispatcher createRequestDispatcher()
   {
      if (deployment == null) {
         throw new IllegalArgumentException("A ResteasyDeployment object required");
      }

      return new RequestDispatcher((SynchronousDispatcher)deployment.getDispatcher(),
               deployment.getProviderFactory(), domain);
   }

   private ChannelInitializer<SocketChannel> createChannelInitializer(final Configuration configuration, final String contextPath) {
      final RequestDispatcher dispatcher = createRequestDispatcher();
      final String protocol = configuration.protocol().toLowerCase(Locale.ROOT);
      final SSLContext sslContext;
      if ("https".equals(protocol)) {
         sslContext = configuration.sslContext();
      } else {
         sslContext = null;
      }
      if (sslContext == null && sniConfiguration == null) {
         return new ChannelInitializer<SocketChannel>() {
            @Override
            public void initChannel(SocketChannel ch) throws Exception {
               setupHandlers(ch, dispatcher, protocol, contextPath);
            }
         };
      } else if (sniConfiguration == null) {
         return new ChannelInitializer<SocketChannel>() {
            @Override
            public void initChannel(SocketChannel ch) throws Exception {
               SSLEngine engine = sslContext.createSSLEngine();
               engine.setUseClientMode(false);
               engine.setWantClientAuth(configuration.sslClientAuthentication() == Configuration.SSLClientAuthentication.OPTIONAL);
               engine.setNeedClientAuth(configuration.sslClientAuthentication() == Configuration.SSLClientAuthentication.MANDATORY);
               ch.pipeline().addFirst(new SslHandler(engine));
               setupHandlers(ch, dispatcher, protocol, contextPath);
            }
         };
      } else {
         return new ChannelInitializer<SocketChannel>() {
            @Override
            public void initChannel(SocketChannel ch) throws Exception {
               ch.pipeline().addFirst(new SniHandler(sniConfiguration.buildMapping()));
               setupHandlers(ch, dispatcher, protocol, contextPath);
            }
         };
      }
   }

   private void setupHandlers(SocketChannel ch, RequestDispatcher dispatcher, String protocol, final String contextPath) {
      ChannelPipeline channelPipeline = ch.pipeline();
      channelPipeline.addLast(channelHandlers.toArray(new ChannelHandler[channelHandlers.size()]));
      if (idleTimeout > 0) {
         channelPipeline.addLast("idleStateHandler", new IdleStateHandler(0, 0, idleTimeout));
      }
      channelPipeline.addLast(new HttpRequestDecoder(maxInitialLineLength, maxHeaderSize, maxChunkSize));
      channelPipeline.addLast(new HttpResponseEncoder());
      channelPipeline.addLast(new HttpObjectAggregator(maxRequestSize));
      channelPipeline.addLast(httpChannelHandlers.toArray(new ChannelHandler[httpChannelHandlers.size()]));
      channelPipeline.addLast(new RestEasyHttpRequestDecoder(dispatcher.getDispatcher(), contextPath, protocol));
      channelPipeline.addLast(new RestEasyHttpResponseEncoder());
      channelPipeline.addLast(eventExecutor, new RequestHandler(dispatcher));
   }

}
