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

import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.TooLongFrameException;
import io.netty.handler.codec.http.DefaultHttpResponse;
import io.netty.handler.codec.http.HttpResponse;

import io.netty.handler.timeout.IdleStateEvent;
import org.jboss.resteasy.plugins.server.netty.i18n.LogMessages;
import org.jboss.resteasy.plugins.server.netty.i18n.Messages;
import org.jboss.resteasy.spi.Failure;

import static io.netty.handler.codec.http.HttpResponseStatus.CONTINUE;
import static io.netty.handler.codec.http.HttpResponseStatus.REQUEST_ENTITY_TOO_LARGE;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;

/**
 * {@link SimpleChannelInboundHandler} which handles the requests and dispatch them.
 *
 * This class is {@link Sharable}.
 *
 * @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: 2368 $, $Date: 2010-10-18 17:19:03 +0900 (Mon, 18 Oct 2010) $
 */
@Sharable
public class RequestHandler extends SimpleChannelInboundHandler
{
   protected final RequestDispatcher dispatcher;

   public RequestHandler(RequestDispatcher dispatcher)
   {
      this.dispatcher = dispatcher;
   }

   @Override
   protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception
   {
      if (msg instanceof NettyHttpRequest) {
          NettyHttpRequest request = (NettyHttpRequest) msg;

          if (request.is100ContinueExpected())
          {
             send100Continue(ctx);
          }

          NettyHttpResponse response = request.getResponse();
          try
          {
             dispatcher.service(ctx, request, response, true);
          }
          catch (Failure e1)
          {
             response.reset();
             response.setStatus(e1.getErrorCode());
          }
          catch (Exception ex)
          {
             response.reset();
             response.setStatus(500);
             LogMessages.LOGGER.error(Messages.MESSAGES.unexpected(), ex);
          }

          if (!request.getAsyncContext().isSuspended()) {
             response.finish();
          }
      }
   }

   private void send100Continue(ChannelHandlerContext ctx)
   {
      HttpResponse response = new DefaultHttpResponse(HTTP_1_1, CONTINUE);
      ctx.writeAndFlush(response);
   }

   @Override
   public void exceptionCaught(ChannelHandlerContext ctx, Throwable e)
           throws Exception
   {
      // handle the case of to big requests.
      if (e.getCause() instanceof TooLongFrameException)
      {
          DefaultHttpResponse response = new DefaultHttpResponse(HTTP_1_1, REQUEST_ENTITY_TOO_LARGE);
          ctx.write(response).addListener(ChannelFutureListener.CLOSE);
      }
      else
      {
          e.getCause().printStackTrace();
          ctx.close();
      }
   }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
        if (evt instanceof IdleStateEvent) {
            ctx.close();
        }
    }
}
