/*
    * Copyright 2015 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.example.http2.tiles;
  
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.handler.codec.http.HttpObjectAggregator;
  import io.netty.handler.codec.http.HttpServerCodec;
  import io.netty.handler.codec.http2.DefaultHttp2Connection;
  import io.netty.handler.codec.http2.HttpToHttp2ConnectionHandlerBuilder;
  import io.netty.handler.codec.http2.InboundHttp2ToHttpAdapter;
  import io.netty.handler.codec.http2.InboundHttp2ToHttpAdapterBuilder;
  import io.netty.handler.ssl.ApplicationProtocolNames;
  import io.netty.handler.ssl.ApplicationProtocolNegotiationHandler;
  
  /**
   * Used during protocol negotiation, the main function of this handler is to
   * return the HTTP/1.1 or HTTP/2 handler once the protocol has been negotiated.
   */
  public class Http2OrHttpHandler extends ApplicationProtocolNegotiationHandler {
  
      private static final int MAX_CONTENT_LENGTH = 1024 * 100;
  
      protected Http2OrHttpHandler() {
          super(ApplicationProtocolNames.HTTP_1_1);
      }
  
      @Override
      protected void configurePipeline(ChannelHandlerContext ctx, String protocol) throws Exception {
          if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
              configureHttp2(ctx);
              return;
          }
  
          if (ApplicationProtocolNames.HTTP_1_1.equals(protocol)) {
              configureHttp1(ctx);
              return;
          }
  
          throw new IllegalStateException("unknown protocol: " + protocol);
      }
  
      private static void configureHttp2(ChannelHandlerContext ctx) {
          DefaultHttp2Connection connection = new DefaultHttp2Connection(true);
          InboundHttp2ToHttpAdapter listener = new InboundHttp2ToHttpAdapterBuilder(connection)
                  .propagateSettings(true).validateHttpHeaders(false)
                  .maxContentLength(MAX_CONTENT_LENGTH).build();
  
          ctx.pipeline().addLast(new HttpToHttp2ConnectionHandlerBuilder()
                  .frameListener(listener)
                  // .frameLogger(TilesHttp2ToHttpHandler.logger)
                  .connection(connection).build());
  
          ctx.pipeline().addLast(new Http2RequestHandler());
      }
  
      private static void configureHttp1(ChannelHandlerContext ctx) throws Exception {
          ctx.pipeline().addLast(new HttpServerCodec(),
                                 new HttpObjectAggregator(MAX_CONTENT_LENGTH),
                                 new FallbackRequestHandler());
      }
  }