package com.foxinmy.weixin4j.socket;
   
   import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
   import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
   import static io.netty.handler.codec.http.HttpResponseStatus.METHOD_NOT_ALLOWED;
   
   import com.foxinmy.weixin4j.dispatcher.WeixinMessageDispatcher;
   import com.foxinmy.weixin4j.request.WeixinRequest;
   import com.foxinmy.weixin4j.response.SingleResponse;
  import com.foxinmy.weixin4j.type.EncryptType;
  import com.foxinmy.weixin4j.util.AesToken;
  import com.foxinmy.weixin4j.util.HttpUtil;
  import com.foxinmy.weixin4j.util.MessageUtil;
  import com.foxinmy.weixin4j.util.ServerToolkits;
  
  import io.netty.channel.ChannelFutureListener;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.SimpleChannelInboundHandler;
  import io.netty.handler.codec.http.DefaultFullHttpResponse;
  import io.netty.handler.codec.http.FullHttpResponse;
  import io.netty.handler.codec.http.HttpMethod;
  import io.netty.handler.codec.http.HttpResponseStatus;
  import io.netty.util.internal.logging.InternalLogger;
  import io.netty.util.internal.logging.InternalLoggerFactory;
  
  /**
   * 微信请求处理类
   *
   * @className WeixinRequestHandler
   * @author jinyu(foxinmy@gmail.com)
   * @date 2014年11月16日
   * @since JDK 1.6
   * @see com.foxinmy.weixin4j.dispatcher.WeixinMessageDispatcher
   */
  public class WeixinRequestHandler extends SimpleChannelInboundHandler<WeixinRequest> {
      private final InternalLogger logger = InternalLoggerFactory.getInstance(getClass());
  
      private final WeixinMessageDispatcher messageDispatcher;
  
      public WeixinRequestHandler(WeixinMessageDispatcher messageDispatcher) {
          this.messageDispatcher = messageDispatcher;
      }
  
      public void channelReadComplete(ChannelHandlerContext ctx) {
          ctx.flush();
      }
  
      @Override
      public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
          ctx.close();
          logger.error(cause);
      }
  
      @Override
      protected void channelRead0(ChannelHandlerContext ctx, WeixinRequest request) {
          AesToken aesToken = request.getAesToken();
          // 消息字段不完整返回400
          if (aesToken == null || (ServerToolkits.isBlank(request.getSignature())
                  && ServerToolkits.isBlank(request.getMsgSignature()))) {
              ctx.writeAndFlush(resolveResponse(BAD_REQUEST, request)).addListener(ChannelFutureListener.CLOSE);
              return;
          }
          /**
           * 公众平台:无论Get,Post都带signature参数,当开启aes模式时带msg_signature参数
           * 企业号:无论Get,Post都带msg_signature参数
           * 一般来说：signature验证url上的参数签名，msg_signature验证消息体签名
           **/
          if (request.getMethod() == HttpMethod.GET) {
              // URL参数签名验证
              if (!ServerToolkits.isBlank(request.getSignature())
                      && MessageUtil.signature(aesToken.getToken(), request.getTimeStamp(), request.getNonce())
                              .equals(request.getSignature())) {
                  ctx.writeAndFlush(new SingleResponse(request.getEchoStr()));
                  return;
              }
              // XML消息签名验证
              if (!ServerToolkits.isBlank(request.getMsgSignature()) && MessageUtil
                      .signature(aesToken.getToken(), request.getTimeStamp(), request.getNonce(), request.getEchoStr())
                      .equals(request.getMsgSignature())) {
                  ctx.writeAndFlush(
                          new SingleResponse(MessageUtil.aesDecrypt(null, aesToken.getAesKey(), request.getEchoStr())));
                  return;
              }
              ctx.writeAndFlush(resolveResponse(FORBIDDEN, request)).addListener(ChannelFutureListener.CLOSE);
              return;
          } else if (request.getMethod() == HttpMethod.POST) {
              // URL参数签名验证
              if (!ServerToolkits.isBlank(request.getSignature())
                      && !MessageUtil.signature(aesToken.getToken(), request.getTimeStamp(), request.getNonce())
                              .equals(request.getSignature())) {
                  ctx.writeAndFlush(resolveResponse(FORBIDDEN, request)).addListener(ChannelFutureListener.CLOSE);
                  return;
              }
              // XML消息签名验证
              if (request.getEncryptType() == EncryptType.AES
                      && !MessageUtil.signature(aesToken.getToken(), request.getTimeStamp(), request.getNonce(),
                              request.getEncryptContent()).equals(request.getMsgSignature())) {
                  ctx.writeAndFlush(resolveResponse(FORBIDDEN, request)).addListener(ChannelFutureListener.CLOSE);
                  return;
             }
         } else {
             // 访问其它URL
             ctx.writeAndFlush(resolveResponse(METHOD_NOT_ALLOWED, request)).addListener(ChannelFutureListener.CLOSE);
             return;
         }
         messageDispatcher.doDispatch(ctx, request);
     }
 
     private FullHttpResponse resolveResponse(HttpResponseStatus responseStatus, WeixinRequest request) {
         FullHttpResponse response = new DefaultFullHttpResponse(request.getProtocolVersion(), responseStatus);
         HttpUtil.resolveHeaders(response);
         return response;
     }
 }