package cn.home1.oss.lib.errorhandle.internal.rpc;
   
   import static com.google.common.base.Charsets.UTF_8;
   import static com.google.common.collect.Lists.newArrayList;
   import static org.apache.commons.lang3.StringUtils.toEncodedString;
   
   import cn.home1.oss.lib.errorhandle.api.ResolvedError;
   import cn.home1.oss.lib.errorhandle.api.ResolvedErrorException;
   
  import com.fasterxml.jackson.databind.ObjectMapper;
  import cn.home1.oss.lib.common.JaxbUtils;
  
  import feign.codec.DecodeException;
  
  import lombok.Setter;
  import lombok.extern.slf4j.Slf4j;
  
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.http.HttpHeaders;
  import org.springframework.http.HttpStatus;
  import org.springframework.oxm.jaxb.Jaxb2Marshaller;
  import org.springframework.util.StreamUtils;
  import org.springframework.web.client.HttpClientErrorException;
  import org.springframework.web.client.HttpServerErrorException;
  
  @Setter
  @Slf4j
  public class GenericFeignErrorDecoder implements feign.codec.ErrorDecoder {
  
    private final feign.codec.ErrorDecoder delegate = new Default();
  
    private final Jaxb2Marshaller jaxb2Marshaller = JaxbUtils.jaxb2Marshaller();
    @Autowired
    private ObjectMapper objectMapper;
  
    private static HttpHeaders cloneHeaders(final feign.Response response) {
      final HttpHeaders responseHeaders = new HttpHeaders();
      response.headers().entrySet().stream()
          .forEach(entry -> responseHeaders.put(entry.getKey(), newArrayList(entry.getValue())));
      return responseHeaders;
    }
  
    private static byte[] responseBody(final feign.Response response) {
      try {
        return StreamUtils.copyToByteArray(response.body().asInputStream());
      } catch (final Exception wrapped) {
        log.info("Failed to process response body.", wrapped);
        throw new DecodeException("Failed to process response body.", wrapped);
      }
    }
  
    @Override
    public Exception decode(final String methodKey, final feign.Response response) {
      if (log.isDebugEnabled()) {
        log.debug("decode : {}", methodKey);
      }
  
      final HttpHeaders responseHeaders = cloneHeaders(response);
      final byte[] responseBody = responseBody(response);
      final Exception result;
      if (ResolvedErrorException.isResolvedError(responseHeaders)) {
        final String info = toEncodedString(responseBody, UTF_8);
        try {
          // 如果被调用的服务配置了XmlHttpMessageConverter(使用XStreamMarshaller) 可能导致数据被包裹在<string></string>里面
          final String json =
              info.startsWith("<string>") ? JaxbUtils.unmarshal(this.jaxb2Marshaller, info, String.class) : info;
          result = new ResolvedErrorException(this.objectMapper.readValue(json, ResolvedError.class));
        } catch (final Exception wrapped) {
          log.info("Failed to decode resolvedError. info: " + info, wrapped);
          throw new DecodeException("Failed to decode resolvedError. info: " + info, wrapped);
        }
      } else {
        final HttpStatus statusCode = HttpStatus.valueOf(response.status());
        final String statusText = response.reason();
        if (response.status() >= 400 && response.status() <= 499) {
          result = new HttpClientErrorException( //
              statusCode, //
              statusText, //
              responseHeaders, //
              responseBody, //
              null);
        } else if (response.status() >= 500 && response.status() <= 599) {
          result = new HttpServerErrorException( //
              statusCode, //
              statusText, //
              responseHeaders, //
              responseBody, //
              null);
        } else {
          result = delegate.decode(methodKey, response);
        }
      }
      return result;
    }
  }