content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.instrumentation.api.semconv.http;
  
  import static io.opentelemetry.instrumentation.api.internal.AttributesExtractorUtil.internalSet;
  import static io.opentelemetry.instrumentation.api.internal.HttpConstants._OTHER;
  import static io.opentelemetry.instrumentation.api.semconv.http.CapturedHttpHeadersUtil.lowercase;
  import static io.opentelemetry.instrumentation.api.semconv.http.CapturedHttpHeadersUtil.requestAttributeKey;
  import static io.opentelemetry.instrumentation.api.semconv.http.CapturedHttpHeadersUtil.responseAttributeKey;
  
  import io.opentelemetry.api.common.AttributesBuilder;
  import io.opentelemetry.context.Context;
  import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
  import io.opentelemetry.instrumentation.api.semconv.network.NetworkAttributesGetter;
  import io.opentelemetry.semconv.ErrorAttributes;
  import io.opentelemetry.semconv.HttpAttributes;
  import io.opentelemetry.semconv.NetworkAttributes;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Locale;
  import java.util.Set;
  import javax.annotation.Nullable;
  
  /**
   * Extractor of <a
   * href="https://github.com/open-telemetry/semantic-conventions/blob/v1.23.0/docs/http/http-spans.md#common-attributes">HTTP
   * attributes</a> that are common to client and server instrumentations.
   */
  abstract class HttpCommonAttributesExtractor<
          REQUEST,
          RESPONSE,
          GETTER extends
              HttpCommonAttributesGetter<REQUEST, RESPONSE>
                  & NetworkAttributesGetter<REQUEST, RESPONSE>>
      implements AttributesExtractor<REQUEST, RESPONSE> {
  
    final GETTER getter;
    private final HttpStatusCodeConverter statusCodeConverter;
    private final String[] capturedRequestHeaders;
    private final String[] capturedResponseHeaders;
    private final Set<String> knownMethods;
  
    HttpCommonAttributesExtractor(
        GETTER getter,
        HttpStatusCodeConverter statusCodeConverter,
        List<String> capturedRequestHeaders,
        List<String> capturedResponseHeaders,
        Set<String> knownMethods) {
      this.getter = getter;
      this.statusCodeConverter = statusCodeConverter;
      this.capturedRequestHeaders = lowercase(capturedRequestHeaders);
      this.capturedResponseHeaders = lowercase(capturedResponseHeaders);
      this.knownMethods = new HashSet<>(knownMethods);
    }
  
    @Override
    public void onStart(AttributesBuilder attributes, Context parentContext, REQUEST request) {
      String method = getter.getHttpRequestMethod(request);
      if (method == null || knownMethods.contains(method)) {
        internalSet(attributes, HttpAttributes.HTTP_REQUEST_METHOD, method);
      } else {
        internalSet(attributes, HttpAttributes.HTTP_REQUEST_METHOD, _OTHER);
        internalSet(attributes, HttpAttributes.HTTP_REQUEST_METHOD_ORIGINAL, method);
      }
  
      for (String name : capturedRequestHeaders) {
        List<String> values = getter.getHttpRequestHeader(request, name);
        if (!values.isEmpty()) {
          internalSet(attributes, requestAttributeKey(name), values);
        }
      }
    }
  
    @Override
    public void onEnd(
        AttributesBuilder attributes,
        Context context,
        REQUEST request,
        @Nullable RESPONSE response,
        @Nullable Throwable error) {
  
      Integer statusCode = null;
      if (response != null) {
        statusCode = getter.getHttpResponseStatusCode(request, response, error);
        if (statusCode != null && statusCode > 0) {
          internalSet(attributes, HttpAttributes.HTTP_RESPONSE_STATUS_CODE, (long) statusCode);
        }
  
        for (String name : capturedResponseHeaders) {
          List<String> values = getter.getHttpResponseHeader(request, response, name);
          if (!values.isEmpty()) {
            internalSet(attributes, responseAttributeKey(name), values);
          }
        }
      }
  
      String errorType = null;
      if (statusCode != null && statusCode > 0) {
        if (statusCodeConverter.isError(statusCode)) {
          errorType = statusCode.toString();
        }
      } else {
        errorType = getter.getErrorType(request, response, error);
        // fall back to exception class name & _OTHER
        if (errorType == null && error != null) {
          errorType = error.getClass().getName();
        }
        if (errorType == null) {
          errorType = _OTHER;
        }
      }
      internalSet(attributes, ErrorAttributes.ERROR_TYPE, errorType);
  
      String protocolName = lowercaseStr(getter.getNetworkProtocolName(request, response));
      String protocolVersion = lowercaseStr(getter.getNetworkProtocolVersion(request, response));
  
      if (protocolVersion != null) {
        if (!"http".equals(protocolName)) {
          internalSet(attributes, NetworkAttributes.NETWORK_PROTOCOL_NAME, protocolName);
        }
        internalSet(attributes, NetworkAttributes.NETWORK_PROTOCOL_VERSION, protocolVersion);
      }
    }
  
    @Nullable
    static String firstHeaderValue(List<String> values) {
      return values.isEmpty() ? null : values.get(0);
    }
  
    @Nullable
    private static String lowercaseStr(@Nullable String str) {
      return str == null ? null : str.toLowerCase(Locale.ROOT);
    }
  }
  