code: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF 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
   *
   *     http://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 org.apache.skywalking.oap.server.receiver.otel.otlp;
  
  import com.google.common.base.Strings;
  import io.grpc.stub.StreamObserver;
  import io.opentelemetry.proto.collector.logs.v1.ExportLogsServiceRequest;
  import io.opentelemetry.proto.collector.logs.v1.ExportLogsServiceResponse;
  import io.opentelemetry.proto.collector.logs.v1.LogsServiceGrpc;
  import io.opentelemetry.proto.common.v1.KeyValue;
  import io.opentelemetry.proto.logs.v1.LogRecord;
  import lombok.RequiredArgsConstructor;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.apm.network.common.v3.KeyStringValuePair;
  import org.apache.skywalking.apm.network.logging.v3.LogData;
  import org.apache.skywalking.apm.network.logging.v3.LogDataBody;
  import org.apache.skywalking.apm.network.logging.v3.LogTags;
  import org.apache.skywalking.apm.network.logging.v3.TextLog;
  import org.apache.skywalking.oap.log.analyzer.module.LogAnalyzerModule;
  import org.apache.skywalking.oap.log.analyzer.provider.log.ILogAnalyzerService;
  import org.apache.skywalking.oap.server.core.server.GRPCHandlerRegister;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  import org.apache.skywalking.oap.server.library.module.ModuleStartException;
  import org.apache.skywalking.oap.server.receiver.otel.Handler;
  import org.apache.skywalking.oap.server.receiver.sharing.server.SharingServerModule;
  
  import java.util.Map;
  import java.util.stream.Collectors;
  
  import static java.util.stream.Collectors.toMap;
  
  @Slf4j
  @RequiredArgsConstructor
  public class OpenTelemetryLogHandler
      extends LogsServiceGrpc.LogsServiceImplBase
      implements Handler {
      private final ModuleManager manager;
  
      private ILogAnalyzerService logAnalyzerService;
  
      @Override
      public String type() {
          return "otlp-logs";
      }
  
      @Override
      public void active() throws ModuleStartException {
          GRPCHandlerRegister grpcHandlerRegister = manager.find(SharingServerModule.NAME)
                                                           .provider()
                                                           .getService(GRPCHandlerRegister.class);
          grpcHandlerRegister.addHandler(this);
      }
  
      @Override
      public void export(ExportLogsServiceRequest request, StreamObserver<ExportLogsServiceResponse> responseObserver) {
          request.getResourceLogsList().forEach(resourceLogs -> {
              final var resource = resourceLogs.getResource();
              final var attributes = resource
                  .getAttributesList().stream()
                  .map(it -> Map.entry(it.getKey(), buildTagValue(it)))
                  .collect(toMap(Map.Entry::getKey, Map.Entry::getValue));
              final var service = attributes.get("service.name");
              if (Strings.isNullOrEmpty(service)) {
                  log.warn("No service name found in resource attributes, discarding the log");
                  return;
              }
              final var layer = attributes.getOrDefault("service.layer", "");
              final var serviceInstance = attributes.getOrDefault("service.instance", "");
  
              resourceLogs
                  .getScopeLogsList()
                  .stream()
                  .flatMap(it -> it.getLogRecordsList().stream())
                  .forEach(
                      logRecord ->
                          doAnalysisQuietly(service, layer, serviceInstance, logRecord));
              responseObserver.onNext(ExportLogsServiceResponse.getDefaultInstance());
              responseObserver.onCompleted();
          });
      }
  
      private void doAnalysisQuietly(String service, String layer, String serviceInstance, LogRecord logRecord) {
          try {
              logAnalyzerService().doAnalysis(
                  LogData
                      .newBuilder()
                      .setService(service)
                      .setServiceInstance(serviceInstance)
                      .setTimestamp(logRecord.getTimeUnixNano() / 1_000_000)
                      .setTags(buildTags(logRecord))
                      .setBody(buildBody(logRecord))
                      .setLayer(layer),
                  null);
          } catch (Exception e) {
              log.error("Failed to analyze logs", e);
          }
      }
  
      private static LogDataBody buildBody(LogRecord logRecord) {
          return LogDataBody.newBuilder().setText(
              TextLog.newBuilder().setText(
                  logRecord.getBody().getStringValue()
              ).build()
          ).build();
      }
  
      private LogTags buildTags(LogRecord logRecord) {
          return LogTags.newBuilder().addAllData(
              logRecord
                  .getAttributesList()
                  .stream()
                  .collect(toMap(KeyValue::getKey, this::buildTagValue))
                  .entrySet()
                  .stream()
                  .map(it -> KeyStringValuePair
                      .newBuilder()
                      .setKey(it.getKey())
                      .setValue(it.getValue())
                      .build())
                  .collect(Collectors.toList())
          ).build();
      }
  
      private String buildTagValue(KeyValue it) {
          final var value = it.getValue();
          return value.hasStringValue() ? value.getStringValue() :
              value.hasIntValue() ? String.valueOf(value.getIntValue()) :
                  value.hasDoubleValue() ? String.valueOf(value.getDoubleValue()) :
                      value.hasBoolValue() ? String.valueOf(value.getBoolValue()) :
                          value.hasArrayValue() ? value.getArrayValue().toString() :
                              "";
      }
  
      private ILogAnalyzerService logAnalyzerService() {
          if (logAnalyzerService == null) {
              logAnalyzerService =
                  manager.find(LogAnalyzerModule.NAME)
                         .provider()
                         .getService(ILogAnalyzerService.class);
          }
          return logAnalyzerService;
      }
  }
  