content: /*
   * 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.bookkeeper.server.http.service;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNull;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.CALLS_REAL_METHODS;
  import static org.mockito.Mockito.doAnswer;
  import static org.mockito.Mockito.doThrow;
  import static org.mockito.Mockito.mock;
  
  import java.io.IOException;
  import java.io.Writer;
  import org.apache.bookkeeper.conf.ServerConfiguration;
  import org.apache.bookkeeper.http.HttpServer.Method;
  import org.apache.bookkeeper.http.HttpServer.StatusCode;
  import org.apache.bookkeeper.http.service.HttpServiceRequest;
  import org.apache.bookkeeper.http.service.HttpServiceResponse;
  import org.apache.bookkeeper.stats.StatsProvider;
  import org.junit.Before;
  import org.junit.Test;
  
  /**
   * Unit test {@link MetricsService}.
   */
  public class MetricsServiceTest {
  
      private StatsProvider mockStatsProvider;
      private MetricsService service;
  
      @Before
      public void setup() {
          this.mockStatsProvider = mock(StatsProvider.class);
          this.service = new MetricsService(new ServerConfiguration(), mockStatsProvider);
      }
  
      @Test
      public void testForbiddenMethods() throws Exception {
          HttpServiceRequest request = new HttpServiceRequest().setMethod(Method.PUT);
          HttpServiceResponse response = service.handle(request);
          assertEquals(StatusCode.FORBIDDEN.getValue(), response.getStatusCode());
          assertNull(response.getContentType());
          assertEquals(
              "PUT is forbidden. Should be GET method",
              response.getBody());
      }
  
      @Test
      public void testNullStatsProvider() throws Exception {
          service = new MetricsService(new ServerConfiguration(), null);
          HttpServiceRequest request = new HttpServiceRequest().setMethod(Method.GET);
          HttpServiceResponse response = service.handle(request);
          assertEquals(StatusCode.INTERNAL_ERROR.getValue(), response.getStatusCode());
          assertNull(response.getContentType());
          assertEquals(
              "Stats provider is not enabled. Please enable it by set statsProviderClass"
                  + " on bookie configuration",
              response.getBody());
      }
  
      @Test
      public void testWriteMetrics() throws Exception {
          String content = "test-metrics";
  
          doAnswer(invocationOnMock -> {
              Writer writer = invocationOnMock.getArgument(0);
              writer.write(content);
              return null;
          }).when(mockStatsProvider).writeAllMetrics(any(Writer.class));
  
          HttpServiceRequest request = new HttpServiceRequest().setMethod(Method.GET);
          HttpServiceResponse response = service.handle(request);
  
          assertEquals(StatusCode.OK.getValue(), response.getStatusCode());
          assertEquals(MetricsService.PROMETHEUS_CONTENT_TYPE_004, response.getContentType());
          assertEquals(content, response.getBody());
      }
  
      @Test
      public void testWriteMetricsException() throws Exception {
          doThrow(new IOException("write-metrics-exception"))
              .when(mockStatsProvider).writeAllMetrics(any(Writer.class));
  
          HttpServiceRequest request = new HttpServiceRequest().setMethod(Method.GET);
          HttpServiceResponse response = service.handle(request);
  
          assertEquals(StatusCode.INTERNAL_ERROR.getValue(), response.getStatusCode());
          assertNull(response.getContentType());
          assertEquals("Exceptions are thrown when exporting metrics : write-metrics-exception",
              response.getBody());
      }
  
      @Test
      public void testWriteMetricsUnimplemented() throws Exception {
          mockStatsProvider = mock(StatsProvider.class, CALLS_REAL_METHODS);
          service = new MetricsService(new ServerConfiguration(), mockStatsProvider);
  
          HttpServiceRequest request = new HttpServiceRequest().setMethod(Method.GET);
          HttpServiceResponse response = service.handle(request);
  
          assertEquals(StatusCode.INTERNAL_ERROR.getValue(), response.getStatusCode());
          assertNull(response.getContentType());
          assertEquals("Currently stats provider doesn't support exporting metrics in http service",
              response.getBody());
      }
  
  }
  