chore(admin): add endpoint to count unique task workers

Related to CAM-12486
Closes #320

webapps/src/main/java/org/camunda/bpm/admin/impl/plugin/AdminPlugins.java

@@ -20,6 +20,7 @@
 import java.util.Set;
 
 import org.camunda.bpm.admin.impl.plugin.resources.AdminPluginsRootResource;
+import org.camunda.bpm.admin.impl.plugin.resources.BaseRootResource;
 import org.camunda.bpm.admin.plugin.spi.impl.AbstractAdminPlugin;
 
 /**
@@ -40,6 +41,7 @@ public Set<Class<?>> getResourceClasses() {
     HashSet<Class<?>> classes = new HashSet<Class<?>>();
 
     classes.add(AdminPluginsRootResource.class);
+    classes.add(BaseRootResource.class);
 
     return classes;
   }

webapps/src/main/java/org/camunda/bpm/admin/impl/plugin/resources/BaseRootResource.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH
+ * under one or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information regarding copyright
+ * ownership. Camunda licenses this file to you under the Apache License,
+ * Version 2.0; 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.camunda.bpm.admin.impl.plugin.resources;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.camunda.bpm.admin.resource.AbstractAdminPluginRootResource;
+import org.camunda.bpm.engine.rest.util.ProvidersUtil;
+
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.ext.Providers;
+
+@Path("plugin/base")
+public class BaseRootResource extends AbstractAdminPluginRootResource {
+
+  @Context
+  protected Providers providers;
+
+  public BaseRootResource() {
+    super("base");
+  }
+
+  @Path("{engine}" + MetricsRestService.PATH)
+  public MetricsRestService getProcessDefinitionResource(@PathParam("engine") String engineName) {
+    MetricsRestService metricsRestService = new MetricsRestService(engineName);
+    metricsRestService.setObjectMapper(getObjectMapper());
+    return subResource(metricsRestService, engineName);
+  }
+
+  protected ObjectMapper getObjectMapper() {
+    if (providers != null) {
+      return ProvidersUtil
+        .resolveFromContext(providers, ObjectMapper.class, MediaType.APPLICATION_JSON_TYPE, this.getClass());
+    } else {
+      return null;
+    }
+  }
+
+}

webapps/src/main/java/org/camunda/bpm/admin/impl/plugin/resources/MetricsRestService.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH
+ * under one or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information regarding copyright
+ * ownership. Camunda licenses this file to you under the Apache License,
+ * Version 2.0; 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.camunda.bpm.admin.impl.plugin.resources;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.camunda.bpm.admin.Admin;
+import org.camunda.bpm.admin.resource.AbstractAdminPluginResource;
+import org.camunda.bpm.engine.ProcessEngine;
+import org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl;
+import org.camunda.bpm.engine.rest.dto.converter.DateConverter;
+import org.camunda.bpm.engine.rest.dto.metrics.MetricsResultDto;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.MediaType;
+import java.util.Date;
+
+@Produces(MediaType.APPLICATION_JSON)
+public class MetricsRestService extends AbstractAdminPluginResource {
+
+  public static final String PATH = "/metrics";
+
+  public static final String QUERY_PARAM_START_DATE = "startDate";
+  public static final String QUERY_PARAM_END_DATE = "endDate";
+
+  protected ObjectMapper objectMapper;
+
+  public MetricsRestService(String engineName) {
+    super(engineName);
+  }
+
+  @GET
+  @Path("/task-worker/sum")
+  @Produces(MediaType.APPLICATION_JSON)
+  public MetricsResultDto countUniqueTaskWorkers(@QueryParam(QUERY_PARAM_START_DATE) String startDateAsString,
+                                                 @QueryParam(QUERY_PARAM_END_DATE) String endDateAsString) {
+    ProcessEngine processEngine = Admin.getRuntimeDelegate().getProcessEngine(engineName);
+    ProcessEngineConfigurationImpl engineConfig =
+      ((ProcessEngineConfigurationImpl)processEngine.getProcessEngineConfiguration());
+    return engineConfig.getCommandExecutorTxRequired().execute(commandContext -> {
+      // analogous to metrics, no permission check is performed
+
+      DateConverter dateConverter = new DateConverter();
+      dateConverter.setObjectMapper(objectMapper);
+
+      Date startDate = convertToDate(dateConverter, startDateAsString);
+      Date endDate = convertToDate(dateConverter, endDateAsString);
+
+      MetricsResultDto result = new MetricsResultDto();
+      long count = commandContext.getHistoricTaskInstanceManager()
+        .findUniqueTaskWorkerCount(startDate, endDate);
+
+      result.setResult(count);
+
+      return result;
+    });
+  }
+
+  protected Date convertToDate(DateConverter dateConverter,
+                               String dateAsString) {
+    return dateConverter.convertQueryParameterToType(dateAsString);
+  }
+
+  public void setObjectMapper(ObjectMapper objectMapper) {
+    this.objectMapper = objectMapper;
+  }
+
+}

webapps/src/test/java/org/camunda/bpm/admin/plugin/base/AbstractAdminPluginTest.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH
+ * under one or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information regarding copyright
+ * ownership. Camunda licenses this file to you under the Apache License,
+ * Version 2.0; 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.camunda.bpm.admin.plugin.base;
+
+import org.apache.ibatis.logging.LogFactory;
+import org.camunda.bpm.admin.Admin;
+import org.camunda.bpm.admin.impl.DefaultAdminRuntimeDelegate;
+import org.camunda.bpm.engine.ProcessEngine;
+import org.camunda.bpm.engine.impl.util.LogUtil;
+import org.camunda.bpm.engine.test.ProcessEngineRule;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Rule;
+
+public abstract class AbstractAdminPluginTest {
+
+  protected static final TestAdminRuntimeDelegate RUNTIME_DELEGATE = new TestAdminRuntimeDelegate();
+
+  static {
+    LogUtil.readJavaUtilLoggingConfigFromClasspath();
+    LogFactory.useJdkLogging();
+  }
+
+  @Rule
+  public ProcessEngineRule processEngineRule = new ProcessEngineRule(true);
+
+  @BeforeClass
+  public static void beforeClass() {
+    Admin.setAdminRuntimeDelegate(RUNTIME_DELEGATE);
+  }
+
+  @AfterClass
+  public static void afterClass() {
+    Admin.setAdminRuntimeDelegate(null);
+  }
+
+  @Before
+  public void before() {
+    RUNTIME_DELEGATE.ENGINE = getProcessEngine();
+  }
+
+  @After
+  public void after() {
+    RUNTIME_DELEGATE.ENGINE = null;
+    getProcessEngine().getIdentityService().clearAuthentication();
+  }
+
+  public ProcessEngine getProcessEngine() {
+    return processEngineRule.getProcessEngine();
+  }
+
+  private static class TestAdminRuntimeDelegate extends DefaultAdminRuntimeDelegate {
+
+    public ProcessEngine ENGINE;
+
+    @Override
+    public ProcessEngine getProcessEngine(String processEngineName) {
+
+      // always return default engine for plugin tests
+      return ENGINE;
+    }
+  }
+}

webapps/src/test/java/org/camunda/bpm/admin/plugin/base/MetricsRestServiceTest.java

@@ -0,0 +1,141 @@
+/*
+ * Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH
+ * under one or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information regarding copyright
+ * ownership. Camunda licenses this file to you under the Apache License,
+ * Version 2.0; 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.camunda.bpm.admin.plugin.base;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.camunda.bpm.admin.impl.plugin.resources.MetricsRestService;
+import org.camunda.bpm.engine.ProcessEngine;
+import org.camunda.bpm.engine.ProcessEngineConfiguration;
+import org.camunda.bpm.engine.RuntimeService;
+import org.camunda.bpm.engine.TaskService;
+import org.camunda.bpm.engine.impl.util.ClockUtil;
+import org.camunda.bpm.engine.rest.dto.metrics.MetricsResultDto;
+import org.camunda.bpm.engine.test.Deployment;
+import org.camunda.bpm.engine.test.RequiredHistoryLevel;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RequiredHistoryLevel(ProcessEngineConfiguration.HISTORY_ACTIVITY)
+public class MetricsRestServiceTest extends AbstractAdminPluginTest {
+
+  public static final SimpleDateFormat DATE_FORMAT =
+    new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+
+  protected MetricsRestService resource;
+  protected ProcessEngine processEngine;
+  protected RuntimeService runtimeService;
+  protected TaskService taskService;
+
+  @Before
+  public void setUp() {
+    super.before();
+    processEngine = getProcessEngine();
+    runtimeService = processEngine.getRuntimeService();
+    resource = new MetricsRestService(processEngine.getName());
+    ObjectMapper objectMapper = new ObjectMapper();
+    resource.setObjectMapper(objectMapper);
+    taskService = processEngine.getTaskService();
+  }
+
+  @After
+  public void reset() {
+    ClockUtil.reset();
+  }
+
+  @Test
+  @Deployment(resources = {
+    "processes/user-task-process.bpmn"
+  })
+  public void shouldCountUniqueTaskWorkers_StartTimeInBetween() throws ParseException {
+    // given
+    Date currentTime = DATE_FORMAT.parse("2020-01-02T00:00:00.000+0100");
+    ClockUtil.setCurrentTime(currentTime);
+
+    runtimeService.startProcessInstanceByKey("userTaskProcess");
+    String taskId = taskService.createTaskQuery().singleResult().getId();
+
+    taskService.setAssignee(taskId, "foo");
+
+    String startDateAsString = "2020-01-01T00:00:00.000+0100";
+    String endDateAsString = "2020-01-03T00:00:00.000+0100";
+
+    // when
+    MetricsResultDto metricsResultDto =
+      resource.countUniqueTaskWorkers(startDateAsString, endDateAsString);
+
+    // then
+    assertThat(metricsResultDto.getResult()).isEqualTo(1L);
+  }
+
+  @Test
+  @Deployment(resources = {
+    "processes/user-task-process.bpmn"
+  })
+  public void shouldCountUniqueTaskWorkers_StartTimeBefore() throws ParseException {
+    // given
+    Date currentTime = DATE_FORMAT.parse("2019-12-31T00:00:00.000+0100");
+    ClockUtil.setCurrentTime(currentTime);
+
+    runtimeService.startProcessInstanceByKey("userTaskProcess");
+    String taskId = taskService.createTaskQuery().singleResult().getId();
+
+    taskService.setAssignee(taskId, "foo");
+
+    String startDateAsString = "2020-01-01T00:00:00.000+0100";
+    String endDateAsString = "2020-01-03T00:00:00.000+0100";
+
+    // when
+    MetricsResultDto metricsResultDto =
+      resource.countUniqueTaskWorkers(startDateAsString, endDateAsString);
+
+    // then
+    assertThat(metricsResultDto.getResult()).isEqualTo(0L);
+  }
+
+  @Test
+  @Deployment(resources = {
+    "processes/user-task-process.bpmn"
+  })
+  public void shouldCountUniqueTaskWorkers_StartTimeAfter() throws ParseException {
+    // given
+    Date currentTime = DATE_FORMAT.parse("2020-01-04T00:00:00.000+0100");
+    ClockUtil.setCurrentTime(currentTime);
+
+    runtimeService.startProcessInstanceByKey("userTaskProcess");
+    String taskId = taskService.createTaskQuery().singleResult().getId();
+
+    taskService.setAssignee(taskId, "foo");
+
+    String startDateAsString = "2020-01-01T00:00:00.000+0100";
+    String endDateAsString = "2020-01-03T00:00:00.000+0100";
+
+    // when
+    MetricsResultDto metricsResultDto =
+      resource.countUniqueTaskWorkers(startDateAsString, endDateAsString);
+
+    // then
+    assertThat(metricsResultDto.getResult()).isEqualTo(0L);
+  }
+
+}