/**
 * 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.hadoop.hbase;

import java.io.IOException;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.naming.ServiceUnavailableException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
import org.apache.hadoop.hbase.coprocessor.MasterCoprocessorEnvironment;
import org.apache.hadoop.hbase.coprocessor.ObserverContext;
import org.apache.hadoop.hbase.coprocessor.RegionServerCoprocessorEnvironment;
import org.apache.hadoop.hbase.security.AccessDeniedException;
import org.apache.hadoop.hbase.security.access.AccessController;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.testclassification.MiscTests;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Test case for JMX Connector Server.
 */
@Category({ MiscTests.class, MediumTests.class })
public class TestJMXConnectorServer {

  @ClassRule
  public static final HBaseClassTestRule CLASS_RULE =
      HBaseClassTestRule.forClass(TestJMXConnectorServer.class);

  private static final Logger LOG = LoggerFactory.getLogger(TestJMXConnectorServer.class);
  private static HBaseTestingUtility UTIL = new HBaseTestingUtility();

  private static Configuration conf = null;
  private static Admin admin;
  // RMI registry port
  private static int rmiRegistryPort;
  // Switch for customized Accesscontroller to throw ACD exception while executing test case
  private volatile static boolean hasAccess;

  @BeforeClass
  public static void setUpBeforeClass() throws Exception {
    conf = UTIL.getConfiguration();
    String cps = JMXListener.class.getName() + "," + MyAccessController.class.getName();
    conf.set(CoprocessorHost.MASTER_COPROCESSOR_CONF_KEY, cps);
    conf.set(CoprocessorHost.REGIONSERVER_COPROCESSOR_CONF_KEY, cps);
    rmiRegistryPort = UTIL.randomFreePort();
    conf.setInt("master.rmi.registry.port", rmiRegistryPort);
    conf.setInt("regionserver.rmi.registry.port", rmiRegistryPort);
    UTIL.startMiniCluster();
    admin = UTIL.getConnection().getAdmin();
  }

  @AfterClass
  public static void tearDownAfterClass() throws Exception {
    admin.close();
    UTIL.shutdownMiniCluster();
  }

  @Before
  public void setUp() {
    hasAccess = false;
  }

  @After
  public void tearDown() {
    hasAccess = true;
  }

  /**
   * This tests to validate the HMaster's ConnectorServer after unauthorised stopMaster call.
   */
  @Test
  public void testHMConnectorServerWhenStopMaster() throws Exception {
    // try to stop master
    boolean accessDenied = false;
    try {
      LOG.info("Stopping HMaster...");
      admin.stopMaster();
    } catch (AccessDeniedException e) {
      LOG.info("Exception occurred while stopping HMaster. ", e);
      accessDenied = true;
    }
    Assert.assertTrue(accessDenied);

    checkConnector();
  }

  /**
   * This tests to validate the RegionServer's ConnectorServer after unauthorised stopRegionServer
   * call.
   */
  @Test
  public void testRSConnectorServerWhenStopRegionServer() throws Exception {
    ServerName serverName = UTIL.getHBaseCluster().getRegionServer(0).getServerName();
    LOG.info("Stopping Region Server...");
    admin.stopRegionServer(serverName.getHostname() + ":" + serverName.getPort());

    checkConnector();
  }

  /**
   * This tests to validate the HMaster's ConnectorServer after unauthorised shutdown call.
   */
  @Test
  public void testHMConnectorServerWhenShutdownCluster() throws Exception {
    boolean accessDenied = false;
    try {
      LOG.info("Stopping HMaster...");
      admin.shutdown();
    } catch (AccessDeniedException e) {
      LOG.error("Exception occurred while stopping HMaster. ", e);
      accessDenied = true;
    }
    Assert.assertTrue(accessDenied);

    checkConnector();
  }

  private void checkConnector() throws Exception {
    // Check whether HMaster JMX Connector server can be connected
    JMXConnector connector = null;
    try {
      connector = JMXConnectorFactory
        .connect(JMXListener.buildJMXServiceURL(rmiRegistryPort, rmiRegistryPort));
    } catch (IOException e) {
      if (e.getCause() instanceof ServiceUnavailableException) {
        Assert.fail("Can't connect to ConnectorServer.");
      }
    }
    Assert.assertNotNull("JMXConnector should not be null.", connector);
    connector.close();
  }

  /*
   * Customized class for test case execution which will throw ACD exception while executing
   * stopMaster/preStopRegionServer/preShutdown explicitly.
   */
  public static class MyAccessController extends AccessController {
    @Override
    public void postStartMaster(ObserverContext<MasterCoprocessorEnvironment> ctx) {
      // Do nothing. In particular, stop the creation of the hbase:acl table. It makes the
      // shutdown take time.
    }

    @Override
    public void preStopMaster(ObserverContext<MasterCoprocessorEnvironment> c) throws IOException {
      if (!hasAccess) {
        throw new AccessDeniedException("Insufficient permissions to stop master");
      }
    }

    @Override
    public void preStopRegionServer(ObserverContext<RegionServerCoprocessorEnvironment> ctx)
        throws IOException {
      if (!hasAccess) {
        throw new AccessDeniedException("Insufficient permissions to stop region server.");
      }
    }

    @Override
    public void preShutdown(ObserverContext<MasterCoprocessorEnvironment> c) throws IOException {
      if (!hasAccess) {
        throw new AccessDeniedException("Insufficient permissions to shut down cluster.");
      }
    }

    @Override
    public void preExecuteProcedures(ObserverContext<RegionServerCoprocessorEnvironment> ctx)
        throws IOException {
      // FIXME: ignore the procedure permission check since in our UT framework master is neither
      // the systemuser nor the superuser so we can not call executeProcedures...
    }
  }
}