/*
    * 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.client;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  
  import java.io.IOException;
  import java.net.UnknownHostException;
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.HRegionLocation;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.ServerName;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.testclassification.ClientTests;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  /**
   * Tests that we fail fast when hostname resolution is not working and do not cache
   * unresolved InetSocketAddresses.
   */
  @Category({MediumTests.class, ClientTests.class})
  public class TestConnectionImplementation {
    private static HBaseTestingUtility testUtil;
    private static ConnectionManager.HConnectionImplementation conn;
  
    @BeforeClass
    public static void setupBeforeClass() throws Exception {
      testUtil = HBaseTestingUtility.createLocalHTU();
      testUtil.startMiniCluster();
      conn = (ConnectionManager.HConnectionImplementation) testUtil.getConnection();
    }
  
    @AfterClass
    public static void teardownAfterClass() throws Exception {
      conn.close();
      testUtil.shutdownMiniCluster();
    }
  
    @Test(expected = UnknownHostException.class)
    public void testGetAdminBadHostname() throws Exception {
      // verify that we can get an instance with the cluster hostname
      ServerName master = testUtil.getHBaseCluster().getMaster().getServerName();
      try {
        conn.getAdmin(master);
      } catch (UnknownHostException uhe) {
        fail("Obtaining admin to the cluster master should have succeeded");
      }
  
      // test that we fail to get a client to an unresolvable hostname, which
      // means it won't be cached
      ServerName badHost =
          ServerName.valueOf("unknownhost.invalid:" + HConstants.DEFAULT_MASTER_PORT,
          System.currentTimeMillis());
      conn.getAdmin(badHost);
      fail("Obtaining admin to unresolvable hostname should have failed");
    }
  
    @Test(expected = UnknownHostException.class)
    public void testGetClientBadHostname() throws Exception {
      // verify that we can get an instance with the cluster hostname
      ServerName rs = testUtil.getHBaseCluster().getRegionServer(0).getServerName();
      try {
        conn.getClient(rs);
      } catch (UnknownHostException uhe) {
        fail("Obtaining client to the cluster regionserver should have succeeded");
      }
  
      // test that we fail to get a client to an unresolvable hostname, which
      // means it won't be cached
     ServerName badHost =
         ServerName.valueOf("unknownhost.invalid:" + HConstants.DEFAULT_REGIONSERVER_PORT,
         System.currentTimeMillis());
     conn.getAdmin(badHost);
     fail("Obtaining client to unresolvable hostname should have failed");
   }
 
   @Test
   public void testLocateRegionsWithRegionReplicas() throws IOException {
     int regionReplication = 3;
     byte[] family = Bytes.toBytes("cf");
     TableName tableName = TableName.valueOf("testLocateRegionsWithRegionReplicas");
 
     // Create a table with region replicas
     HTableDescriptor desc = new HTableDescriptor(tableName);
     desc.addFamily(new HColumnDescriptor(family));
     desc.setRegionReplication(regionReplication);
     testUtil.getConnection().getAdmin().createTable(desc);
 
     try (ConnectionManager.HConnectionImplementation con =
       (ConnectionManager.HConnectionImplementation) ConnectionFactory.
         createConnection(testUtil.getConfiguration())) {
 
       // Get locations of the regions of the table
       List<HRegionLocation> locations = con.locateRegions(tableName, false, false);
 
       // The size of the returned locations should be 3
       assertEquals(regionReplication, locations.size());
 
       // The replicaIds of the returned locations should be 0, 1 and 2
       Set<Integer> expectedReplicaIds = new HashSet<>(Arrays.asList(0, 1, 2));
       for (HRegionLocation location : locations) {
         assertTrue(expectedReplicaIds.remove(location.getRegionInfo().getReplicaId()));
       }
     } finally {
       testUtil.deleteTable(tableName);
     }
   }
 }