/**
 * 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.hdfs.server.datanode;

import static org.junit.Assert.assertEquals;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSUtil;
import org.junit.Before;
import org.junit.Test;
import org.mockito.Mockito;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;


public class TestBlockPoolManager {
  private Log LOG = LogFactory.getLog(TestBlockPoolManager.class);
  private DataNode mockDN = Mockito.mock(DataNode.class);
  private BlockPoolManager bpm;
  private StringBuilder log = new StringBuilder();
  private int mockIdx = 1;
  
  @Before
  public void setupBPM() {
    bpm = new BlockPoolManager(mockDN){

      @Override
      protected BPOfferService createBPOS(List<InetSocketAddress> nnAddrs) {
        final int idx = mockIdx++;
        doLog("create #" + idx);
        final BPOfferService bpos = Mockito.mock(BPOfferService.class);
        Mockito.doReturn("Mock BPOS #" + idx).when(bpos).toString();
        // Log refreshes
        try {
          Mockito.doAnswer(
              new Answer<Void>() {
                @Override
                public Void answer(InvocationOnMock invocation) throws Throwable {
                  doLog("refresh #" + idx);
                  return null;
                }
              }).when(bpos).refreshNNList(
                  Mockito.<ArrayList<InetSocketAddress>>any());
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
        // Log stops
        Mockito.doAnswer(
            new Answer<Void>() {
              @Override
              public Void answer(InvocationOnMock invocation) throws Throwable {
                doLog("stop #" + idx);
                bpm.remove(bpos);
                return null;
              }
            }).when(bpos).stop();
        return bpos;
      }
    };
  }
  
  private void doLog(String string) {
    synchronized(log) {
      LOG.info(string);
      log.append(string).append("\n");
    }
  }

  @Test
  public void testSimpleSingleNS() throws Exception {
    Configuration conf = new Configuration();
    conf.set(DFSConfigKeys.FS_DEFAULT_NAME_KEY,
        "hdfs://mock1:8020");
    bpm.refreshNamenodes(conf);
    assertEquals("create #1\n", log.toString());
  }

  @Test
  public void testFederationRefresh() throws Exception {
    Configuration conf = new Configuration();
    conf.set(DFSConfigKeys.DFS_NAMESERVICES,
        "ns1,ns2");
    addNN(conf, "ns1", "mock1:8020");
    addNN(conf, "ns2", "mock1:8020");
    bpm.refreshNamenodes(conf);
    assertEquals(
        "create #1\n" +
        "create #2\n", log.toString());
    log.setLength(0);

    // Remove the first NS
    conf.set(DFSConfigKeys.DFS_NAMESERVICES,
        "ns1");
    bpm.refreshNamenodes(conf);
    assertEquals(
        "stop #1\n" +
        "refresh #2\n", log.toString());
    log.setLength(0);
    
    // Add back an NS -- this creates a new BPOS since the old
    // one for ns2 should have been previously retired
    conf.set(DFSConfigKeys.DFS_NAMESERVICES,
        "ns1,ns2");
    bpm.refreshNamenodes(conf);
    assertEquals(
        "create #3\n" +
        "refresh #2\n", log.toString());
  }

  private static void addNN(Configuration conf, String ns, String addr) {
    String key = DFSUtil.addKeySuffixes(
        DFSConfigKeys.DFS_NAMENODE_RPC_ADDRESS_KEY, ns);
    conf.set(key, addr);
  }
}
