/*
 * 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.replication;

import static org.hamcrest.CoreMatchers.hasItems;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.replication.ReplicationPeer.PeerState;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.hbase.zookeeper.MiniZooKeeperCluster;
import org.apache.hadoop.hbase.zookeeper.ZKConfig;
import org.apache.zookeeper.KeeperException;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.hbase.thirdparty.com.google.common.collect.ImmutableMap;

/**
 * White box testing for replication state interfaces. Implementations should extend this class, and
 * initialize the interfaces properly.
 */
public abstract class TestReplicationStateBasic {

  private static final Logger LOG = LoggerFactory.getLogger(TestReplicationStateBasic.class);

  protected ReplicationQueueStorage rqs;
  protected ServerName server1 = ServerName.valueOf("hostname1.example.org", 1234, 12345);
  protected ServerName server2 = ServerName.valueOf("hostname2.example.org", 1234, 12345);
  protected ServerName server3 = ServerName.valueOf("hostname3.example.org", 1234, 12345);
  protected ReplicationPeers rp;
  protected static final String ID_ONE = "1";
  protected static final String ID_TWO = "2";
  protected static String KEY_ONE;
  protected static String KEY_TWO;

  // For testing when we try to replicate to ourself
  protected String OUR_KEY;

  protected static int zkTimeoutCount;
  protected static final int ZK_MAX_COUNT = 300;
  protected static final int ZK_SLEEP_INTERVAL = 100; // millis

  @Test
  public void testReplicationQueueStorage() throws ReplicationException {
    // Test methods with empty state
    assertEquals(0, rqs.getListOfReplicators().size());
    assertTrue(rqs.getWALsInQueue(server1, "qId1").isEmpty());
    assertTrue(rqs.getAllQueues(server1).isEmpty());

    /*
     * Set up data Two replicators: -- server1: three queues with 0, 1 and 2 log files each --
     * server2: zero queues
     */
    rqs.addWAL(server1, "qId1", "trash");
    rqs.removeWAL(server1, "qId1", "trash");
    rqs.addWAL(server1, "qId2", "filename1");
    rqs.addWAL(server1, "qId3", "filename2");
    rqs.addWAL(server1, "qId3", "filename3");
    rqs.addWAL(server2, "trash", "trash");
    rqs.removeQueue(server2, "trash");

    List<ServerName> reps = rqs.getListOfReplicators();
    assertEquals(2, reps.size());
    assertTrue(server1.getServerName(), reps.contains(server1));
    assertTrue(server2.getServerName(), reps.contains(server2));

    assertTrue(rqs.getWALsInQueue(ServerName.valueOf("bogus", 12345, 12345), "bogus").isEmpty());
    assertTrue(rqs.getWALsInQueue(server1, "bogus").isEmpty());
    assertEquals(0, rqs.getWALsInQueue(server1, "qId1").size());
    assertEquals(1, rqs.getWALsInQueue(server1, "qId2").size());
    assertEquals("filename1", rqs.getWALsInQueue(server1, "qId2").get(0));

    assertTrue(rqs.getAllQueues(ServerName.valueOf("bogus", 12345, -1L)).isEmpty());
    assertEquals(0, rqs.getAllQueues(server2).size());
    List<String> list = rqs.getAllQueues(server1);
    assertEquals(3, list.size());
    assertTrue(list.contains("qId2"));
    assertTrue(list.contains("qId3"));
  }

  private void removeAllQueues(ServerName serverName) throws ReplicationException {
    for (String queue : rqs.getAllQueues(serverName)) {
      rqs.removeQueue(serverName, queue);
    }
  }

  @Test
  public void testReplicationQueues() throws ReplicationException {
    // Initialize ReplicationPeer so we can add peers (we don't transfer lone queues)
    rp.init();

    rqs.removeQueue(server1, "bogus");
    rqs.removeWAL(server1, "bogus", "bogus");
    removeAllQueues(server1);
    assertEquals(0, rqs.getAllQueues(server1).size());
    assertEquals(0, rqs.getWALPosition(server1, "bogus", "bogus"));
    assertTrue(rqs.getWALsInQueue(server1, "bogus").isEmpty());
    assertTrue(rqs.getAllQueues(ServerName.valueOf("bogus", 1234, 12345)).isEmpty());

    populateQueues();

    assertEquals(3, rqs.getListOfReplicators().size());
    assertEquals(0, rqs.getWALsInQueue(server2, "qId1").size());
    assertEquals(5, rqs.getWALsInQueue(server3, "qId5").size());
    assertEquals(0, rqs.getWALPosition(server3, "qId1", "filename0"));
    rqs.setWALPosition(server3, "qId5", "filename4", 354L, Collections.emptyMap());
    assertEquals(354L, rqs.getWALPosition(server3, "qId5", "filename4"));

    assertEquals(5, rqs.getWALsInQueue(server3, "qId5").size());
    assertEquals(0, rqs.getWALsInQueue(server2, "qId1").size());
    assertEquals(0, rqs.getAllQueues(server1).size());
    assertEquals(1, rqs.getAllQueues(server2).size());
    assertEquals(5, rqs.getAllQueues(server3).size());

    assertEquals(0, rqs.getAllQueues(server1).size());
    rqs.removeReplicatorIfQueueIsEmpty(server1);
    assertEquals(2, rqs.getListOfReplicators().size());

    List<String> queues = rqs.getAllQueues(server3);
    assertEquals(5, queues.size());
    for (String queue : queues) {
      rqs.claimQueue(server3, queue, server2);
    }
    rqs.removeReplicatorIfQueueIsEmpty(server3);
    assertEquals(1, rqs.getListOfReplicators().size());

    assertEquals(6, rqs.getAllQueues(server2).size());
    removeAllQueues(server2);
    rqs.removeReplicatorIfQueueIsEmpty(server2);
    assertEquals(0, rqs.getListOfReplicators().size());
  }

  @Test
  public void testHfileRefsReplicationQueues() throws ReplicationException, KeeperException {
    rp.init();

    List<Pair<Path, Path>> files1 = new ArrayList<>(3);
    files1.add(new Pair<>(null, new Path("file_1")));
    files1.add(new Pair<>(null, new Path("file_2")));
    files1.add(new Pair<>(null, new Path("file_3")));
    assertTrue(rqs.getReplicableHFiles(ID_ONE).isEmpty());
    assertEquals(0, rqs.getAllPeersFromHFileRefsQueue().size());
    rp.getPeerStorage().addPeer(ID_ONE,
      ReplicationPeerConfig.newBuilder().setClusterKey(KEY_ONE).build(), true,
      SyncReplicationState.NONE);
    rqs.addPeerToHFileRefs(ID_ONE);
    rqs.addHFileRefs(ID_ONE, files1);
    assertEquals(1, rqs.getAllPeersFromHFileRefsQueue().size());
    assertEquals(3, rqs.getReplicableHFiles(ID_ONE).size());
    List<String> hfiles2 = new ArrayList<>(files1.size());
    for (Pair<Path, Path> p : files1) {
      hfiles2.add(p.getSecond().getName());
    }
    String removedString = hfiles2.remove(0);
    rqs.removeHFileRefs(ID_ONE, hfiles2);
    assertEquals(1, rqs.getReplicableHFiles(ID_ONE).size());
    hfiles2 = new ArrayList<>(1);
    hfiles2.add(removedString);
    rqs.removeHFileRefs(ID_ONE, hfiles2);
    assertEquals(0, rqs.getReplicableHFiles(ID_ONE).size());
    rp.getPeerStorage().removePeer(ID_ONE);
  }

  @Test
  public void testRemovePeerForHFileRefs() throws ReplicationException, KeeperException {
    rp.init();
    rp.getPeerStorage().addPeer(ID_ONE,
      ReplicationPeerConfig.newBuilder().setClusterKey(KEY_ONE).build(), true,
      SyncReplicationState.NONE);
    rqs.addPeerToHFileRefs(ID_ONE);
    rp.getPeerStorage().addPeer(ID_TWO,
      ReplicationPeerConfig.newBuilder().setClusterKey(KEY_TWO).build(), true,
      SyncReplicationState.NONE);
    rqs.addPeerToHFileRefs(ID_TWO);

    List<Pair<Path, Path>> files1 = new ArrayList<>(3);
    files1.add(new Pair<>(null, new Path("file_1")));
    files1.add(new Pair<>(null, new Path("file_2")));
    files1.add(new Pair<>(null, new Path("file_3")));
    rqs.addHFileRefs(ID_ONE, files1);
    rqs.addHFileRefs(ID_TWO, files1);
    assertEquals(2, rqs.getAllPeersFromHFileRefsQueue().size());
    assertEquals(3, rqs.getReplicableHFiles(ID_ONE).size());
    assertEquals(3, rqs.getReplicableHFiles(ID_TWO).size());

    rp.getPeerStorage().removePeer(ID_ONE);
    rqs.removePeerFromHFileRefs(ID_ONE);
    assertEquals(1, rqs.getAllPeersFromHFileRefsQueue().size());
    assertTrue(rqs.getReplicableHFiles(ID_ONE).isEmpty());
    assertEquals(3, rqs.getReplicableHFiles(ID_TWO).size());

    rp.getPeerStorage().removePeer(ID_TWO);
    rqs.removePeerFromHFileRefs(ID_TWO);
    assertEquals(0, rqs.getAllPeersFromHFileRefsQueue().size());
    assertTrue(rqs.getReplicableHFiles(ID_TWO).isEmpty());
  }

  @Test
  public void testReplicationPeers() throws Exception {
    rp.init();

    try {
      rp.getPeerStorage().setPeerState("bogus", true);
      fail("Should have thrown an IllegalArgumentException when passed a bogus peerId");
    } catch (ReplicationException e) {
    }
    try {
      rp.getPeerStorage().setPeerState("bogus", false);
      fail("Should have thrown an IllegalArgumentException when passed a bogus peerId");
    } catch (ReplicationException e) {
    }

    try {
      assertFalse(rp.addPeer("bogus"));
      fail("Should have thrown an ReplicationException when passed a bogus peerId");
    } catch (ReplicationException e) {
    }

    assertNumberOfPeers(0);

    // Add some peers
    rp.getPeerStorage().addPeer(ID_ONE,
      ReplicationPeerConfig.newBuilder().setClusterKey(KEY_ONE).build(), true,
      SyncReplicationState.NONE);
    assertNumberOfPeers(1);
    rp.getPeerStorage().addPeer(ID_TWO,
      ReplicationPeerConfig.newBuilder().setClusterKey(KEY_TWO).build(), true,
      SyncReplicationState.NONE);
    assertNumberOfPeers(2);

    assertEquals(KEY_ONE, ZKConfig.getZooKeeperClusterKey(ReplicationUtils
      .getPeerClusterConfiguration(rp.getPeerStorage().getPeerConfig(ID_ONE), rp.getConf())));
    rp.getPeerStorage().removePeer(ID_ONE);
    rp.removePeer(ID_ONE);
    assertNumberOfPeers(1);

    // Add one peer
    rp.getPeerStorage().addPeer(ID_ONE,
      ReplicationPeerConfig.newBuilder().setClusterKey(KEY_ONE).build(), true,
      SyncReplicationState.NONE);
    rp.addPeer(ID_ONE);
    assertNumberOfPeers(2);
    assertTrue(rp.getPeer(ID_ONE).isPeerEnabled());
    rp.getPeerStorage().setPeerState(ID_ONE, false);
    // now we do not rely on zk watcher to trigger the state change so we need to trigger it
    // manually...
    ReplicationPeerImpl peer = rp.getPeer(ID_ONE);
    rp.refreshPeerState(peer.getId());
    assertEquals(PeerState.DISABLED, peer.getPeerState());
    assertConnectedPeerStatus(false, ID_ONE);
    rp.getPeerStorage().setPeerState(ID_ONE, true);
    // now we do not rely on zk watcher to trigger the state change so we need to trigger it
    // manually...
    rp.refreshPeerState(peer.getId());
    assertEquals(PeerState.ENABLED, peer.getPeerState());
    assertConnectedPeerStatus(true, ID_ONE);

    // Disconnect peer
    rp.removePeer(ID_ONE);
    assertNumberOfPeers(2);
  }

  private String getFileName(String base, int i) {
    return String.format(base + "-%04d", i);
  }

  @Test
  public void testPersistLogPositionAndSeqIdAtomically() throws Exception {
    ServerName serverName1 = ServerName.valueOf("127.0.0.1", 8000, 10000);
    assertTrue(rqs.getAllQueues(serverName1).isEmpty());
    String queue1 = "1";
    String region0 = "6b2c8f8555335cc9af74455b94516cbe",
        region1 = "6ecd2e9e010499f8ddef97ee8f70834f";
    for (int i = 0; i < 10; i++) {
      rqs.addWAL(serverName1, queue1, getFileName("file1", i));
    }
    List<String> queueIds = rqs.getAllQueues(serverName1);
    assertEquals(1, queueIds.size());
    assertThat(queueIds, hasItems("1"));

    List<String> wals1 = rqs.getWALsInQueue(serverName1, queue1);
    assertEquals(10, wals1.size());
    for (int i = 0; i < 10; i++) {
      assertThat(wals1, hasItems(getFileName("file1", i)));
    }

    for (int i = 0; i < 10; i++) {
      assertEquals(0, rqs.getWALPosition(serverName1, queue1, getFileName("file1", i)));
    }
    assertEquals(HConstants.NO_SEQNUM, rqs.getLastSequenceId(region0, queue1));
    assertEquals(HConstants.NO_SEQNUM, rqs.getLastSequenceId(region1, queue1));

    for (int i = 0; i < 10; i++) {
      rqs.setWALPosition(serverName1, queue1, getFileName("file1", i), (i + 1) * 100,
        ImmutableMap.of(region0, i * 100L, region1, (i + 1) * 100L));
    }

    for (int i = 0; i < 10; i++) {
      assertEquals((i + 1) * 100, rqs.getWALPosition(serverName1, queue1, getFileName("file1", i)));
    }
    assertEquals(900L, rqs.getLastSequenceId(region0, queue1));
    assertEquals(1000L, rqs.getLastSequenceId(region1, queue1));

    // Try to decrease the last pushed id by setWALPosition method.
    rqs.setWALPosition(serverName1, queue1, getFileName("file1", 0), 11 * 100,
      ImmutableMap.of(region0, 899L, region1, 1001L));
    assertEquals(900L, rqs.getLastSequenceId(region0, queue1));
    assertEquals(1001L, rqs.getLastSequenceId(region1, queue1));
  }

  protected void assertConnectedPeerStatus(boolean status, String peerId) throws Exception {
    // we can first check if the value was changed in the store, if it wasn't then fail right away
    if (status != rp.getPeerStorage().isPeerEnabled(peerId)) {
      fail("ConnectedPeerStatus was " + !status + " but expected " + status + " in ZK");
    }
    while (true) {
      if (status == rp.getPeer(peerId).isPeerEnabled()) {
        return;
      }
      if (zkTimeoutCount < ZK_MAX_COUNT) {
        LOG.debug("ConnectedPeerStatus was " + !status + " but expected " + status
          + ", sleeping and trying again.");
        Thread.sleep(ZK_SLEEP_INTERVAL);
      } else {
        fail("Timed out waiting for ConnectedPeerStatus to be " + status);
      }
    }
  }

  protected void assertNumberOfPeers(int total) throws ReplicationException {
    assertEquals(total, rp.getPeerStorage().listPeerIds().size());
  }

  /*
   * three replicators: rq1 has 0 queues, rq2 has 1 queue with no logs, rq3 has 5 queues with 1, 2,
   * 3, 4, 5 log files respectively
   */
  protected void populateQueues() throws ReplicationException {
    rqs.addWAL(server1, "trash", "trash");
    rqs.removeQueue(server1, "trash");

    rqs.addWAL(server2, "qId1", "trash");
    rqs.removeWAL(server2, "qId1", "trash");

    for (int i = 1; i < 6; i++) {
      for (int j = 0; j < i; j++) {
        rqs.addWAL(server3, "qId" + i, "filename" + j);
      }
      // Add peers for the corresponding queues so they are not orphans
      rp.getPeerStorage().addPeer("qId" + i,
        ReplicationPeerConfig.newBuilder()
          .setClusterKey(MiniZooKeeperCluster.HOST + ":2818:/bogus" + i).build(),
        true, SyncReplicationState.NONE);
    }
  }
}