/**
    * 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.util.hbck;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.Abortable;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.client.HConnection;
  import org.apache.hadoop.hbase.replication.ReplicationException;
  import org.apache.hadoop.hbase.replication.ReplicationFactory;
  import org.apache.hadoop.hbase.replication.ReplicationPeers;
  import org.apache.hadoop.hbase.replication.ReplicationQueueInfo;
  import org.apache.hadoop.hbase.replication.ReplicationQueuesClient;
  import org.apache.hadoop.hbase.replication.ReplicationStateZKBase;
  import org.apache.hadoop.hbase.util.HBaseFsck;
  import org.apache.hadoop.hbase.util.HBaseFsck.ErrorReporter;
  import org.apache.hadoop.hbase.zookeeper.ZKUtil;
  import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
  import org.apache.zookeeper.KeeperException;
  
  /*
   * Check and fix undeleted replication queues for removed peerId.
   */
  @InterfaceAudience.Private
  public class ReplicationChecker {
    private static final Log LOG = LogFactory.getLog(ReplicationChecker.class);
    private final ZooKeeperWatcher zkw;
    private ErrorReporter errorReporter;
    private ReplicationQueuesClient queuesClient;
    private ReplicationPeers replicationPeers;
    private ReplicationQueueDeletor queueDeletor;
    // replicator with its queueIds for removed peers
    private Map<String, List<String>> undeletedQueueIds = new HashMap<String, List<String>>();
    // Set of un deleted hfile refs queue Ids
    private Set<String> undeletedHFileRefsQueueIds = new HashSet<>();
    private final String hfileRefsZNode;
  
    public ReplicationChecker(Configuration conf, ZooKeeperWatcher zkw, HConnection connection,
        ErrorReporter errorReporter) throws IOException {
      try {
        this.zkw = zkw;
        this.errorReporter = errorReporter;
        this.queuesClient = ReplicationFactory.getReplicationQueuesClient(zkw, conf, connection);
        this.queuesClient.init();
        this.replicationPeers = ReplicationFactory.getReplicationPeers(zkw, conf, this.queuesClient,
          connection);
        this.replicationPeers.init();
        this.queueDeletor = new ReplicationQueueDeletor(zkw, conf, connection);
      } catch (ReplicationException e) {
        throw new IOException("failed to construct ReplicationChecker", e);
      }
  
      String replicationZNodeName = conf.get("zookeeper.znode.replication", "replication");
      String replicationZNode = ZKUtil.joinZNode(this.zkw.baseZNode, replicationZNodeName);
      String hfileRefsZNodeName =
          conf.get(ReplicationStateZKBase.ZOOKEEPER_ZNODE_REPLICATION_HFILE_REFS_KEY,
            ReplicationStateZKBase.ZOOKEEPER_ZNODE_REPLICATION_HFILE_REFS_DEFAULT);
      hfileRefsZNode = ZKUtil.joinZNode(replicationZNode, hfileRefsZNodeName);
    }
  
    public boolean hasUnDeletedQueues() {
      return errorReporter.getErrorList()
          .contains(HBaseFsck.ErrorReporter.ERROR_CODE.UNDELETED_REPLICATION_QUEUE);
    }
  
    public void checkUnDeletedQueues() throws IOException {
      Set<String> peerIds = new HashSet<String>(this.replicationPeers.getAllPeerIds());
      try {
        List<String> replicators = this.queuesClient.getListOfReplicators();
        if (replicators == null || replicators.isEmpty()) {
          return;
        }
       for (String replicator : replicators) {
         List<String> queueIds = this.queuesClient.getAllQueues(replicator);
         for (String queueId : queueIds) {
           ReplicationQueueInfo queueInfo = new ReplicationQueueInfo(queueId);
           if (!peerIds.contains(queueInfo.getPeerId())) {
             if (!undeletedQueueIds.containsKey(replicator)) {
               undeletedQueueIds.put(replicator, new ArrayList<String>());
             }
             undeletedQueueIds.get(replicator).add(queueId);
 
             String msg = "Undeleted replication queue for removed peer found: "
                 + String.format("[removedPeerId=%s, replicator=%s, queueId=%s]",
                   queueInfo.getPeerId(), replicator, queueId);
             errorReporter.reportError(
               HBaseFsck.ErrorReporter.ERROR_CODE.UNDELETED_REPLICATION_QUEUE, msg);
           }
         }
       }
     } catch (KeeperException ke) {
       throw new IOException(ke);
     }
 
     checkUnDeletedHFileRefsQueues(peerIds);
   }
 
   private void checkUnDeletedHFileRefsQueues(Set<String> peerIds) throws IOException {
     try {
       if (-1 == ZKUtil.checkExists(zkw, hfileRefsZNode)) {
         return;
       }
       List<String> listOfPeers = this.queuesClient.getAllPeersFromHFileRefsQueue();
       Set<String> peers = new HashSet<>(listOfPeers);
       peers.removeAll(peerIds);
       if (!peers.isEmpty()) {
         undeletedHFileRefsQueueIds.addAll(peers);
         String msg =
             "Undeleted replication hfile-refs queue for removed peer found: "
                 + undeletedHFileRefsQueueIds + " under hfile-refs node " + hfileRefsZNode;
         errorReporter.reportError(HBaseFsck.ErrorReporter.ERROR_CODE.UNDELETED_REPLICATION_QUEUE,
           msg);
       }
     } catch (KeeperException e) {
       throw new IOException("Failed to get list of all peers from hfile-refs znode "
           + hfileRefsZNode, e);
     }
   }
 
   private static class ReplicationQueueDeletor extends ReplicationStateZKBase {
     public ReplicationQueueDeletor(ZooKeeperWatcher zk, Configuration conf, Abortable abortable) {
       super(zk, conf, abortable);
     }
 
     public void removeQueue(String replicator, String queueId) throws IOException {
       String queueZnodePath = ZKUtil.joinZNode(ZKUtil.joinZNode(this.queuesZNode, replicator),
         queueId);
       try {
         ZKUtil.deleteNodeRecursively(this.zookeeper, queueZnodePath);
         LOG.info("remove replication queue, replicator: " + replicator + ", queueId: " + queueId);
       } catch (KeeperException e) {
         throw new IOException("failed to delete queue, replicator: " + replicator + ", queueId: "
             + queueId);
       }
     }
   }
 
   public void fixUnDeletedQueues() throws IOException {
     for (Entry<String, List<String>> replicatorAndQueueIds : undeletedQueueIds.entrySet()) {
       String replicator = replicatorAndQueueIds.getKey();
       for (String queueId : replicatorAndQueueIds.getValue()) {
         queueDeletor.removeQueue(replicator, queueId);
       }
     }
     fixUnDeletedHFileRefsQueue();
   }
 
   private void fixUnDeletedHFileRefsQueue() throws IOException {
     for (String hfileRefsQueueId : undeletedHFileRefsQueueIds) {
       String node = ZKUtil.joinZNode(hfileRefsZNode, hfileRefsQueueId);
       try {
         ZKUtil.deleteNodeRecursively(this.zkw, node);
         LOG.info("Successfully deleted hfile-refs queue " + hfileRefsQueueId + " from path "
             + hfileRefsZNode);
       } catch (KeeperException e) {
         throw new IOException("Failed to delete hfile-refs queue " + hfileRefsQueueId
             + " from path " + hfileRefsZNode);
       }
     }
   }
 }