/**
    * 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.regionserver;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.conf.Configured;
  import org.apache.hadoop.fs.FileStatus;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.*;
  import org.apache.hadoop.hbase.client.ClusterConnection;
  import org.apache.hadoop.hbase.client.ConnectionFactory;
  import org.apache.hadoop.hbase.client.HBaseAdmin;
  import org.apache.hadoop.hbase.client.replication.ReplicationAdmin;
  import org.apache.hadoop.hbase.io.WALLink;
  import org.apache.hadoop.hbase.procedure2.util.StringUtils;
  import org.apache.hadoop.hbase.replication.*;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.apache.hadoop.hbase.zookeeper.ZKUtil;
  import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
  import org.apache.hadoop.util.Tool;
  import org.apache.hadoop.util.ToolRunner;
  import org.apache.zookeeper.KeeperException;
  import org.mortbay.util.IO;
  
  import java.io.IOException;
  import java.util.*;
  
  /**
   * Provides information about the existing states of replication, replication peers and queues.
   *
   * Usage: hbase org.apache.hadoop.hbase.replication.regionserver.DumpReplicationQueues [args]
   * Arguments: --distributed    Polls each RS to dump information about the queue
   *            --hdfs           Reports HDFS usage by the replication queues (note: can be overestimated).
   */
  
  public class DumpReplicationQueues extends Configured implements Tool {
  
    private static final Log LOG = LogFactory.getLog(DumpReplicationQueues.class.getName());
  
    static class DumpOptions {
      boolean hdfs = false;
      boolean distributed = false;
  
      public DumpOptions() {
      }
  
      public DumpOptions(DumpOptions that) {
        this.hdfs = that.hdfs;
        this.distributed = that.distributed;
      }
  
      boolean isHdfs () {
        return hdfs;
      }
  
      boolean isDistributed() {
        return distributed;
      }
  
      void setHdfs (boolean hdfs) {
        this.hdfs = hdfs;
      }
  
      void setDistributed(boolean distributed) {
        this.distributed = distributed;
      }
    }
  
    static DumpOptions parseOpts(Queue<String> args) {
      DumpOptions opts = new DumpOptions();
  
      String cmd = null;
      while ((cmd = args.poll()) != null) {
        if (cmd.equals("-h") || cmd.equals("--h") || cmd.equals("--help")) {
          // place item back onto queue so that caller knows parsing was incomplete
          args.add(cmd);
          break;
        }
        final String hdfs = "--hdfs";
        if (cmd.equals(hdfs)) {
          opts.setHdfs(true);
         continue;
       }
       final String distributed = "--distributed";
       if (cmd.equals(distributed)) {
         opts.setDistributed(true);
         continue;
       } else {
         printUsageAndExit("ERROR: Unrecognized option/command: " + cmd, -1);
       }
       // check that --distributed is present when --hdfs is in the arguments
       if (!opts.isDistributed()  && opts.isHdfs()) {
         printUsageAndExit("ERROR: --hdfs option can only be used with --distributed: " + cmd, -1);
       }
     }
     return opts;
   }
 
   /**
    * Main
    *
    * @param args
    * @throws Exception
    */
   public static void main(String[] args) throws Exception {
     Configuration conf = HBaseConfiguration.create();
     int ret = ToolRunner.run(conf, new DumpReplicationQueues(), args);
     System.exit(ret);
   }
 
   @Override
   public int run(String[] args) throws Exception {
 
     int errCode = -1;
     LinkedList<String> argv = new LinkedList<String>();
     argv.addAll(Arrays.asList(args));
     DumpOptions opts = parseOpts(argv);
 
     // args remaining, print help and exit
     if (!argv.isEmpty()) {
       errCode = 0;
       printUsage();
       return errCode;
     }
     return dumpReplicationQueues(opts);
   }
 
   protected void printUsage() {
     printUsage(this.getClass().getName(), null);
   }
 
   protected static void printUsage(final String message) {
     printUsage(DumpReplicationQueues.class.getName(), message);
   }
 
   protected static void printUsage(final String className, final String message) {
     if (message != null && message.length() > 0) {
       System.err.println(message);
     }
     System.err.println("Usage: java " + className + " \\");
     System.err.println("  <OPTIONS> [-D<property=value>]*");
     System.err.println();
     System.err.println("General Options:");
     System.err.println(" distributed  Poll each RS and print its own replication queue. "
         + "Default only polls ZooKeeper");
     System.err.println(" hdfs         Use HDFS to calculate usage of WALs by replication. It could be overestimated"
         + " if replicating to multiple peers. --distributed flag is also needed.");
   }
 
   protected static void printUsageAndExit(final String message, final int exitCode) {
     printUsage(message);
     System.exit(exitCode);
   }
 
   private int dumpReplicationQueues(DumpOptions opts) throws Exception {
 
     Configuration conf = getConf();
     HBaseAdmin.checkHBaseAvailable(conf);
     ReplicationAdmin replicationAdmin = new ReplicationAdmin(conf);
     ClusterConnection connection = (ClusterConnection) ConnectionFactory.createConnection(conf);
     long deleted = 0;
 
     ZooKeeperWatcher zkw = new ZooKeeperWatcher(conf, "DumpReplicationQueues" + System.currentTimeMillis(),
         new WarnOnlyAbortable(), true);
 
     try {
       // Our zk watcher
       LOG.info("Our Quorum: " + zkw.getQuorum());
       List<HashMap<String, String>> replicatedTables = replicationAdmin.listReplicated();
       if (replicatedTables.isEmpty()) {
         LOG.info("No tables with a configured replication peer were found.");
         return(0);
       } else {
         LOG.info("Replicated Tables: " + replicatedTables);
       }
 
       Map<String, ReplicationPeerConfig> peerConfigs = replicationAdmin.listPeerConfigs();
 
       if (peerConfigs.isEmpty()) {
         LOG.info("Replication is enabled but no peer configuration was found.");
       }
 
       System.out.println("Dumping replication peers and configurations:");
       System.out.println(dumpPeersState(replicationAdmin, peerConfigs));
 
       if (opts.isDistributed()) {
         LOG.info("Found [--distributed], will poll each RegionServer.");
         System.out.println(dumpQueues(connection, zkw, opts.isHdfs(), deleted));
         if (deleted > 0) {
           LOG.warn("Found " + deleted +" deleted queues"
               + ", run hbck -fixReplication in order to remove the deleted replication queues");
         }
       } else {
         // use ZK instead
         System.out.print("Dumping replication znodes via ZooKeeper:");
         System.out.println(ZKUtil.getReplicationZnodesDump(zkw));
       }
       return (0);
     } catch (IOException e) {
       return (-1);
     } finally {
       zkw.close();
     }
   }
 
   public String dumpPeersState(ReplicationAdmin replicationAdmin,
                               Map<String, ReplicationPeerConfig> peerConfigs) throws Exception {
     Map<String, String> currentConf;
     StringBuilder sb = new StringBuilder();
     for (Map.Entry<String, ReplicationPeerConfig> peer : peerConfigs.entrySet()) {
       try {
         sb.append("Peer: " + peer.getKey() + "\n");
         sb.append("    " + "State: " + (replicationAdmin.getPeerState(peer.getKey()) ? "ENABLED" : "DISABLED") + "\n");
         sb.append("    " + "Cluster Name: " + peer.getValue() + "\n");
         currentConf = peer.getValue().getConfiguration();
         // Only show when we have a custom configuration for the peer
         if (currentConf.size() > 1) {
           sb.append("    " + "Peer Configuration: " + currentConf + "\n");
         }
         sb.append("    " + "Peer Table CFs: " + replicationAdmin.getPeerTableCFs(peer.getKey()) + "\n");
       } catch (ReplicationException re) {
         sb.append("Got an exception while invoking ReplicationAdmin: " + re + "\n");
       }
     }
     return sb.toString();
   }
 
   public String dumpQueues(ClusterConnection connection, ZooKeeperWatcher zkw, boolean hdfs, long deleted)
       throws Exception {
     ReplicationQueuesClient queuesClient;
     ReplicationPeers replicationPeers;
     ReplicationQueues replicationQueues;
 
     StringBuilder sb = new StringBuilder();
 
     queuesClient = ReplicationFactory.getReplicationQueuesClient(zkw, getConf(), connection);
     queuesClient.init();
     replicationQueues = ReplicationFactory.getReplicationQueues(zkw, getConf(), connection);
     replicationPeers = ReplicationFactory.getReplicationPeers(zkw, getConf(), queuesClient, connection);
     replicationPeers.init();
 
     // Loops each peer on each RS and dumps the queues
 
     Set<String> peerIds = new HashSet<String>(replicationPeers.getAllPeerIds());
     try {
       List<String> regionservers = queuesClient.getListOfReplicators();
       for (String regionserver : regionservers) {
         List<String> queueIds = queuesClient.getAllQueues(regionserver);
         replicationQueues.init(regionserver);
         for (String queueId : queueIds) {
           ReplicationQueueInfo queueInfo = new ReplicationQueueInfo(queueId);
           List<String> wals = queuesClient.getLogsInQueue(regionserver, queueId);
           if (!peerIds.contains(queueInfo.getPeerId())) {
             deleted++;
             sb.append(formatQueue(regionserver, replicationQueues, queueInfo, queueId, wals, true, hdfs));
           } else {
             sb.append(formatQueue(regionserver, replicationQueues, queueInfo, queueId, wals, false, hdfs));
           }
         }
       }
     } catch (KeeperException ke) {
       throw new IOException(ke);
     }
     return sb.toString();
   }
 
   private String formatQueue(String regionserver, ReplicationQueues replicationQueues, ReplicationQueueInfo queueInfo,
                            String queueId, List<String> wals, boolean isDeleted, boolean hdfs) throws Exception {
 
     StringBuilder sb = new StringBuilder();
 
     List<String> deadServers ;
 
     sb.append("Dumping replication queue info for RegionServer: [" + regionserver + "]" + "\n");
     sb.append("    PeerID: " + queueInfo.getPeerId() + "\n");
     sb.append("    Recovered: " + queueInfo.isQueueRecovered() + "\n");
     deadServers = queueInfo.getDeadRegionServers();
     if (deadServers.isEmpty()) {
       sb.append("    No dead RegionServers found in this queue." + "\n");
     } else {
       sb.append("    Dead RegionServers: " + deadServers + "\n");
     }
     sb.append("    Was deleted: " + isDeleted + "\n");
     sb.append("    Number of WALs in replication queue: " + wals.size() + "\n");
     for (String wal : wals) {
       long position = replicationQueues.getLogPosition(queueInfo.getPeerId(), wal);
       sb.append("    Replication position for " + wal + ": " + (position > 0 ? position : "0"
           + " (not started or nothing to replicate)") + "\n");
     }
 
     if (hdfs) {
       FileSystem fs = FileSystem.get(getConf());
       sb.append("    Total size of WALs on HDFS for this queue: "
           + StringUtils.humanSize(getTotalWALSize(fs, wals, regionserver)) + "\n");
     }
     return sb.toString();
   }
   /**
    *  return total size in bytes from a list of WALs
    */
   private long getTotalWALSize(FileSystem fs, List<String> wals, String server) throws IOException {
     int size = 0;
     FileStatus fileStatus;
 
     for (String wal : wals) {
       try {
         fileStatus = (new WALLink(getConf(), server, wal)).getFileStatus(fs);
       } catch (IOException e) {
         LOG.warn("WAL " + wal + " couldn't be found, skipping");
         break;
       }
       size += fileStatus.getLen();
     }
     return size;
   }
 
   private static class WarnOnlyAbortable implements Abortable {
     @Override
     public void abort(String why, Throwable e) {
       LOG.warn("DumpReplicationQueue received abort, ignoring.  Reason: " + why);
       if (LOG.isDebugEnabled()) {
         LOG.debug(e);
       }
     }
 
     @Override
     public boolean isAborted() {
       return false;
     }
   }
 
   private static void usage(final String errorMsg) {
     if (errorMsg != null && errorMsg.length() > 0) {
       LOG.error(errorMsg);
     }
   }
 }