/**
 * 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.backup.master;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ThreadPoolExecutor;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.CoordinatedStateManagerFactory;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.backup.BackupRestoreConstants;
import org.apache.hadoop.hbase.backup.impl.BackupManager;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.coordination.BaseCoordinatedStateManager;
import org.apache.hadoop.hbase.errorhandling.ForeignException;
import org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher;
import org.apache.hadoop.hbase.master.MasterServices;
import org.apache.hadoop.hbase.master.MetricsMaster;
import org.apache.hadoop.hbase.procedure.MasterProcedureManager;
import org.apache.hadoop.hbase.procedure.Procedure;
import org.apache.hadoop.hbase.procedure.ProcedureCoordinator;
import org.apache.hadoop.hbase.procedure.ProcedureCoordinatorRpcs;
import org.apache.hadoop.hbase.procedure.RegionServerProcedureManager;
import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.NameStringPair;
import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.ProcedureDescription;
import org.apache.zookeeper.KeeperException;

/**
 * Master procedure manager for coordinated cluster-wide WAL roll operation, which is run during
 * backup operation, see {@link MasterProcedureManager} and and {@link RegionServerProcedureManager}
 */
@InterfaceAudience.Private
public class LogRollMasterProcedureManager extends MasterProcedureManager {

  public static final String ROLLLOG_PROCEDURE_SIGNATURE = "rolllog-proc";
  public static final String ROLLLOG_PROCEDURE_NAME = "rolllog";
  private static final Log LOG = LogFactory.getLog(LogRollMasterProcedureManager.class);

  private MasterServices master;
  private ProcedureCoordinator coordinator;
  private boolean done;

  @Override
  public void stop(String why) {
    LOG.info("stop: " + why);
  }

  @Override
  public boolean isStopped() {
    return false;
  }

  @Override
  public void initialize(MasterServices master, MetricsMaster metricsMaster)
      throws KeeperException, IOException, UnsupportedOperationException {
    this.master = master;
    this.done = false;

    // setup the default procedure coordinator
    String name = master.getServerName().toString();
    ThreadPoolExecutor tpool = ProcedureCoordinator.defaultPool(name, 1);
    BaseCoordinatedStateManager coordManager =
        (BaseCoordinatedStateManager) CoordinatedStateManagerFactory
            .getCoordinatedStateManager(master.getConfiguration());
    coordManager.initialize(master);

    ProcedureCoordinatorRpcs comms =
        coordManager.getProcedureCoordinatorRpcs(getProcedureSignature(), name);

    this.coordinator = new ProcedureCoordinator(comms, tpool);
  }

  @Override
  public String getProcedureSignature() {
    return ROLLLOG_PROCEDURE_SIGNATURE;
  }

  @Override
  public void execProcedure(ProcedureDescription desc) throws IOException {
    if (!isBackupEnabled()) {
      LOG.warn("Backup is not enabled. Check your " + BackupRestoreConstants.BACKUP_ENABLE_KEY
          + " setting");
      return;
    }
    this.done = false;
    // start the process on the RS
    ForeignExceptionDispatcher monitor = new ForeignExceptionDispatcher(desc.getInstance());
    List<ServerName> serverNames = master.getServerManager().getOnlineServersList();
    List<String> servers = new ArrayList<String>();
    for (ServerName sn : serverNames) {
      servers.add(sn.toString());
    }

    List<NameStringPair> conf = desc.getConfigurationList();
    byte[] data = new byte[0];
    if (conf.size() > 0) {
      // Get backup root path
      data = conf.get(0).getValue().getBytes();
    }
    Procedure proc = coordinator.startProcedure(monitor, desc.getInstance(), data, servers);
    if (proc == null) {
      String msg = "Failed to submit distributed procedure for '" + desc.getInstance() + "'";
      LOG.error(msg);
      throw new IOException(msg);
    }

    try {
      // wait for the procedure to complete. A timer thread is kicked off that should cancel this
      // if it takes too long.
      proc.waitForCompleted();
      LOG.info("Done waiting - exec procedure for " + desc.getInstance());
      LOG.info("Distributed roll log procedure is successful!");
      this.done = true;
    } catch (InterruptedException e) {
      ForeignException ee =
          new ForeignException("Interrupted while waiting for roll log procdure to finish", e);
      monitor.receive(ee);
      Thread.currentThread().interrupt();
    } catch (ForeignException e) {
      ForeignException ee =
          new ForeignException("Exception while waiting for roll log procdure to finish", e);
      monitor.receive(ee);
    }
    monitor.rethrowException();
  }

  private boolean isBackupEnabled() {
    return BackupManager.isBackupEnabled(master.getConfiguration());
  }

  @Override
  public boolean isProcedureDone(ProcedureDescription desc) throws IOException {
    return done;
  }

}