/**
 * 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.namenode;

import io.hops.exception.StorageException;
import io.hops.transaction.handler.HDFSOperationType;
import io.hops.transaction.handler.HopsTransactionalRequestHandler;
import io.hops.transaction.lock.TransactionLockTypes.LockType;
import io.hops.transaction.lock.TransactionLocks;
import org.apache.hadoop.fs.UnresolvedLinkException;
import org.apache.hadoop.fs.permission.PermissionStatus;
import org.apache.hadoop.hdfs.TestLease;
import org.apache.hadoop.hdfs.protocol.DatanodeID;
import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenSecretManager;
import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
import org.apache.hadoop.hdfs.server.namenode.FSNamesystem.SafeModeInfo;
import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
import org.apache.hadoop.hdfs.server.protocol.HeartbeatResponse;
import org.apache.hadoop.ipc.Server;
import org.apache.hadoop.ipc.StandbyException;
import org.apache.hadoop.security.AccessControlException;

import java.io.IOException;

/**
 * This is a utility class to expose NameNode functionality for unit tests.
 */
public class NameNodeAdapter {
  /**
   * Get the namesystem from the namenode
   */
  public static FSNamesystem getNamesystem(NameNode namenode) {
    return namenode.getNamesystem();
  }

  /**
   * Get block locations within the specified range.
   */
  public static LocatedBlocks getBlockLocations(NameNode namenode, String src,
      long offset, long length) throws IOException {
    return namenode.getNamesystem()
        .getBlockLocations(src, offset, length, false, true, true);
  }
  
  public static HdfsFileStatus getFileInfo(NameNode namenode, String src,
      boolean resolveLink)
      throws AccessControlException, UnresolvedLinkException, StandbyException,
      IOException {
    return namenode.getNamesystem().getFileInfo(src, resolveLink);
  }
  
  public static boolean mkdirs(NameNode namenode, String src,
      PermissionStatus permissions, boolean createParent)
      throws UnresolvedLinkException, IOException {
    return namenode.getNamesystem().mkdirs(src, permissions, createParent);
  }
  
  public static void enterSafeMode(NameNode namenode, boolean resourcesLow)
      throws IOException {
    namenode.getNamesystem().enterSafeMode(resourcesLow);
  }
  
  public static void leaveSafeMode(NameNode namenode) throws IOException {
    namenode.getNamesystem().leaveSafeMode();
  }
  
  
  /**
   * Get the internal RPC server instance.
   *
   * @return rpc server
   */
  public static Server getRpcServer(NameNode namenode) {
    return ((NameNodeRpcServer) namenode.getRpcServer()).clientRpcServer;
  }

  public static DelegationTokenSecretManager getDtSecretManager(
      final FSNamesystem ns) {
    return ns.getDelegationTokenSecretManager();
  }

  public static HeartbeatResponse sendHeartBeat(DatanodeRegistration nodeReg,
      DatanodeDescriptor dd, FSNamesystem namesystem)
      throws IOException, StorageException {
    return namesystem
        .handleHeartbeat(nodeReg, dd.getCapacity(), dd.getDfsUsed(),
            dd.getRemaining(), dd.getBlockPoolUsed(), 0, 0, 0);
  }

  public static boolean setReplication(final FSNamesystem ns, final String src,
      final short replication) throws IOException {
    return ns.setReplication(src, replication);
  }
  
  public static LeaseManager getLeaseManager(final FSNamesystem ns) {
    return ns.leaseManager;
  }

  /**
   * Set the softLimit and hardLimit of client lease periods.
   */
  public static void setLeasePeriod(final FSNamesystem namesystem, long soft,
      long hard) {
    getLeaseManager(namesystem).setLeasePeriod(soft, hard);
    namesystem.leaseManager.triggerMonitorCheckNow();
  }

  public static String getLeaseHolderForPath(final NameNode namenode,
      final String path) throws IOException {

    return (String) new HopsTransactionalRequestHandler(
        HDFSOperationType.TEST) {
      @Override
      public void acquireLock(TransactionLocks locks) throws IOException {
        locks.add(new TestLease.TestLeaseLock(LockType.READ, LockType.READ,
            path));
      }

      @Override
      public Object performTask() throws StorageException, IOException {
        Lease l = namenode.getNamesystem().leaseManager.getLeaseByPath(path);
        return l == null ? null : l.getHolder();
      }
    }.handle();
  }

  /**
   * @return the timestamp of the last renewal of the given lease,
   * or -1 in the case that the lease doesn't exist.
   */
  public static long getLeaseRenewalTime(final NameNode nn, final String path)
      throws IOException {

    HopsTransactionalRequestHandler leaseRenewalTimeHandler =
        new HopsTransactionalRequestHandler(HDFSOperationType.TEST) {
          @Override
          public void acquireLock(TransactionLocks locks) throws IOException {
            locks.add(
                new TestLease.TestLeaseLock(LockType.READ, LockType.READ,
                    path));
          }

          @Override
          public Object performTask() throws StorageException, IOException {
            LeaseManager lm = nn.getNamesystem().leaseManager;
            Lease l = lm.getLeaseByPath(path);
            if (l == null) {
              return -1;
            }
            return (Object) l.getLastUpdate();
          }
        };
    return (Long) leaseRenewalTimeHandler.handle();
  }

  /**
   * Return the datanode descriptor for the given datanode.
   */
  public static DatanodeDescriptor getDatanode(final FSNamesystem ns,
      DatanodeID id) throws IOException {
    return ns.getBlockManager().getDatanodeManager().getDatanode(id);
  }
  
  /**
   * Return the FSNamesystem stats
   */
  public static long[] getStats(final FSNamesystem fsn) throws IOException {
    return fsn.getStats();
  }
  
  /**
   * @return the number of blocks marked safe by safemode, or -1
   * if safemode is not running.
   */
  public static int getSafeModeSafeBlocks(NameNode nn) throws IOException {
    SafeModeInfo smi = nn.getNamesystem().getSafeModeInfoForTests();
    if (smi == null) {
      return -1;
    }
    return smi.blockSafe();
  }
  
  /**
   * @return true if safemode is not running, or if safemode has already
   * initialized the replication queues
   */
  public static boolean safeModeInitializedReplQueues(NameNode nn) {
    SafeModeInfo smi = nn.getNamesystem().getSafeModeInfoForTests();
    if (smi == null) {
      return true;
    }
    return smi.initializedReplQueues;
  }
}