/**
    *
    * 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.protobuf;
  
  
  import com.google.protobuf.ServiceException;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellScanner;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.io.SizedCellScanner;
  import org.apache.hadoop.hbase.ipc.HBaseRpcController;
  import org.apache.hadoop.hbase.ipc.HBaseRpcControllerImpl;
  import org.apache.hadoop.hbase.protobuf.generated.AdminProtos;
  import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.AdminService;
  import org.apache.hadoop.hbase.protobuf.generated.WALProtos;
  import org.apache.hadoop.hbase.regionserver.wal.WALCellCodec;
  import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
  import org.apache.hadoop.hbase.util.ByteStringer;
  import org.apache.hadoop.hbase.util.Pair;
  import org.apache.hadoop.hbase.wal.WAL.Entry;
  import org.apache.hadoop.hbase.wal.WALKey;
  
  @InterfaceAudience.Private
  public class ReplicationProtbufUtil {
    /**
     * A helper to replicate a list of WAL entries using admin protocol.
     * @param admin Admin service
     * @param entries Array of WAL entries to be replicated
     * @param replicationClusterId Id which will uniquely identify source cluster FS client
     *          configurations in the replication configuration directory
     * @param sourceBaseNamespaceDir Path to source cluster base namespace directory
     * @param sourceHFileArchiveDir Path to the source cluster hfile archive directory
     * @throws java.io.IOException
     */
    public static void replicateWALEntry(final AdminService.BlockingInterface admin,
        final Entry[] entries, String replicationClusterId, Path sourceBaseNamespaceDir,
        Path sourceHFileArchiveDir) throws IOException {
      Pair<AdminProtos.ReplicateWALEntryRequest, CellScanner> p =
          buildReplicateWALEntryRequest(entries, null, replicationClusterId, sourceBaseNamespaceDir,
            sourceHFileArchiveDir);
      HBaseRpcController controller = new HBaseRpcControllerImpl(p.getSecond());
      try {
        admin.replicateWALEntry(controller, p.getFirst());
      } catch (ServiceException se) {
        throw ProtobufUtil.getServiceException(se);
      }
    }
  
    /**
     * Create a new ReplicateWALEntryRequest from a list of WAL entries
     *
     * @param entries the WAL entries to be replicated
     * @return a pair of ReplicateWALEntryRequest and a CellScanner over all the WALEdit values
     * found.
     */
    public static Pair<AdminProtos.ReplicateWALEntryRequest, CellScanner>
        buildReplicateWALEntryRequest(final Entry[] entries) throws IOException {
      // Accumulate all the Cells seen in here.
      return buildReplicateWALEntryRequest(entries, null, null, null, null);
    }
  
    /**
     * Create a new ReplicateWALEntryRequest from a list of HLog entries
     * @param entries the HLog entries to be replicated
     * @param encodedRegionName alternative region name to use if not null
     * @param replicationClusterId Id which will uniquely identify source cluster FS client
     *          configurations in the replication configuration directory
     * @param sourceBaseNamespaceDir Path to source cluster base namespace directory
     * @param sourceHFileArchiveDir Path to the source cluster hfile archive directory
     * @return a pair of ReplicateWALEntryRequest and a CellScanner over all the WALEdit values found.
     */
    public static Pair<AdminProtos.ReplicateWALEntryRequest, CellScanner>
        buildReplicateWALEntryRequest(final Entry[] entries, byte[] encodedRegionName,
            String replicationClusterId, Path sourceBaseNamespaceDir, Path sourceHFileArchiveDir)
     throws IOException {
     // Accumulate all the KVs seen in here.
     List<List<? extends Cell>> allCells = new ArrayList<List<? extends Cell>>(entries.length);
     int size = 0;
     AdminProtos.WALEntry.Builder entryBuilder = AdminProtos.WALEntry.newBuilder();
     AdminProtos.ReplicateWALEntryRequest.Builder builder =
       AdminProtos.ReplicateWALEntryRequest.newBuilder();
     for (Entry entry: entries) {
       entryBuilder.clear();
       WALKey key = entry.getKey();
       WALProtos.WALKey.Builder keyBuilder;
       try {
         keyBuilder = key.getBuilder(WALCellCodec.getNoneCompressor());
       } catch (IOException e) {
         throw new IOException(
           "There should not throw exception since NoneCompressor do not throw any exceptions", e);
       }
       if(encodedRegionName != null){
         keyBuilder.setEncodedRegionName(
           ByteStringer.wrap(encodedRegionName));
       }
       entryBuilder.setKey(keyBuilder.build());
       WALEdit edit = entry.getEdit();
       List<Cell> cells = edit.getCells();
       // Add up the size.  It is used later serializing out the cells.
       for (Cell cell: cells) {
         size += CellUtil.estimatedSerializedSizeOf(cell);
       }
       // Collect up the cells
       allCells.add(cells);
       // Write out how many cells associated with this entry.
       entryBuilder.setAssociatedCellCount(cells.size());
       builder.addEntry(entryBuilder.build());
     }
 
     if (replicationClusterId != null) {
       builder.setReplicationClusterId(replicationClusterId);
     }
     if (sourceBaseNamespaceDir != null) {
       builder.setSourceBaseNamespaceDirPath(sourceBaseNamespaceDir.toString());
     }
     if (sourceHFileArchiveDir != null) {
       builder.setSourceHFileArchiveDirPath(sourceHFileArchiveDir.toString());
     }
 
     return new Pair<AdminProtos.ReplicateWALEntryRequest, CellScanner>(builder.build(),
       getCellScanner(allCells, size));
   }
 
   /**
    * @param cells
    * @return <code>cells</code> packaged as a CellScanner
    */
   static CellScanner getCellScanner(final List<List<? extends Cell>> cells, final int size) {
     return new SizedCellScanner() {
       private final Iterator<List<? extends Cell>> entries = cells.iterator();
       private Iterator<? extends Cell> currentIterator = null;
       private Cell currentCell;
 
       @Override
       public Cell current() {
         return this.currentCell;
       }
 
       @Override
       public boolean advance() {
         if (this.currentIterator == null) {
           if (!this.entries.hasNext()) return false;
           this.currentIterator = this.entries.next().iterator();
         }
         if (this.currentIterator.hasNext()) {
           this.currentCell = this.currentIterator.next();
           return true;
         }
         this.currentCell = null;
         this.currentIterator = null;
         return advance();
       }
 
       @Override
       public long heapSize() {
         return size;
       }
     };
   }
 }