/**
    *
    * 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 java.io.IOException;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.NavigableMap;
  import java.util.UUID;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellScanner;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.io.SizedCellScanner;
  import org.apache.hadoop.hbase.ipc.PayloadCarryingRpcController;
  import org.apache.hadoop.hbase.protobuf.generated.AdminProtos;
  import org.apache.hadoop.hbase.protobuf.generated.AdminProtos.AdminService;
  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos;
  import org.apache.hadoop.hbase.protobuf.generated.WALProtos;
  import org.apache.hadoop.hbase.wal.WAL.Entry;
  import org.apache.hadoop.hbase.wal.WALKey;
  import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
  import org.apache.hadoop.hbase.util.ByteStringer;
  import org.apache.hadoop.hbase.util.Pair;
  
  import com.google.protobuf.ServiceException;
  
  @InterfaceAudience.Private
  public class ReplicationProtbufUtil {
    /**
     * A helper to replicate a list of WAL entries using admin protocol.
     *
     * @param admin
     * @param entries
     * @throws java.io.IOException
     */
    public static void replicateWALEntry(final AdminService.BlockingInterface admin,
        final Entry[] entries) throws IOException {
      Pair<AdminProtos.ReplicateWALEntryRequest, CellScanner> p =
        buildReplicateWALEntryRequest(entries, null);
      PayloadCarryingRpcController controller = new PayloadCarryingRpcController(p.getSecond());
      try {
        admin.replicateWALEntry(controller, p.getFirst());
      } catch (ServiceException se) {
        throw ProtobufUtil.getRemoteException(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) {
      // Accumulate all the Cells seen in here.
      return buildReplicateWALEntryRequest(entries, 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
     * @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) {
      // Accumulate all the KVs seen in here.
      List<List<? extends Cell>> allCells = new ArrayList<List<? extends Cell>>(entries.length);
      int size = 0;
      WALProtos.FamilyScope.Builder scopeBuilder = WALProtos.FamilyScope.newBuilder();
      AdminProtos.WALEntry.Builder entryBuilder = AdminProtos.WALEntry.newBuilder();
      AdminProtos.ReplicateWALEntryRequest.Builder builder =
       AdminProtos.ReplicateWALEntryRequest.newBuilder();
     HBaseProtos.UUID.Builder uuidBuilder = HBaseProtos.UUID.newBuilder();
     for (Entry entry: entries) {
       entryBuilder.clear();
       // TODO: this duplicates a lot in WALKey#getBuilder
       WALProtos.WALKey.Builder keyBuilder = entryBuilder.getKeyBuilder();
       WALKey key = entry.getKey();
       keyBuilder.setEncodedRegionName(
         ByteStringer.wrap(encodedRegionName == null
             ? key.getEncodedRegionName()
             : encodedRegionName));
       keyBuilder.setTableName(ByteStringer.wrap(key.getTablename().getName()));
       keyBuilder.setLogSequenceNumber(key.getLogSeqNum());
       keyBuilder.setWriteTime(key.getWriteTime());
       if (key.getNonce() != HConstants.NO_NONCE) {
         keyBuilder.setNonce(key.getNonce());
       }
       if (key.getNonceGroup() != HConstants.NO_NONCE) {
         keyBuilder.setNonceGroup(key.getNonceGroup());
       }
       for(UUID clusterId : key.getClusterIds()) {
         uuidBuilder.setLeastSigBits(clusterId.getLeastSignificantBits());
         uuidBuilder.setMostSigBits(clusterId.getMostSignificantBits());
         keyBuilder.addClusterIds(uuidBuilder.build());
       }
       if(key.getOrigLogSeqNum() > 0) {
         keyBuilder.setOrigSequenceNumber(key.getOrigLogSeqNum());
       }
       WALEdit edit = entry.getEdit();
       NavigableMap<byte[], Integer> scopes = key.getScopes();
       if (scopes != null && !scopes.isEmpty()) {
         for (Map.Entry<byte[], Integer> scope: scopes.entrySet()) {
           scopeBuilder.setFamily(ByteStringer.wrap(scope.getKey()));
           WALProtos.ScopeType scopeType =
               WALProtos.ScopeType.valueOf(scope.getValue().intValue());
           scopeBuilder.setScopeType(scopeType);
           keyBuilder.addScopes(scopeBuilder.build());
         }
       }
       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());
     }
     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;
       }
     };
   }
 }