/*
    *
    * 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.filter;
  
  import com.google.common.base.Preconditions;
  import com.google.protobuf.InvalidProtocolBufferException;
  
  import java.util.ArrayList;
  
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.exceptions.DeserializationException;
  import org.apache.hadoop.hbase.protobuf.generated.FilterProtos;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.ByteStringer;
  
  /**
   * Pass results that have same row prefix.
   */
  @InterfaceAudience.Public
  @InterfaceStability.Stable
  public class PrefixFilter extends FilterBase {
    protected byte [] prefix = null;
    protected boolean passedPrefix = false;
    protected boolean filterRow = true;
  
    public PrefixFilter(final byte [] prefix) {
      this.prefix = prefix;
    }
  
    public byte[] getPrefix() {
      return prefix;
    }
  
    @Override
    public boolean filterRowKey(byte[] buffer, int offset, int length) {
      if (buffer == null || this.prefix == null)
        return true;
      if (length < prefix.length)
        return true;
      // if they are equal, return false => pass row
      // else return true, filter row
      // if we are passed the prefix, set flag
      int cmp = Bytes.compareTo(buffer, offset, this.prefix.length, this.prefix, 0,
          this.prefix.length);
      if ((!isReversed() && cmp > 0) || (isReversed() && cmp < 0)) {
        passedPrefix = true;
      }
      filterRow = (cmp != 0);
      return filterRow;
    }
  
    @Override
    public ReturnCode filterKeyValue(Cell v) {
      if (filterRow) return ReturnCode.NEXT_ROW;
      return ReturnCode.INCLUDE;
    }
  
    // Override here explicitly as the method in super class FilterBase might do a KeyValue recreate.
    // See HBASE-12068
    @Override
    public Cell transformCell(Cell v) {
      return v;
    }
  
    @Override
    public boolean filterRow() {
      return filterRow;
    }
  
    @Override
    public void reset() {
      filterRow = true;
    }
  
    @Override
    public boolean filterAllRemaining() {
      return passedPrefix;
    }
  
    public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
     Preconditions.checkArgument(filterArguments.size() == 1,
                                 "Expected 1 but got: %s", filterArguments.size());
     byte [] prefix = ParseFilter.removeQuotesFromByteArray(filterArguments.get(0));
     return new PrefixFilter(prefix);
   }
 
   /**
    * @return The filter serialized using pb
    */
   @Override
   public byte [] toByteArray() {
     FilterProtos.PrefixFilter.Builder builder =
       FilterProtos.PrefixFilter.newBuilder();
     if (this.prefix != null) builder.setPrefix(ByteStringer.wrap(this.prefix));
     return builder.build().toByteArray();
   }
 
   /**
    * @param pbBytes A pb serialized {@link PrefixFilter} instance
    * @return An instance of {@link PrefixFilter} made from <code>bytes</code>
    * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
    * @see #toByteArray
    */
   public static PrefixFilter parseFrom(final byte [] pbBytes)
   throws DeserializationException {
     FilterProtos.PrefixFilter proto;
     try {
       proto = FilterProtos.PrefixFilter.parseFrom(pbBytes);
     } catch (InvalidProtocolBufferException e) {
       throw new DeserializationException(e);
     }
     return new PrefixFilter(proto.hasPrefix()?proto.getPrefix().toByteArray():null);
   }
 
   /**
    * @param other
    * @return true if and only if the fields of the filter that are serialized
    * are equal to the corresponding fields in other.  Used for testing.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
     if (o == this) return true;
     if (!(o instanceof PrefixFilter)) return false;
 
     PrefixFilter other = (PrefixFilter)o;
     return Bytes.equals(this.getPrefix(), other.getPrefix());
   }
 
   @Override
   public String toString() {
     return this.getClass().getSimpleName() + " " + Bytes.toStringBinary(this.prefix);
   }
 
   @Override
   public boolean equals(Object obj) {
     return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
   public int hashCode() {
     return Bytes.hashCode(this.getPrefix());
   }
 }