/**
    *
    * 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.protobuf.InvalidProtocolBufferException;
  import java.util.Locale;
  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.ComparatorProtos;
  import org.apache.hadoop.hbase.util.Bytes;
  
  
  /**
   * This comparator is for use with SingleColumnValueFilter, for filtering based on
   * the value of a given column. Use it to test if a given substring appears
   * in a cell value in the column. The comparison is case insensitive.
   * <p>
   * Only EQUAL or NOT_EQUAL tests are valid with this comparator.
   * <p>
   * For example:
   * <p>
   * <pre>
   * SingleColumnValueFilter scvf =
   *   new SingleColumnValueFilter("col", CompareOp.EQUAL,
   *     new SubstringComparator("substr"));
   * </pre>
   */
  @InterfaceAudience.Public
  @InterfaceStability.Stable
  public class SubstringComparator extends ByteArrayComparable {
  
    private String substr;
  
    /**
     * Constructor
     * @param substr the substring
     */
    public SubstringComparator(String substr) {
      super(Bytes.toBytes(substr.toLowerCase(Locale.ROOT)));
      this.substr = substr.toLowerCase(Locale.ROOT);
    }
  
    @Override
    public byte[] getValue() {
      return Bytes.toBytes(substr);
    }
  
    @Override
    public int compareTo(byte[] value, int offset, int length) {
      return Bytes.toString(value, offset, length).toLowerCase(Locale.ROOT).contains(substr) ? 0
          : 1;
    }
  
    /**
     * @return The comparator serialized using pb
     */
    @Override
    public byte [] toByteArray() {
      ComparatorProtos.SubstringComparator.Builder builder =
        ComparatorProtos.SubstringComparator.newBuilder();
      builder.setSubstr(this.substr);
      return builder.build().toByteArray();
    }
  
    /**
     * @param pbBytes A pb serialized {@link SubstringComparator} instance
     * @return An instance of {@link SubstringComparator} made from <code>bytes</code>
     * @throws DeserializationException
     * @see #toByteArray
     */
    public static SubstringComparator parseFrom(final byte [] pbBytes)
    throws DeserializationException {
      ComparatorProtos.SubstringComparator proto;
      try {
        proto = ComparatorProtos.SubstringComparator.parseFrom(pbBytes);
      } catch (InvalidProtocolBufferException e) {
        throw new DeserializationException(e);
      }
      return new SubstringComparator(proto.getSubstr());
    }
  
    /**
    * @param other
    * @return true if and only if the fields of the comparator that are serialized
    * are equal to the corresponding fields in other.  Used for testing.
    */
   @Override
   boolean areSerializedFieldsEqual(ByteArrayComparable other) {
     if (other == this) return true;
     if (!(other instanceof SubstringComparator)) return false;
 
     SubstringComparator comparator = (SubstringComparator)other;
     return super.areSerializedFieldsEqual(comparator)
       && this.substr.equals(comparator.substr);
   }
 
 }