/*
 * 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.hive.accumulo.predicate.compare;

import java.math.BigDecimal;
import java.nio.ByteBuffer;

/**
 * Set of comparison operations over a double constant. Used for Hive predicates involving double
 * comparison.
 *
 * Used by {@link org.apache.hadoop.hive.accumulo.predicate.PrimitiveComparisonFilter}
 */
public class DoubleCompare implements PrimitiveComparison {

  private BigDecimal constant;

  /**
     *
     */
  public void init(byte[] constant) {
    this.constant = serialize(constant);
  }

  /**
   * @return BigDecimal holding double byte [] value
   */
  public BigDecimal serialize(byte[] value) {
    try {
      return new BigDecimal(ByteBuffer.wrap(value).asDoubleBuffer().get());
    } catch (Exception e) {
      throw new RuntimeException(e.toString() + " occurred trying to build double value. "
          + "Make sure the value type for the byte[] is double.");
    }
  }

  /**
   * @return true if double value is equal to constant, false otherwise.
   */
  @Override
  public boolean isEqual(byte[] value) {
    return serialize(value).compareTo(constant) == 0;
  }

  /**
   * @return true if double value not equal to constant, false otherwise.
   */
  @Override
  public boolean isNotEqual(byte[] value) {
    return serialize(value).compareTo(constant) != 0;
  }

  /**
   * @return true if value greater than or equal to constant, false otherwise.
   */
  @Override
  public boolean greaterThanOrEqual(byte[] value) {
    return serialize(value).compareTo(constant) >= 0;
  }

  /**
   * @return true if value greater than constant, false otherwise.
   */
  @Override
  public boolean greaterThan(byte[] value) {
    return serialize(value).compareTo(constant) > 0;
  }

  /**
   * @return true if value less than or equal than constant, false otherwise.
   */
  @Override
  public boolean lessThanOrEqual(byte[] value) {
    return serialize(value).compareTo(constant) <= 0;
  }

  /**
   * @return true if value less than constant, false otherwise.
   */
  @Override
  public boolean lessThan(byte[] value) {
    return serialize(value).compareTo(constant) < 0;
  }

  /**
   * not supported for this PrimitiveCompare implementation.
   */
  @Override
  public boolean like(byte[] value) {
    throw new UnsupportedOperationException("Like not supported for " + getClass().getName());
  }
}