/*
 * 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.phoenix.expression;

import java.util.List;
import org.apache.phoenix.schema.types.PDataType;

abstract public class BaseAddSubtractExpression extends ArithmeticExpression {
  public BaseAddSubtractExpression() {
  }

  public BaseAddSubtractExpression(List<Expression> children) {
    super(children);
  }

  protected static Integer getPrecision(Integer lp, Integer rp, Integer ls, Integer rs) {
    if (ls == null || rs == null) {
      return PDataType.MAX_PRECISION;
    }
    int val = getScale(lp, rp, ls, rs) + Math.max(lp - ls, rp - rs) + 1;
    return Math.min(PDataType.MAX_PRECISION, val);
  }

  protected static Integer getScale(Integer lp, Integer rp, Integer ls, Integer rs) {
    // If we are adding a decimal with scale and precision to a decimal
    // with no precision nor scale, the scale system does not apply.
    if (ls == null || rs == null) {
      return null;
    }
    int val = Math.max(ls, rs);
    return Math.min(PDataType.MAX_PRECISION, val);
  }
}
