/*
 * 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.math.BigDecimal;
import java.util.List;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.phoenix.query.QueryConstants;
import org.apache.phoenix.schema.SortOrder;
import org.apache.phoenix.schema.tuple.Tuple;
import org.apache.phoenix.schema.types.PDataType;
import org.apache.phoenix.schema.types.PDate;
import org.apache.phoenix.schema.types.PDecimal;
import org.apache.phoenix.schema.types.PDouble;
import org.apache.phoenix.schema.types.PLong;

public class DateAddExpression extends AddExpression {
  static private final BigDecimal BD_MILLIS_IN_DAY =
    BigDecimal.valueOf(QueryConstants.MILLIS_IN_DAY);

  public DateAddExpression() {
  }

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

  @Override
  public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
    long finalResult = 0;

    for (int i = 0; i < children.size(); i++) {
      if (!children.get(i).evaluate(tuple, ptr)) {
        return false;
      }
      if (ptr.getLength() == 0) {
        return true;
      }
      long value;
      PDataType type = children.get(i).getDataType();
      SortOrder sortOrder = children.get(i).getSortOrder();
      if (type == PDecimal.INSTANCE) {
        BigDecimal bd = (BigDecimal) PDecimal.INSTANCE.toObject(ptr, type, sortOrder);
        value = bd.multiply(BD_MILLIS_IN_DAY).longValue();
      } else if (type.isCoercibleTo(PLong.INSTANCE)) {
        value = type.getCodec().decodeLong(ptr, sortOrder) * QueryConstants.MILLIS_IN_DAY;
      } else if (type.isCoercibleTo(PDouble.INSTANCE)) {
        value =
          (long) (type.getCodec().decodeDouble(ptr, sortOrder) * QueryConstants.MILLIS_IN_DAY);
      } else {
        value = type.getCodec().decodeLong(ptr, sortOrder);
      }
      finalResult += value;
    }
    byte[] resultPtr = new byte[getDataType().getByteSize()];
    getDataType().getCodec().encodeLong(finalResult, resultPtr, 0);
    ptr.set(resultPtr);
    return true;
  }

  @Override
  public final PDataType getDataType() {
    return PDate.INSTANCE;
  }

  @Override
  public ArithmeticExpression clone(List<Expression> children) {
    return new DateAddExpression(children);
  }

}
