/**
 * 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.ql.optimizer.calcite.reloperators;

import java.util.Set;

import org.apache.calcite.sql.SqlFunction;
import org.apache.calcite.sql.SqlFunctionCategory;
import org.apache.calcite.sql.SqlKind;
import org.apache.calcite.sql.type.OperandTypes;
import org.apache.calcite.sql.type.ReturnTypes;
import org.apache.calcite.sql.type.SqlTypeTransforms;

import com.google.common.collect.Sets;

public class HiveExtractDate extends SqlFunction {

  public static final SqlFunction YEAR = new HiveExtractDate("YEAR");
  public static final SqlFunction QUARTER = new HiveExtractDate("QUARTER");
  public static final SqlFunction MONTH = new HiveExtractDate("MONTH");
  public static final SqlFunction WEEK = new HiveExtractDate("WEEK");
  public static final SqlFunction DAY = new HiveExtractDate("DAY");
  public static final SqlFunction HOUR = new HiveExtractDate("HOUR");
  public static final SqlFunction MINUTE = new HiveExtractDate("MINUTE");
  public static final SqlFunction SECOND = new HiveExtractDate("SECOND");

  public static final Set<SqlFunction> ALL_FUNCTIONS =
          Sets.newHashSet(YEAR, QUARTER, MONTH, WEEK, DAY, HOUR, MINUTE, SECOND);

  private HiveExtractDate(String name) {
    super(name, SqlKind.EXTRACT, 
       ReturnTypes.cascade(ReturnTypes.INTEGER, SqlTypeTransforms.FORCE_NULLABLE), null,
       OperandTypes.INTERVALINTERVAL_INTERVALDATETIME,
       SqlFunctionCategory.SYSTEM);
  }

}