/*
 * 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.spark.sql.sources

import org.apache.spark.annotation.DeveloperApi
import org.apache.spark.rdd.RDD
import org.apache.spark.sql._
import org.apache.spark.sql.catalyst.expressions._

@DeveloperApi
trait PushDownAggregateScan {

  var aggregateExpressions: Seq[NamedExpression] = null
  var groupingExpressions: Seq[Expression] = null
  var orders: Seq[SortOrder] = Seq.empty[SortOrder]
  var limit: Int = 20

  def buildScan(requiredColumns: Array[String], filters: Array[Filter]): RDD[Row]

  def setAggregateExpressions(ae: Seq[NamedExpression]): Unit = {
    aggregateExpressions = ae
  }

  def setGroupingExpressions(ge: Seq[Expression]): Unit = {
    groupingExpressions = ge
  }

  def setOrders(o: Seq[SortOrder]): Unit = {
    orders = o
  }

  def setLimit(l: Int): Unit = {
    limit = l
  }
}