/*
 * 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.execute;

import java.sql.SQLException;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.phoenix.compile.ExplainPlan;
import org.apache.phoenix.compile.QueryPlan;
import org.apache.phoenix.compile.StatementContext;
import org.apache.phoenix.execute.visitor.QueryPlanVisitor;
import org.apache.phoenix.iterate.CursorResultIterator;
import org.apache.phoenix.iterate.LookAheadResultIterator;
import org.apache.phoenix.iterate.ParallelScanGrouper;
import org.apache.phoenix.iterate.ResultIterator;

public class CursorFetchPlan extends DelegateQueryPlan {

  private CursorResultIterator resultIterator;
  private int fetchSize;
  private boolean isAggregate;
  private String cursorName;

  public CursorFetchPlan(QueryPlan cursorQueryPlan, String cursorName) {
    super(cursorQueryPlan);
    this.isAggregate =
      delegate.getStatement().isAggregate() || delegate.getStatement().isDistinct();
    this.cursorName = cursorName;
  }

  @Override
  public ResultIterator iterator(ParallelScanGrouper scanGrouper, Scan scan) throws SQLException {
    StatementContext context = delegate.getContext();
    if (resultIterator == null) {
      context.getOverallQueryMetrics().startQuery();
      resultIterator = new CursorResultIterator(
        LookAheadResultIterator.wrap(delegate.iterator(scanGrouper, scan)), cursorName);
    }
    return resultIterator;
  }

  @Override
  public <T> T accept(QueryPlanVisitor<T> visitor) {
    return visitor.visit(this);
  }

  @Override
  public ExplainPlan getExplainPlan() throws SQLException {
    return delegate.getExplainPlan();
  }

  public void setFetchSize(int fetchSize) {
    this.fetchSize = fetchSize;
  }

  public int getFetchSize() {
    return fetchSize;
  }

  public boolean isAggregate() {
    return this.isAggregate;
  }
}
