/**
 * Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
 *
 * Licensed 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 com.linkedin.pinot.core.operator.docidsets;

import com.linkedin.pinot.common.utils.Pairs.IntPair;
import com.linkedin.pinot.core.common.BlockDocIdIterator;
import com.linkedin.pinot.core.operator.blocks.BlockFactory;
import com.linkedin.pinot.core.operator.dociditerators.SortedDocIdIterator;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;


public class SortedDocIdSet implements FilterBlockDocIdSet {

  public final List<IntPair> pairs;
  public final AtomicLong timeMeasure = new AtomicLong(0);
  int startDocId;
  int endDocId;
  private String datasourceName;

  public SortedDocIdSet(String datasourceName,List<IntPair> pairs) {
    this.datasourceName = datasourceName;
    this.pairs = pairs;
  }

  @Override
  public int getMinDocId() {
    if (pairs.size() > 0) {
      return pairs.get(0).getLeft();
    } else {
      return 0;
    }
  }

  @Override
  public int getMaxDocId() {
    if (pairs.size() > 0) {
      return pairs.get(pairs.size() - 1).getRight();
    } else {
      return 0;
    }
  }

  /**
   * After setting the startDocId, next calls will always return from >=startDocId
   * @param startDocId
   */
  @Override
  public void setStartDocId(int startDocId) {
    this.startDocId = startDocId;
  }

  /**
   * After setting the endDocId, next call will return Constants.EOF after currentDocId exceeds endDocId
   * @param endDocId
   */
  @Override
  public void setEndDocId(int endDocId) {
    this.endDocId = endDocId;
  }

  @Override
  public long getNumEntriesScannedInFilter() {
    return 0L;
  }

  @Override
  public BlockDocIdIterator iterator() {
    if (pairs == null || pairs.isEmpty()) {
      return BlockFactory.emptyBlockDocIdSetIterator();
    }
    return new SortedDocIdIterator(datasourceName, pairs);
  }

  @SuppressWarnings("unchecked")
  @Override
  public <T> T getRaw() {
    return (T) pairs;
  }

  @Override
  public String toString() {
    return pairs.toString();
  }
}