/**
 * 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.segment.creator.impl.fwd;

import java.io.Closeable;
import java.io.File;
import java.io.IOException;

import com.linkedin.pinot.common.data.FieldSpec;
import com.linkedin.pinot.core.io.writer.impl.FixedByteSingleValueMultiColWriter;
import com.linkedin.pinot.core.segment.creator.SingleValueForwardIndexCreator;
import com.linkedin.pinot.core.segment.creator.impl.V1Constants;


public class SingleValueSortedForwardIndexCreator implements SingleValueForwardIndexCreator, Closeable {
  private FixedByteSingleValueMultiColWriter indexWriter;
  private int[] mins;
  private int[] maxs;
  private int cardinality;

  public SingleValueSortedForwardIndexCreator(File indexDir, int cardinality, FieldSpec spec) throws Exception {
    File indexFile = new File(indexDir, spec.getName() + V1Constants.Indexes.SORTED_FWD_IDX_FILE_EXTENTION);
    indexWriter = new FixedByteSingleValueMultiColWriter(indexFile, cardinality, 2, new int[] { 4, 4 });
    mins = new int[cardinality];
    maxs = new int[cardinality];

    for (int i = 0; i < mins.length; i++) {
      mins[i] = Integer.MAX_VALUE;
    }
    for (int i = 0; i < maxs.length; i++) {
      maxs[i] = -1;
    }
    this.cardinality = cardinality;
  }

  public void add(int dictionaryId, int docId) {

    if (mins[dictionaryId] > docId) {
      mins[dictionaryId] = docId;
    }
    if (maxs[dictionaryId] < docId) {
      maxs[dictionaryId] = docId;
    }
  }

  public void seal() throws IOException {
    for (int i = 0; i < cardinality; i++) {
      indexWriter.setInt(i, 0, mins[i]);
      indexWriter.setInt(i, 1, maxs[i]);
    }

    indexWriter.close();
  }

  @Override
  public void index(int docId, int dictionaryIndex) {
    add(dictionaryIndex, docId);
  }

  @Override
  public void close() throws IOException {
    seal();
  }
}