/*
 * 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.iterate;

import static org.apache.phoenix.query.QueryConstants.SINGLE_COLUMN;
import static org.apache.phoenix.query.QueryConstants.SINGLE_COLUMN_FAMILY;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.phoenix.compile.ExplainPlanAttributes.ExplainPlanAttributesBuilder;
import org.apache.phoenix.query.KeyRange;
import org.apache.phoenix.schema.tuple.SingleKeyValueTuple;
import org.apache.phoenix.schema.tuple.Tuple;
import org.apache.phoenix.util.AssertResults;
import org.junit.Test;

public class MergeSortResultIteratorTest {
  private final static byte[] A = Bytes.toBytes("a");
  private final static byte[] B = Bytes.toBytes("b");

  @Test
  public void testMergeSort() throws Throwable {
    Tuple[] results1 = new Tuple[] { new SingleKeyValueTuple(
      new KeyValue(A, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))), };
    Tuple[] results2 = new Tuple[] { new SingleKeyValueTuple(
      new KeyValue(B, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))) };
    Tuple[] results3 = new Tuple[] {
      new SingleKeyValueTuple(
        new KeyValue(A, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))),
      new SingleKeyValueTuple(
        new KeyValue(B, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))), };

    final List<PeekingResultIterator> results = new ArrayList<PeekingResultIterator>(Arrays
      .asList(new PeekingResultIterator[] { new MaterializedResultIterator(Arrays.asList(results1)),
        new MaterializedResultIterator(Arrays.asList(results2)),
        new MaterializedResultIterator(Arrays.asList(results3)) }));

    Tuple[] expectedResults = new Tuple[] {
      new SingleKeyValueTuple(
        new KeyValue(A, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))),
      new SingleKeyValueTuple(
        new KeyValue(A, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))),
      new SingleKeyValueTuple(
        new KeyValue(B, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))),
      new SingleKeyValueTuple(
        new KeyValue(B, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))), };

    ResultIterators iterators = new ResultIterators() {

      @Override
      public List<PeekingResultIterator> getIterators() throws SQLException {
        return results;
      }

      @Override
      public void explain(List<String> planSteps,
        ExplainPlanAttributesBuilder explainPlanAttributesBuilder) {
      }

      @Override
      public int size() {
        return results.size();
      }

      @Override
      public void explain(List<String> planSteps) {
      }

      @Override
      public List<KeyRange> getSplits() {
        return Collections.emptyList();
      }

      @Override
      public List<List<Scan>> getScans() {
        return Collections.emptyList();
      }

      @Override
      public void close() throws SQLException {
      }
    };
    ResultIterators reverseIterators = new ResultIterators() {

      @Override
      public List<PeekingResultIterator> getIterators() throws SQLException {
        return results;
      }

      @Override
      public void explain(List<String> planSteps,
        ExplainPlanAttributesBuilder explainPlanAttributesBuilder) {
      }

      @Override
      public int size() {
        return results.size();
      }

      @Override
      public void explain(List<String> planSteps) {
      }

      @Override
      public List<KeyRange> getSplits() {
        return Collections.emptyList();
      }

      @Override
      public List<List<Scan>> getScans() {
        return Collections.emptyList();
      }

      @Override
      public void close() throws SQLException {
      }
    };
    ResultIterator scanner = new MergeSortRowKeyResultIterator(iterators);
    AssertResults.assertResults(scanner, expectedResults);
  }

  @Test
  public void testReverseMergeSort() throws Throwable {
    Tuple[] results1 = new Tuple[] { new SingleKeyValueTuple(
      new KeyValue(A, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))), };
    Tuple[] results2 = new Tuple[] { new SingleKeyValueTuple(
      new KeyValue(B, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))) };
    Tuple[] results3 = new Tuple[] {
      new SingleKeyValueTuple(
        new KeyValue(B, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))),
      new SingleKeyValueTuple(
        new KeyValue(A, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))), };
    final List<PeekingResultIterator> results = new ArrayList<PeekingResultIterator>(Arrays
      .asList(new PeekingResultIterator[] { new MaterializedResultIterator(Arrays.asList(results1)),
        new MaterializedResultIterator(Arrays.asList(results2)),
        new MaterializedResultIterator(Arrays.asList(results3)) }));
    Tuple[] expectedResults = new Tuple[] {
      new SingleKeyValueTuple(
        new KeyValue(B, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))),
      new SingleKeyValueTuple(
        new KeyValue(B, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))),
      new SingleKeyValueTuple(
        new KeyValue(A, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))),
      new SingleKeyValueTuple(
        new KeyValue(A, SINGLE_COLUMN_FAMILY, SINGLE_COLUMN, Bytes.toBytes(1))), };
    ResultIterators iterators = new ResultIterators() {

      @Override
      public List<PeekingResultIterator> getIterators() throws SQLException {
        return results;
      }

      @Override
      public void explain(List<String> planSteps,
        ExplainPlanAttributesBuilder explainPlanAttributesBuilder) {
      }

      @Override
      public int size() {
        return results.size();
      }

      @Override
      public void explain(List<String> planSteps) {
      }

      @Override
      public List<KeyRange> getSplits() {
        return Collections.emptyList();
      }

      @Override
      public List<List<Scan>> getScans() {
        return Collections.emptyList();
      }

      @Override
      public void close() throws SQLException {
      }
    };
    ResultIterator scanner = new MergeSortRowKeyResultIterator(iterators, 0, true);
    AssertResults.assertResults(scanner, expectedResults);
  }

}
