/*
 * Licensed to Crate under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.  Crate 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.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial
 * agreement.
 */

package io.crate.data;

import io.crate.testing.BatchIteratorTester;
import io.crate.testing.BatchSimulatingIterator;
import io.crate.testing.TestingBatchIterators;
import org.junit.Test;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.is;

public class CompositeBatchIteratorTest {

    private List<Object[]> expectedResult = IntStream.concat(IntStream.range(0, 5), IntStream.range(5, 10))
        .mapToObj(i -> new Object[] { i })
        .collect(Collectors.toList());


    @Test
    public void testDataRowInputsCanBeRetrievedEagerly() throws Exception {
        CompositeBatchIterator iterator = new CompositeBatchIterator(
            TestingBatchIterators.range(0, 1),
            TestingBatchIterators.range(1, 2)
        );
        Input<?> input = iterator.rowData().get(0);
        assertThat(iterator.moveNext(), is(true));
        assertThat(input.value(), is(0));

        assertThat(iterator.moveNext(), is(true));
        assertThat(input.value(), is(1));
    }

    @Test
    public void testCompositeBatchIterator() throws Exception {
        BatchIteratorTester tester = new BatchIteratorTester(
            () -> new CompositeBatchIterator(
                TestingBatchIterators.range(0, 5),
                TestingBatchIterators.range(5, 10))
        );
        tester.verifyResultAndEdgeCaseBehaviour(expectedResult);
    }

    @Test
    public void testCompositeBatchIteratorWithBatchedSources() throws Exception {
        List<Object[]> expectedResult = new ArrayList<>();
        // consumes the unbatched/loaded iterator first
        expectedResult.add(new Object[] { 5 });
        expectedResult.add(new Object[] { 6 });
        expectedResult.add(new Object[] { 7 });
        expectedResult.add(new Object[] { 8 });
        expectedResult.add(new Object[] { 9 });
        expectedResult.add(new Object[] { 0 });
        expectedResult.add(new Object[] { 1 });
        expectedResult.add(new Object[] { 2 });
        expectedResult.add(new Object[] { 3 });
        expectedResult.add(new Object[] { 4 });
        BatchIteratorTester tester = new BatchIteratorTester(
            () -> new CompositeBatchIterator(
                new CloseAssertingBatchIterator(
                    new BatchSimulatingIterator(TestingBatchIterators.range(0, 5), 2, 6, null)),
                TestingBatchIterators.range(5, 10)
            )
        );
        tester.verifyResultAndEdgeCaseBehaviour(expectedResult);
    }
}