/*
 * 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.flink.graph.asm.dataset;

import org.apache.flink.api.common.typeinfo.TypeHint;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.graph.asm.dataset.ChecksumHashCode.Checksum;

import org.apache.commons.lang3.ArrayUtils;
import org.junit.Before;
import org.junit.Test;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import static org.junit.Assert.assertEquals;

/**
 * Tests for {@link ChecksumHashCode}.
 */
public class ChecksumHashCodeTest {

	private ExecutionEnvironment env;

	@Before
	public void setup() throws Exception {
		env = ExecutionEnvironment.createCollectionsEnvironment();
		env.getConfig().enableObjectReuse();
	}

	@Test
	public void testList() throws Exception {
		List<Long> list = Arrays.asList(ArrayUtils.toObject(
			new long[]{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }));

		DataSet<Long> dataset = env.fromCollection(list);

		Checksum checksum = new ChecksumHashCode<Long>().run(dataset).execute();

		assertEquals(list.size(), checksum.getCount());
		assertEquals(list.size() * (list.size() - 1) / 2, checksum.getChecksum());
	}

	@Test
	public void testEmptyList() throws Exception {
		DataSet<Long> dataset = env.fromCollection(Collections.emptyList(), TypeInformation.of(new TypeHint<Long>(){}));

		Checksum checksum = new ChecksumHashCode<Long>().run(dataset).execute();

		assertEquals(0, checksum.getCount());
		assertEquals(0, checksum.getChecksum());
	}
}