/*
 * 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.test.api.java.operators.lambdas;

import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple5;
import org.apache.flink.api.java.typeutils.TupleTypeInfo;
import org.apache.flink.test.util.JavaProgramTestBase;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * IT cases for lambda reduce functions.
 */
public class ReduceITCase extends JavaProgramTestBase {

	private static final String EXPECTED_RESULT = "1,1,0,Hallo,1\n" +
			"2,3,2,Hallo Welt wie,1\n" +
			"2,2,1,Hallo Welt,2\n" +
			"3,9,0,P-),2\n" +
			"3,6,5,BCD,3\n" +
			"4,17,0,P-),1\n" +
			"4,17,0,P-),2\n" +
			"5,11,10,GHI,1\n" +
			"5,29,0,P-),2\n" +
			"5,25,0,P-),3\n";

	public static DataSet<Tuple5<Integer, Long, Integer, String, Long>> get5TupleDataSet(ExecutionEnvironment env) {

		List<Tuple5<Integer, Long, Integer, String, Long>> data = new ArrayList<Tuple5<Integer, Long, Integer, String, Long>>();
		data.add(new Tuple5<>(1, 1L, 0, "Hallo", 1L));
		data.add(new Tuple5<>(2, 2L, 1, "Hallo Welt", 2L));
		data.add(new Tuple5<>(2, 3L, 2, "Hallo Welt wie", 1L));
		data.add(new Tuple5<>(3, 4L, 3, "Hallo Welt wie gehts?", 2L));
		data.add(new Tuple5<>(3, 5L, 4, "ABC", 2L));
		data.add(new Tuple5<>(3, 6L, 5, "BCD", 3L));
		data.add(new Tuple5<>(4, 7L, 6, "CDE", 2L));
		data.add(new Tuple5<>(4, 8L, 7, "DEF", 1L));
		data.add(new Tuple5<>(4, 9L, 8, "EFG", 1L));
		data.add(new Tuple5<>(4, 10L, 9, "FGH", 2L));
		data.add(new Tuple5<>(5, 11L, 10, "GHI", 1L));
		data.add(new Tuple5<>(5, 12L, 11, "HIJ", 3L));
		data.add(new Tuple5<>(5, 13L, 12, "IJK", 3L));
		data.add(new Tuple5<>(5, 14L, 13, "JKL", 2L));
		data.add(new Tuple5<>(5, 15L, 14, "KLM", 2L));

		Collections.shuffle(data);

		TupleTypeInfo<Tuple5<Integer, Long,  Integer, String, Long>> type = new
				TupleTypeInfo<Tuple5<Integer, Long,  Integer, String, Long>>(
				BasicTypeInfo.INT_TYPE_INFO,
				BasicTypeInfo.LONG_TYPE_INFO,
				BasicTypeInfo.INT_TYPE_INFO,
				BasicTypeInfo.STRING_TYPE_INFO,
				BasicTypeInfo.LONG_TYPE_INFO
		);

		return env.fromCollection(data, type);
	}

	private String resultPath;

	@Override
	protected void preSubmit() throws Exception {
		resultPath = getTempDirPath("result");
	}

	@Override
	protected void testProgram() throws Exception {
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		DataSet<Tuple5<Integer, Long, Integer, String, Long>> ds = get5TupleDataSet(env);
		DataSet<Tuple5<Integer, Long, Integer, String, Long>> reduceDs = ds
				.groupBy(4, 0)
				.reduce((in1, in2) -> {
					Tuple5<Integer, Long, Integer, String, Long> out = new Tuple5<Integer, Long, Integer, String, Long>();
					out.setFields(in1.f0, in1.f1 + in2.f1, 0, "P-)", in1.f4);
					return out;
				});

		reduceDs.writeAsCsv(resultPath);
		env.execute();
	}

	@Override
	protected void postSubmit() throws Exception {
		compareResultsByLinesInMemory(EXPECTED_RESULT, resultPath);
	}
}