/*
 * 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.hadoop.mapred;

import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.hadoop.mapred.HadoopOutputFormat;
import org.apache.flink.api.java.tuple.Tuple2;
import static org.apache.flink.hadoopcompatibility.HadoopInputs.readHadoopFile;
import org.apache.flink.test.testdata.WordCountData;
import org.apache.flink.test.util.JavaProgramTestBase;
import org.apache.flink.test.testfunctions.Tokenizer;
import org.apache.flink.util.OperatingSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.junit.Assume;
import org.junit.Before;

public class WordCountMapredITCase extends JavaProgramTestBase {

	protected String textPath;
	protected String resultPath;

	@Before
	public void checkOperatingSystem() {
		// FLINK-5164 - see https://wiki.apache.org/hadoop/WindowsProblems
		Assume.assumeTrue("This test can't run successfully on Windows.", !OperatingSystem.isWindows());
	}

	@Override
	protected void preSubmit() throws Exception {
		textPath = createTempFile("text.txt", WordCountData.TEXT);
		resultPath = getTempDirPath("result");
	}

	@Override
	protected void postSubmit() throws Exception {
		compareResultsByLinesInMemory(WordCountData.COUNTS, resultPath, new String[] {".", "_"});
	}

	@Override
	protected void testProgram() throws Exception {
		internalRun(true);
		postSubmit();
		resultPath = getTempDirPath("result2");
		internalRun(false);
	}

	private void internalRun(boolean isTestDeprecatedAPI) throws Exception {
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		DataSet<Tuple2<LongWritable, Text>> input;

		if (isTestDeprecatedAPI) {
			input = env.readHadoopFile(new TextInputFormat(),
				LongWritable.class, Text.class, textPath);
		} else {
			input = env.createInput(readHadoopFile(new TextInputFormat(),
				LongWritable.class, Text.class, textPath));
		}

		DataSet<String> text = input.map(new MapFunction<Tuple2<LongWritable, Text>, String>() {
			@Override
			public String map(Tuple2<LongWritable, Text> value) throws Exception {
				return value.f1.toString();
			}
		});


		DataSet<Tuple2<String, Integer>> counts =
				// split up the lines in pairs (2-tuples) containing: (word,1)
				text.flatMap(new Tokenizer())
						// group by the tuple field "0" and sum up tuple field "1"
						.groupBy(0)
						.sum(1);

		DataSet<Tuple2<Text, LongWritable>> words = counts.map(new MapFunction<Tuple2<String, Integer>, Tuple2<Text, LongWritable>>() {


			@Override
			public Tuple2<Text, LongWritable> map(Tuple2<String, Integer> value) throws Exception {
				return new Tuple2<Text, LongWritable>(new Text(value.f0), new LongWritable(value.f1));
			}
		});

		// Set up Hadoop Output Format
		HadoopOutputFormat<Text, LongWritable> hadoopOutputFormat =
				new HadoopOutputFormat<Text, LongWritable>(new TextOutputFormat<Text, LongWritable>(), new JobConf());
		hadoopOutputFormat.getJobConf().set("mapred.textoutputformat.separator", " ");
		TextOutputFormat.setOutputPath(hadoopOutputFormat.getJobConf(), new Path(resultPath));

		// Output & Execute
		words.output(hadoopOutputFormat);
		env.execute("Hadoop Compat WordCount");
	}
}