/*
 * 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.distributedCache;

import org.apache.flink.api.common.functions.RichFlatMapFunction;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple1;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.runtime.minicluster.LocalFlinkMiniCluster;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.util.TestStreamEnvironment;
import org.apache.flink.test.util.AbstractTestBase;
import org.apache.flink.test.util.TestBaseUtils;
import org.apache.flink.test.util.TestEnvironment;
import org.apache.flink.util.Collector;

import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import static org.junit.Assert.assertTrue;


public class DistributedCacheTest extends AbstractTestBase {

	public static final String data
			= "machen\n"
			+ "zeit\n"
			+ "heerscharen\n"
			+ "keiner\n"
			+ "meine\n";

	private static final int PARALLELISM = 4;

	private static LocalFlinkMiniCluster cluster;

	@BeforeClass
	public static void setup() throws Exception {
		cluster = TestBaseUtils.startCluster(1, PARALLELISM, false, false, true);
		TestStreamEnvironment.setAsContext(cluster, PARALLELISM);
		TestEnvironment.setAsContext(cluster, PARALLELISM);
	}

	@AfterClass
	public static void teardown() throws Exception {
		TestStreamEnvironment.unsetAsContext();
		TestEnvironment.unsetAsContext();
		TestBaseUtils.stopCluster(cluster, TestBaseUtils.DEFAULT_TIMEOUT);
	}

	// ------------------------------------------------------------------------

	public DistributedCacheTest() {
		super(new Configuration());
	}
	
	// ------------------------------------------------------------------------

	@Test
	public void testStreamingDistributedCache() throws Exception {
		String textPath = createTempFile("count.txt", data);
		StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
		env.registerCachedFile(textPath, "cache_test");
		env.readTextFile(textPath).flatMap(new WordChecker());
		env.execute();
	}

	@Test
	public void testBatchDistributedCache() throws Exception {
		String textPath = createTempFile("count.txt", data);
		ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		env.registerCachedFile(textPath, "cache_test");
		env.readTextFile(textPath).flatMap(new WordChecker()).count();
	}

	public static class WordChecker extends RichFlatMapFunction<String, Tuple1<String>> {
		private static final long serialVersionUID = 1L;

		private final List<String> wordList = new ArrayList<>();

		@Override
		public void open(Configuration conf) throws IOException {
			File file = getRuntimeContext().getDistributedCache().getFile("cache_test");
			try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
				String tempString;
				while ((tempString= reader.readLine()) != null) {
					wordList.add(tempString);
				}
			}
		}

		@Override
		public void flatMap(String word, Collector<Tuple1<String>> out) throws Exception {
			assertTrue("Unexpected word in stream! wordFromStream: " + word + ", shouldBeOneOf: " +
				wordList.toString(), wordList.contains(word));

			out.collect(new Tuple1<>(word));
		}
	}
}