/*
 * 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.spark.streaming.kafka;

import java.io.Serializable;
import java.util.*;

import scala.Tuple2;

import kafka.serializer.StringDecoder;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.function.Function;
import org.apache.spark.api.java.function.VoidFunction;
import org.apache.spark.storage.StorageLevel;
import org.apache.spark.streaming.Duration;
import org.apache.spark.streaming.api.java.JavaDStream;
import org.apache.spark.streaming.api.java.JavaPairDStream;
import org.apache.spark.streaming.api.java.JavaStreamingContext;

public class JavaKafkaStreamSuite implements Serializable {
  private transient JavaStreamingContext ssc = null;
  private transient Random random = new Random();
  private transient KafkaTestUtils kafkaTestUtils = null;

  @Before
  public void setUp() {
    kafkaTestUtils = new KafkaTestUtils();
    kafkaTestUtils.setup();
    SparkConf sparkConf = new SparkConf()
      .setMaster("local[4]").setAppName(this.getClass().getSimpleName());
    ssc = new JavaStreamingContext(sparkConf, new Duration(500));
  }

  @After
  public void tearDown() {
    if (ssc != null) {
      ssc.stop();
      ssc = null;
    }

    if (kafkaTestUtils != null) {
      kafkaTestUtils.teardown();
      kafkaTestUtils = null;
    }
  }

  @Test
  public void testKafkaStream() throws InterruptedException {
    String topic = "topic1";
    Map<String, Integer> topics = new HashMap<>();
    topics.put(topic, 1);

    Map<String, Integer> sent = new HashMap<>();
    sent.put("a", 5);
    sent.put("b", 3);
    sent.put("c", 10);

    kafkaTestUtils.createTopic(topic, 1);
    kafkaTestUtils.sendMessages(topic, sent);

    Map<String, String> kafkaParams = new HashMap<>();
    kafkaParams.put("zookeeper.connect", kafkaTestUtils.zkAddress());
    kafkaParams.put("group.id", "test-consumer-" + random.nextInt(10000));
    kafkaParams.put("auto.offset.reset", "smallest");

    JavaPairDStream<String, String> stream = KafkaUtils.createStream(ssc,
      String.class,
      String.class,
      StringDecoder.class,
      StringDecoder.class,
      kafkaParams,
      topics,
      StorageLevel.MEMORY_ONLY_SER());

    final Map<String, Long> result = Collections.synchronizedMap(new HashMap<String, Long>());

    JavaDStream<String> words = stream.map(
      new Function<Tuple2<String, String>, String>() {
        @Override
        public String call(Tuple2<String, String> tuple2) {
          return tuple2._2();
        }
      }
    );

    words.countByValue().foreachRDD(new VoidFunction<JavaPairRDD<String, Long>>() {
        @Override
        public void call(JavaPairRDD<String, Long> rdd) {
          List<Tuple2<String, Long>> ret = rdd.collect();
          for (Tuple2<String, Long> r : ret) {
            if (result.containsKey(r._1())) {
              result.put(r._1(), result.get(r._1()) + r._2());
            } else {
              result.put(r._1(), r._2());
            }
          }
        }
      }
    );

    ssc.start();

    long startTime = System.currentTimeMillis();
    AssertionError lastError = null;
    while (System.currentTimeMillis() - startTime < 20000) {
      try {
        Assert.assertEquals(sent.size(), result.size());
        for (Map.Entry<String, Integer> e : sent.entrySet()) {
          Assert.assertEquals(e.getValue().intValue(), result.get(e.getKey()).intValue());
        }
        return;
      } catch (AssertionError e) {
        lastError = e;
      }
      Thread.sleep(200);
    }
    if (lastError != null) {
      throw lastError;
    } else {
      Assert.fail("timeout");
    }
  }
}
