/**
 * 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 com.alibaba.jstorm.topology;

import java.math.BigInteger;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import junit.framework.Assert;

import org.junit.Test;

import backtype.storm.Config;
import backtype.storm.LocalCluster;
import backtype.storm.coordination.BatchOutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.testing.MemoryTransactionalSpout;
import backtype.storm.topology.BasicOutputCollector;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseBasicBolt;
import backtype.storm.topology.base.BaseTransactionalBolt;
import backtype.storm.transactional.ICommitter;
import backtype.storm.transactional.TransactionAttempt;
import backtype.storm.transactional.TransactionalTopologyBuilder;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;

import com.alibaba.jstorm.utils.JStormUtils;

/**
 * This class defines a more involved transactional topology then TransactionalGlobalCount. This topology processes a stream of words and produces two outputs:
 * <p/>
 * 1. A count for each word (stored in a database) 2. The number of words for every bucket of 10 counts. So it stores in the database how many words have
 * appeared 0-9 times, how many have appeared 10-19 times, and so on.
 * <p/>
 * A batch of words can cause the bucket counts to decrement for some buckets and increment for others as words move between buckets as their counts accumulate.
 */
public class TransactionalWordsTest {
    public static class CountValue {
        Integer prev_count = null;
        int count = 0;
        BigInteger txid = null;
    }

    public static class BucketValue {
        int count = 0;
        BigInteger txid;
    }

    public static final int BUCKET_SIZE = 10;

    public static Map<String, CountValue> COUNT_DATABASE = new HashMap<String, CountValue>();
    public static Map<Integer, BucketValue> BUCKET_DATABASE = new HashMap<Integer, BucketValue>();

    public static final int PARTITION_TAKE_PER_BATCH = 3;

    public static final Map<Integer, List<List<Object>>> DATA = new HashMap<Integer, List<List<Object>>>() {
        {
            put(0, new ArrayList<List<Object>>() {
                {
                    add(new Values("cat"));
                    add(new Values("dog"));
                    add(new Values("chicken"));
                    add(new Values("cat"));
                    add(new Values("dog"));
                    add(new Values("apple"));
                }
            });
            put(1, new ArrayList<List<Object>>() {
                {
                    add(new Values("cat"));
                    add(new Values("dog"));
                    add(new Values("apple"));
                    add(new Values("banana"));
                }
            });
            put(2, new ArrayList<List<Object>>() {
                {
                    add(new Values("cat"));
                    add(new Values("cat"));
                    add(new Values("cat"));
                    add(new Values("cat"));
                    add(new Values("cat"));
                    add(new Values("dog"));
                    add(new Values("dog"));
                    add(new Values("dog"));
                    add(new Values("dog"));
                }
            });
        }
    };

    public static class KeyedCountUpdater extends BaseTransactionalBolt implements ICommitter {
        Map<String, Integer> _counts = new HashMap<String, Integer>();
        BatchOutputCollector _collector;
        TransactionAttempt _id;

        int _count = 0;

        @Override
        public void prepare(Map conf, TopologyContext context, BatchOutputCollector collector, TransactionAttempt id) {
            _collector = collector;
            _id = id;
        }

        @Override
        public void execute(Tuple tuple) {
            String key = tuple.getString(1);
            Integer curr = _counts.get(key);
            if (curr == null)
                curr = 0;
            _counts.put(key, curr + 1);
        }

        @Override
        public void finishBatch() {
            for (String key : _counts.keySet()) {
                CountValue val = COUNT_DATABASE.get(key);
                CountValue newVal;
                if (val == null || !val.txid.equals(_id.getTransactionId())) {
                    newVal = new CountValue();
                    newVal.txid = _id.getTransactionId();
                    if (val != null) {
                        newVal.prev_count = val.count;
                        newVal.count = val.count;
                    }
                    newVal.count = newVal.count + _counts.get(key);
                    COUNT_DATABASE.put(key, newVal);
                } else {
                    newVal = val;
                }
                _collector.emit(new Values(_id, key, newVal.count, newVal.prev_count));
            }
        }

        @Override
        public void declareOutputFields(OutputFieldsDeclarer declarer) {
            declarer.declare(new Fields("id", "key", "count", "prev-count"));
        }
    }

    public static class Bucketize extends BaseBasicBolt {
        @Override
        public void execute(Tuple tuple, BasicOutputCollector collector) {
            TransactionAttempt attempt = (TransactionAttempt) tuple.getValue(0);
            int curr = tuple.getInteger(2);
            Integer prev = tuple.getInteger(3);

            int currBucket = curr / BUCKET_SIZE;
            Integer prevBucket = null;
            if (prev != null) {
                prevBucket = prev / BUCKET_SIZE;
            }

            if (prevBucket == null) {
                collector.emit(new Values(attempt, currBucket, 1));
            } else if (currBucket != prevBucket) {
                collector.emit(new Values(attempt, currBucket, 1));
                collector.emit(new Values(attempt, prevBucket, -1));
            }
        }

        @Override
        public void declareOutputFields(OutputFieldsDeclarer declarer) {
            declarer.declare(new Fields("attempt", "bucket", "delta"));
        }
    }

    public static class BucketCountUpdater extends BaseTransactionalBolt {
        Map<Integer, Integer> _accum = new HashMap<Integer, Integer>();
        BatchOutputCollector _collector;
        TransactionAttempt _attempt;

        int _count = 0;

        @Override
        public void prepare(Map conf, TopologyContext context, BatchOutputCollector collector, TransactionAttempt attempt) {
            _collector = collector;
            _attempt = attempt;
        }

        @Override
        public void execute(Tuple tuple) {
            Integer bucket = tuple.getInteger(1);
            Integer delta = tuple.getInteger(2);
            Integer curr = _accum.get(bucket);
            if (curr == null)
                curr = 0;
            _accum.put(bucket, curr + delta);
        }

        @Override
        public void finishBatch() {
            for (Integer bucket : _accum.keySet()) {
                BucketValue currVal = BUCKET_DATABASE.get(bucket);
                BucketValue newVal;
                if (currVal == null || !currVal.txid.equals(_attempt.getTransactionId())) {
                    newVal = new BucketValue();
                    newVal.txid = _attempt.getTransactionId();
                    newVal.count = _accum.get(bucket);
                    if (currVal != null)
                        newVal.count += currVal.count;
                    BUCKET_DATABASE.put(bucket, newVal);
                } else {
                    newVal = currVal;
                }
                _collector.emit(new Values(_attempt, bucket, newVal.count));
            }
        }

        @Override
        public void declareOutputFields(OutputFieldsDeclarer declarer) {
            declarer.declare(new Fields("id", "bucket", "count"));
        }
    }

    @Test
    public void test_transaction_word() {
        try {
            MemoryTransactionalSpout spout = new MemoryTransactionalSpout(DATA, new Fields("word"), PARTITION_TAKE_PER_BATCH);
            TransactionalTopologyBuilder builder = new TransactionalTopologyBuilder("top-n-words", "spout", spout, 2);
            builder.setBolt("count", new KeyedCountUpdater(), 5).fieldsGrouping("spout", new Fields("word"));
            builder.setBolt("bucketize", new Bucketize()).shuffleGrouping("count");
            builder.setBolt("buckets", new BucketCountUpdater(), 5).fieldsGrouping("bucketize", new Fields("bucket"));

            LocalCluster cluster = new LocalCluster();

            Config config = new Config();
            config.setDebug(true);
            config.setMaxSpoutPending(3);

            cluster.submitTopology("top-n-topology", config, builder.buildTopology());

            JStormUtils.sleepMs(60 * 1000);
            cluster.shutdown();
        } catch (Exception e) {
            Assert.fail("Failed to run simple transaction");
        }

    }
}