/**
 * 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.storm.hdfs.spout;

import org.apache.storm.Config;
import org.apache.storm.StormSubmitter;
import org.apache.storm.generated.KillOptions;
import org.apache.storm.generated.Nimbus;
import org.apache.storm.generated.TopologyInfo;
import org.apache.storm.generated.TopologySummary;
import org.apache.storm.generated.ExecutorSummary;
import org.apache.storm.generated.SpoutStats;
import org.apache.storm.generated.ClusterSummary;
import org.apache.storm.metric.LoggingMetricsConsumer;
import org.apache.storm.topology.TopologyBuilder;
import org.apache.storm.utils.NimbusClient;
import org.apache.storm.utils.Utils;
import org.apache.storm.topology.base.BaseRichBolt;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.tuple.Fields;
import org.apache.storm.tuple.Tuple;
import org.apache.storm.task.OutputCollector;
import org.apache.storm.task.TopologyContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Map;


public class HdfsSpoutTopology {

  public static final String SPOUT_ID = "hdfsspout";
  public static final String BOLT_ID = "constbolt";


  public static class ConstBolt extends BaseRichBolt {
    private static final long serialVersionUID = -5313598399155365865L;
    public static final String FIELDS = "message";
    private OutputCollector collector;
    private static final Logger log = LoggerFactory.getLogger(ConstBolt.class);
    int count =0;

    public ConstBolt() {
    }

    @Override
    public void prepare(Map conf, TopologyContext context, OutputCollector collector) {
      this.collector = collector;
    }

    @Override
    public void execute(Tuple tuple) {
      log.info("Received tuple : {}", tuple.getValue(0));
      count++;
      if(count==3) {
        collector.fail(tuple);
      }
      else {
        collector.ack(tuple);
      }
    }

    @Override
    public void declareOutputFields(OutputFieldsDeclarer declarer) {
      declarer.declare(new Fields(FIELDS));
    }
  } // class

  /** Copies text file content from sourceDir to destinationDir. Moves source files into sourceDir after its done consuming */
  public static void main(String[] args) throws Exception {
    // 0 - validate args
    if (args.length < 7) {
      System.err.println("Please check command line arguments.");
      System.err.println("Usage :");
      System.err.println(HdfsSpoutTopology.class.toString() + " topologyName hdfsUri fileFormat sourceDir sourceArchiveDir badDir destinationDir.");
      System.err.println(" topologyName - topology name.");
      System.err.println(" hdfsUri - hdfs name node URI");
      System.err.println(" fileFormat -  Set to 'TEXT' for reading text files or 'SEQ' for sequence files.");
      System.err.println(" sourceDir  - read files from this HDFS dir using HdfsSpout.");
      System.err.println(" archiveDir - after a file in sourceDir is read completely, it is moved to this HDFS location.");
      System.err.println(" badDir - files that cannot be read properly will be moved to this HDFS location.");
      System.err.println(" spoutCount - Num of spout instances.");
      System.err.println();
      System.exit(-1);
    }

    // 1 - parse cmd line args
    String topologyName = args[0];
    String hdfsUri = args[1];
    String fileFormat = args[2];
    String sourceDir = args[3];
    String archiveDir = args[4];
    String badDir = args[5];
    int spoutNum = Integer.parseInt(args[6]);

    // 2 - create and configure spout and bolt
    ConstBolt bolt = new ConstBolt();

    HdfsSpout spout =  new HdfsSpout().withOutputFields(TextFileReader.defaultFields)
                                      .setReaderType(fileFormat)
                                      .setHdfsUri(hdfsUri)
                                      .setSourceDir(sourceDir)
                                      .setArchiveDir(archiveDir)
                                      .setBadFilesDir(badDir);

    // 3 - Create and configure topology
    Config conf = new Config();
    conf.setNumWorkers(1);
    conf.setNumAckers(1);
    conf.setMaxTaskParallelism(1);
    conf.setDebug(true);
    conf.registerMetricsConsumer(LoggingMetricsConsumer.class);

    TopologyBuilder builder = new TopologyBuilder();
    builder.setSpout(SPOUT_ID, spout, spoutNum);
    builder.setBolt(BOLT_ID, bolt, 1).shuffleGrouping(SPOUT_ID);

    // 4 - submit topology, wait for a few min and terminate it
    Map clusterConf = Utils.readStormConfig();
    StormSubmitter.submitTopologyWithProgressBar(topologyName, conf, builder.createTopology());
    Nimbus.Client client = NimbusClient.getConfiguredClient(clusterConf).getClient();

    // 5 - Print metrics every 30 sec, kill topology after 20 min
    for (int i = 0; i < 40; i++) {
      Thread.sleep(30 * 1000);
      printMetrics(client, topologyName);
    }
    kill(client, topologyName);
  } // main

  private static void kill(Nimbus.Client client, String topologyName) throws Exception {
    KillOptions opts = new KillOptions();
    opts.set_wait_secs(0);
    client.killTopologyWithOpts(topologyName, opts);
  }

  static void printMetrics(Nimbus.Client client, String name) throws Exception {
    ClusterSummary summary = client.getClusterInfo();
    String id = null;
    for (TopologySummary ts: summary.get_topologies()) {
      if (name.equals(ts.get_name())) {
        id = ts.get_id();
      }
    }
    if (id == null) {
      throw new Exception("Could not find a topology named "+name);
    }
    TopologyInfo info = client.getTopologyInfo(id);
    int uptime = info.get_uptime_secs();
    long acked = 0;
    long failed = 0;
    double weightedAvgTotal = 0.0;
    for (ExecutorSummary exec: info.get_executors()) {
      if ("spout".equals(exec.get_component_id())) {
        SpoutStats stats = exec.get_stats().get_specific().get_spout();
        Map<String, Long> failedMap = stats.get_failed().get(":all-time");
        Map<String, Long> ackedMap = stats.get_acked().get(":all-time");
        Map<String, Double> avgLatMap = stats.get_complete_ms_avg().get(":all-time");
        for (String key: ackedMap.keySet()) {
          if (failedMap != null) {
            Long tmp = failedMap.get(key);
            if (tmp != null) {
              failed += tmp;
            }
          }
          long ackVal = ackedMap.get(key);
          double latVal = avgLatMap.get(key) * ackVal;
          acked += ackVal;
          weightedAvgTotal += latVal;
        }
      }
    }
    double avgLatency = weightedAvgTotal/acked;
    System.out.println("uptime: "+uptime+" acked: "+acked+" avgLatency: "+avgLatency+" acked/sec: "+(((double)acked)/uptime+" failed: "+failed));
  }
}
