/*
    * 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.hadoop.chukwa.dataloader;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.HashSet;
  import java.util.concurrent.CompletionService;
  import java.util.concurrent.ExecutorCompletionService;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.TimeUnit;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.fs.FileStatus;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.util.ToolRunner;
  import org.apache.hadoop.chukwa.analysis.salsa.fsm.FSMBuilder;
  import org.apache.hadoop.chukwa.conf.ChukwaConfiguration;
  import org.apache.hadoop.chukwa.util.ExceptionUtil;
  import org.apache.hadoop.conf.Configuration;
  
  public class FSMDataLoader extends DataLoaderFactory {
    private static Log log = LogFactory.getLog(FSMDataLoader.class);
  
    protected MetricDataLoader threads[] = null;
    private static String DATA_LOADER_THREAD_LIMIT = "chukwa.data.loader.threads.limit";
    private int size = 1;
    private static CompletionService completion = null;
    private static ExecutorService executor = null;
    private static String[] mappers = {
      "org.apache.hadoop.chukwa.analysis.salsa.fsm.DataNodeClientTraceMapper",
      "org.apache.hadoop.chukwa.analysis.salsa.fsm.TaskTrackerClientTraceMapper",
      "org.apache.hadoop.chukwa.analysis.salsa.fsm.JobHistoryTaskDataMapper"
    };
    
    public FSMDataLoader() {
    }
    
    public void load(ChukwaConfiguration conf, FileSystem fs, FileStatus[] fileList) throws IOException {
  
      if(executor==null) {
        try {
          this.size = Integer.parseInt(conf.get(DATA_LOADER_THREAD_LIMIT));
        } catch(Exception e) {
          this.size = 1;
        }
        executor = Executors.newFixedThreadPool(size);
      }
      if(completion==null) {
        completion = new ExecutorCompletionService(executor);
      }
      
      try {
        // Locate directory output directories of the current demux, and create a unique directory list.
        HashSet<Path> inputPaths = new HashSet<Path>();
        HashSet<Path> outputPaths = new HashSet<Path>();
        int counter = 0;
        for(int i=0;i<fileList.length;i++) {
          Path temp = fileList[i].getPath().getParent();
          if(!inputPaths.contains(temp)) {
            inputPaths.add(temp);
          }
        }
        String outputDir= conf.get("chukwa.tmp.data.dir")+File.separator+"fsm_"+System.currentTimeMillis()+"_";
        if(inputPaths.size()>0) {
          Configuration fsmConf = new Configuration();
          // Run fsm map reduce job for dn, tt, and jobhist.
          for(String mapper : mappers) {
            String[] args = new String[inputPaths.size()+3];
            args[0]="-in";
            int k=2;
            boolean hasData=false;
            for(Path temp : inputPaths) {
              String tempPath = temp.toUri().toString();
              if((mapper.intern()==mappers[0].intern() && tempPath.indexOf("ClientTraceDetailed")>0) ||
                  (mapper.intern()==mappers[1].intern() && tempPath.indexOf("ClientTraceDetailed")>0) ||
                  (mapper.intern()==mappers[2].intern() && tempPath.indexOf("TaskData")>0) ||
                  (mapper.intern()==mappers[2].intern() && tempPath.indexOf("JobData")>0)) {
                args[k]=tempPath;
                k++;
                hasData=true;
             }
           }
           args[1]=k-2+"";
           fsmConf.set("chukwa.salsa.fsm.mapclass", mapper);
           args[k]=outputDir+mapper;
           Path outputPath = new Path(args[k]);
           outputPaths.add(outputPath);
           if(hasData) {
             int res = ToolRunner.run(fsmConf, new FSMBuilder(), args);
             log.debug("Job Status: "+res);
           }
         }
       }
       // Find the mapreduce output and load to MDL.
       for(Path outputPath : outputPaths) {
         Path searchDir = new Path(outputPath.toUri().toString()+"/*/*/*.evt");
         log.info("Search dir:"+searchDir.toUri().toString());
         FileStatus[] outputList = fs.globStatus(searchDir);
         if(outputList!=null) {
           for(int j=0;j<outputList.length;j++) {
             String outputFile = outputList[j].getPath().toUri().toString();
             log.info("FSM -> MDL loading: "+outputFile);
             completion.submit(new MetricDataLoader(conf, fs, outputFile));
             counter++;
           }
         } else {
           log.warn("No output to load.");
         }
       }
       for(int i=0;i<counter;i++) {
         completion.take().get();
       }
       // Clean up mapreduce output of fsm.
       for(Path dir : outputPaths) {
         fs.delete(dir, true);
       }
     } catch(Exception e) {
       log.error(ExceptionUtil.getStackTrace(e));
       throw new IOException();
     }
   }
 
   public void shutdown() throws InterruptedException {
     executor.shutdown();
     executor.awaitTermination(30, TimeUnit.SECONDS);
     executor.shutdownNow();
   }
 }