/*
 * 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.extraction.demux;


import java.io.IOException;
import org.apache.hadoop.chukwa.conf.ChukwaConfiguration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;
import org.apache.hadoop.chukwa.util.ExceptionUtil;

public class RecordMerger extends Thread {
  static Logger log = Logger.getLogger(RecordMerger.class);
  ChukwaConfiguration conf = null;
  FileSystem fs = null;
  String[] mergeArgs = null;
  Tool tool = null;
  boolean deleteRawData = false;

  public RecordMerger(ChukwaConfiguration conf, FileSystem fs, Tool tool,
                      String[] mergeArgs, boolean deleteRawData) {
    this.conf = conf;
    this.fs = fs;
    this.tool = tool;
    this.mergeArgs = mergeArgs.clone();
    this.deleteRawData = deleteRawData;
  }

  @Override
  public void run() {
    mergeRecords();
  }

  void mergeRecords() {
    System.out.println("\t Running Merge! : output [" + mergeArgs[1] + "]");
    int res;
    try {
      res = ToolRunner.run(conf, tool, mergeArgs);
      System.out.println("MR exit status: " + res);
      if (res == 0) {
        writeRecordFile(mergeArgs[1] + "/part-00000", mergeArgs[2],
            mergeArgs[3]);

        // delete input
        if (deleteRawData) {
          FileUtil.fullyDelete(fs, new Path(mergeArgs[0]));

          Path hours = new Path(mergeArgs[2]);
          FileStatus[] hoursOrMinutesFS = fs.listStatus(hours);
          for (FileStatus hourOrMinuteFS : hoursOrMinutesFS) {
            String dirName = hourOrMinuteFS.getPath().getName();

            try {
              Integer.parseInt(dirName);
              FileUtil.fullyDelete(fs, new Path(mergeArgs[2] + "/" + dirName));
              if (log.isDebugEnabled()) {
                log.debug("Deleting Hour directory: " + mergeArgs[2] + "/"
                    + dirName);
              }
            } catch (NumberFormatException e) { /*
                                                 * Not an Hour or Minutes
                                                 * directory- Do nothing
                                                 */
              log.debug(ExceptionUtil.getStackTrace(e));
            }
          }
        }

        // delete rolling tag
        FileUtil.fullyDelete(fs, new Path(mergeArgs[3]));
        // delete M/R temp directory
        FileUtil.fullyDelete(fs, new Path(mergeArgs[1]));
      } else {
        throw new RuntimeException("Error in M/R merge operation!");
      }

    } catch (Exception e) {
      e.printStackTrace();
      throw new RuntimeException("Error in M/R merge operation!", e);
    }
  }

  void writeRecordFile(String input, String outputDir, String fileName)
      throws IOException {
    boolean done = false;
    int count = 1;
    Path recordFile = new Path(input);
    do {
      Path destDirPath = new Path(outputDir);
      Path destFilePath = new Path(outputDir + "/" + fileName + "." + count
          + ".evt");

      if (!fs.exists(destDirPath)) {
        fs.mkdirs(destDirPath);
        log.info(">>>>>>>>>>>> create Dir" + destDirPath);
      }

      if (!fs.exists(destFilePath)) {
        boolean res = fs.rename(recordFile, destFilePath);

        if (res == false) {
          log.info(">>>>>>>>>>>> Use standard copy rename failded");
          FileUtil.copy(fs, recordFile, fs, destFilePath, false, false, conf);
        }
        done = true;
      } else {
        log.info("Start MoveToRepository main()");
      }
      count++;
      // Just put a limit here
      // TODO read from config
      if (count > 1000) {
        throw new IOException("too many files in this directory: "
            + destDirPath);
      }
    } while (!done);
  }
}