/*
 * 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.database;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.chukwa.util.DatabaseWriter;

@SuppressWarnings("unused")
public class Aggregator {

  private static Log log = LogFactory.getLog(Aggregator.class);
  private String table = null;
  private String jdbc = null;
  private int[] intervals;
  private long current = 0;
  private DatabaseWriter db = null;

  public Aggregator() {
    Calendar now = Calendar.getInstance();
    current = now.getTimeInMillis();
  }

  public static String getContents(File aFile) {
    StringBuffer contents = new StringBuffer();
    try {
      BufferedReader input = new BufferedReader(new InputStreamReader(new FileInputStream(aFile.getAbsolutePath()), Charset.forName("UTF-8")));
      try {
        String line = null; // not declared within while loop
        while ((line = input.readLine()) != null) {
          contents.append(line);
          contents.append(System.getProperty("line.separator"));
        }
      } finally {
        input.close();
      }
    } catch (IOException ex) {
      ex.printStackTrace();
    }
    return contents.toString();
  }

  public void process(long start, long end, String query) throws Throwable {
    try {
      Macro macroProcessor = new Macro(start, end, query);
      query = macroProcessor.toString();
      db.execute(query);
    } catch(Exception e) {
      log.error("Query: "+query);
      throw new Exception("Aggregation failed for: "+query);
    } finally {
      db.close();
    }
  }

  public void process(String query) throws Throwable {
    long start = current;
    long end = current;
    process(current, current, query);
  }

  public void setWriter(DatabaseWriter dbw) {
    db = dbw;
  }

  public static void main(String[] args) {
    long startTime = 0;
    long endTime = 0;
    long aggregatorStart = Calendar.getInstance().getTimeInMillis();
    long longest = 0;
    if(args.length>=4) {
      ParsePosition pp = new ParsePosition(0);
      SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm");
      String buffer = args[0]+" "+args[1];
      Date tmp = format.parse(buffer, pp);
      startTime = tmp.getTime();
      buffer = args[2]+" "+args[3];
      pp = new ParsePosition(0);
      tmp = format.parse(buffer, pp);
      endTime = tmp.getTime();
    }
    String longQuery = null;
    log.info("Aggregator started.");
    String cluster = System.getProperty("CLUSTER");
    if (cluster == null) {
      cluster = "unknown";
    }
    String queries = Aggregator.getContents(new File(System
        .getenv("CHUKWA_CONF_DIR")
        + File.separator + "aggregator.sql"));
    String[] query = queries.split("\n");
    while(startTime<=endTime) {
      for (int i = 0; i < query.length; i++) {
        if (query[i].indexOf("#") == 0) {
          log.debug("skipping: " + query[i]);
        } else if(!query[i].equals("")) {
          Aggregator dba = new Aggregator();
          dba.setWriter(new DatabaseWriter(cluster));
          long start = Calendar.getInstance().getTimeInMillis();
          try {
            if(startTime!=0 && endTime!=0) {
              dba.process(startTime, startTime, query[i]);
            } else {
              dba.process(query[i]);
            }
          } catch(Throwable e) {
            log.error("Invalid query:"+query[i]);
          }
          long end = Calendar.getInstance().getTimeInMillis();
          long duration = end - start;
          if (duration >= longest) {
            longest = duration;
            longQuery = query[i];
          }
        }
      }
      startTime = startTime + 5*60000;
    }
    long aggregatorEnd = Calendar.getInstance().getTimeInMillis();
    log.info("Longest running query: " + longQuery + " (" + (double) longest
        / 1000 + " seconds)");
    log.info("Total running time: ("+(double) (aggregatorEnd-aggregatorStart)/1000+" seconds)");
    log.info("Aggregator finished.");
  }

}