/*
    * 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.sql.SQLException;
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.Map.Entry;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.chukwa.util.DatabaseWriter;
  import org.apache.hadoop.chukwa.util.RegexUtil;
  
  public class DataExpiration {
    private static DatabaseConfig dbc = null;
    private static Log log = LogFactory.getLog(DataExpiration.class);
  
    public DataExpiration() {
      if (dbc == null) {
        dbc = new DatabaseConfig();
      }
    }
  
    @edu.umd.cs.findbugs.annotations.SuppressWarnings(value =
        "SQL_NONCONSTANT_STRING_PASSED_TO_EXECUTE", 
        justification = "Dynamic based upon tables in the database")
    public void dropTables(long start, long end) {
      String cluster = System.getProperty("CLUSTER");
      if (cluster == null) {
        cluster = "unknown";
      }
      DatabaseWriter dbw = new DatabaseWriter(cluster);
      try {
        HashMap<String, String> dbNames = dbc.startWith("report.db.name.");
        for(Entry<String, String> entry : dbNames.entrySet()) {
          String tableName = entry.getValue();
          if (!RegexUtil.isRegex(tableName)) {
            log.warn("Skipping tableName: '" + tableName
                + "' because there was an error parsing it as a regex: "
                + RegexUtil.regexError(tableName));
            return;
          }
          String[] tableList = dbc.findTableName(tableName, start, end);
          for (String tl : tableList) {
            log.debug("table name: " + tableList[0]);
            try {
              String[] parts = tl.split("_");
              int partition = Integer.parseInt(parts[parts.length - 2]);
              StringBuilder table = new StringBuilder();
              for (int i = 0; i < parts.length - 2; i++) {
                if (i != 0) {
                  table.append("_");
                }
                table.append(parts[i]);
              }
              partition = partition - 3;
              if(partition>=0) {
                StringBuilder dropPartition = new StringBuilder();
                dropPartition.append("drop table if exists ");
                dropPartition.append(table);
                dropPartition.append("_");
                dropPartition.append(partition);
                dropPartition.append("_");
                dropPartition.append(parts[parts.length - 1]);
                final String query = dropPartition.toString();
                dbw.execute(query);
              }
            } catch (NumberFormatException e) {
              log
                  .error("Error in parsing table partition number, skipping table:"
                      + tableList[0]);
            } catch (ArrayIndexOutOfBoundsException e) {
              log.debug("Skipping table:" + tableList[0]
                  + ", because it has no partition configuration.");
            }
          }
        }
        dbw.close();
      } catch (SQLException e) {
       e.printStackTrace();
     }
   }
 
   public static void usage() {
     System.out.println("DataExpiration usage:");
     System.out
         .println("java -jar chukwa-core.jar org.apache.hadoop.chukwa.DataExpiration <date> <time window size>");
     System.out.println("     date format: YYYY-MM-DD");
     System.out.println("     time window size: 7, 30, 91, 365");
   }
 
   public static void main(String[] args) {
     DataExpiration de = new DataExpiration();
     long now = (new Date()).getTime();
     long start = now;
     long end = now;
     if (args.length == 2) {
       SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
       try {
         long dataExpStart = Calendar.getInstance().getTimeInMillis();
         start = sdf.parse(args[0]).getTime();
         end = start + (Long.parseLong(args[1]) * 1440 * 60 * 1000L);
         de.dropTables(start, end);
         long dataExpEnd = Calendar.getInstance().getTimeInMillis();
         log.info("DataExpiration for: "+args[0]+" "+args[1]+" finished: ("+(double) (dataExpEnd-dataExpStart)/1000+" seconds)");
       } catch (ParseException e) {
         usage();
       }
     } else {
       usage();
     }
   }
 }