/*
 * 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.
 */

// Log Event Prototype 
// From event_viewer.jsp
package org.apache.hadoop.chukwa.extraction.engine.datasource.database;


import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.LinkedList;
import java.util.List;
import java.util.TreeMap;
import org.apache.hadoop.chukwa.extraction.engine.ChukwaRecord;
import org.apache.hadoop.chukwa.extraction.engine.Record;
import org.apache.hadoop.chukwa.extraction.engine.SearchResult;
import org.apache.hadoop.chukwa.extraction.engine.Token;
import org.apache.hadoop.chukwa.extraction.engine.datasource.DataSource;
import org.apache.hadoop.chukwa.extraction.engine.datasource.DataSourceException;
import org.apache.hadoop.chukwa.util.ExceptionUtil;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

//import org.apache.hadoop.chukwa.hicc.ClusterConfig;

public class DatabaseDS implements DataSource {
  private static final Log log = LogFactory.getLog(DatabaseDS.class);

  @edu.umd.cs.findbugs.annotations.SuppressWarnings(value =
      "SQL_NONCONSTANT_STRING_PASSED_TO_EXECUTE", 
      justification = "Dynamic based upon tables in the database")
  public SearchResult search(SearchResult result, String cluster,
      String dataSource, long t0, long t1, String filter, Token token)
      throws DataSourceException {
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd kk:mm:ss");
    String timeField = null;
    TreeMap<Long, List<Record>> records = result.getRecords();

    if (cluster == null) {
      cluster = "demo";
    }

    if (dataSource.equalsIgnoreCase("MRJob")) {
      timeField = "LAUNCH_TIME";
    } else if (dataSource.equalsIgnoreCase("HodJob")) {
      timeField = "StartTime";
    } else {
      timeField = "timestamp";
    }
    String startS = formatter.format(t0);
    String endS = formatter.format(t1);
    Statement stmt = null;
    ResultSet rs = null;
    try {
      String dateclause = timeField + " >= '" + startS + "' and " + timeField
          + " <= '" + endS + "'";

      // ClusterConfig cc = new ClusterConfig();
      String jdbc = ""; // cc.getURL(cluster);

      Connection conn = org.apache.hadoop.chukwa.util.DriverManagerUtil.getConnection(jdbc);

      stmt = conn.createStatement();
      String query = "";
      query = "select * from " + dataSource + " where " + dateclause + ";";
      rs = stmt.executeQuery(query);
      if (stmt.execute(query)) {
        rs = stmt.getResultSet();
        ResultSetMetaData rmeta = rs.getMetaData();
        int col = rmeta.getColumnCount();
        while (rs.next()) {
          ChukwaRecord event = new ChukwaRecord();
          StringBuilder cell = new StringBuilder();;
          long timestamp = 0;

          for (int i = 1; i < col; i++) {
            String value = rs.getString(i);
            if (value != null) {
              cell.append(" ");
              cell.append(rmeta.getColumnName(i));
              cell.append(":");
              cell.append(value);
            }
            if (rmeta.getColumnName(i).equals(timeField)) {
              timestamp = rs.getLong(i);
              event.setTime(timestamp);
            }
          }
          boolean isValid = false;
          if (filter == null || filter.equals("")) {
            isValid = true;
          } else if (cell.indexOf(filter) > 0) {
            isValid = true;
          }
          if (!isValid) {
            continue;
          }

          event.add(Record.bodyField, cell.toString());
          event.add(Record.sourceField, cluster + "." + dataSource);
          if (records.containsKey(timestamp)) {
            records.get(timestamp).add(event);
          } else {
            List<Record> list = new LinkedList<Record>();
            list.add(event);
            records.put(event.getTime(), list);
          }
        }
      }
    } catch (SQLException e) {
      e.printStackTrace();
      throw new DataSourceException(e);
    } finally {
      if (rs != null) {
        try {
          rs.close();
        } catch (SQLException sqlEx) {
          log.debug(ExceptionUtil.getStackTrace(sqlEx));
        }
        rs = null;
      }
      if (stmt != null) {
        try {
          stmt.close();
        } catch (SQLException sqlEx) {
          log.debug(ExceptionUtil.getStackTrace(sqlEx));
        }
        stmt = null;
      }
    }
    return result;
  }

  public boolean isThreadSafe() {
    return true;
  }

}