/*
    The MIT License (MIT)

    Copyright (c) 2014 sinfonier-project

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    THE SOFTWARE.
*/

package com.sinfonier.bolts;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;

/**
 * JDBC Bolt to insert or update row
 *
 * @author jmdiez
 */

public class JDBCBolt extends BaseSinfonierBolt {


  private static final long serialVersionUID = 7799073747630789816L;

  private static final boolean CHECKNOTNULL = true;

  private boolean debug = true;
  private String driver; // p.e. "com.mysql.jdbc.Driver"
  private String url; // p.e. "jdbc:mysql://localhost:3306/mydb"
  private String user;
  private String password;
  private String tableName;
  private String[] fields;
  private List<String> pks;
  private String errorField;
  private transient Connection conn;
  private boolean error = false;
  private Date lastConn;

  public JDBCBolt(String xmlFile) {
    super(xmlFile);
  }

  @Override
  public void userprepare() {

    conn = null;
    driver = getParam("driver");
    url = getParam("url");
    user = getParam("user");
    password = getParam("password");
    this.tableName = this.getParam("tablename", JDBCBolt.CHECKNOTNULL);
    this.errorField = this.getParam("errorField");
    if (errorField == null) {
      errorField = "error";
    }

    List<Object> list = this.getParamList("fields");
    fields = new String[list.size()];
    list.toArray(fields);

    open();
    pks = getPks();

  }

  @Override
  public void userexecute() {
    if (!existsField(errorField)) {
      Map<String,Object> tuple = getJson();
      if (existsRow(tuple))
      {
        createAndExecuteUpdate(tuple);
      } else
      {
        createAndExecuteInsert(tuple);
      }

    }
    emit();
  }

  public void usercleanup() {
    closedb();
  }

  /**
   * Connect to a jdbc database
   *
   */
  public Connection open() {
    try {
      Class.forName(driver);
    } catch (ClassNotFoundException e) {
      debug("JDBC driver not found");
      e.printStackTrace();
      error = true;
      return null;
    }

    try {
      conn = DriverManager.getConnection(url, user, password);

    } catch (SQLException e) {
      debug("Connection Failed! Check output console");
      e.printStackTrace();
      error = true;
      return conn;
    }

    if (conn != null) {
      debug("Connected To Database");
    } else {
      error = true;
      debug("Failed to make connection!");
    }
    lastConn = new Date();
    error = false;
    return conn;
  }

  private boolean existsRow(Map<String, Object> tuple)
  {
    String firstPk = pks.get(0);
    StringBuilder query = new StringBuilder(String.format("SELECT %s FROM %s ",firstPk, tableName));
    query.append(buildWherePks());
    try {
      PreparedStatement preparedStatement = conn.prepareStatement(query.toString());
      int i=1;
      for ( String key: pks )
      {
        preparedStatement.setObject(i++,  tuple.get(key));
      }

      ResultSet rs = preparedStatement.executeQuery();
      while(rs.next())
      {
        return true;
      }
    } catch (Exception ex) {
      addField(errorField, ex.getMessage());
      addField(errorField + "Query", query.toString());
    }

    return false;
  }

  private String buildWherePks() {

    String sep = " WHERE ";
    StringBuilder where = new StringBuilder(" ");
    for ( String key: pks )
    {
      where.append(sep);
      where.append(String.format("%s = ?", key));
      sep = " AND ";
    }

    return where.toString();

  }

  /**
   * Create a valid query for JDBC from a Map<String, Object> and executes
   * it
   *
   * @param tuple
   *          Map with the keys and values for each field.
   */
  private void createAndExecuteInsert(Map<String, Object> tuple) {
    StringBuilder query = new StringBuilder(String.format("INSERT INTO %s (",tableName));
    List<Object> fieldValues = new ArrayList<Object>();
    List<String> questions = new ArrayList<String>(fields.length);
    if (fields != null && fields.length > 0) {

      query.append(String.join(",",fields));
      query.append(") VALUES (");
      for (int i = 0; i < fields.length; i++) {
        fieldValues.add(tuple.get(fields[i]));
        questions.add("?");
      }
      query.append(String.join(",",questions));
      query.append(") ");
    } else {
      List<String> fieldNames = new ArrayList<String>(tuple.size());
      for (Map.Entry<String, Object> entry : tuple.entrySet()) {
        fieldNames.add(entry.getKey());
        questions.add("?");
        fieldValues.add(entry.getValue());
      }
      query.append(String.join(",",fieldNames));
      query.append(") VALUES (");
      query.append(String.join(",",questions));
      query.append(") ");
    }

    try {
      PreparedStatement preparedStatement = conn.prepareStatement(query.toString());
      int i=1;
      for (Object obj: fieldValues)
      {
        preparedStatement.setObject(i++, obj);
      }

      preparedStatement.executeUpdate();
    } catch (Exception ex) {
      addField(errorField, ex.getMessage());
      addField(errorField + "Query", query.toString());
    }
  }

  /**
   * Gets the primary keys of the table;
   */
  private List<String> getPks()
  {
    List<String> lsPks = new ArrayList<String>();
    try {
      DatabaseMetaData dmd = conn.getMetaData();
      ResultSet rs = dmd.getPrimaryKeys(null, null, tableName);


      while(rs.next()){
          lsPks.add(rs.getString("COLUMN_NAME"));
      }
    }catch (SQLException e) {
      e.printStackTrace();
    }

    return lsPks;
  }

  /**
   * Create a valid query for JDBC from a Map<String, Object> and executes
   * it
   *
   * @param tuple
   *          Map with the keys and values for each field.
   */
  private void createAndExecuteUpdate(Map<String, Object> tuple) {
    StringBuilder query = new StringBuilder(String.format("UPDATE %s SET ",tableName));
    List<Object> fieldValues = new ArrayList<Object>();
    String sep = "";
    if (fields != null && fields.length > 0) {

      for (int i = 0; i < fields.length; i++) {
        if (! pks.contains(fields[i]))
        {
          query.append(String.format("%s %s = ?",sep,fields[i]));
          fieldValues.add(tuple.get(fields[i]));
          sep = ",";
        }
      }
    } else {
      for (Map.Entry<String, Object> entry : tuple.entrySet()) {
        if (!pks.contains(entry.getKey()))
        {
          query.append(String.format("%s %s = ?",sep, entry.getKey()));
          fieldValues.add(entry.getValue());
          sep = ",";
        }
      }

    }
    query.append(buildWherePks());
    try {
      PreparedStatement preparedStatement = conn.prepareStatement(query.toString());
      int i=1;
      for (Object obj: fieldValues)
      {
        preparedStatement.setObject(i++, obj);
      }
      for (String pk: pks)
      {
        preparedStatement.setObject(i++, tuple.get(pk));
      }
      preparedStatement.executeUpdate();
    } catch (Exception ex) {
      addField(errorField, ex.getMessage());
      addField(errorField + "Query", query.toString());
    }
  }


  public void closedb()
  {
      if (conn != null)
      {
          try {
              conn.close();
          } catch (SQLException e) {
              error = true;
              e.printStackTrace();
          }
      }
  }
  public void reopen()
  {
      debug("Reconnecting to Database");
      closedb();

      open();
  }

  private void debug(String str)
  {
      if (debug)
          System.out.println(str);
  }


}