/*
 *  BaseLink - Generic object relational mapping
 *  Copyright (C) 2024  Ulrich Hilger, http://uhilger.de
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/
 */
package de.uhilger.baselink;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Methoden zum Ausfuehren von SQL DELETE-Anweisungen
 * 
 * @author Copyright (c) Ulrich Hilger, <a href="http://uhilger.de">http://uhilger.de</a>
 * @author Published under the terms and conditions of
 * the <a href="http://www.gnu.org/licenses/" target="_blank">GNU General Public License</a>
 * @version 1, January 22, 2024
 */
public class Eraser extends DBActor {

  private static final Logger logger = Logger.getLogger(Eraser.class.getName());
  
  public Eraser(PersistenceManager pm) {
    this.pm = pm;
  }

  /**
   * Delete a given object from the database
   *
   * <p>Use this method for single deletes. In cases where
   * several subsequent deletes for objects of the same class
   * are required the use of method <code>delete(Object, Record)</code>
   * is recommended instead to minimise instantiation
   * overhead.</p>
   *
   * @param o object to delete
   * @return  the deleted object
   */
  public Object delete(Object o) {
    return delete(o, new GenericRecord(o.getClass()));
  }

  /**
   * Delete a given object from the database
   *
   * <p>Use this method for single deletes. In cases where
   * several subsequent deletes for objects of the same class
   * are required the use of method <code>delete(Connection, Object, Record)</code>
   * is recommended instead to minimise instantiation
   * overhead.</p>
   *
   * @param c  the connection to use, expected to be open and established
   * @param o  object to delete
   * @return  the deleted object
   */
  public Object delete(Connection c, Object o) {
    return delete(c, o, new GenericRecord(o.getClass()));
  }

  /**
   * Delete a given object from the database
   * @param o object to delete
   * @param record  reference to object to use to map between object and database
   * @return  the deleted object
   */
  public Object delete(Object o, Record record) {
    Connection c = null;
    try {
      c = pm.getConnection();
      o = delete(c, o, record);
      c.close();
      c = null;
    } catch (SQLException ex) {
      logger.log(Level.SEVERE, ex.getLocalizedMessage(), ex);
    } finally {
      pm.closeConnectionFinally(c);
    }
    return o;
  }

  /**
   * Delete a given object from the database
   * @param c  the connection to use, expected to be open and established
   * @param o  object to delete
   * @param record reference to object to use to map between object and database
   * @return the deleted object
   */
  public Object delete(Connection c, Object o, Record record) {
    Object deletedObject = null;
    PreparedStatement ps = null;
    try {
      ps = record.getDeleteStatment(c, o);
      ps.executeUpdate();
      ps.close();
      ps = null;
      deletedObject = o;
    } catch (Exception ex) {
      logger.log(Level.SEVERE, ex.getLocalizedMessage(), ex);
    } finally {
      pm.closeStatementFinally(ps);
    }
    return deletedObject;
  }
    
}