//License
/***
 * Java Modbus Library (jamod)
 * Copyright (c) 2002-2004, jamod development team
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the author nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS
 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 ***/
package net.wimpi.modbus;

import net.wimpi.modbus.procimg.DefaultProcessImageFactory;
import net.wimpi.modbus.procimg.ProcessImage;
import net.wimpi.modbus.procimg.ProcessImageFactory;

/**
 * Class implemented following a Singleton pattern,
 * to couple the slave side with a master side or
 * with a device.<p>
 * At the moment  it only provides a reference to the
 * OO model of the process image.
 *
 * @author Dieter Wimberger
 * @version 1.2rc2 (14/04/2014)
 */
public class ModbusCoupler {

  //class attributes
  private static ModbusCoupler c_Self;  //Singleton reference

  //instance attributes
  private ProcessImage m_ProcessImage;
  private int m_UnitID = Modbus.DEFAULT_UNIT_ID;
  private boolean m_Master = true;
  private ProcessImageFactory m_PIFactory;

  static {
    c_Self = new ModbusCoupler();
  }//initializer

  private ModbusCoupler() {
    m_PIFactory = new DefaultProcessImageFactory();
  }//constructor

  /**
   * Private constructor to prevent multiple
   * instantiation.
   * <p/>
   *
   * @param procimg a <tt>ProcessImage</tt>.
   */
  private ModbusCoupler(ProcessImage procimg) {
    setProcessImage(procimg);
    c_Self = this;
  }//contructor(ProcessImage)

  /**
   * Returns the actual <tt>ProcessImageFactory</tt> instance.
   *
   * @return a <tt>ProcessImageFactory</tt> instance.
   */
  public ProcessImageFactory getProcessImageFactory() {
    return m_PIFactory;
  }//getProcessImageFactory

 /**
  * Sets the <tt>ProcessImageFactory</tt> instance.
  *
  * @param factory the instance to be used for creating process
  *        image instances.
  */
  public void setProcessImageFactory(ProcessImageFactory factory) {
    m_PIFactory = factory;
  }//setProcessImageFactory

  /**
   * Returns a reference to the <tt>ProcessImage</tt>
   * of this <tt>ModbusCoupler</tt>.
   * <p/>
   *
   * @return the <tt>ProcessImage</tt>.
   */
  public synchronized ProcessImage getProcessImage() {
    return m_ProcessImage;
  }//getProcessImage

  /**
   * Sets the reference to the <tt>ProcessImage</tt>
   * of this <tt>ModbusCoupler</tt>.
   * <p/>
   *
   * @param procimg the <tt>ProcessImage</tt> to be set.
   */
  public synchronized void setProcessImage(ProcessImage procimg) {
    m_ProcessImage = procimg;
  }//setProcessImage

  /**
   * Returns the identifier of this unit.
   * This identifier is required to be set
   * for serial protocol slave implementations.
   *
   * @return the unit identifier as <tt>int</tt>.
   */
  public int getUnitID() {
    return m_UnitID;
  }//getUnitID

  /**
   * Sets the identifier of this unit, which is needed
   * to be determined in a serial network.
   *
   * @param id the new unit identifier as <tt>int</tt>.
   */
  public void setUnitID(int id) {
    m_UnitID = id;
  }//setUnitID

  /**
   * Tests if this instance is a master device.
   *
   * @return true if master, false otherwise.
   */
  public boolean isMaster() {
    return m_Master;
  }//isMaster

  /**
   * Tests if this instance is not a master device.
   *
   * @return true if slave, false otherwise.
   */
  public boolean isSlave() {
    return !m_Master;
  }//isSlave

  /**
   * Sets this instance to be or not to be
   * a master device.
   *
   * @param master true if master device, false otherwise.
   */
  public void setMaster(boolean master) {
    m_Master = master;
  }//setMaster

  /**
   * Returns a reference to the singleton instance.
   * <p/>
   *
   * @return the <tt>ModbusCoupler</tt> instance reference.
   */
  public static final ModbusCoupler getReference() {
    return c_Self;
  }//getReference

}//class ModbusCoupler