/*!
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* 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 Lesser General Public License for more details.
*
* Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
*/

package org.pentaho.reporting.engine.classic.wizard.model;

import org.pentaho.reporting.engine.classic.core.util.ObjectStreamResolveException;

import java.io.ObjectStreamException;
import java.io.Serializable;

public final class LengthUnit implements Serializable {
  public static final LengthUnit POINTS = new LengthUnit( "pt", 1 );
  public static final LengthUnit PERCENTAGE = new LengthUnit( "%", -1 );
  public static final LengthUnit PICA = new LengthUnit( "pc", 12 );
  public static final LengthUnit MM = new LengthUnit( "mm", 72 / ( 2.54 * 10 ) );
  public static final LengthUnit CM = new LengthUnit( "cm", 72.0 / 2.54 );
  public static final LengthUnit INCH = new LengthUnit( "in", 72 );

  private double dotsPerUnit;
  private String name;

  private LengthUnit( final String name, final double dotsPerUnit ) {
    this.name = name;
    this.dotsPerUnit = dotsPerUnit;
  }

  public String getName() {
    return name;
  }

  public double getDotsPerUnit() {
    return dotsPerUnit;
  }

  public double convertFromPoints( final double points ) {
    return points / dotsPerUnit;
  }

  public double convertToPoints( final double unit ) {
    return unit * dotsPerUnit;
  }

  public static LengthUnit[] values() {
    return new LengthUnit[] { INCH, CM, MM, PICA, PERCENTAGE, POINTS };
  }

  /**
   * Replaces the automatically generated instance with one of the enumeration instances.
   *
   * @return the resolved element
   * @throws ObjectStreamException if the element could not be resolved.
   */
  private Object readResolve()
    throws ObjectStreamException {
    if ( this.dotsPerUnit == INCH.dotsPerUnit ) {
      return INCH;
    }
    if ( this.dotsPerUnit == CM.dotsPerUnit ) {
      return CM;
    }
    if ( this.dotsPerUnit == MM.dotsPerUnit ) {
      return MM;
    }
    if ( this.dotsPerUnit == PICA.dotsPerUnit ) {
      return PICA;
    }
    if ( this.dotsPerUnit == PERCENTAGE.dotsPerUnit ) {
      return PERCENTAGE;
    }
    if ( this.dotsPerUnit == POINTS.dotsPerUnit ) {
      return POINTS;
    }
    // unknown element alignment...
    throw new ObjectStreamResolveException();
  }

}