/*
 * 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) 2000 - 2009 Pentaho Corporation, Object Refinery Limited and Contributors.  All rights reserved.
 */

package org.pentaho.reporting.libraries.pixie.wmf;

import java.awt.Color;

/**
 * A color implementation, that supports some additional flags defined by the Windows API,
 * but has no Alpha-Channel. This is a BGR color implementation, the flags are stored in
 * the highest byte.
 */
public class GDIColor extends Color
{
  private static final long serialVersionUID = 1161533883291249918L;

  public static final int PC_RESERVED = 0x01;
  public static final int PC_EXPLICIT = 0x02;
  public static final int PC_NOCOLLAPSE = 0x04;

  /**
   * The color flags.
   */
  private int flags;

  /**
   * Creates a new GDI color instance by parsing the color reference.
   *
   * @param colorref the integer color reference.
   */
  public GDIColor(final int colorref)
  {
    this(getR(colorref), getG(colorref), getB(colorref), getFlags(colorref));
  }

  /**
   * Creates a new GDI Color instance.
   *
   * @param r     the red channel.
   * @param g     the green channel.
   * @param b     the blue channel.
   * @param flags the Windows Color flags.
   */
  public GDIColor(final int r, final int g, final int b, final int flags)
  {
    super(r, g, b);
    this.flags = flags;
  }

  /**
   * Extracts the RED channel from the given ColorReference.
   *
   * @param ref the color reference.
   * @return the red channel.
   */
  private static int getR(final int ref)
  {
    int retval = (ref & 0x000000ff);
    if (retval < 0)
    {
      retval = (retval + 256);
    }
    return retval;
  }

  /**
   * Extracts the GREEN channel from the given ColorReference.
   *
   * @param ref the color reference.
   * @return the green channel.
   */
  private static int getG(final int ref)
  {
    return (ref & 0x0000ff00) >> 8;
  }

  /**
   * Extracts the BLUE channel from the given ColorReference.
   *
   * @param ref the color reference.
   * @return the blue channel.
   */
  private static int getB(final int ref)
  {
    return (ref & 0x00ff0000) >> 16;
  }

  /**
   * Extracts the Color Flags from the given ColorReference.
   *
   * @param ref the color reference.
   * @return the color flags.
   */
  private static int getFlags(final int ref)
  {
    return (ref & 0xff000000) >> 24;
  }

  /**
   * Returns the PC_RESERVED flag state for this color.
   *
   * @return true, if PC_RESERVED is set, false otherwise.
   */
  public boolean isReserved()
  {
    return (this.flags & PC_RESERVED) == PC_RESERVED;
  }

  /**
   * Returns the PC_EXPLICIT flag state for this color.
   *
   * @return true, if PC_EXPLICIT is set, false otherwise.
   */
  public boolean isExplicit()
  {
    return (this.flags & PC_EXPLICIT) == PC_EXPLICIT;
  }

  /**
   * Returns the PC_NOCOLLAPSE flag state for this color.
   *
   * @return true, if PC_NOCOLLAPSE is set, false otherwise.
   */
  public boolean isNoCollapse()
  {
    return (this.flags & PC_NOCOLLAPSE) == PC_NOCOLLAPSE;
  }

  /**
   * Gets the assigned flag for the color.
   *
   * @return the flags.
   */
  public int getFlags()
  {
    return flags;
  }

  /**
   * Translates the given color instance into a GDI color reference.
   *
   * @param c the color that should be translated.
   * @return the created color reference.
   */
  public static int translateColor(final Color c)
  {
    final int red = c.getRed();
    final int green = c.getGreen();
    final int blue = c.getBlue();
    int flags = 0;

    if (c instanceof GDIColor)
    {
      final GDIColor gc = (GDIColor) c;
      flags = gc.getFlags();
    }

    int retval = flags;
    retval = (retval << 8) + blue;
    retval = (retval << 8) + green;
    retval = (retval << 8) + red;
    return retval;
  }
}
