/*
 * 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.records;

import java.awt.Rectangle;

import org.pentaho.reporting.libraries.pixie.wmf.MfRecord;
import org.pentaho.reporting.libraries.pixie.wmf.WmfFile;

/**
 * This is the base class for all WMF-Records. A WMF record specifies a single command for
 * drawing a element of the image.
 */
public abstract class MfCmd
{
  /**
   * The X-Scale for the command.
   */
  private float scaleX;
  /**
   * The Y-Scale for the command.
   */
  private float scaleY;

  /**
   * The default constructor, adjusts the scale to 1.
   */
  protected MfCmd()
  {
    scaleX = 1;
    scaleY = 1;
  }

  /**
   * Creates a new record based on the data stored in the MfCommand.
   *
   * @return the created record.
   * @throws RecordCreationException if an error occured while generating the record.
   */
  public abstract MfRecord getRecord()
      throws RecordCreationException;

  /**
   * Reads the command data from the given record and adjusts the internal parameters
   * according to the data parsed.
   * <p/>
   * After the raw record was read from the datasource, the record is parsed by the
   * concrete implementation.
   *
   * @param record the raw data that makes up the record.
   */
  public abstract void setRecord(MfRecord record);

  /**
   * Reads the function identifier. Every record type is identified by a function number
   * corresponding to one of the Windows GDI functions used.
   *
   * @return the function identifier.
   */
  public abstract int getFunction();

  /**
   * Creates a empty unintialized copy of this command implementation.
   *
   * @return a new instance of the command.
   */
  public abstract MfCmd getInstance();

  /**
   * Replays the command on the given WmfFile.
   *
   * @param metafile the meta file.
   */
  public abstract void replay(WmfFile metafile);

  /**
   * Set the scale for the command.
   *
   * @param scaleX the horizontal scale
   * @param scaleY the vertical scale
   */
  public void setScale(final float scaleX, final float scaleY)
  {
    final float oldScaleX = this.scaleX;
    final float oldScaleY = this.scaleY;
    this.scaleX = scaleX;
    this.scaleY = scaleY;
    if (oldScaleX != scaleX)
    {
      scaleXChanged();
    }
    if (oldScaleY != scaleY)
    {
      scaleYChanged();
    }
  }

  /**
   * A callback function to inform the object, that the x scale has changed and the
   * internal coordinate values have to be adjusted.
   */
  protected abstract void scaleXChanged();

  /**
   * A callback function to inform the object, that the y scale has changed and the
   * internal coordinate values have to be adjusted.
   */
  protected abstract void scaleYChanged();

  /**
   * Scales the given rectangle.
   *
   * @param r the source rectangle.
   * @return a new rectangle containing the scaled values.
   */
  protected Rectangle scaleRect(final Rectangle r)
  {
    final Rectangle retval = new Rectangle();
    retval.x = getScaledX(r.x);
    retval.y = getScaledY(r.y);

    retval.width = getScaledWidth(r.width);
    retval.height = getScaledHeight(r.height);
    return retval;
  }

  /**
   * Scales the given horizontal length and makes sure that the lenght is at least 1.
   *
   * @param length the value that should be scaled.
   * @return the scaled value.
   */
  protected int getScaledWidth(int length)
  {
    if (length == 0)
    {
      return 1;
    }
    length = (int) (length * scaleX + 0.5f);
    return (length == 0) ? 1 : length;
  }

  /**
   * Scales the given vertical length and makes sure that the lenght is at least 1.
   *
   * @param length the value that should be scaled.
   * @return the scaled value.
   */
  protected int getScaledHeight(int length)
  {
    if (length == 0)
    {
      return 1;
    }
    length = (int) (length * scaleY + 0.5f);
    return (length == 0) ? 1 : length;
  }

  /**
   * Applies the new x-scaling to all values in the array n and places the values in the
   * array dest. Additionally dest is also returned as return value.
   *
   * @param n    the unscaled source values
   * @param dest the array to store the scaled values
   * @return dest.
   */
  protected int[] applyScaleX(final int[] n, int[] dest)
  {
    if (dest == null)
    {
      dest = new int[n.length];
    }
    else if (dest.length < n.length)
    {
      dest = new int[n.length];
    }

    for (int i = 0; i < n.length; i++)
    {
      dest[i] = (int) (n[i] * scaleX + 0.5f);
    }
    return dest;
  }

  /**
   * Applies the new y-scaling to all values in the array n and places the values in the
   * array dest. Additionally dest is also returned as return value.
   *
   * @param n    the unscaled source values
   * @param dest the array to store the scaled values
   * @return dest.
   */
  protected int[] applyScaleY(final int[] n, int[] dest)
  {
    if (dest == null)
    {
      dest = new int[n.length];
    }
    else if (dest.length < n.length)
    {
      dest = new int[n.length];
    }

    for (int i = 0; i < n.length; i++)
    {
      dest[i] = (int) (n[i] * scaleY + 0.5f);
    }
    return dest;
  }

  /**
   * Return integer scaled to output units.
   *
   * @param y the unscaled y
   * @return the scaled y value
   */
  public int getScaledY(final int y)
  {
    return (int) (y * scaleY + 0.5f);
  }

  /**
   * Return integer scaled to output units.
   *
   * @param x the unscaled x
   * @return the scaled x value
   */
  public int getScaledX(final int x)
  {
    return (int) (x * scaleX + 0.5f);
  }

}
