/**
 * 
 */
package at.gv.egiz.pdfas.api.sign.pos;

import at.gv.egiz.pdfas.api.sign.pos.axis.AbsoluteAxisAlgorithm;
import at.gv.egiz.pdfas.api.sign.pos.axis.AutoAxisAlgorithm;
import at.gv.egiz.pdfas.api.sign.pos.axis.AxisAlgorithm;
import at.gv.egiz.pdfas.api.sign.pos.page.AbsolutePageAlgorithm;
import at.gv.egiz.pdfas.api.sign.pos.page.AutoPageAlgorithm;
import at.gv.egiz.pdfas.api.sign.pos.page.NewPageAlgorithm;
import at.gv.egiz.pdfas.api.sign.pos.page.PageAlgorithm;

/**
 * Defines how the signature positioning is to be performed.
 * 
 * <p>
 * This positioning allows to select the location where the signature block is
 * placed in the document.
 * </p>
 * 
 * @author wprinz
 */
public class SignaturePositioning
{
  /**
   * The x axis algorithm.
   * 
   * <p>
   * May be {@link AutoAxisAlgorithm} or {@link AbsoluteAxisAlgorithm}
   * </p>
   */
  protected AxisAlgorithm xAlgorithm = new AutoAxisAlgorithm();

  /**
   * The y axis algorithm.
   * 
   * <p>
   * May be {@link AutoAxisAlgorithm} or {@link AbsoluteAxisAlgorithm}
   * </p>
   */
  protected AxisAlgorithm yAlgorithm = new AutoAxisAlgorithm();

  /**
   * The width algorithm.
   * 
   * <p>
   * May be {@link AutoAxisAlgorithm} or {@link AbsoluteAxisAlgorithm}
   * </p>
   */
  protected AxisAlgorithm widthAlgorithm = new AutoAxisAlgorithm();

  /**
   * The page algorithm.
   * 
   * <p>
   * May be {@link AutoPageAlgorithm}, {@link AbsolutePageAlgorithm} or
   * {@link NewPageAlgorithm}
   * </p>
   */
  protected PageAlgorithm pageAlgorithm = new AutoPageAlgorithm();

  /**
   * Provides the position of the footline.
   * 
   * <p>
   * Only used if the pageAlgorithm is {@link AutoPageAlgorithm} and the
   * yAlgorithm is {@link AutoAxisAlgorithm}
   * </p>
   */
  protected float footerLine = 0.0f;

  protected void checkAxisAlgorithm(AxisAlgorithm algorithm)
  {
    if (algorithm == null)
    {
      throw new IllegalArgumentException("The algorithm must not be null.");
    }
    if (!(algorithm instanceof AutoAxisAlgorithm) && !(algorithm instanceof AbsoluteAxisAlgorithm))
    {
      throw new IllegalArgumentException("The algorithm must be either Auto or Absolute.");
    }
  }

  protected void checkPageAlgorithm(PageAlgorithm algorithm)
  {
    if (algorithm == null)
    {
      throw new IllegalArgumentException("The algorithm must not be null.");
    }
    if (!(algorithm instanceof AutoPageAlgorithm) && !(algorithm instanceof AbsolutePageAlgorithm) && !(algorithm instanceof NewPageAlgorithm))
    {
      throw new IllegalArgumentException("The algorithm must be either Auto or Absolute.");
    }

  }

  /**
   * @return the xAlgorithm
   */
  public AxisAlgorithm getXAlgorithm()
  {
    return this.xAlgorithm;
  }

  /**
   * @param algorithm
   *          the xAlgorithm to set
   */
  public void setXAlgorithm(AxisAlgorithm algorithm)
  {
    checkAxisAlgorithm(algorithm);
    xAlgorithm = algorithm;
  }

  /**
   * @return the yAlgorithm
   */
  public AxisAlgorithm getYAlgorithm()
  {
    return this.yAlgorithm;
  }

  /**
   * @param algorithm
   *          the yAlgorithm to set
   */
  public void setYAlgorithm(AxisAlgorithm algorithm)
  {
    checkAxisAlgorithm(algorithm);

    yAlgorithm = algorithm;
  }

  /**
   * @return the widthAlgorithm
   */
  public AxisAlgorithm getWidthAlgorithm()
  {
    return this.widthAlgorithm;
  }

  /**
   * @param widthAlgorithm
   *          the widthAlgorithm to set
   */
  public void setWidthAlgorithm(AxisAlgorithm widthAlgorithm)
  {
    checkAxisAlgorithm(widthAlgorithm);

    this.widthAlgorithm = widthAlgorithm;
  }

  /**
   * @return the pageAlgorithm
   */
  public PageAlgorithm getPageAlgorithm()
  {
    return this.pageAlgorithm;
  }

  /**
   * @param pageAlgorithm
   *          the pageAlgorithm to set
   */
  public void setPageAlgorithm(PageAlgorithm pageAlgorithm)
  {
    checkPageAlgorithm(pageAlgorithm);
    this.pageAlgorithm = pageAlgorithm;
  }

  /**
   * @return the footerLine
   */
  public float getFooterLine()
  {
    return this.footerLine;
  }

  /**
   * @param footerLine
   *          the footerLine to set
   */
  public void setFooterLine(float footerLine)
  {
    this.footerLine = footerLine;
  }

}