/**
 * <copyright> Copyright (c) 2006 by Know-Center, Graz, Austria </copyright>
 * 
 * This software is the confidential and proprietary information of Know-Center,
 * Graz, Austria. You shall not disclose such Confidential Information and shall
 * use it only in accordance with the terms of the license agreement you entered
 * into with Know-Center.
 * 
 * KNOW-CENTER MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
 * NON-INFRINGEMENT. KNOW-CENTER SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
 * LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES.
 * 
 * $Id: SignatorFactory.java,v 1.2 2006/08/30 14:02:35 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.framework;

import at.knowcenter.wag.egov.egiz.PdfASID;
import at.knowcenter.wag.egov.egiz.exceptions.SignatorFactoryException;
import at.knowcenter.wag.egov.egiz.framework.signators.BinarySignator_1_0_0;
import at.knowcenter.wag.egov.egiz.framework.signators.DetachedSignator_1_0_0;
import at.knowcenter.wag.egov.egiz.framework.signators.TextualSignator_1_0_0;

/**
 * This factory creates instances of Signator classes corresponding to the given
 * PdfAS Algorithm IDs.
 * 
 * @author wprinz
 */
public abstract class SignatorFactory
{
  /**
   * The Vendor.
   */
  public static final String VENDOR = "bka.gv.at";

  /**
   * The binary Signator algorithm.
   */
  public static final String TYPE_BINARY = "binaer";

  /**
   * The textual Signator algorithm.
   */
  public static final String TYPE_TEXTUAL = "text";

  /**
   * This signator is only for testing the framework.
   */
  public static final String TYPE_TEST = "testalgo";

  /**
   * This application's current algorithm versions.
   */
  public static final String VERSION_1_0_0 = "v1.0.0";

  /**
   * The most recent binary algorithm this application provides.
   */
  public static final PdfASID MOST_RECENT_BINARY_SIGNATOR_ID = BinarySignator_1_0_0.MY_ID;

  /**
   * The most recent textual algorithm this application provides.
   */
  public static final PdfASID MOST_RECENT_TEXTUAL_SIGNATOR_ID = TextualSignator_1_0_0.MY_ID;
  
  /**
   * The most recent test algorithm this application provides.
   */
  public static final PdfASID MOST_RECENT_DETACHED_SIGNATOR_ID = DetachedSignator_1_0_0.MY_ID;

  /**
   * Creates a Signator for the given ID.
   * 
   * @param id
   *          The ID of the Signator to be created.
   * @return Returns the created Signator object.
   * @throws SignatorFactoryException
   *           Thrown, if there is no appropriate Signator for the given ID.
   */
  public static Signator createSignator(PdfASID id) throws SignatorFactoryException
  {
    if (!id.getVendor().equals(VENDOR))
    {
      throw new SignatorFactoryException("The vendor '" + id.getVendor() + "' is unrecognized by this SignatorFactory. (id='" + id + "')");
    }

    if (id.getType().equals(TYPE_BINARY))
    {
      if (id.getVersion().equals(VERSION_1_0_0))
      {
        return new BinarySignator_1_0_0();
      }

      throw new SignatorFactoryException("The version '" + id.getVersion() + "' of type '" + id.getType() + "' is not supported by this SignatorFactory. (id='" + id + "')");
    }

    if (id.getType().equals(TYPE_TEXTUAL))
    {
      if (id.getVersion().equals(VERSION_1_0_0))
      {
        return new TextualSignator_1_0_0();
      }

      throw new SignatorFactoryException("The version '" + id.getVersion() + "' of type '" + id.getType() + "' is not supported by this SignatorFactory. (id='" + id + "')");
    }

    if (id.getType().equals(TYPE_TEST))
    {
      if (id.getVersion().equals(VERSION_1_0_0))
      {
        return new DetachedSignator_1_0_0();
      }

      throw new SignatorFactoryException("The version '" + id.getVersion() + "' of type '" + id.getType() + "' is not supported by this SignatorFactory. (id='" + id + "')");
    }

    throw new SignatorFactoryException("The type '" + id.getType() + "' is not supported by this SignatorFactory. (id='" + id + "')");
  }

  /**
   * Creates the most recent signator the application provides for the given
   * type.
   * 
   * @param signator_type
   *          The type of the signator to be created (see the type field of
   *          PdfASID).
   * @return Returns the created Signator instance.
   * @throws SignatorFactoryException
   *           Thrown, if the type is unknown.
   */
  public static Signator createMostRecentSignator(String signator_type) throws SignatorFactoryException
  {
    PdfASID id = null;
    if (signator_type.equals(TYPE_BINARY))
    {
      id = MOST_RECENT_BINARY_SIGNATOR_ID;
    }
    if (signator_type.equals(TYPE_TEXTUAL))
    {
      id = MOST_RECENT_TEXTUAL_SIGNATOR_ID;
    }
    if (signator_type.equals(TYPE_TEST))
    {
      id = MOST_RECENT_TEXTUAL_SIGNATOR_ID;
    }

    if (id == null)
    {
      throw new SignatorFactoryException("The type '" + signator_type + "' is not supported by this SignatorFactory.");
    }

    return createSignator(id);
  }

  /**
   * Returns the list of available Signator algorithms of this application.
   * 
   * <p>
   * Use createMostRecentSignator to create the most recent signator for the
   * type.
   * </p>
   * 
   * @return Returns the list of available Signator algorithms of this
   *         application.
   */
  public static String[] getAvailableTyes()
  {
    String[] types = new String[] { TYPE_BINARY, TYPE_TEXTUAL, TYPE_TEST };
    return types;
  }
}