/**
 * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>
 * PDF-AS has been contracted by the E-Government Innovation Center EGIZ, a
 * joint initiative of the Federal Chancellery Austria and Graz University of
 * Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 *
 * $Id: SignatorFactory.java,v 1.2 2006/08/30 14:02:35 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.framework;

import at.gv.egiz.pdfas.impl.signator.textual.TextualSignator_1_2_0;
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.BinarySignator_1_1_0;
import at.knowcenter.wag.egov.egiz.framework.signators.DetachedSignator_1_0_0;
import at.knowcenter.wag.egov.egiz.framework.signators.DetachedfTextualSignator_1_0_0;
import at.knowcenter.wag.egov.egiz.framework.signators.TextualSignator_1_0_0;
import at.knowcenter.wag.egov.egiz.framework.signators.TextualSignator_1_1_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"; //$NON-NLS-1$

  /**
   * The binary Signator algorithm.
   */
  public static final String TYPE_BINARY = "binaer"; //$NON-NLS-1$

  /**
   * The textual Signator algorithm.
   */
  public static final String TYPE_TEXTUAL = "text"; //$NON-NLS-1$

  /**
   * This signator is only for testing the framework.
   */
  public static final String TYPE_TEST = "testalgo"; //$NON-NLS-1$
  
  /**
   * This signator is only for testing the framework.
   */
  public static final String TYPE_DETACHED_TEXTUAL = "detachedtext"; //$NON-NLS-1$

  /**
   * This application's current algorithm versions.
   */
  public static final String VERSION_1_0_0 = "v1.0.0"; //$NON-NLS-1$

  /**
   * This application's current algorithm versions.
   */
  public static final String VERSION_1_1_0 = "v1.1.0"; //$NON-NLS-1$
  
  /**
   * This application's current algorithm versions.
   */
  public static final String VERSION_1_2_0 = "v1.2.0"; //$NON-NLS-1$


  /**
   * The most recent binary algorithm this application provides.
   */
  public static final PdfASID MOST_RECENT_BINARY_SIGNATOR_ID = BinarySignator_1_1_0.MY_ID;

  /**
   * The most recent textual algorithm this application provides.
   */
  public static final PdfASID MOST_RECENT_TEXTUAL_SIGNATOR_ID = TextualSignator_1_2_0.MY_ID;
  
  /**
   * The most recent test algorithm this application provides.
   */
  public static final PdfASID MOST_RECENT_DETACHED_SIGNATOR_ID = DetachedfTextualSignator_1_0_0.MY_ID;

  /**
   * The most recent test algorithm this application provides.
   */
  public static final PdfASID MOST_RECENT_DETACHEDTEXT_SIGNATOR_ID = DetachedfTextualSignator_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 + "')"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
    }

    if (id.getType().equals(TYPE_BINARY))
    {
      if (id.getVersion().equals(VERSION_1_0_0))
      {
        return new BinarySignator_1_0_0();
      }
      if (id.getVersion().equals(VERSION_1_1_0))
      {
        return new BinarySignator_1_1_0();
      }

      throw new SignatorFactoryException("The version '" + id.getVersion() + "' of type '" + id.getType() + "' is not supported by this SignatorFactory. (id='" + id + "')"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
    }

    if (id.getType().equals(TYPE_TEXTUAL))
    {
      if (id.getVersion().equals(VERSION_1_0_0))
      {
        return new TextualSignator_1_0_0();
      }
      if (id.getVersion().equals(VERSION_1_1_0))
      {
        return new TextualSignator_1_1_0();
      }

      throw new SignatorFactoryException("The version '" + id.getVersion() + "' of type '" + id.getType() + "' is not supported by this SignatorFactory. (id='" + id + "')"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
    }

    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 + "')"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
    }
    
    if (id.getType().equals(TYPE_DETACHED_TEXTUAL))
    {
      if (id.getVersion().equals(VERSION_1_0_0))
      {
        return new DetachedfTextualSignator_1_0_0();
      }

      throw new SignatorFactoryException("The version '" + id.getVersion() + "' of type '" + id.getType() + "' is not supported by this SignatorFactory. (id='" + id + "')"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
    }

    throw new SignatorFactoryException("The type '" + id.getType() + "' is not supported by this SignatorFactory. (id='" + id + "')"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
  }

  /**
   * 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."); //$NON-NLS-1$ //$NON-NLS-2$
    }

    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;
  }
}