/**
 * <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: TextualSignator_1_0_0.java,v 1.3 2006/10/31 08:07:50 wprinz Exp $
 */
package at.gv.egiz.pdfas.impl.signator.textual;

import java.util.HashMap;
import java.util.Iterator;

import at.gv.egiz.pdfas.api.timestamp.TimeStamper;
import at.gv.egiz.pdfas.exceptions.ErrorCode;
import at.gv.egiz.pdfas.exceptions.framework.SignatorException;
import at.gv.egiz.pdfas.framework.input.DataSource;
import at.gv.egiz.pdfas.framework.input.PdfDataSource;
import at.gv.egiz.pdfas.framework.output.DataSink;
import at.gv.egiz.pdfas.framework.signator.Signator;
import at.gv.egiz.pdfas.framework.signator.SignatorInformation;
import at.gv.egiz.pdfas.impl.input.TextDataSourceImpl;
import at.gv.egiz.pdfas.impl.signator.IncrementalUpdateHelper;
import at.gv.egiz.pdfas.utils.OgnlUtil;
import at.knowcenter.wag.egov.egiz.PdfAS;
import at.knowcenter.wag.egov.egiz.PdfASID;
import at.knowcenter.wag.egov.egiz.cfg.OverridePropertyHolder;
import at.knowcenter.wag.egov.egiz.exceptions.PresentableException;
import at.knowcenter.wag.egov.egiz.framework.SignatorFactory;
import at.knowcenter.wag.egov.egiz.pdf.IncrementalUpdateInformation;
import at.knowcenter.wag.egov.egiz.pdf.ObjectExtractor;
import at.knowcenter.wag.egov.egiz.pdf.PositioningInstruction;
import at.knowcenter.wag.egov.egiz.pdf.TablePos;
import at.knowcenter.wag.egov.egiz.sig.SignatureDataImpl;
import at.knowcenter.wag.egov.egiz.sig.SignatureEntry;
import at.knowcenter.wag.egov.egiz.sig.SignatureObject;
import at.knowcenter.wag.egov.egiz.sig.SignatureTypeDefinition;
import at.knowcenter.wag.egov.egiz.sig.SignatureTypes;
import at.knowcenter.wag.egov.egiz.sig.signatureobject.SignatureObjectHelper;

import com.lowagie.text.pdf.PdfPTable;

/**
 * Signs a document textually.
 * 
 * <p>
 * In prepareSign, the document text is extracted and normalized.
 * </p>
 * <p>
 * In finishSign, the signed SignatureObject is transformed into a Signature
 * block, which is then written as an Incremental Update.
 * </p>
 * 
 * @author wprinz
 */
public class TextualSignator_1_0_0 implements Signator
{
  /**
   * The Pdf-AS ID of this Signator.
   */
  public static final PdfASID MY_ID = new PdfASID(SignatorFactory.VENDOR, SignatorFactory.TYPE_TEXTUAL, SignatorFactory.VERSION_1_0_0);

  /**
   * @see at.knowcenter.wag.egov.egiz.framework.Signator#getMyId()
   */
  public PdfASID getMyId()
  {
    return MY_ID;
  }

  /**
   * Default constructor.
   */
  public TextualSignator_1_0_0()
  {
    // Default constructor.
  }

  /**
   * <p>
   * The parameter has_SIG_ID is not used by this Signator because it doesn't
   * pre-format the signature block.
   * </p>
   * 
   * @see at.gv.egiz.pdfas.framework.signator.Signator#prepareSign(at.gv.egiz.pdfas.framework.input.PdfDataSource,
   *      java.lang.String, at.knowcenter.wag.egov.egiz.pdf.TablePos, boolean)
   */
  public SignatorInformation prepareSign(PdfDataSource pdfDataSource, String profile, TablePos pos, TimeStamper timestamper) throws SignatorException
  {
    try
    {
       
      SignatureTypeDefinition std = SignatureTypes.getInstance().getSignatureTypeDefinition(profile);
      if (!std.isTextExtractable())
      {
        throw new SignatorException(ErrorCode.PROFILE_NOT_USABLE_FOR_TEXT, "The signature profile " + profile + " is not text extractable and thereby cannot be used for textual signature.");
      }      
      
      TextualSignatorInformation tsi = new TextualSignatorInformation();
      tsi.originalDocument = pdfDataSource;
      tsi.profile = profile;
      tsi.pos = pos;

      String document_text = PdfAS.extractNormalizedTextTextual(pdfDataSource, this.getEncoding());
      tsi.setNonTextualObjects(ObjectExtractor.extractNonTextInfo(pdfDataSource));
      // logger_.debug("signed_text = " + document_text);

      DataSource ds = new TextDataSourceImpl(document_text);
      tsi.signatureData = new SignatureDataImpl(ds, "text/plain", "UTF-8");

      return tsi;
    }
    catch (PresentableException pe)
    {
      throw new SignatorException(pe);
    }
  }

  /**
   * @see at.gv.egiz.pdfas.framework.signator.Signator#finishSign(at.gv.egiz.pdfas.framework.signator.SignatorInformation,
   *      at.gv.egiz.pdfas.framework.output.DataSink)
   */
  public void finishSign(SignatorInformation signatorInformation, DataSink dataSink) throws SignatorException
  {
    try
    {
      TextualSignatorInformation tsi = (TextualSignatorInformation) signatorInformation;

      // PdfAS.prefixID(iui.signed_signature_object, PdfAS.TEXT_ID);

      // iui.signed_signature_object.kz = getMyId().toString();
      tsi.signSignatureObject.kz = getMyId().toString();
      // TODO what is this for?

      SignatureObject so = SignatureObjectHelper.convertSignSignatureObjectToSignatureObject(tsi.signSignatureObject, tsi.profile);

      evaluteOgnl(so, tsi);
      
      PdfPTable pdf_table = PdfAS.createPdfPTableFromSignatureObject(so);

      PositioningInstruction pi = PdfAS.determineTablePositioning(tsi.pos, tsi.profile, tsi.originalDocument, pdf_table);

      IncrementalUpdateInformation iui = IncrementalUpdateHelper.writeIncrementalUpdateToDataSink(tsi.originalDocument, dataSink, pdf_table, tsi.profile, pi, null, signatorInformation, so);
      tsi.atp = iui.actualTablePos;

//      OutputStream os = dataSink.createOutputStream(PdfAS.PDF_MIME_TYPE);
//      os.write(signed_iui.signed_pdf);
//      os.close();

//      SignResult sign_result = new SignResult(PdfAS.PDF_MIME_TYPE, signed_iui.signed_pdf);
//      return sign_result;
    }
    catch (PresentableException pe)
    {
      throw new SignatorException(pe);
    }
    finally {
       OverridePropertyHolder.removeOgnlUtil();
    }
//    catch (IOException e)
//    {
//      throw new SignatorException(ErrorCode.DOCUMENT_CANNOT_BE_READ, e);
//    }
  }

   private void evaluteOgnl(SignatureObject so, TextualSignatorInformation tsi) {             
     HashMap ognlCtx = new HashMap();
     //ognlCtx.put("iui", tsi.);
     ognlCtx.put("sso", tsi.signSignatureObject);
     ognlCtx.put("issuer", tsi.signSignatureObject.getIssuerDNMap());
     ognlCtx.put("subject", tsi.signSignatureObject.getSubjectDNMap());
     OgnlUtil ognl = new OgnlUtil(ognlCtx);
     OverridePropertyHolder.setOgnlUtil(ognl);

     Iterator it = so.getSigEntries().values().iterator();
     while (it.hasNext())
     {
       SignatureEntry se = (SignatureEntry) it.next();
       
       if (ognl.containsExpression(se.getValue())) {
          // evaluate expression
          String res = ognl.compileMessage(se.getValue());
          se.setValue(res);
          //ri.value = this.normalizer.normalize(res, true);                 
          
       }
     }   
   }

   public String getEncoding() {
      // old signatures used this encoding implicit most of the time (windows default)
      return "cp1252";
   }

}