/* 
    * Copyright (C) 2016 Hobrasoft s.r.o.
    *
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Affero General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
    * 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 Affero General Public License for more details.
   *
   * You should have received a copy of the GNU Affero General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  package cz.hobrasoft.pdfmu.operation.signature;
  
  import com.itextpdf.text.pdf.PdfSignatureAppearance;
  import com.itextpdf.text.pdf.PdfStamper;
  import cz.hobrasoft.pdfmu.operation.args.ArgsConfiguration;
  import java.util.Calendar;
  import java.util.logging.Logger;
  import net.sourceforge.argparse4j.inf.ArgumentGroup;
  import net.sourceforge.argparse4j.inf.ArgumentParser;
  import net.sourceforge.argparse4j.inf.Namespace;
  
  /**
   *
   * @author <a href="mailto:filip.bartek@hobrasoft.cz">Filip Bartek</a>
   */
  class SignatureAppearanceParameters implements ArgsConfiguration {
  
      public String reason = null;
      public String location = null;
      public String contact = null;
      public Calendar signDate = null;
      public int certificationLevel = PdfSignatureAppearance.NOT_CERTIFIED;
  
      private static final Logger logger = Logger.getLogger(SignatureAppearanceParameters.class.getName());
  
      @Override
      public void addArguments(ArgumentParser parser) {
          ArgumentGroup group = parser.addArgumentGroup("signature metadata");
          // TODO: Add description
  
          // The fields are explained in the following documents:
          // digitalsignatures20130304.pdf : Section 2.3.3
          // http://www.adobe.com/devnet-docs/acrobatetk/tools/DigSig/appearances.html
          // https://www.pdfill.com/document_sign.html
          group.addArgument("--reason")
                  .help("What was the reason for signing? (default: <none>)")
                  .type(String.class);
          group.addArgument("--location")
                  .help("Where was the document signed? (default: <none>)")
                  .type(String.class);
          group.addArgument("--contact")
                  .help("signer contact information (defualt: <none>)")
                  .type(String.class);
          // TODO: Unify the help strings
      }
  
      @Override
      public void setFromNamespace(Namespace namespace) {
          reason = namespace.getString("reason");
          location = namespace.getString("location");
          contact = namespace.getString("contact");
          // TODO?: Expose `signDate`
          // Note: Argparse4j does not seem to support time
          // (namely {@link Calendar}) natively.
          // TODO?: Expose `certificationLevel`
      }
  
      public void configureSignatureAppearance(PdfSignatureAppearance sap) {
          assert sap != null;
          // Configure signature metadata
          if (reason != null) {
              logger.info(String.format("Reason: %s", reason));
              sap.setReason(reason);
          }
          if (location != null) {
              logger.info(String.format("Location: %s", location));
              sap.setLocation(location);
          }
          if (contact != null) {
              logger.info(String.format("Contact: %s", contact));
              sap.setContact(contact);
          }
          if (signDate != null) {
              // `setSignDate(null)` crashes
              logger.info(String.format("Date: %s", signDate));
              sap.setSignDate(signDate);
          }
          sap.setCertificationLevel(certificationLevel);
  
          // TODO?: Set signer's name
          // digitalsignatures20130304.pdf : Code sample 2.12
      }
  
     public PdfSignatureAppearance getSignatureAppearance(PdfStamper stp) {
         assert stp != null;
 
         // Initialize the signature appearance
         PdfSignatureAppearance sap = stp.getSignatureAppearance();
         configureSignatureAppearance(sap);
 
         return sap;
     }
 
 }