/* 
    * 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.security.MakeSignature;
  import cz.hobrasoft.pdfmu.operation.OperationException;
  import cz.hobrasoft.pdfmu.operation.args.ArgsConfiguration;
  import net.sourceforge.argparse4j.inf.Argument;
  import net.sourceforge.argparse4j.inf.ArgumentParser;
  import net.sourceforge.argparse4j.inf.Namespace;
  import org.apache.commons.lang3.StringUtils;
  
  /**
   *
   * @author <a href="mailto:filip.bartek@hobrasoft.cz">Filip Bartek</a>
   */
  class SignatureParameters implements ArgsConfiguration {
  
      public SignatureAppearanceParameters appearance = new SignatureAppearanceParameters();
      public KeystoreParameters keystore = new KeystoreParameters("signing keystore");
      public KeyParameters key = new KeyParameters();
      public TimestampParameters timestamp = new TimestampParameters();
  
      private final ArgsConfiguration[] configurations = {appearance, keystore, key, timestamp};
  
      // digitalsignatures20130304.pdf : Code sample 2.19; Section 2.1.4; Code sample 2.2
      public String digestAlgorithm = "SHA256";
      public MakeSignature.CryptoStandard format = MakeSignature.CryptoStandard.CMS;
  
      private static final String[] digestAlgorithmChoices = {
          // Source: {@link DigestAlgorithms#digestNames}
          // Alternative source:
          // digitalsignatures20130304.pdf : Section 1.2.2; Code sample 1.5
          // TODO?: Add dashes in the algorithm names
          "MD2",
          "MD5",
          "SHA1",
          "SHA224",
          "SHA256",
          "SHA384",
          "SHA512",
          "RIPEMD128",
          "RIPEMD160",
          "RIPEMD256",
          "GOST3411"
      };
  
      private Argument digestAlgorithmArgument;
      private Argument formatArgument;
  
      @Override
      public void addArguments(ArgumentParser parser) {
          keystore.fileArgument = parser.addArgument("--keystore")
                  .help("keystore file that contains the signing private key");
          // Valid types:
          // https://docs.oracle.com/javase/7/docs/technotes/guides/security/StandardNames.html#KeyStore
          // Type "pkcs12" file extensions: P12, PFX
          // Source: https://en.wikipedia.org/wiki/PKCS_12
          // Another type: "Windows-MY" - Windows Certificate Store
          // TODO?: Guess type from file extension by default
          // TODO?: Default to "pkcs12"
          // TODO: Do not allow "Windows-MY" when running in a different OS than Windows
          keystore.typeArgument = parser.addArgument("--keystore-type")
                  .help("type of the signing keystore")
                  .choices(new String[]{"jceks", "jks", "pkcs12", "Windows-MY"});
          keystore.passwordArgs.passwordArgument = parser.addArgument("--keystore-password")
                  .help("signing keystore password (default: <empty>)");
          keystore.passwordArgs.environmentVariableArgument = parser.addArgument("--keystore-password-envvar")
                  .help("signing keystore password environment variable")
                  .setDefault("PDFMU_STOREPASS");
  
          for (ArgsConfiguration configuration : configurations) {
              configuration.addArguments(parser);
          }
  
          // Possible names:
          // - digest algorithm
          // - Hash Algorithm
          // - hash algorithm for making the signature
          digestAlgorithmArgument = parser.addArgument("--digest-algorithm")
                  .help("hash algorithm for making the signature")
                  // Java 8 (using `String.join`):
                  //.metavar(String.format("{%s}", String.join(",", digestAlgorithmChoices)))
                  // Java 7 (using `org.apache.commons.lang3.StringUtils.join`):
                  .metavar(String.format("{%s}", StringUtils.join(digestAlgorithmChoices, ",")))
                 // TODO?: Limit the choices to `digestAlgorithmChoices`
                 .type(String.class)
                 .setDefault(digestAlgorithm);
 
         formatArgument = parser.addArgument("--format")
                 .help("signature format (CMS: adbe.pkcs7.detached, CADES: ETSI.CAdES.detached)")
                 .type(MakeSignature.CryptoStandard.class)
                 .choices(MakeSignature.CryptoStandard.values())
                 .setDefault(format);
     }
 
     @Override
     public void setFromNamespace(Namespace namespace) throws OperationException {
         for (ArgsConfiguration configuration : configurations) {
             configuration.setFromNamespace(namespace);
         }
 
         assert digestAlgorithmArgument != null;
         digestAlgorithm = namespace.getString(digestAlgorithmArgument.getDest());
         assert formatArgument != null;
         format = namespace.get(formatArgument.getDest());
     }
 
 }