/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2013, Regents of the University of California
 * BSD license, See the LICENSE file for more information
 * Author: Yingdi Yu <yingdi@cs.ucla.edu>
 */

#ifndef NDNSEC_DSK_GEN_HPP
#define NDNSEC_DSK_GEN_HPP

#include "ndnsec-util.hpp"

int 
ndnsec_dsk_gen(int argc, char** argv)
{
  using namespace ndn;
  namespace po = boost::program_options;

  std::string identityName;
  char keyType = 'r';
  int keySize = 2048;

  po::options_description desc("General Usage\n  ndnsec dsk-gen [-h] identity\nGeneral options");
  desc.add_options()
    ("help,h", "produce help message")
    ("identity,i", po::value<std::string>(&identityName), "identity name, for example, /ndn/ucla.edu/alice")
    // ("type,t", po::value<char>(&keyType)->default_value('r'), "optional, key type, r for RSA key (default)")
    // ("size,s", po::value<int>(&keySize)->default_value(2048), "optional, key size, 2048 (default)")
    ;

  po::positional_options_description p;
  p.add("identity", 1);

  po::variables_map vm;
  po::store(po::command_line_parser(argc, argv).options(desc).positional(p).run(), vm);
  po::notify(vm);

  if (vm.count("help"))
    {
      std::cerr << desc << std::endl;
      return 0;
    }

  if (0 == vm.count("identity"))
    {
      std::cerr << "identity must be specified" << std::endl;
      std::cerr << desc << std::endl;
      return 1;
    }

  shared_ptr<IdentityCertificate> kskCert;
  Name signingCertName;
  try
    {
      KeyChain keyChain;

      Name defaultCertName = keyChain.getDefaultCertificateNameForIdentity(identityName);
      bool isDefaultDsk = false;
      if(defaultCertName.get(-3).toEscapedString().substr(0,4) == "dsk-")
        isDefaultDsk = true;

      if(isDefaultDsk)
        {
          shared_ptr<IdentityCertificate> dskCert = keyChain.getCertificate(defaultCertName);
          SignatureSha256WithRsa sha256sig(dskCert->getSignature());

          Name keyLocatorName = sha256sig.getKeyLocator().getName(); // will throw exception if keylocator is absent or it is not a name

          Name kskName = IdentityCertificate::certificateNameToPublicKeyName(keyLocatorName);
          Name kskCertName = keyChain.getDefaultCertificateNameForKey(kskName);
          signingCertName = kskCertName;
          kskCert = keyChain.getCertificate(kskCertName);
        }
      else
        {
          signingCertName = defaultCertName;
          kskCert = keyChain.getCertificate(defaultCertName);
        }
    }
  catch(SignatureSha256WithRsa::Error& e)
    {
      std::cerr << "ERROR: " << e.what() << std::endl;
      return 1;
    }
  catch(KeyLocator::Error& e)
    {
      std::cerr << "ERROR: " << e.what() << std::endl;
      return 1;
    }
  catch(SecPublicInfo::Error& e)
    {
      std::cerr << "ERROR: " << e.what() << std::endl;
      return 1;
    }

  if(!static_cast<bool>(kskCert))
    {
      std::cerr << "ERROR: no KSK certificate." << std::endl;
      return 1;
    }

  try
    {
      KeyChain keyChain;
      Name newKeyName;
      switch(keyType)
        {
        case 'r':
          {
            newKeyName = keyChain.generateRSAKeyPair(Name(identityName), false, keySize);
            if(0 == newKeyName.size())
              {
                std::cerr << "fail to generate key!" << std::endl;
                return 1;
              }
            break;
          }
        default:
          std::cerr << "Unrecongized key type" << "\n";
          std::cerr << desc << std::endl;
          return 1;
        }
    
      Name certName = newKeyName.getPrefix(-1);
      certName.append("KEY").append(newKeyName.get(-1)).append("ID-CERT").appendVersion();

      shared_ptr<IdentityCertificate> certificate = make_shared<IdentityCertificate>();
      certificate->setName(certName);
      certificate->setNotBefore(kskCert->getNotBefore());
      certificate->setNotAfter(kskCert->getNotAfter());

      certificate->setPublicKeyInfo(*keyChain.getPublicKey(newKeyName));

      const std::vector<CertificateSubjectDescription>& subList = kskCert->getSubjectDescriptionList();
      std::vector<CertificateSubjectDescription>::const_iterator it = subList.begin();
      for(; it != subList.end(); it++)
        certificate->addSubjectDescription(*it);
      
      certificate->encode();

      keyChain.sign(*certificate, signingCertName);

      keyChain.addCertificateAsIdentityDefault(*certificate);

      return 0;
    }
  catch(SecPublicInfo::Error& e)
    {
      std::cerr << "ERROR: " << e.what() << std::endl;
      return 1;
    }
  catch(SecTpm::Error& e)
    {
      std::cerr << "ERROR: " << e.what() << std::endl;
      return 1;
    }
}

#endif //NDNSEC_DSK_GEN_HPP