/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (c) 2013-2017 Regents of the University of California.
 *
 * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
 *
 * ndn-cxx library is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 *
 * ndn-cxx library 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 Lesser General Public License for more details.
 *
 * You should have received copies of the GNU General Public License and GNU Lesser
 * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
 *
 * @author Yingdi Yu <http://irl.cs.ucla.edu/~yingdi/>
 */

#ifndef NDN_TOOLS_NDNSEC_UTIL_HPP
#define NDN_TOOLS_NDNSEC_UTIL_HPP

#include <iostream>
#include <fstream>
#include <string>
#include <cstring>

#include <boost/program_options/options_description.hpp>
#include <boost/program_options/variables_map.hpp>
#include <boost/program_options/parsers.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/tokenizer.hpp>
#include <boost/asio.hpp>
#include <boost/exception/all.hpp>

#include "encoding/buffer-stream.hpp"
#include "security/v1/key-chain.hpp"
#include "security/transform.hpp"
#include "util/io.hpp"

bool
getPassword(std::string& password, const std::string& prompt)
{
#ifdef NDN_CXX_HAVE_GETPASS
  bool isReady = false;

  char* pw0 = 0;

  pw0 = getpass(prompt.c_str());
  if (!pw0)
    return false;
  std::string password1 = pw0;
  memset(pw0, 0, strlen(pw0));

  pw0 = getpass("Confirm:");
  if (!pw0)
    {
      char* pw1 = const_cast<char*>(password1.c_str());
      memset(pw1, 0, password1.size());
      return false;
    }

  if (!password1.compare(pw0))
    {
      isReady = true;
      password.swap(password1);
    }

  char* pw1 = const_cast<char*>(password1.c_str());
  memset(pw1, 0, password1.size());
  memset(pw0, 0, strlen(pw0));

  if (password.empty())
    return false;

  return isReady;
#else
  return false;
#endif // NDN_CXX_HAVE_GETPASS
}

ndn::shared_ptr<ndn::security::v1::IdentityCertificate>
getIdentityCertificate(const std::string& fileName)
{

  if (fileName == "-")
    return ndn::io::load<ndn::security::v1::IdentityCertificate>(std::cin);
  else
    return ndn::io::load<ndn::security::v1::IdentityCertificate>(fileName);
}


/**
 * @brief An accumulating option value to handle multiple incrementing options.
 *
 * Based on https://gitorious.org/bwy/bwy/source/8753148c324ddfacb1f3cdc315650586bd7b75a4:use/accumulator.hpp
 * @sa http://benjaminwolsey.de/node/103
 */
template<typename T>
class AccumulatorType : public boost::program_options::value_semantic
{
public:
  explicit
  AccumulatorType(T* store)
    : m_store(store)
    , m_interval(1)
    , m_default(0)
  {
  }

  virtual
  ~AccumulatorType()
  {
  }

  /// @brief Set the default value for this option.
  AccumulatorType*
  setDefaultValue(const T& t)
  {
    m_default = t;
    return this;
  }

  /**
   * @brief Set the interval for this option.
   *
   * Unlike for program_options::value, this specifies a value
   * to be applied on each occurrence of the option.
   */
  AccumulatorType*
  setInterval(const T& t) {
    m_interval = t;
    return this;
  }

  std::string
  name() const final
  {
    return std::string();
  }

  // There are no tokens for an AccumulatorType
  unsigned
  min_tokens() const final
  {
    return 0;
  }

  unsigned
  max_tokens() const final
  {
    return 0;
  }

  // Accumulating from different sources is silly.
  bool
  is_composing() const final
  {
    return false;
  }

  // Requiring one or more appearances is unlikely.
  bool
  is_required() const final
  {
    return false;
  }

  /**
   * @brief Parse options
   *
   * Every appearance of the option simply increments the value
   * There should never be any tokens.
   */
  void
  parse(boost::any& value_store,
        const std::vector<std::string>& new_tokens,
        bool utf8) const final
  {
    if (value_store.empty())
      value_store = T();
    boost::any_cast<T&>(value_store) += m_interval;
  }

  /**
   * @brief If the option doesn't appear, this is the default value.
   */
  bool
  apply_default(boost::any& value_store) const final
  {
    value_store = m_default;
    return true;
  }

  /**
   * @brief Notify the user function with the value of the value store.
   */
  void
  notify(const boost::any& value_store) const final
  {
    const T* val = boost::any_cast<T>(&value_store);
    if (m_store)
      *m_store = *val;
  }

#if BOOST_VERSION >= 105900
  bool
  adjacent_tokens_only() const final
  {
    return false;
  }
#endif // BOOST_VERSION >= 105900

private:
    T* m_store;
    T m_interval;
    T m_default;
};

template<typename T>
AccumulatorType<T>* accumulator()
{
  return new AccumulatorType<T>(0);
}

template<typename T>
AccumulatorType<T>* accumulator(T* store)
{
  return new AccumulatorType<T>(store);
}

#endif // NDN_TOOLS_NDNSEC_UTIL_HPP