// Copyright (c) 2012-2015, The CryptoNote developers, The Bytecoin developers
//
// This file is part of Bytecoin.
//
// Bytecoin 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.
//
// Bytecoin 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 a copy of the GNU Lesser General Public License
// along with Bytecoin.  If not, see <http://www.gnu.org/licenses/>.

#pragma once

#include <iostream>
#include <type_traits>

#include <boost/program_options/parsers.hpp>
#include <boost/program_options/options_description.hpp>
#include <boost/program_options/variables_map.hpp>

namespace command_line
{
  template<typename T, bool required = false>
  struct arg_descriptor;

  template<typename T>
  struct arg_descriptor<T, false>
  {
    typedef T value_type;

    const char* name;
    const char* description;
    T default_value;
    bool not_use_default;
  };

  template<typename T>
  struct arg_descriptor<std::vector<T>, false>
  {
    typedef std::vector<T> value_type;

    const char* name;
    const char* description;
  };

  template<typename T>
  struct arg_descriptor<T, true>
  {
    static_assert(!std::is_same<T, bool>::value, "Boolean switch can't be required");

    typedef T value_type;

    const char* name;
    const char* description;
  };

  template<typename T>
  boost::program_options::typed_value<T, char>* make_semantic(const arg_descriptor<T, true>& /*arg*/)
  {
    return boost::program_options::value<T>()->required();
  }

  template<typename T>
  boost::program_options::typed_value<T, char>* make_semantic(const arg_descriptor<T, false>& arg)
  {
    auto semantic = boost::program_options::value<T>();
    if (!arg.not_use_default)
      semantic->default_value(arg.default_value);
    return semantic;
  }

  template<typename T>
  boost::program_options::typed_value<T, char>* make_semantic(const arg_descriptor<T, false>& arg, const T& def)
  {
    auto semantic = boost::program_options::value<T>();
    if (!arg.not_use_default)
      semantic->default_value(def);
    return semantic;
  }

  template<typename T>
  boost::program_options::typed_value<std::vector<T>, char>* make_semantic(const arg_descriptor<std::vector<T>, false>& /*arg*/)
  {
    auto semantic = boost::program_options::value< std::vector<T> >();
    semantic->default_value(std::vector<T>(), "");
    return semantic;
  }

  template<typename T, bool required>
  void add_arg(boost::program_options::options_description& description, const arg_descriptor<T, required>& arg, bool unique = true)
  {
    if (unique && 0 != description.find_nothrow(arg.name, false))
    {
      std::cerr << "Argument already exists: " << arg.name << std::endl;
      return;
    }

    description.add_options()(arg.name, make_semantic(arg), arg.description);
  }

  template<typename T>
  void add_arg(boost::program_options::options_description& description, const arg_descriptor<T, false>& arg, const T& def, bool unique = true)
  {
    if (unique && 0 != description.find_nothrow(arg.name, false))
    {
      std::cerr << "Argument already exists: " << arg.name << std::endl;
      return;
    }

    description.add_options()(arg.name, make_semantic(arg, def), arg.description);
  }

  template<>
  inline void add_arg(boost::program_options::options_description& description, const arg_descriptor<bool, false>& arg, bool unique)
  {
    if (unique && 0 != description.find_nothrow(arg.name, false))
    {
      std::cerr << "Argument already exists: " << arg.name << std::endl;
      return;
    }

    description.add_options()(arg.name, boost::program_options::bool_switch(), arg.description);
  }

  template<typename charT>
  boost::program_options::basic_parsed_options<charT> parse_command_line(int argc, const charT* const argv[],
    const boost::program_options::options_description& desc, bool allow_unregistered = false)
  {
    auto parser = boost::program_options::command_line_parser(argc, argv);
    parser.options(desc);
    if (allow_unregistered)
    {
      parser.allow_unregistered();
    }
    return parser.run();
  }

  template<typename F>
  bool handle_error_helper(const boost::program_options::options_description& desc, F parser)
  {
    try
    {
      return parser();
    }
    catch (std::exception& e)
    {
      std::cerr << "Failed to parse arguments: " << e.what() << std::endl;
      std::cerr << desc << std::endl;
      return false;
    }
    catch (...)
    {
      std::cerr << "Failed to parse arguments: unknown exception" << std::endl;
      std::cerr << desc << std::endl;
      return false;
    }
  }

  template<typename T, bool required>
  bool has_arg(const boost::program_options::variables_map& vm, const arg_descriptor<T, required>& arg)
  {
    auto value = vm[arg.name];
    return !value.empty();
  }


  template<typename T, bool required>
  T get_arg(const boost::program_options::variables_map& vm, const arg_descriptor<T, required>& arg)
  {
    return vm[arg.name].template as<T>();
  }
 
  template<>
  inline bool has_arg<bool, false>(const boost::program_options::variables_map& vm, const arg_descriptor<bool, false>& arg)
  {
    return get_arg<bool, false>(vm, arg);
  }


  extern const arg_descriptor<bool> arg_help;
  extern const arg_descriptor<bool> arg_version;
  extern const arg_descriptor<std::string> arg_data_dir;
}