//    OpenVPN -- An application to securely tunnel IP networks
//               over a single port, with support for SSL/TLS-based
//               session authentication and key exchange,
//               packet encryption, packet authentication, and
//               packet compression.
//
//    Copyright (C) 2012-2020 OpenVPN Inc.
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU Affero General Public License Version 3
//    as published by the Free Software Foundation.
//
//    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 in the COPYING file.
//    If not, see <http://www.gnu.org/licenses/>.

// These objects are primary concerned with generating the Peer Info on the
// client side before transmission to server.  For the reverse case (parsing
// the Peer Info on the server) we normally use an OptionList.

#ifndef OPENVPN_SSL_PEERINFO_H
#define OPENVPN_SSL_PEERINFO_H

#include <string>
#include <vector>

#include <openvpn/common/rc.hpp>
#include <openvpn/common/string.hpp>
#include <openvpn/common/file.hpp>
#include <openvpn/common/split.hpp>
#include <openvpn/common/unicode.hpp>
#include <openvpn/common/jsonlib.hpp>

#ifdef HAVE_JSON
#include <openvpn/common/jsonhelper.hpp>
#endif

namespace openvpn {
  namespace PeerInfo {

    OPENVPN_EXCEPTION(peer_info_error);

    struct KeyValue
    {
      KeyValue(const std::string& key_arg, const std::string& value_arg)
	: key(key_arg),
	  value(value_arg)
      {
      }

      std::string key;
      std::string value;

      std::string to_string() const
      {
	return key + '=' + value;
      }
    };

    struct Set : public std::vector<KeyValue>, public RCCopyable<thread_unsafe_refcount>
    {
      typedef RCPtr<Set> Ptr;

      template <typename SET>
      static Ptr new_from_foreign_set(const SET& other)
      {
	Ptr sp = new Set();
	for (const auto &kv : other)
	  sp->emplace_back(kv.key, kv.value);
	return sp;
      }

      template <typename SET>
      void append_foreign_set_ptr(const SET* other)
      {
	if (other)
	  for (const auto &kv : *other)
	    emplace_back(kv.key, kv.value);
      }

      template <typename SET>
      void append_foreign_set_ref(const SET& other)
      {
	for (const auto &kv : other)
	  emplace_back(kv.key, kv.value);
      }

      Ptr copy() const
      {
	return new Set(*this);
      }

      // src may be comma-separated key=value pairs or @filename, where
      // filename contains a JSON dictionary of key/value pairs.
      template <typename SET>
      static void parse_flexible(const std::string& src, SET& dest)
      {
	if (src.length() >= 1 && src[0] == '@')
	  {
	    const std::string fn = src.substr(1);
#ifdef OPENVPN_JSON_INTERNAL
	    const Json::Value root = json::parse_from_file(fn);
	    parse_json(root, dest, fn);
#else
	    OPENVPN_THROW(peer_info_error, fn << ": JSON library not available");
#endif
	  }
	else
	  parse_csv(src, dest);
      }

      // Parse src in the form K1=V1,K2=V2,...
      template <typename SET>
      static void parse_csv(const std::string& src, SET& dest)
      {
	if (!string::is_empty(src))
	  {
	    if (string::is_multiline(src))
	      OPENVPN_THROW(peer_info_error, "key/value list must be a single line: " << Unicode::utf8_printable(src, 256));
	    const auto list = Split::by_char<std::vector<std::string>, StandardLex, Split::NullLimit>(src, ',', Split::TRIM_LEADING_SPACES|Split::TRIM_SPECIAL);
	    for (const auto &kvstr : list)
	      {
		const auto kv = Split::by_char<std::vector<std::string>, StandardLex, Split::NullLimit>(kvstr, '=', 0, 1);
		if (kv.size() == 2)
		  dest.emplace_back(kv[0], kv[1]);
		else
		  OPENVPN_THROW(peer_info_error, "key/value must be in the form K=V, not: " << Unicode::utf8_printable(kvstr, 256));
	      }
	  }
      }

#ifdef OPENVPN_JSON_INTERNAL
      template <typename SET>
      static void parse_json(const Json::Value& src, SET& dest, const std::string& title)
      {
	if (!src.isObject())
	  OPENVPN_THROW(peer_info_error, title << ": top level JSON object must be a dictionary");
	auto m = src.map();
	for (auto &e : m)
	  {
	    if (e.second.isString())
	      dest.emplace_back(e.first, e.second.asStringRef());
	    else
	      dest.emplace_back(e.first, e.second.toCompactString());
	  }
      }
#endif

      std::string to_string() const
      {
	std::string ret;
	ret.reserve(256);
	for (const auto &kv : *this)
	  {
	    ret += kv.to_string();
	    ret += '\n';
	  }
	return ret;
      }
    };

  }
}

#endif