/*
 * AuthBackendFile.cpp
 *
 * Copyright (C) 2009 Matthias Schiffer <matthias@gamezock.de>
 *
 * This program 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.
 *
 * 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "AuthBackendFile.h"
#include <Core/ConfigEntry.h>
#include <Core/ConfigManager.h>

#include <fstream>

#include <boost/regex.hpp>

namespace Mad {
namespace Modules {
namespace AuthBackendFile {

void AuthBackendFile::readFile(const std::string &name) {
  std::ifstream stream(name.c_str());
  if(!stream.good()) {
    application->logf(Core::LoggerBase::LOG_WARNING, "AuthBackendFile: Can't read file '%s'.", name.c_str());
    return;
  }

  while(stream.good() && !stream.eof()) {
    std::string line;
    std::getline(stream, line);

    if(line.empty())
      continue;

    static const boost::regex regex("([^:]+):(.+)", boost::regex_constants::perl);
    boost::smatch match;

    if(!boost::regex_match(line, match, regex)) {
      application->logf(Core::LoggerBase::LOG_WARNING, "AuthBackendFile: Malformed line in file '%s'.", name.c_str());
      continue;
    }


    userMap.insert(std::make_pair(match[1].str(), match[2].str()));
  }
}

bool AuthBackendFile::handleConfigEntry(const Core::ConfigEntry &entry, bool /*handled*/) {
  if(!entry[0].getKey().matches("AuthBackendFile"))
    return false;

  if(entry[1].empty())
    return true;

  if(entry[1].getKey().matches("File")) {
    if(entry[2].empty()) {
      readFile(entry[1][0]);
    }
  }
  else if(!entry[2].empty())
    return false;

  return true;
}

boost::shared_ptr<Common::AuthContext> AuthBackendFile::authenticate(const std::string &method, const std::string &subMethod,
    const std::string &user, const std::vector<boost::uint8_t> &data, std::vector<boost::uint8_t>& /*response*/,
    boost::shared_ptr<Common::AuthContext> context) throw(Core::Exception) {
  if(method != "Password")
    throw(Core::Exception(Core::Exception::NOT_IMPLEMENTED));

  if(context.get() != 0 && dynamic_cast<AuthContextFile*>(context.get()) == 0)
    throw(Core::Exception(Core::Exception::INVALID_INPUT));

  if(context.get() == 0)
    context.reset(new AuthContextFile);

  std::map<std::string, std::string>::iterator userIt = userMap.find(user);
  if(userIt == userMap.end())
    throw(Core::Exception(Core::Exception::AUTHENTICATION));

  if(subMethod == "Clear") {
    if(userIt->second != std::string(data.begin(), data.end()))
      throw(Core::Exception(Core::Exception::AUTHENTICATION));
  }
  else {
    if(!std::equal(data.begin(), data.end(), Common::Hash::hash(userIt->second, subMethod).begin()))
      throw(Core::Exception(Core::Exception::AUTHENTICATION));
  }


  return context;
}

}
}
}