/* Copyright (C) 2021 MariaDB Corporation

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; version 2 of
   the License.

   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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

#include <iostream>
#include <string>
#include <ftw.h>
#include <boost/algorithm/string/case_conv.hpp>

#include "configcpp.h"
#include "rebuildEM.h"
#include "IDBPolicy.h"
#include "IDBFileSystem.h"

using namespace idbdatafile;
using namespace RebuildExtentMap;

static void usage(const std::string& pname)
{
  std::cout << "usage: " << pname << " [-vdhs]" << std::endl;
  std::cout << "rebuilds the extent map from the contents of the database file "
               "system."
            << std::endl;
  std::cout << "   -v display verbose progress information. More v's, more debug" << std::endl;
  std::cout << "   -d display what would be done--don't do it" << std::endl;
  std::cout << "   -h display this help text" << std::endl;
  std::cout << "   -s show extent map and quit" << std::endl;
}

static bool isYes()
{
  std::string confirmation;
  std::cin >> confirmation;
  if (confirmation.size() == 0)
    return false;

  boost::algorithm::to_lower(confirmation);
  if (!(confirmation == "y" || confirmation == "yes"))
    return false;

  return true;
}

int main(int argc, char** argv)
{
  int32_t option;
  std::string pname(argv[0]);
  bool showExtentMap = false;
  bool verbose = false;
  bool display = false;

  while ((option = getopt(argc, argv, "vdhs")) != EOF)
  {
    switch (option)
    {
      case 'v': verbose = true; break;

      case 'd': display = true; break;

      case 's': showExtentMap = true; break;

      case 'h':
      case '?':
      default:
        usage(pname);
        return (option == 'h' ? 0 : 1);
        break;
    }
  }

  EMReBuilder emReBuilder(verbose, display);
  // Just show EM and quit.
  if (showExtentMap)
  {
    emReBuilder.showExtentMap();
    return 0;
  }

  // MCOL-4685
  std::cout << "The launch of mcsRebuildEM tool must be sanctioned by MariaDB support. " << std::endl;
  std::cout << "Do you want to continue Y/N? ";
  if (!isYes())
    return 0;

  auto* config = config::Config::makeConfig();
  const auto BRMSavesEM = config->getConfig("SystemConfig", "DBRMRoot") + "_em";

  // Check for `BRM_saves_em` file presents.
  // TODO: Should we add force option to remove file?
  if (IDBPolicy::exists(BRMSavesEM.c_str()))
  {
    std::cout << BRMSavesEM << " file exists. " << std::endl;
    std::cout << "Do you want to delete this file Y/N? ";
    if (!isYes())
      return 0;

    if (IDBPolicy::remove(BRMSavesEM.c_str()) == -1)
    {
      std::cout << "Cannot remove " << BRMSavesEM << std::endl;
      std::cout << "Exiting. " << std::endl;
      return 0;
    }
  }

  // Initialize system extents from the binary blob.
  auto rc = emReBuilder.initializeSystemExtents();
  if (rc == -1)
  {
    std::cerr << "Cannot initialize system extents from binary blob." << std::endl;
    std::cerr << "Exiting. " << std::endl;
    return 1;
  }

  // Make config from default path.
  std::string count = config->getConfig("SystemConfig", "DBRootCount");
  // Read the number of DBRoots.
  uint32_t dbRootCount = config->uFromText(count);

  // Iterate over DBRoots starting from the first one.
  for (uint32_t dbRootNumber = 1; dbRootNumber <= dbRootCount; ++dbRootNumber)
  {
    std::string dbRootName = "DBRoot" + std::to_string(dbRootNumber);
    auto dbRootPath = config->getConfig("SystemConfig", dbRootName);
    emReBuilder.setDBRoot(dbRootNumber);
    emReBuilder.collectExtents(dbRootPath.c_str());
  }

  emReBuilder.rebuildExtentMap();
  emReBuilder.clear();

  // Save restored extent map.
  emReBuilder.getEM().save(BRMSavesEM);
  std::cout << "Completed." << std::endl;
  return 0;
}
