// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
// Mobius Forensic Toolkit
// Copyright (C) 2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020,2021,2022,2023,2024 Eduardo Aguiar
//
// 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; either version 2, 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 General
// Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
#include <mobius/core/application.h>
#include <mobius/crypt/hash.h>
#include <mobius/io/file.h>
#include <mobius/vfs/vfs.h>
#include <iostream>
#include <unistd.h>

void process_file (const mobius::io::file&, const std::string&, const std::string&);
void process_folder (const mobius::io::folder&, const std::string&, const std::string&);

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Show usage text
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
void
usage ()
{
  std::cerr << std::endl;
  std::cerr << "use: hashfs [OPTIONS] <URL>" << std::endl;
  std::cerr << "e.g: hashfs -t md5 file://disk.raw" << std::endl;
  std::cerr << "     hashfs file://disk.ewf" << std::endl;
  std::cerr << std::endl;
  std::cerr << "options are:" << std::endl;
  std::cerr << "  -t hash type\t\t" << std::endl;
  std::cerr << std::endl;
}

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Process entry
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
void
process_entry (
  const mobius::io::entry& entry,
  const std::string& hash_type,
  const std::string& path=""
)
{
  try
    {
      if (entry.is_file ())
        {
          auto fchild = entry.get_file ();
          process_file (fchild, hash_type, path + '/' + fchild.get_name ());
        }

      else
        {
          auto fchild = entry.get_folder ();
          process_folder (fchild, hash_type, path + '/' + fchild.get_name ());
        }
    }
  catch (const std::exception& e)
    {
      std::cerr << "Warning: " << e.what () << std::endl;
    }
}

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Process file
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
void
process_file (
  const mobius::io::file& f,
  const std::string& hash_type,
  const std::string& path
)
{
  try
    {
      if (f.is_reallocated ())
        return;

      auto reader = f.new_reader ();

      if (!reader)
        return;

      mobius::crypt::hash h (hash_type);

      constexpr int BLOCK_SIZE = 65536;
      auto data = reader.read (BLOCK_SIZE);

      while (data)
        {
          h.update (data);
          data = reader.read (BLOCK_SIZE);
        }

      std::cout << h.get_hex_digest () << '\t' << path << std::endl;
    }
  catch (const std::exception& e)
    {
      std::cerr << "Warning: " << e.what () << std::endl;
    }
}

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Process folder
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
void
process_folder (
  const mobius::io::folder& folder,
  const std::string& hash_type,
  const std::string& path=""
)
{
  if (folder.is_reallocated ())
    return;

  try
    {
      for (const auto& entry : folder.get_children ())
        process_entry (entry, hash_type, path);
    }
  catch (const std::exception& e)
    {
      std::cerr << "Warning: " << e.what () << std::endl;
    }
}

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief main function
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
int
main (int argc, char **argv)
{
  mobius::core::application app;
  app.start ();

  std::cerr << app.get_name () << " v" << app.get_version () << std::endl;
  std::cerr << app.get_copyright () << std::endl;
  std::cerr << "HashFS v1.3" << std::endl;
  std::cerr << "by Eduardo Aguiar" << std::endl;

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  // parse command line
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  int opt;
  std::string hash_type = "md5";

  while ((opt = getopt (argc, argv, "ht:")) != EOF)
    {
      switch (opt)
        {
        case 'h':
          usage ();
          exit (EXIT_SUCCESS);
          break;

        case 't':
          hash_type = optarg;
          break;

        default:
          usage ();
          exit (EXIT_FAILURE);
        }
    }

  if (optind >= argc)
    {
      std::cerr << std::endl;
      std::cerr << "Error: You must enter a valid URL to an imagefile" << std::endl;
      usage ();
      exit (EXIT_FAILURE);
    }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  // Create VFS and check if it is available
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  mobius::vfs::vfs vfs;
  vfs.add_disk (mobius::vfs::new_disk_by_url (argv[optind]));

  if (!vfs.is_available ())
    {
      std::cerr << std::endl;
      std::cerr << "Error: Image file is not available" << std::endl;
      usage ();
      exit (EXIT_FAILURE);
    }

  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  // calculate hashes
  // =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  for (const auto& entry : vfs.get_root_entries ())
    process_entry (entry, hash_type);

  app.stop ();
  return EXIT_SUCCESS;
}
