/**
 * Author......: See docs/credits.txt
 * License.....: MIT
 */

#include "common.h"
#include "types.h"
#include "memory.h"
#include "event.h"
#include "user_options.h"
#include "shared.h"
#include "pidfile.h"
#include "folder.h"
#include "restore.h"

#if defined (_WIN)
static void fsync (int fd)
{
  HANDLE h = (HANDLE) _get_osfhandle (fd);

  FlushFileBuffers (h);
}
#endif

static int init_restore (hashcat_ctx_t *hashcat_ctx)
{
  restore_ctx_t *restore_ctx = hashcat_ctx->restore_ctx;

  restore_data_t *rd = (restore_data_t *) hcmalloc (sizeof (restore_data_t));

  restore_ctx->rd = rd;

  rd->version = RESTORE_VERSION_CUR;

  rd->argc = restore_ctx->argc;
  rd->argv = restore_ctx->argv;

  if (getcwd (rd->cwd, 255) == NULL)
  {
    event_log_error (hashcat_ctx, "getcwd(): %s", strerror (errno));

    return -1;
  }

  return 0;
}

static int read_restore (hashcat_ctx_t *hashcat_ctx)
{
  restore_ctx_t   *restore_ctx   = hashcat_ctx->restore_ctx;
  folder_config_t *folder_config = hashcat_ctx->folder_config;

  if (restore_ctx->enabled == false) return 0;

  char *eff_restore_file = restore_ctx->eff_restore_file;

  FILE *fp = fopen (eff_restore_file, "rb");

  if (fp == NULL)
  {
    event_log_error (hashcat_ctx, "Restore file '%s': %s", eff_restore_file, strerror (errno));

    return -1;
  }

  restore_data_t *rd = restore_ctx->rd;

  if (fread (rd, sizeof (restore_data_t), 1, fp) != 1)
  {
    event_log_error (hashcat_ctx, "Cannot read %s", eff_restore_file);

    fclose (fp);

    return -1;
  }

  // we only use these 2 checks to avoid "tainted string" warnings

  if (rd->argc < 1)
  {
    event_log_error (hashcat_ctx, "Unusually low number of arguments (argc) within restore file %s", eff_restore_file);

    fclose (fp);

    return -1;
  }

  if (rd->argc > 250) // some upper bound check is always good (with some dirs/dicts it could be a large string)
  {
    event_log_error (hashcat_ctx, "Unusually high number of arguments (argc) within restore file %s", eff_restore_file);

    fclose (fp);

    return -1;
  }

  rd->argv = (char **) hccalloc (rd->argc, sizeof (char *));

  char *buf = (char *) hcmalloc (HCBUFSIZ_LARGE);

  for (u32 i = 0; i < rd->argc; i++)
  {
    if (fgets (buf, HCBUFSIZ_LARGE - 1, fp) == NULL)
    {
      event_log_error (hashcat_ctx, "Cannot read %s", eff_restore_file);

      fclose (fp);

      return -1;
    }

    size_t len = strlen (buf);

    if (len) buf[len - 1] = 0;

    rd->argv[i] = hcstrdup (buf);
  }

  hcfree (buf);

  fclose (fp);

  if (hc_path_exist (rd->cwd) == false)
  {
    event_log_error (hashcat_ctx, "%s: %s", rd->cwd, strerror (errno));

    return -1;
  }

  if (hc_path_is_directory (rd->cwd) == false)
  {
    event_log_error (hashcat_ctx, "%s: %s", rd->cwd, strerror (errno));

    return -1;
  }

  if (strncmp (rd->cwd, folder_config->cwd, sizeof (rd->cwd)) != 0) // check if we need to change the current working directory
  {
    event_log_warning (hashcat_ctx, "Changing current working directory to '%s'", rd->cwd);
    event_log_warning (hashcat_ctx, NULL);

    if (chdir (rd->cwd))
    {
      event_log_error (hashcat_ctx, "Directory '%s' needed to restore the session was not found.", rd->cwd);

      event_log_warning (hashcat_ctx, "Either create the directory, or update the directory within the .restore file.");
      event_log_warning (hashcat_ctx, "Restore files can be analyzed and modified with analyze_hc_restore.pl:");
      event_log_warning (hashcat_ctx, "    https://github.com/philsmd/analyze_hc_restore");
      event_log_warning (hashcat_ctx, "Directory must contain all files and folders from the original command line.");
      event_log_warning (hashcat_ctx, NULL);

      return -1;
    }

    // if we are here, we also need to update the folder_config and .pid file:

    /**
     * updated folders
     */

    // copy the paths of INSTALL_FOLDER and SHARED_FOLDER from the folder config:

    char *install_folder = hcstrdup (folder_config->install_dir);
    char *shared_folder  = hcstrdup (folder_config->shared_dir);

    folder_config_destroy (hashcat_ctx);

    const int rc_folder_config_init = folder_config_init (hashcat_ctx, install_folder, shared_folder);

    hcfree (install_folder);
    hcfree (shared_folder);

    if (rc_folder_config_init == -1) return -1;

    /**
     * updated pidfile
     */

    pidfile_ctx_destroy (hashcat_ctx);

    const int rc_pidfile_init = pidfile_ctx_init (hashcat_ctx);

    if (rc_pidfile_init == -1) return -1;
  }

  return 0;
}

static int write_restore (hashcat_ctx_t *hashcat_ctx)
{
  const mask_ctx_t     *mask_ctx     = hashcat_ctx->mask_ctx;
  const restore_ctx_t  *restore_ctx  = hashcat_ctx->restore_ctx;
  const status_ctx_t   *status_ctx   = hashcat_ctx->status_ctx;
  const straight_ctx_t *straight_ctx = hashcat_ctx->straight_ctx;

  if (restore_ctx->enabled == false) return 0;

  restore_data_t *rd = restore_ctx->rd;

  rd->masks_pos = mask_ctx->masks_pos;
  rd->dicts_pos = straight_ctx->dicts_pos;
  rd->words_cur = status_ctx->words_cur;

  char *new_restore_file = restore_ctx->new_restore_file;

  FILE *fp = fopen (new_restore_file, "wb");

  if (fp == NULL)
  {
    event_log_error (hashcat_ctx, "%s: %s", new_restore_file, strerror (errno));

    return -1;
  }

  if (setvbuf (fp, NULL, _IONBF, 0))
  {
    event_log_error (hashcat_ctx, "setvbuf file '%s': %s", new_restore_file, strerror (errno));

    fclose (fp);

    return -1;
  }

  hc_fwrite (rd, sizeof (restore_data_t), 1, fp);

  for (u32 i = 0; i < rd->argc; i++)
  {
    fprintf (fp, "%s", rd->argv[i]);

    fputc ('\n', fp);
  }

  fflush (fp);

  fsync (fileno (fp));

  fclose (fp);

  rd->masks_pos = 0;
  rd->dicts_pos = 0;
  rd->words_cur = 0;

  return 0;
}

int cycle_restore (hashcat_ctx_t *hashcat_ctx)
{
  restore_ctx_t *restore_ctx = hashcat_ctx->restore_ctx;

  if (restore_ctx->enabled == false) return 0;

  const char *eff_restore_file = restore_ctx->eff_restore_file;
  const char *new_restore_file = restore_ctx->new_restore_file;

  const int rc_write_restore = write_restore (hashcat_ctx);

  if (rc_write_restore == -1) return -1;

  if (hc_path_exist (eff_restore_file) == true)
  {
    if (unlink (eff_restore_file) == -1)
    {
      event_log_warning (hashcat_ctx, "Unlink file '%s': %s", eff_restore_file, strerror (errno));
    }
  }

  if (rename (new_restore_file, eff_restore_file) == -1)
  {
    event_log_warning (hashcat_ctx, "Rename file '%s' to '%s': %s", new_restore_file, eff_restore_file, strerror (errno));
  }

  return 0;
}

void unlink_restore (hashcat_ctx_t *hashcat_ctx)
{
  restore_ctx_t *restore_ctx = hashcat_ctx->restore_ctx;
  status_ctx_t  *status_ctx  = hashcat_ctx->status_ctx;

  if (restore_ctx->enabled == false) return;

  if ((status_ctx->devices_status == STATUS_EXHAUSTED) && (status_ctx->run_thread_level1 == true)) // this is to check for [c]heckpoint
  {
    unlink (restore_ctx->eff_restore_file);
    unlink (restore_ctx->new_restore_file);
  }

  if (status_ctx->devices_status == STATUS_CRACKED)
  {
    unlink (restore_ctx->eff_restore_file);
    unlink (restore_ctx->new_restore_file);
  }
}

int restore_ctx_init (hashcat_ctx_t *hashcat_ctx, int argc, char **argv)
{
  folder_config_t *folder_config = hashcat_ctx->folder_config;
  restore_ctx_t   *restore_ctx   = hashcat_ctx->restore_ctx;
  user_options_t  *user_options  = hashcat_ctx->user_options;

  restore_ctx->enabled = false;

  if (user_options->benchmark       == true) return 0;
  if (user_options->example_hashes  == true) return 0;
  if (user_options->keyspace        == true) return 0;
  if (user_options->left            == true) return 0;
  if (user_options->opencl_info     == true) return 0;
  if (user_options->show            == true) return 0;
  if (user_options->stdout_flag     == true) return 0;
  if (user_options->speed_only      == true) return 0;
  if (user_options->progress_only   == true) return 0;
  if (user_options->usage           == true) return 0;
  if (user_options->version         == true) return 0;
  if (user_options->restore_disable == true) return 0;

  if (argc ==    0) return 0;
  if (argv == NULL) return 0;

  if (user_options->restore_file_path == NULL)
  {
    hc_asprintf (&restore_ctx->eff_restore_file, "%s/%s.restore",     folder_config->session_dir, user_options->session);
    hc_asprintf (&restore_ctx->new_restore_file, "%s/%s.restore.new", folder_config->session_dir, user_options->session);
  }
  else
  {
    restore_ctx->eff_restore_file = hcstrdup (user_options->restore_file_path);
    hc_asprintf (&restore_ctx->new_restore_file, "%s.new", user_options->restore_file_path);
  }

  restore_ctx->argc = argc;
  restore_ctx->argv = argv;

  const int rc_init_restore = init_restore (hashcat_ctx);

  if (rc_init_restore == -1) return -1;

  restore_ctx->enabled = true;

  if (user_options->restore == true)
  {
    const int rc_read_restore = read_restore (hashcat_ctx);

    if (rc_read_restore == -1) return -1;

    restore_data_t *rd = restore_ctx->rd;

    if (rd->version < RESTORE_VERSION_MIN)
    {
      event_log_error (hashcat_ctx, "Incompatible restore-file version.");

      return -1;
    }

    user_options_init (hashcat_ctx);

    const int rc_options_getopt = user_options_getopt (hashcat_ctx, rd->argc, rd->argv);

    if (rc_options_getopt == -1) return -1;
  }

  return 0;
}

void restore_ctx_destroy (hashcat_ctx_t *hashcat_ctx)
{
  restore_ctx_t *restore_ctx = hashcat_ctx->restore_ctx;

  if (restore_ctx->enabled == false) return;

  hcfree (restore_ctx->eff_restore_file);
  hcfree (restore_ctx->new_restore_file);

  hcfree (restore_ctx->rd);

  memset (restore_ctx, 0, sizeof (restore_ctx_t));
}
