/*
      This file is part of GNUnet
      Copyright (C) 2021 GNUnet e.V.

      GNUnet is free software: you can redistribute it and/or modify it
      under the terms of the GNU Affero General Public License as published
      by the Free Software Foundation, either version 3 of the License,
      or (at your option) any later version.

      GNUnet 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.  If not, see <http://www.gnu.org/licenses/>.

     SPDX-License-Identifier: AGPL3.0-or-later
 */

/**
 * @file testing/testing_api_cmd_netjail_start.c
 * @brief Command to start the netjail script.
 * @author t3sserakt
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_testing_ng_lib.h"
#include "gnunet_testing_netjail_lib.h"

#define NETJAIL_START_SCRIPT "netjail_start.sh"

#define LOG(kind, ...) GNUNET_log (kind, __VA_ARGS__)

/**
 * Struct to hold information for callbacks.
 *
 */
struct NetJailState
{
  /**
   * Context for our asynchronous completion.
   */
  struct GNUNET_TESTING_AsyncContext ac;

  // Child Wait handle
  struct GNUNET_ChildWaitHandle *cwh;

  /**
   * The process id of the start script.
   */
  struct GNUNET_OS_Process *start_proc;

  /**
   * Configuration file for the test topology.
   */
  char *topology_config;

  /**
   * Shall we read the topology from file, or from a string.
   */
  unsigned int *read_file;
};


/**
 * The cleanup function of this cmd frees resources the cmd allocated.
 *
 */
static void
netjail_start_cleanup (void *cls)
{
  struct NetJailState *ns = cls;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "netjail_start_cleanup!\n");

  if (NULL != ns->cwh)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Cancel child\n");
    GNUNET_wait_child_cancel (ns->cwh);
    ns->cwh = NULL;
  }
  if (NULL != ns->start_proc)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Kill process\n");
    GNUNET_assert (0 ==
                   GNUNET_OS_process_kill (ns->start_proc,
                                           SIGKILL));
    GNUNET_assert (GNUNET_OK ==
                   GNUNET_OS_process_wait (ns->start_proc));
    GNUNET_OS_process_destroy (ns->start_proc);
    ns->start_proc = NULL;
  }
  GNUNET_free (ns);
}


/**
 * Callback which will be called if the setup script finished.
 *
 */
static void
child_completed_callback (void *cls,
                          enum GNUNET_OS_ProcessStatusType type,
                          long unsigned int exit_code)
{
  struct NetJailState *ns = cls;

  GNUNET_OS_process_destroy (ns->start_proc);
  ns->start_proc = NULL;
  ns->cwh = NULL;
  if (0 == exit_code)
  {
    GNUNET_TESTING_async_finish (&ns->ac);
  }
  else
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Child failed with error %lu!\n",
                exit_code);
    GNUNET_TESTING_async_fail (&ns->ac);
  }
}


/**
* The run method starts the script which setup the network namespaces.
*
* @param cls closure.
* @param is interpreter state.
*/
static void
netjail_start_run (void *cls,
                   struct GNUNET_TESTING_Interpreter *is)
{
  struct NetJailState *ns = cls;
  char pid[15];
  enum GNUNET_GenericReturnValue helper_check;
  char *data_dir;
  char *script_name;
  char *read_file;

  data_dir = GNUNET_OS_installation_get_path (GNUNET_OS_IPK_DATADIR);
  GNUNET_asprintf (&script_name, "%s%s", data_dir, NETJAIL_START_SCRIPT);
  GNUNET_asprintf (&read_file, "%u", *(ns->read_file));

  helper_check = GNUNET_OS_check_helper_binary (
    script_name,
    GNUNET_YES,
    NULL);

  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "script_name %s\n",
       script_name);

  if (GNUNET_NO == helper_check)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "No SUID for %s!\n",
                script_name);
    GNUNET_TESTING_interpreter_fail (is);
    return;
  }
  if (GNUNET_SYSERR == helper_check)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "%s not found!\n",
                script_name);
    GNUNET_TESTING_interpreter_fail (is);
    return;
  }

  GNUNET_snprintf (pid,
                   sizeof (pid),
                   "%u",
                   getpid ());
  {
    char *const script_argv[] = {
      script_name,
      ns->topology_config,
      pid,
      read_file,
      NULL
    };

    ns->start_proc
      = GNUNET_OS_start_process_vap (GNUNET_OS_INHERIT_STD_ERR,
                                     NULL,
                                     NULL,
                                     NULL,
                                     script_name,
                                     script_argv);

  }
  ns->cwh = GNUNET_wait_child (ns->start_proc,
                               &child_completed_callback,
                               ns);
  GNUNET_break (NULL != ns->cwh);
  GNUNET_free (read_file);
  GNUNET_free (script_name);
  GNUNET_free (data_dir);
}


/**
 * Create command.
 *
 * @param label name for command.
 * @param topology_config Configuration file for the test topology.
 * @return command.
 */
struct GNUNET_TESTING_Command
GNUNET_TESTING_cmd_netjail_start (const char *label,
                                  char *topology_config,
                                  unsigned int *read_file)
{
  struct NetJailState *ns;

  ns = GNUNET_new (struct NetJailState);
  ns->topology_config = topology_config;
  ns->read_file = read_file;
  {
    struct GNUNET_TESTING_Command cmd = {
      .cls = ns,
      .label = label,
      .run = &netjail_start_run,
      .ac = &ns->ac,
      .cleanup = &netjail_start_cleanup
    };

    return cmd;
  }
}