/*
     This file is part of GNUnet.
     (C) 2009, 2012, 2013 Christian Grothoff (and other contributing authors)

     GNUnet 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 3, 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
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file arm/gnunet-arm.c
 * @brief arm for writing a tool
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_arm_service.h"
#include "gnunet_constants.h"
#include "gnunet_util_lib.h"

/**
 * Timeout for stopping services.  Long to give some services a real chance.
 */
#define STOP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 1)

/**
 * Timeout for stopping ARM.  Extra-long since ARM needs to stop everyone else.
 */
#define STOP_TIMEOUT_ARM GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)

/**
 * Timeout for starting services, very short because of the strange way start works
 * (by checking if running before starting, so really this time is always waited on
 * startup (annoying)).
 */
#define START_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)

/**
 * Timeout for listing all running services.
 */
#define LIST_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 2)

/**
 * Set if we are to shutdown all services (including ARM).
 */
static int end;

/**
 * Set if we are to start default services (including ARM).
 */
static int start;

/**
 * Set if we are to stop/start default services (including ARM).
 */
static int restart;

/**
 * Set if we should delete configuration and temp directory on exit.
 */
static int delete;

/**
 * Set if we should not print status messages.
 */
static int quiet;

/**
 * Set if we should print a list of currently running services.
 */
static int list;

/**
 * Set to the name of a service to start.
 */
static char *init;

/**
 * Set to the name of a service to kill.
 */
static char *term;

/**
 * Set to the name of the config file used.
 */
static const char *config_file;

/**
 * Set to the directory where runtime files are stored.
 */
static char *dir;

/**
 * Final status code.
 */
static int ret;

/**
 * Connection with ARM.
 */
static struct GNUNET_ARM_Handle *h;

/**
 * Our configuration.
 */
static struct GNUNET_CONFIGURATION_Handle *cfg;

/**
 * Processing stage that we are in.  Simple counter.
 */
static unsigned int phase;

/**
 * User defined timestamp for completing operations.
 */
static struct GNUNET_TIME_Relative timeout;

/**
 * Do we want to give our stdout to gnunet-service-arm?
 */
static unsigned int no_stdout;

/**
 * Do we want to give our stderr to gnunet-service-arm?
 */
static unsigned int no_stderr;


/**
 * Main continuation-passing-style loop.  Runs the various
 * jobs that we've been asked to do in order.
 *
 * @param cls closure, unused
 * @param tc context, unused
 */
static void
cps_loop (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);


/**
 * Callback invoked with the status of the last operation.  Reports to the
 * user and then runs the next phase in the FSM.
 *
 * @param cls pointer to "const char*" identifying service that was manipulated
 * @param result result of the operation
 */
static void
confirm_cb (void *cls, 
	    enum GNUNET_ARM_ProcessStatus result)
{
  const char *service = cls;

  switch (result)
  {
  case GNUNET_ARM_PROCESS_UNKNOWN:
    FPRINTF (stderr, _("Service `%s' is unknown to ARM.\n"), service);
    ret = 1;
    break;
  case GNUNET_ARM_PROCESS_DOWN:
    if (quiet != GNUNET_YES)
      FPRINTF (stdout, _("Service `%s' has been stopped.\n"), service);
    break;
  case GNUNET_ARM_PROCESS_ALREADY_RUNNING:
    FPRINTF (stderr, _("Service `%s' was already running.\n"), service);
    ret = 1;
    break;
  case GNUNET_ARM_PROCESS_STARTING:
    if (quiet != GNUNET_YES)
      FPRINTF (stdout, _("Service `%s' has been started.\n"), service);
    break;
  case GNUNET_ARM_PROCESS_ALREADY_STOPPING:
    FPRINTF (stderr, _("Service `%s' was already being stopped.\n"), service);
    ret = 1;
    break;
  case GNUNET_ARM_PROCESS_ALREADY_DOWN:
    FPRINTF (stderr, _("Service `%s' was already not running.\n"), service);
    ret = 1;
    break;
  case GNUNET_ARM_PROCESS_SHUTDOWN:
    FPRINTF (stderr, "%s", _("Request ignored as ARM is shutting down.\n"));
    ret = 1;
    break;
  case GNUNET_ARM_PROCESS_COMMUNICATION_ERROR:
    FPRINTF (stderr, "%s", _("Error communicating with ARM service.\n"));
    ret = 1;
    break;
  case GNUNET_ARM_PROCESS_COMMUNICATION_TIMEOUT:
    FPRINTF (stderr, "%s",  _("Timeout communicating with ARM service.\n"));
    ret = 1;
    break;
  case GNUNET_ARM_PROCESS_FAILURE:
    FPRINTF (stderr, "%s",  _("Operation failed.\n"));
    ret = 1;
    break;
  default:
    FPRINTF (stderr, "%s",  _("Unknown response code from ARM.\n"));
    break;
  }
  GNUNET_SCHEDULER_add_now (&cps_loop, NULL);
}


/**
 * Callback invoked with the list of running services.  
 * Reports to the user and then runs the next phase in the FSM.
 *
 * @param cls currently not used
 * @param result result of the operation
 * @param count number of running services
 * @param list copy of the list of running services
 */
static void
list_cb (void *cls, int result, unsigned int count, const char *const*list)
{
  unsigned int i;

  if ( (result != GNUNET_YES) || (NULL == list) )
  {
    FPRINTF (stderr, "%s", _("Error communicating with ARM. ARM not running?\n"));
    return;
  }
  FPRINTF (stdout, "%s", _("Running services:\n"));
  for (i=0; i<count; i++)
    FPRINTF (stdout, "%s\n", list[i]);
}


/**
 * Attempts to delete configuration file and SERVICEHOME
 * on arm shutdown provided the end and delete options
 * were specified when gnunet-arm was run.
 */
static void
delete_files ()
{
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
	      "Will attempt to remove configuration file %s and service directory %s\n",
	      config_file, dir);

  if (UNLINK (config_file) != 0)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
		  _("Failed to remove configuration file %s\n"), config_file);
    }

  if (GNUNET_DISK_directory_remove (dir) != GNUNET_OK)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
		  _("Failed to remove servicehome directory %s\n"), dir);

    }
}


/**
 * Main continuation-passing-style loop.  Runs the various
 * jobs that we've been asked to do in order.
 *
 * @param cls closure, unused
 * @param tc context, unused
 */
static void
shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  GNUNET_ARM_disconnect (h);
  h = NULL;
  if ((end == GNUNET_YES) && (delete == GNUNET_YES))
    delete_files ();	
  GNUNET_CONFIGURATION_destroy (cfg);
  cfg = NULL;
}


/**
 * Main function that will be run by the scheduler.
 *
 * @param cls closure
 * @param args remaining command-line arguments
 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 * @param c configuration
 */
static void
run (void *cls, char *const *args, const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *c)
{
  char *armconfig;

  cfg = GNUNET_CONFIGURATION_dup (c);
  config_file = cfgfile;
  if (GNUNET_CONFIGURATION_get_value_string
      (cfg, "PATHS", "SERVICEHOME", &dir) != GNUNET_OK)
  {
    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
			       "PATHS", "SERVICEHOME");
    return;
    }
  if (NULL != cfgfile)
  {
    if (GNUNET_OK !=
        GNUNET_CONFIGURATION_get_value_filename (cfg, "arm", "CONFIG",
						 &armconfig))
    {
      GNUNET_CONFIGURATION_set_value_string (cfg, "arm", "CONFIG",
                                             cfgfile);
    }
    else
      GNUNET_free (armconfig);
  }
  if (NULL == (h = GNUNET_ARM_connect (cfg, NULL)))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
		_("Fatal error initializing ARM API.\n"));
    ret = 1;
    GNUNET_CONFIGURATION_destroy (cfg);
    cfg = NULL;
    return;
  }
  GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
				&shutdown_task, NULL);
  GNUNET_SCHEDULER_add_now (&cps_loop, NULL);
}


/**
 * Main continuation-passing-style loop.  Runs the various
 * jobs that we've been asked to do in order.
 *
 * @param cls closure, unused
 * @param tc context, unused
 */
static void
cps_loop (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  if (NULL == h)
    return;
  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
    return;
  while (1)
  {
    switch (phase++)
    {
    case 0:
      if (NULL != term)
      {
	GNUNET_ARM_stop_service (h, term,
				 (0 ==
				  timeout.rel_value) ? STOP_TIMEOUT :
				 timeout, &confirm_cb, term);
	return;
      }
      break;
    case 1:
      if ((end) || (restart))
      {
	GNUNET_ARM_stop_service (h, "arm",
				 (0 ==
				  timeout.rel_value) ? STOP_TIMEOUT_ARM
				 : timeout, &confirm_cb, "arm");
	return;
      }
      break;
    case 2:
      if (start)
      {
	GNUNET_ARM_start_service (h, "arm",
				  (no_stdout ? 0 : GNUNET_OS_INHERIT_STD_OUT) |
				  (no_stderr ? 0 : GNUNET_OS_INHERIT_STD_ERR),
				  (0 ==
				   timeout.rel_value) ? START_TIMEOUT :
				  timeout, &confirm_cb, "arm");
	return;
      }
      break;
    case 3:
      if (NULL != init)
       {
	 GNUNET_ARM_start_service (h, init,
				   (no_stdout ? 0 : GNUNET_OS_INHERIT_STD_OUT) |
				   (no_stderr ? 0 : GNUNET_OS_INHERIT_STD_ERR),
				   (0 ==
				    timeout.rel_value) ? START_TIMEOUT :
				   timeout, &confirm_cb, init);
	 return;
       }
      break;
    case 4:
      if (restart)
      {
	GNUNET_ARM_disconnect (h);
	phase = 0;
	end = 0;
	start = 1;
	restart = 0;
	if (NULL == (h = GNUNET_ARM_connect (cfg, NULL)))
	{
	  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
		      _("Fatal error initializing ARM API.\n"));
	  ret = 1;
	  return;
	}
	GNUNET_SCHEDULER_add_now (&cps_loop, NULL);
	return;
      }
      break;
    case 5:
      if (list) 
      {
	GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
		    "Going to list all running services controlled by ARM.\n");
	
	if (NULL == h) 
	{
	  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
		      _("Fatal error initializing ARM API.\n"));
	  return;
	}	
	GNUNET_ARM_list_running_services (h, 
					  (0 == 
					   timeout.rel_value) ? LIST_TIMEOUT : 
					  timeout, &list_cb, NULL);
	return;
      }
      /* Fall through */
    default:		/* last phase */
      GNUNET_SCHEDULER_shutdown ();
      return;
    }
  }
}


/**
 * The main function to obtain arm from gnunetd.
 *
 * @param argc number of arguments from the command line
 * @param argv command line arguments
 * @return 0 ok, 1 on error
 */
int
main (int argc, char *const *argv)
{
  static const struct GNUNET_GETOPT_CommandLineOption options[] = {
    {'e', "end", NULL, gettext_noop ("stop all GNUnet services"),
     GNUNET_NO, &GNUNET_GETOPT_set_one, &end},
    {'i', "init", "SERVICE", gettext_noop ("start a particular service"),
     GNUNET_YES, &GNUNET_GETOPT_set_string, &init},
    {'k', "kill", "SERVICE", gettext_noop ("stop a particular service"),
     GNUNET_YES, &GNUNET_GETOPT_set_string, &term},
    {'s', "start", NULL, gettext_noop ("start all GNUnet default services"),
     GNUNET_NO, &GNUNET_GETOPT_set_one, &start},
    {'r', "restart", NULL,
     gettext_noop ("stop and start all GNUnet default services"),
     GNUNET_NO, &GNUNET_GETOPT_set_one, &restart},
    {'d', "delete", NULL,
     gettext_noop ("delete config file and directory on exit"),
     GNUNET_NO, &GNUNET_GETOPT_set_one, &delete},
    {'q', "quiet", NULL, gettext_noop ("don't print status messages"),
     GNUNET_NO, &GNUNET_GETOPT_set_one, &quiet},
    {'T', "timeout", "MSECS",
     gettext_noop ("timeout in MSECS milliseconds for completing current operation"),
     GNUNET_YES, &GNUNET_GETOPT_set_relative_time, &timeout},
    {'I', "info", NULL, gettext_noop ("list currently running services"),
     GNUNET_NO, &GNUNET_GETOPT_set_one, &list},
    {'O', "no-stdout", NULL, gettext_noop ("don't let gnunet-service-arm inherit standard output"),
     GNUNET_NO, &GNUNET_GETOPT_set_one, &no_stdout},
    {'E', "no-stderr", NULL, gettext_noop ("don't let gnunet-service-arm inherit standard error"),
     GNUNET_NO, &GNUNET_GETOPT_set_one, &no_stderr},
    GNUNET_GETOPT_OPTION_END
  };

  if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
    return 2;

  if (GNUNET_OK ==
      GNUNET_PROGRAM_run (argc, argv, "gnunet-arm",
			  gettext_noop
			  ("Control services and the Automated Restart Manager (ARM)"),
			  options, &run, NULL))
    {
      GNUNET_free ((void *) argv);
      return ret;
    }
  GNUNET_free ((void*) argv);
  return 1;
}

/* end of gnunet-arm.c */