/*
     This file is part of GNUnet.
     (C) 2011, 2012 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.
*/

#include "gnunet_os_lib.h"

/**
 * Actually start a process.  All of the arguments given to this
 * function are strings that are used for the "argv" array.  However,
 * if those strings contain spaces, the given argument is split into
 * multiple argv entries without spaces.  Similarly, if an argument is
 * the empty string, it is skipped.  This function has the inherent
 * limitation that it does NOT allow passing command line arguments
 * with spaces to the new process.
 *
 * @param pipe_control should a pipe be used to send signals to the child?
 * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
 * @param lsocks array of listen sockets to dup starting at fd3 (systemd-style), or NULL
 * @param first_arg first argument for argv (may be an empty string)
 * @param ... more arguments, NULL terminated
 * @return handle of the started process, NULL on error
 */
static struct GNUNET_OS_Process *
do_start_process (int pipe_control, unsigned int std_inheritance,
		  const SOCKTYPE * lsocks, const char *first_arg, ...)
{
  va_list ap;
  char **argv;
  unsigned int argv_size;
  const char *arg;
  const char *rpos;
  char *pos;
  char *cp;
  const char *last;
  struct GNUNET_OS_Process *proc;
  char *binary_path;
  int quote_on;
  unsigned int i;
  size_t len;

  argv_size = 1;
  va_start (ap, first_arg);
  arg = first_arg;
  last = NULL;
  do
  {
    rpos = arg;
    quote_on = 0;
    while ('\0' != *rpos)
    {
      if ('"' == *rpos)
      {
	if (1 == quote_on)
	  quote_on = 0;
	else
	  quote_on = 1;
      }	
      if ( (' ' == *rpos) && (0 == quote_on) )
      {
	if (NULL != last)
	  argv_size++;
	last = NULL;
	rpos++;
	while (' ' == *rpos)
	  rpos++;
      }
      if ( (NULL == last) && ('\0' != *rpos) ) // FIXME: == or !=?
	last = rpos;
      if ('\0' != *rpos)
	rpos++;
    }
    if (NULL != last)
      argv_size++;
  }
  while (NULL != (arg = (va_arg (ap, const char*))));
  va_end (ap);

  argv = GNUNET_malloc (argv_size * sizeof (char *));
  argv_size = 0;
  va_start (ap, first_arg);
  arg = first_arg;
  last = NULL;
  do
  {
    cp = GNUNET_strdup (arg);
    quote_on = 0;
    pos = cp;
    while ('\0' != *pos)
    {	
      if ('"' == *pos)
      {
	if (1 == quote_on)
	  quote_on = 0;
	else
	  quote_on = 1;
      }
      if ( (' ' == *pos) && (0 == quote_on) )
      {
	*pos = '\0';
	if (NULL != last)
	  argv[argv_size++] = GNUNET_strdup (last);
	last = NULL;
	pos++;
	while (' ' == *pos)
	  pos++;
      }
      if ( (NULL == last) && ('\0' != *pos)) // FIXME: == or !=?
	last = pos;
      if ('\0' != *pos)
	pos++;
    }
    if (NULL != last)
      argv[argv_size++] = GNUNET_strdup (last);
    last = NULL;
    GNUNET_free (cp);
  }
  while (NULL != (arg = (va_arg (ap, const char*))));
  va_end (ap);
  argv[argv_size] = NULL;
  
  for(i = 0; i < argv_size; i++)
  {
    len = strlen (argv[i]);
    if ( (argv[i][0] == '"') && (argv[i][len-1] == '"'))
    {
      memmove (&argv[i][0], &argv[i][1], len - 2);
      argv[i][len-2] = '\0';  
    }
  }
  binary_path = argv[0];
  proc = GNUNET_OS_start_process_v (pipe_control, std_inheritance, lsocks,
				    binary_path, argv);
  while (argv_size > 0)
    GNUNET_free (argv[--argv_size]);
  GNUNET_free (argv);
  return proc;
}

/* end of do_start_process.c */