/* argcv.c - simple functions for parsing input based on whitespace
   Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.

   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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include <ctype.h>

#include "argcv.h"

/*
 * takes a string and splits it into several strings, breaking at ' '
 * command is the string to split
 * the number of strings is placed into argc
 * the split strings are put into argv
 * returns 0 on success, nonzero on failure
 */

#define isws(c) ((c)==' '||(c)=='\t'||(c)=='\n')
#define isdelim(c,delim) ((c)=='"'||strchr(delim,(c))!=NULL)

static int
argcv_scan (int len, const char *command, const char *delim, const char* cmnt,
	    int *start, int *end, int *save)
{
  int i = 0;

  for (;;)
    {
      i = *save;

      if (i >= len)
	return i + 1;

      /* Skip initial whitespace */
      while (i < len && isws (command[i]))
	i++;
      *start = i;

      switch (command[i])
	{
	case '"':
	case '\'':
	  while (++i < len && command[i] != command[*start])
	    ;
	  if (i < len)		/* found matching quote */
	    break;
	 /*FALLTHRU*/ default:
	  if (isdelim (command[i], delim))
	    break;
	  /* Skip until next whitespace character or end of line */
	  while (++i < len &&
		 !(isws (command[i]) || isdelim (command[i], delim)))
	    ;
	  i--;
	  break;
	}

      *end = i;
      *save = i + 1;

      /* If we have a token, and it starts with a comment character, skip
         to the newline and restart the token search. */
      if (*save < len)
	{
	  if (cmnt && strchr (cmnt, command[*start]) != NULL)
	    {
	      i = *save;
	      while (i < len && command[i] != '\n')
		i++;

	      *save = i;
	      continue;
	    }
	}
      break;
    }
  return *save;
}

int
argcv_get (const char *command, const char *delim, const char* cmnt,
    int *argc, char ***argv)
{
  int len = strlen (command);
  int i = 0;
  int start, end, save;

  *argv = NULL;

  /* Count number of arguments */
  *argc = 0;
  save = 0;

  while (argcv_scan (len, command, delim, cmnt, &start, &end, &save) <= len)
      (*argc)++;

  *argv = calloc ((*argc + 1), sizeof (char *));

  i = 0;
  save = 0;
  for (i = 0; i < *argc; i++)
    {
      int n;
      argcv_scan (len, command, delim, cmnt, &start, &end, &save);

      /* FIXME: this is the right place to do unescaping as well
	 as stripping of quotes. */
      if (command[start] == '"' && command[end] == '"')
	{
	  start++;
	  end--;
	}
      else if (command[start] == '\'' && command[end] == '\'')
	{
	  start++;
	  end--;
	}
      n = end - start + 1;
      (*argv)[i] = calloc (n+1,  sizeof (char));
      if ((*argv)[i] == NULL)
	return 1;
      memcpy ((*argv)[i], &command[start], n);
      (*argv)[i][n] = 0;
    }
  (*argv)[i] = NULL;
  return 0;
}

/*
 * frees all elements of an argv array
 * argc is the number of elements
 * argv is the array
 */
int
argcv_free (int argc, char **argv)
{
  while (--argc >= 0)
    if (argv[argc])
      free (argv[argc]);
  free (argv);
  return 1;
}

/* Take a argv an make string separated by ' '.  */

int
argcv_string (int argc, char **argv, char **pstring)
{
  int i;
  size_t len;
  char *buffer;

  /* No need.  */
  if (pstring == NULL)
    return 1;

  buffer = malloc (1);
  if (buffer == NULL)
    return 1;
  *buffer = '\0';

  for (len = i = 0; i < argc; i++)
    {
      len += strlen (argv[i]) + 2;
      buffer = realloc (buffer, len);
      if (buffer == NULL)
	return 1;
      if (i != 0)
	strcat (buffer, " ");
      strcat (buffer, argv[i]);
    }

  /* Strip off trailing space.  */
  if (*buffer != '\0')
    {
      while (buffer[strlen (buffer) - 1] == ' ')
	{
	  buffer[strlen (buffer) - 1] = '\0';
	}
    }
  if (pstring)
    *pstring = buffer;
  return 0;
}

#if 0
char *command = "set prompt=\"& \" ";

main(int xargc, char **xargv)
{
  int i, argc;
  char **argv;

  argcv_get (xargv[1] ? xargv[1]:command, "=", "#", &argc, &argv);
  printf ("%d args:\n", argc);
  for (i = 0; i < argc; i++)
    printf ("%s\n", argv[i]);
}
#endif