/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "glk/tads/tads2/command_line.h"

namespace Glk {
namespace TADS {
namespace TADS2 {

/* get a toggle argument */
int cmdtog(errcxdef *ec, int prv, char *argp, int ofs,
		   void (*usagefn)(errcxdef *))
{
	switch(argp[ofs + 1])
	{
	case '+':
		return(TRUE);

	case '-':
		return(FALSE);

	case '\0':
		return(!prv);

	default:
		/* invalid - display usage if we have a callback for it */
		if (usagefn != nullptr)
			(*usagefn)(ec);
		NOTREACHEDV(int);
		return 0;
	}
}

/* get an argument to a switch */
char *cmdarg(errcxdef *ec, char ***argpp, int *ip, int argc, int ofs,
			 void (*usagefn)(errcxdef *))
{
	char *ret;

	/*
	 *   check to see if the argument is appended directly to the option;
	 *   if not, look at the next string
	 */
	ret = (**argpp) + ofs + 1;
	if (*ret == '\0')
	{
		/*
		 *   it's not part of this string - get the argument from the next
		 *   string in the vector
		 */
		++(*ip);
		++(*argpp);
		ret = (*ip >= argc ? nullptr : **argpp);
	}

	/*
	 *   if we didn't find the argument, it's an error - display usage if
	 *   we have a valid usage callback
	 */
	if ((ret == nullptr || *ret == 0) && usagefn != nullptr)
		(*usagefn)(ec);

	return ret;
}

} // End of namespace TADS2
} // End of namespace TADS
} // End of namespace Glk