/*
 *	fhist - file history and comparison tools
 *	Copyright (C) 1998, 2002 Peter Miller;
 *	All rights reserved.
 *
 *	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 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, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: functions to manipulate basenames
 */

#include <ac/string.h>

#include <sub/basename.h>
#include <sub/private.h>
#include <trace.h>
#include <wstr_list.h>


static wstring_ty *
entryname(wstring_ty *s)
{
	wchar_t		*start;
	wchar_t		*finish;
	wchar_t		*cp;
	wchar_t		prev;

	start = s->wstr_text;
	finish = s->wstr_text;
	prev = '/';
	cp = s->wstr_text;
	for (;;)
	{
		if (prev == '/')
		{
			if (*cp != '/' && *cp != 0)
				start = cp;
		}
		else
		{
			if (*cp == '/' || *cp == 0)
				finish = cp;
		}
		if (!*cp)
			break;
		prev = *cp++;
	}
	return wstr_n_from_wc(start, finish - start);
}


/*
 * NAME
 *	sub_basename - the basename substitution
 *
 * SYNOPSIS
 *	wstring_ty *sub_basename(wstring_list_ty *arg);
 *
 * DESCRIPTION
 *	The sub_basename function implements the basename substitution.
 *	The basename substitution is replaced by the basename of
 *	the argument path, similar to the basename(1) command.
 *
 * ARGUMENTS
 *	arg	- list of arguments, including the function name as [0]
 *
 * RETURNS
 *	a pointer to a string in dynamic memory;
 *	or NULL on error, setting suberr appropriately.
 */

wstring_ty *
sub_basename(sub_context_ty *scp, wstring_list_ty *arg)
{
	wstring_ty	*result;
	wstring_ty	*suffix;
	wstring_ty	*s1;
	long		len;

	trace(("sub_basename()\n{\n"));
	switch (arg->nitems)
	{
	default:
		sub_context_error_set
		(
			scp,
			i18n("requires one or two arguments")
		);
		result = 0;
		break;
	
	case 2:
		result = entryname(arg->item[1]);
		break;
	
	case 3:
		s1 = entryname(arg->item[1]);
		suffix = arg->item[2];
		len = (long)s1->wstr_length - (long)suffix->wstr_length;
		if
		(
			len > 0
		&&
			!memcmp
			(
				s1->wstr_text + len,
				suffix->wstr_text,
				suffix->wstr_length * sizeof(wchar_t)
			)
		)
		{
			result = wstr_n_from_wc(s1->wstr_text, len);
			wstr_free(s1);
		}
		else
			result = s1;
		break;
	}
	trace(("return %8.8lX;\n", (long)result));
	trace(("}\n"));
	return result;
}